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Sample records for human intestinal bacterial

  1. Small Intestinal Bacterial Overgrowth

    PubMed Central

    Dukowicz, Andrew C.; Levine, Gary M.

    2007-01-01

    Small intestinal bacterial overgrowth (SIBO), defined as excessive bacteria in the small intestine, remains a poorly understood disease. Initially thought to occur in only a small number of patients, it is now apparent that this disorder is more prevalent than previously thought. Patients with SIBO vary in presentation, from being only mildly symptomatic to suffering from chronic diarrhea, weight loss, and malabsorption. A number of diagnostic tests are currently available, although the optimal treatment regimen remains elusive. Recently there has been renewed interest in SIBO and its putative association with irritable bowel syndrome. In this comprehensive review, we will discuss the epidemiology, pathogenesis, clinical manifestations, diagnosis, and treatment of SIBO. PMID:21960820

  2. Small intestinal bacterial overgrowth syndrome

    PubMed Central

    Bures, Jan; Cyrany, Jiri; Kohoutova, Darina; Förstl, Miroslav; Rejchrt, Stanislav; Kvetina, Jaroslav; Vorisek, Viktor; Kopacova, Marcela

    2010-01-01

    Human intestinal microbiota create a complex polymicrobial ecology. This is characterised by its high population density, wide diversity and complexity of interaction. Any dysbalance of this complex intestinal microbiome, both qualitative and quantitative, might have serious health consequence for a macro-organism, including small intestinal bacterial overgrowth syndrome (SIBO). SIBO is defined as an increase in the number and/or alteration in the type of bacteria in the upper gastrointestinal tract. There are several endogenous defence mechanisms for preventing bacterial overgrowth: gastric acid secretion, intestinal motility, intact ileo-caecal valve, immunoglobulins within intestinal secretion and bacteriostatic properties of pancreatic and biliary secretion. Aetiology of SIBO is usually complex, associated with disorders of protective antibacterial mechanisms (e.g. achlorhydria, pancreatic exocrine insufficiency, immunodeficiency syndromes), anatomical abnormalities (e.g. small intestinal obstruction, diverticula, fistulae, surgical blind loop, previous ileo-caecal resections) and/or motility disorders (e.g. scleroderma, autonomic neuropathy in diabetes mellitus, post-radiation enteropathy, small intestinal pseudo-obstruction). In some patients more than one factor may be involved. Symptoms related to SIBO are bloating, diarrhoea, malabsorption, weight loss and malnutrition. The gold standard for diagnosing SIBO is still microbial investigation of jejunal aspirates. Non-invasive hydrogen and methane breath tests are most commonly used for the diagnosis of SIBO using glucose or lactulose. Therapy for SIBO must be complex, addressing all causes, symptoms and complications, and fully individualised. It should include treatment of the underlying disease, nutritional support and cyclical gastro-intestinal selective antibiotics. Prognosis is usually serious, determined mostly by the underlying disease that led to SIBO. PMID:20572300

  3. Intestinal Bacterial Communities That Produce Active Estrogen-Like Compounds Enterodiol and Enterolactone in Humans

    PubMed Central

    Clavel, Thomas; Henderson, Gemma; Alpert, Carl-Alfred; Philippe, Catherine; Rigottier-Gois, Lionel; Doré, Joël; Blaut, Michael

    2005-01-01

    Lignans are dietary diphenolic compounds which require activation by intestinal bacteria to exert possible beneficial health effects. The intestinal ecosystem plays a crucial role in lignan metabolism, but the organisms involved are poorly described. To characterize the bacterial communities responsible for secoisolariciresinol (SECO) activation, i.e., the communities that produce the enterolignans enterodiol (ED) and enterolactone (EL), a study with 24 human subjects was undertaken. SECO activation was detected in all tested fecal samples. The intestinal bacteria involved in ED production were part of the dominant microbiota (6 × 108 CFU g−1), as revealed by most-probable-number enumerations. Conversely, organisms that catalyzed the formation of EL occurred at a mean concentration of approximately 3 × 105 CFU g−1. Women tended to have higher concentrations of both ED- and EL-producing organisms than men. Significantly larger amounts of EL were produced by fecal dilutions from individuals with moderate to high concentrations of EL-producing bacteria. Two organisms able to demethylate and dehydroxylate SECO were isolated from human feces. Based on 16S rRNA gene sequence analyses, they were named Peptostreptococcus productus SECO-Mt75m3 and Eggerthella lenta SECO-Mt75m2. A new 16S rRNA-targeted oligonucleotide probe specific for P. productus and related species was designed and further used in fluorescent in situ hybridization experiments, along with five additional group-specific probes. Significantly higher proportions of P. productus and related species (P = 0.012), as well as bacteria belonging to the Atopobium group (P = 0.035), were typical of individuals with moderate to high concentrations of EL-producing communities. PMID:16204524

  4. Contributions of microbiome and mechanical deformation to intestinal bacterial overgrowth and inflammation in a human gut-on-a-chip

    PubMed Central

    Kim, Hyun Jung; Li, Hu; Collins, James J.; Ingber, Donald E.

    2016-01-01

    A human gut-on-a-chip microdevice was used to coculture multiple commensal microbes in contact with living human intestinal epithelial cells for more than a week in vitro and to analyze how gut microbiome, inflammatory cells, and peristalsis-associated mechanical deformations independently contribute to intestinal bacterial overgrowth and inflammation. This in vitro model replicated results from past animal and human studies, including demonstration that probiotic and antibiotic therapies can suppress villus injury induced by pathogenic bacteria. By ceasing peristalsis-like motions while maintaining luminal flow, lack of epithelial deformation was shown to trigger bacterial overgrowth similar to that observed in patients with ileus and inflammatory bowel disease. Analysis of intestinal inflammation on-chip revealed that immune cells and lipopolysaccharide endotoxin together stimulate epithelial cells to produce four proinflammatory cytokines (IL-8, IL-6, IL-1β, and TNF-α) that are necessary and sufficient to induce villus injury and compromise intestinal barrier function. Thus, this human gut-on-a-chip can be used to analyze contributions of microbiome to intestinal pathophysiology and dissect disease mechanisms in a controlled manner that is not possible using existing in vitro systems or animal models. PMID:26668389

  5. Contributions of microbiome and mechanical deformation to intestinal bacterial overgrowth and inflammation in a human gut-on-a-chip.

    PubMed

    Kim, Hyun Jung; Li, Hu; Collins, James J; Ingber, Donald E

    2016-01-01

    A human gut-on-a-chip microdevice was used to coculture multiple commensal microbes in contact with living human intestinal epithelial cells for more than a week in vitro and to analyze how gut microbiome, inflammatory cells, and peristalsis-associated mechanical deformations independently contribute to intestinal bacterial overgrowth and inflammation. This in vitro model replicated results from past animal and human studies, including demonstration that probiotic and antibiotic therapies can suppress villus injury induced by pathogenic bacteria. By ceasing peristalsis-like motions while maintaining luminal flow, lack of epithelial deformation was shown to trigger bacterial overgrowth similar to that observed in patients with ileus and inflammatory bowel disease. Analysis of intestinal inflammation on-chip revealed that immune cells and lipopolysaccharide endotoxin together stimulate epithelial cells to produce four proinflammatory cytokines (IL-8, IL-6, IL-1β, and TNF-α) that are necessary and sufficient to induce villus injury and compromise intestinal barrier function. Thus, this human gut-on-a-chip can be used to analyze contributions of microbiome to intestinal pathophysiology and dissect disease mechanisms in a controlled manner that is not possible using existing in vitro systems or animal models. PMID:26668389

  6. Mucin Dynamics in Intestinal Bacterial Infection

    PubMed Central

    Lindén, Sara K.; Florin, Timothy H. J.; McGuckin, Michael A.

    2008-01-01

    Background Bacterial gastroenteritis causes morbidity and mortality in humans worldwide. Murine Citrobacter rodentium infection is a model for gastroenteritis caused by the human pathogens enteropathogenic Escherichia coli and enterohaemorrhagic E. coli. Mucin glycoproteins are the main component of the first barrier that bacteria encounter in the intestinal tract. Methodology/Principal Findings Using Immunohistochemistry, we investigated intestinal expression of mucins (Alcian blue/PAS, Muc1, Muc2, Muc4, Muc5AC, Muc13 and Muc3/17) in healthy and C. rodentium infected mice. The majority of the C. rodentium infected mice developed systemic infection and colitis in the mid and distal colon by day 12. C. rodentium bound to the major secreted mucin, Muc2, in vitro, and high numbers of bacteria were found in secreted MUC2 in infected animals in vivo, indicating that mucins may limit bacterial access to the epithelial surface. In the small intestine, caecum and proximal colon, the mucin expression was similar in infected and non-infected animals. In the distal colonic epithelium, all secreted and cell surface mucins decreased with the exception of the Muc1 cell surface mucin which increased after infection (p<0.05). Similarly, during human infection Salmonella St Paul, Campylobacter jejuni and Clostridium difficile induced MUC1 in the colon. Conclusion Major changes in both the cell-surface and secreted mucins occur in response to intestinal infection. PMID:19088856

  7. [The human intestinal microbiota].

    PubMed

    Doré, J; Corthier, G

    2010-09-01

    The human intestinal microbiota constitutes a complex ecosystem which is now well recognized for its impact on human health and well-being. It contributes to maturation of the immune system and provides a direct barrier against colonization by pathogens. Its possible implication in diseases of modern societies, currently increasing in prevalence, has been reported. These include allergies, inflammatory bowel diseases and possibly metabolic and degenerative disorders. The analysis of the molecular composition of the human intestinal microbiota indicates marked inter-individual variations which may seem paradoxical considering the high degree of conservation of major functions of the intestinal microbiota such as anaerobic digestion of alimentary fibres. We have characterized a phylogenetic core within the human intestinal microbiota, in terms of composition, i.e., a set of conserved species that could be responsible for major conserved functions. Based on culture-independent molecular assessments, current knowledge enables a definition of criteria qualifying the normal state of the human intestinal microbiota that we call normobiosis. This further enables the identification of specific deviations from normobiosis, i.e., dysbiosis in immune, metabolic or degenerative diseases. Notably, Crohn's disease, an inflammatory bowel disease of yet unknown aetiology, is associated with intestinal dysbiosis with a lower representation of the Clostridium leptum group among the Firmicutes phylum. We further showed that the bacterial species Faecalibacterium prausnitzii exerts anti-inflammatory properties in vitro and in animal models; this could explain its ability, when detected in the mucosa-associated microbiota of patients in vivo, to protect patients from post-operative recurrence of endoscopic signs of inflammation 6 months after surgical resection of the ileocecal region of the gut. By confirming the major role of the microbiota in bowel-related disorders, which are especially associated with a disruption of homeostasis, we are currently applying high throughput functional metagenomic screens in order to identify signal molecules and mechanisms of bacteria-host cross-talk. Together with the high resolution description of the human intestinal metagenome, as well as explorations of environmental proteins and metabolites, these observations will further our understanding of the functional roles bacteria play in the maintenance of health and well-being in humans. It will open new perspectives for the monitoring and design of strategies for modulating the microbiota for health. PMID:20889008

  8. Reduction of azo dyes and nitroaromatic compounds by bacterial enzymes from the human intestinal tract

    SciTech Connect

    Rafii, F.; Cerniglia, C.E.

    1995-06-01

    Several anaerobic bacteria from the human intestinal tract are capable of reducing azo dyes and nitropolycyclic aromatic hydrocarbons to the corresponding aromatic amines with enzymes that have azoreductase and nitroreductase activities. The majority of bacteria with these activities belong to the genera Clostridium and Eubacterium. The azoreductases and nitroreductases from three Clostridium strains and one Eubacterium strain were studied. Both enzymes were produced constitutively in each of the bacteria; the enzymes from various bacteria had different electrophoretic mobilities. The azoreductases from all of the bacteria had immunological homology, as was evident from the cross-reactivity of an antibody raised against the azoreductase of C perfringens with azoreductases from other bacteria. Comparison of azoreductases and nitroreductases showed that they both had identical electrophoretic mobilities on polyacrylamide gels and reacted with the antibody against the azoreductase from C. perfringens. Furthermore, the nitroaromatic compounds competitively inhibited the azoreductase activity. The data indicate that the reduction of both nitroaromatic compounds and azo dyes may be carried out by the same enzyme, which is possibly a flavin adenine dinucleotide dehydrogenase that is synthesized throughout the cell and not associated with any organized subcellular structure. 15 refs., 1 fig., 2 tabs.

  9. Periarrest intestinal bacterial translocation and resuscitation outcome.

    PubMed

    Chalkias, Athanasios; Scheetz, Marc H; Gulati, Anil; Xanthos, Theodoros

    2016-02-01

    During the periarrest period, intestinal ischemia may result in barrier dysfunction and bacterial translocation, which has clear mechanistic links to inflammation and cascade stimulation, especially in patients who are treated with therapeutic hypothermia. Despite optimal management, periarrest bacterial translocation may worsen the outcome of cardiac arrest victims. PMID:26481507

  10. Nutritional consequences of intestinal bacterial overgrowth.

    PubMed

    Saltzman, J R; Russell, R M

    1994-01-01

    The bacterial overgrowth syndrome occurs when there are alterations in intestinal anatomy, gastrointestinal motility, or a lack of gastric acid secretion. Clinically, patients present with nonspecific gastrointestinal symptoms that include abdominal pain, bloating, excessive gas production, diarrhea, weight loss, and malabsorption. The nutritional consequences of intestinal bacterial overgrowth include vitamin deficiencies, fat malabsorption, and malnutrition. The diagnosis requires a high index of clinical suspicion and can be established by specialized testing, such as the 1-gram 14C-xylose breath test. The goal of treatment is eradication of the bacterial overgrowth (usually with antibiotics) and the correction of nutritional deficiencies. PMID:7805370

  11. Metabolism of homoorientin by human intestinal bacteria.

    PubMed

    Hattori, M; Shu, Y Z; el-Sedawy, A I; Namba, T; Kobashi, K; Tomimori, T

    1988-01-01

    As a part of our studies on the metabolism of bioactive compounds from oriental medicines by intestinal flora, homoorientin, a C-glycosylflavonoid, was anaerobically incubated with a human intestinal bacterial mixture. Homoorientin was transformed to 6-C-glucosyleriodictyol, (+/-)-eriodictyol, luteolin, 3,4-dihydroxyphenylpropionic acid, and phloroglucinol. A novel cleavage of the C-glycosyl bond was discovered for the first time by using intestinal bacteria. PMID:3204379

  12. Inhibition of adhesion of enteroinvasive pathogens to human intestinal Caco-2 cells by Lactobacillus acidophilus strain LB decreases bacterial invasion.

    PubMed

    Coconnier, M H; Bernet, M F; Kernéis, S; Chauvière, G; Fourniat, J; Servin, A L

    1993-07-01

    Salmonella typhimurium and enteropathogenic Escherichia coli (EPEC) were found to adhere to the brush border of differentiated human intestinal epithelial Caco-2 cells in culture, whereas Yersinia pseudotuberculosis and Listeria monocytogenes adhered to the periphery of undifferentiated Caco-2 cells. All these enterovirulent strains invaded the Caco-2 cells. Using a heat-killed human Lactobacillus acidophilus (strain LB) which strongly adheres both to undifferentiated and differentiated Caco-2 cells, we have studied inhibition of cell association with and invasion within Caco-2 cells by enterovirulent bacteria. Living and heat-killed Lactobacillus acidophilus strain LB inhibited both cell association and invasion of Caco-2 cells by enterovirulent bacteria in a concentration-dependent manner. The mechanism of inhibition of both adhesion and invasion appears to be due to steric hindrance of human enterocytic pathogen receptors by whole-cell lactobacilli rather than to a specific blockade of receptors. PMID:8354463

  13. Campylobacter jejuni Outer Membrane Vesicles Play an Important Role in Bacterial Interactions with Human Intestinal Epithelial Cells

    PubMed Central

    Elmi, Abdi; Watson, Eleanor; Sandu, Pamela; Gundogdu, Ozan; Mills, Dominic C.; Inglis, Neil F.; Manson, Erin; Imrie, Lisa; Bajaj-Elliott, Mona; Wren, Brendan W.; Smith, David G. E.

    2012-01-01

    Campylobacter jejuni is the most prevalent cause of food-borne gastroenteritis in the developed world; however, the molecular basis of pathogenesis is unclear. Secretion of virulence factors is a key mechanism by which enteric bacterial pathogens interact with host cells to enhance survival and/or damage the host. However, C. jejuni lacks the virulence-associated secretion systems possessed by other enteric pathogens. Many bacterial pathogens utilize outer membrane vesicles (OMVs) for delivery of virulence factors into host cells. In the absence of prototypical virulence-associated secretion systems, OMVs could be an important alternative for the coordinated delivery of C. jejuni proteins into host cells. Proteomic analysis of C. jejuni 11168H OMVs identified 151 proteins, including periplasmic and outer membrane-associated proteins, but also many determinants known to be important in survival and pathogenesis, including the cytolethal distending toxin (CDT). C. jejuni OMVs contained 16 N-linked glycoproteins, indicating a delivery mechanism by which these periplasm-located yet immunogenic glycoproteins can interact with host cells. C. jejuni OMVs possess cytotoxic activity and induce a host immune response from T84 intestinal epithelial cells (IECs), which was not reduced by OMV pretreatment with proteinase K or polymyxin B prior to coincubation with IECs. Pretreatment of IECs with methyl-beta-cyclodextrin partially blocks OMV-induced host immune responses, indicating a role for lipid rafts in host cell plasma membranes during interactions with C. jejuni OMVs. OMVs isolated from a C. jejuni 11168H cdtA mutant induced interleukin-8 (IL-8) to the same extent as did wild-type OMVs, suggesting OMV induction of IL-8 is independent of CDT. PMID:22966047

  14. Human milk oligosaccharide consumption by intestinal microbiota.

    PubMed

    Marcobal, A; Sonnenburg, J L

    2012-07-01

    Human milk oligosaccharides (HMO) constitute the third most abundant class of molecules in breast milk. Since infants lack the enzymes required for milk glycan digestion, this group of carbohydrates passes undigested to the lower part of the intestinal tract, where they can be consumed by specific members of the infant gut microbiota. We review proposed mechanisms for the depletion and metabolism of HMO by two major bacterial genera within the infant intestinal microbiota, Bifidobacterium and Bacteroides. PMID:22647041

  15. Dysregulated expression of arginine metabolic enzymes in human intestinal tissues of necrotizing enterocolitis and response of CaCO2 cells to bacterial components.

    PubMed

    Leung, Kam Tong; Chan, Kathy Yuen Yee; Ma, Terence Ping Yuen; Yu, Jasmine Wai Sum; Tong, Joanna Hung Man; Tam, Yuk Him; Cheung, Hon Ming; To, Ka Fai; Lam, Hugh Simon; Lee, Kim Hung; Li, Karen; Ng, Pak Cheung

    2016-03-01

    The small intestine is the exclusive site of arginine synthesis in neonates. Low levels of circulating arginine have been associated with the occurrence of necrotizing enterocolitis (NEC) but the mechanism of arginine dysregulation has not been fully elucidated. We aimed to investigate (i) expressional changes of arginine synthesizing and catabolic enzymes in human intestinal tissues of NEC, spontaneous intestinal perforation (SIP) and noninflammatory surgical conditions (Surg-CTL) and to investigate the (ii) mechanisms of arginine dysregulation and enterocyte proliferation upon stimulation by bacterial components, arginine depletion, ARG1 overexpression and nitric oxide (NO) supplementation. Our results showed that expressions of arginine synthesizing enzymes ALDH18A1, ASL, ASS1, CPS1, GLS, OAT and PRODH were significantly decreased in NEC compared with Surg-CTL or SIP tissues. Catabolic enzyme ARG1 was increased (>100-fold) in NEC tissues and histologically demonstrated to be expressed by infiltrating neutrophils. No change in arginine metabolic enzymes was observed between SIP and Surg-CTL tissues. In CaCO2 cells, arginine metabolic enzymes were differentially dysregulated by lipopolysaccharide or lipoteichoic acid. Depletion of arginine reduced cell proliferation and this phenomenon could be partially rescued by NO. Overexpression of ARG1 also reduced enterocyte proliferation. We provided the first expressional profile of arginine metabolic enzymes at the tissue level of NEC. Our findings suggested that arginine homeostasis was severely disturbed and could be triggered by inflammatory responses of enterocytes and infiltrating neutrophils as well as bacterial components. Such reactions could reduce arginine and NO, resulting in mucosal damage. The benefit of arginine supplementation for NEC prophylaxis merits further clinical evaluation. PMID:26895666

  16. Bacterial census of poultry intestinal microbiome.

    PubMed

    Wei, S; Morrison, M; Yu, Z

    2013-03-01

    The objective of this study was to generate a phylogenetic diversity census of bacteria identified in the intestinal tract of chickens and turkeys using a naïve analysis of all the curated 16S rRNA gene sequences archived in public databases. High-quality sequences of chicken and turkey gastrointestinal origin (3,184 and 1,345, respectively) were collected from the GenBank, Ribosomal Database Project, and Silva comprehensive ribosomal RNA database. Through phylogenetic and statistical analysis, 915 and 464 species-equivalent operational taxonomic units (defined at 0.03 phylogenetic distance) were found in the chicken and the turkey sequence collections, respectively. Of the 13 bacterial phyla identified in both bird species, Firmicutes, Bacteroidetes, and Proteobacteria were the largest phyla, accounting for >90% of all the sequences. The chicken sequences represent 117 established bacterial genera, and the turkey sequences represent 69 genera. The most predominant genera found in both the chicken and the turkey sequence data sets were Clostridium, Ruminococcus, Lactobacillus, and Bacteroides, but with different distribution between the 2 bird species. The estimated coverage of bacterial diversity of chicken and turkey reached 89 and 68% at species-equivalent and 93 and 73% at genus-equivalent levels, respectively. Less than 7,000 bacterial sequences from each bird species from various locations would be needed to reach 99% coverage for either bird species. Based on annotation of the sequence records, cecum was the most sampled gut segment. Chickens and turkeys were shown to have distinct intestinal microbiomes, sharing only 16% similarity at the species-equivalent level. Besides identifying gaps in knowledge on bacterial diversity in poultry gastrointestinal tract, the bacterial census generated in this study may serve as a framework for future studies and development of analytic tools. PMID:23436518

  17. Small intestinal bacterial overgrowth in dogs with chronic intestinal disease.

    PubMed

    Rutgers, H C; Batt, R M; Elwood, C M; Lamport, A

    1995-01-15

    Small intestinal bacterial overgrowth (SIBO) was diagnosed by quantitative bacterial culture of duodenal juice samples obtained endoscopically in 41 of 80 dogs that were admitted with chronic diarrhea, vomiting, or weight loss. Thirteen dogs had aerobic bacterial overgrowth, most frequently comprising Escherichia coli, staphylococci, and enterococci, and 28 dogs had mixed anaerobic overgrowth, most frequently including Clostridium and Bacteroides spp. Affected dogs comprised 23 breeds, including 10 German Shepherd Dogs and median age at diagnosis was 2 years (range, 6 months to 11 years). High serum folate and low serum cobalamin concentrations had fair specificity (79 and 87%, respectively), but low sensitivity (51 and 24%, respectively) in detecting SIBO. Histologic examination of duodenal biopsy specimens did not reveal abnormalities (26/41 dogs), or revealed mild to moderate lymphocytic (12/41) or eosinophilic (2/41) infiltrates, or lymphosarcoma (1/41). Oral antibiotic treatment was effective in 77% (23/30 dogs), but prolonged treatment (> 4 weeks) was required to control signs and prevent recurrence in 50% (15/30). Corticosteroids were used alone in a dog with eosinophilic enteritis and in combination with antibiotics in 4 dogs with marked gastrointestinal lymphocytic/plasmacytic infiltrates. This study suggested that SIBO may be observed in dogs of many breeds, without an obvious primary cause, and that, although results of indirect tests may be suggestive of SIBO, bacterial culture of duodenal juice samples remains necessary for definitive diagnosis. PMID:7751219

  18. Small intestinal bacterial overgrowth syndrome in children

    PubMed Central

    Bik-Gawin, Agnieszka; Zeman, Krzysztof; Bąk-Romaniszyn, Leokadia

    2015-01-01

    Introduction Small intestinal bacterial overgrowth syndrome (SIBO) is defined as an increased number of nonpathogenic bacteria over 105 organisms in 1 millilitre of small intestine content. The most common predisposing factors include, among others, gut motility disorders and chronic use of proton pump inhibitors. The results of recent studies indicate the importance of SIBO in gastrointestinal diseases. Aim To assess the prevalence of SIBO in children with abdominal pain. Material and methods One hundred children (59 girls and 41 boys) aged from 4 to 17 years (mean age: 10.47 ±3.73 years), hospitalised due to abdominal pain, were enrolled in the study. Hydrogen breath test (HBT) with lactulose was established among all patients. Expired air was analysed using a Gastrolyzer (Bedfont). Results The HBT result was positive in 63 (63%) children with abdominal pain; including 40 girls (67.8%) and 23 boys (56.1%). The test was positive in the group of 29 (46%) children aged under 10 years and in the group of 34 (54%) children aged over 10 years. Among the patients who reported for the control study 88% achieved a normalisation of HBT after treatment. Conclusions The prevalence of positive HBT results in the group of patients with abdominal pain is over 60%. Small intestinal bacterial overgrowth syndrome should be considered as one of the causes of abdominal pain in children. The SIBO in children shows a good response to treatment. PMID:25960812

  19. A model of bacterial intestinal infections in Drosophila melanogaster.

    PubMed

    Nehme, Nadine T; Liégeois, Samuel; Kele, Beatrix; Giammarinaro, Philippe; Pradel, Elizabeth; Hoffmann, Jules A; Ewbank, Jonathan J; Ferrandon, Dominique

    2007-11-01

    Serratia marcescens is an entomopathogenic bacterium that opportunistically infects a wide range of hosts, including humans. In a model of septic injury, if directly introduced into the body cavity of Drosophila, this pathogen is insensitive to the host's systemic immune response and kills flies in a day. We find that S. marcescens resistance to the Drosophila immune deficiency (imd)-mediated humoral response requires the bacterial lipopolysaccharide O-antigen. If ingested by Drosophila, bacteria cross the gut and penetrate the body cavity. During this passage, the bacteria can be observed within the cells of the intestinal epithelium. In such an oral infection model, the flies succumb to infection only after 6 days. We demonstrate that two complementary host defense mechanisms act together against such food-borne infection: an antimicrobial response in the intestine that is regulated by the imd pathway and phagocytosis by hemocytes of bacteria that have escaped into the hemolymph. Interestingly, bacteria present in the hemolymph elicit a systemic immune response only when phagocytosis is blocked. Our observations support a model wherein peptidoglycan fragments released during bacterial growth activate the imd pathway and do not back a proposed role for phagocytosis in the immune activation of the fat body. Thanks to the genetic tools available in both host and pathogen, the molecular dissection of the interactions between S. marcescens and Drosophila will provide a useful paradigm for deciphering intestinal pathogenesis. PMID:18039029

  20. A Model of Bacterial Intestinal Infections in Drosophila melanogaster

    PubMed Central

    Nehme, Nadine T; Liégeois, Samuel; Kele, Beatrix; Giammarinaro, Philippe; Pradel, Elizabeth; Hoffmann, Jules A; Ewbank, Jonathan J; Ferrandon, Dominique

    2007-01-01

    Serratia marcescens is an entomopathogenic bacterium that opportunistically infects a wide range of hosts, including humans. In a model of septic injury, if directly introduced into the body cavity of Drosophila, this pathogen is insensitive to the host's systemic immune response and kills flies in a day. We find that S. marcescens resistance to the Drosophila immune deficiency (imd)-mediated humoral response requires the bacterial lipopolysaccharide O-antigen. If ingested by Drosophila, bacteria cross the gut and penetrate the body cavity. During this passage, the bacteria can be observed within the cells of the intestinal epithelium. In such an oral infection model, the flies succumb to infection only after 6 days. We demonstrate that two complementary host defense mechanisms act together against such food-borne infection: an antimicrobial response in the intestine that is regulated by the imd pathway and phagocytosis by hemocytes of bacteria that have escaped into the hemolymph. Interestingly, bacteria present in the hemolymph elicit a systemic immune response only when phagocytosis is blocked. Our observations support a model wherein peptidoglycan fragments released during bacterial growth activate the imd pathway and do not back a proposed role for phagocytosis in the immune activation of the fat body. Thanks to the genetic tools available in both host and pathogen, the molecular dissection of the interactions between S. marcescens and Drosophila will provide a useful paradigm for deciphering intestinal pathogenesis. PMID:18039029

  1. Diagnosis and pharmacological management of small intestinal bacterial overgrowth in children with intestinal failure

    PubMed Central

    Malik, Bushra A; Xie, Yuan Y; Wine, Eytan; Huynh, Hien Q

    2011-01-01

    The present article provides a general overview of the possible diagnostic procedures available for the management of small intestinal bacterial overgrowth in pediatric patients with intestinal failure. The focus is to address current diagnostic tools and understand their associated advantages and disadvantages based on a literature search. Culture of small intestinal aspirates, noninvasive breath tests and an emerging interest in quantitative bacterial DNA fingerprinting are discussed. Proper management is critical for preventing the recurrence of small intestinal bacterial overgrowth and its related complications. Antibiotic prophylaxis is one approach to the treatment of bacterial overgrowth in intestinal failure patients. Although treatment trials can be challenging in such a vulnerable population, more investigative clinical studies examining early diagnosis, more effective control of recurrence and the prevention of associated complications must be conducted. PMID:21258668

  2. Intestinal alkaline phosphatase promotes gut bacterial growth by reducing the concentration of luminal nucleotide triphosphates

    PubMed Central

    Malo, Madhu S.; Moaven, Omeed; Muhammad, Nur; Biswas, Brishti; Alam, Sayeda N.; Economopoulos, Konstantinos P.; Gul, Sarah Shireen; Hamarneh, Sulaiman R.; Malo, Nondita S.; Teshager, Abeba; Mohamed, Mussa M. Rafat; Tao, Qingsong; Narisawa, Sonoko; Millán, José Luis; Hohmann, Elizabeth L.; Warren, H. Shaw; Robson, Simon C.

    2014-01-01

    The intestinal microbiota plays a pivotal role in maintaining human health and well-being. Previously, we have shown that mice deficient in the brush-border enzyme intestinal alkaline phosphatase (IAP) suffer from dysbiosis and that oral IAP supplementation normalizes the gut flora. Here we aimed to decipher the molecular mechanism by which IAP promotes bacterial growth. We used an isolated mouse intestinal loop model to directly examine the effect of exogenous IAP on the growth of specific intestinal bacterial species. We studied the effects of various IAP targets on the growth of stool aerobic and anaerobic bacteria as well as on a few specific gut organisms. We determined the effects of ATP and other nucleotides on bacterial growth. Furthermore, we examined the effects of IAP on reversing the inhibitory effects of nucleotides on bacterial growth. We have confirmed that local IAP bioactivity creates a luminal environment that promotes the growth of a wide range of commensal organisms. IAP promotes the growth of stool aerobic and anaerobic bacteria and appears to exert its growth promoting effects by inactivating (dephosphorylating) luminal ATP and other luminal nucleotide triphosphates. We observed that compared with wild-type mice, IAP-knockout mice have more ATP in their luminal contents, and exogenous IAP can reverse the ATP-mediated inhibition of bacterial growth in the isolated intestinal loop. In conclusion, IAP appears to promote the growth of intestinal commensal bacteria by inhibiting the concentration of luminal nucleotide triphosphates. PMID:24722905

  3. Bacterial colonization and intestinal mucosal barrier development.

    PubMed

    Huang, Xiao-Zhong; Zhu, Li-Bin; Li, Zhong-Rong; Lin, Jing

    2013-11-01

    The intestinal tract is colonized soon after birth with a variety of ingested environmental and maternal microflora. This process is influenced by many factors including mode of delivery, diet, environment, and the use of antibiotics. Normal intestinal microflora provides protection against infection, ensures tolerance to foods, and contributes to nutrient digestion and energy harvest. In addition, enteral feeding and colonization with the normal commensal flora are necessary for the maintenance of intestinal barrier function and play a vital role in the regulation of intestinal barrier function. Intestinal commensal microorganisms also provide signals that foster normal immune system development and influence the ensuing immune responses. There is increasingly recognition that alterations of the microbial gut flora and associated changes in intestinal barrier function may be related to certain diseases of the gastrointestinal tract. This review summarizes recent advances in understanding the complex ecosystem of intestinal microbiota and its role in regulating intestinal barrier function and a few common pediatric diseases. Disruption in the establishment of a stable normal gut microflora may contribute to the pathogenesis of diseases including inflammatory bowel disease, nosocomial infection, and neonatal necrotizing enterocolitis. PMID:25254174

  4. Bacterial colonization and intestinal mucosal barrier development

    PubMed Central

    Huang, Xiao-Zhong; Zhu, Li-Bin; Li, Zhong-Rong; Lin, Jing

    2013-01-01

    The intestinal tract is colonized soon after birth with a variety of ingested environmental and maternal microflora. This process is influenced by many factors including mode of delivery, diet, environment, and the use of antibiotics. Normal intestinal microflora provides protection against infection, ensures tolerance to foods, and contributes to nutrient digestion and energy harvest. In addition, enteral feeding and colonization with the normal commensal flora are necessary for the maintenance of intestinal barrier function and play a vital role in the regulation of intestinal barrier function. Intestinal commensal microorganisms also provide signals that foster normal immune system development and influence the ensuing immune responses. There is increasingly recognition that alterations of the microbial gut flora and associated changes in intestinal barrier function may be related to certain diseases of the gastrointestinal tract. This review summarizes recent advances in understanding the complex ecosystem of intestinal microbiota and its role in regulating intestinal barrier function and a few common pediatric diseases. Disruption in the establishment of a stable normal gut microflora may contribute to the pathogenesis of diseases including inflammatory bowel disease, nosocomial infection, and neonatal necrotizing enterocolitis. PMID:25254174

  5. Pediatric Small Intestinal Bacterial Overgrowth in Low-Income Countries

    PubMed Central

    Donowitz, Jeffrey R.; Petri, William A.

    2015-01-01

    Small intestine bacterial overgrowth (SIBO) occurs when colonic quantities of commensal bacteria are present in the small bowel. SIBO is associated with conditions of disrupted GI motility leading to stasis of luminal contents. Recent data show that SIBO is also found in children living in unsanitary conditions that do not have access to clean water. SIBO leads to impaired micronutrient absorption and increased GI permeability, both of which may contribute to growth stunting in children. SIBO also disrupts mucosal immunity and has been implicated in oral vaccination underperformance and the development of celiac disease. SIBO in the setting of the impoverished human habitat may be an under recognized cause of pediatric morbidity and mortality in the developing world. PMID:25486880

  6. Pediatric small intestine bacterial overgrowth in low-income countries.

    PubMed

    Donowitz, Jeffrey R; Petri, William A

    2015-01-01

    Small intestine bacterial overgrowth (SIBO) occurs when colonic quantities of commensal bacteria are present in the small bowel. SIBO is associated with conditions of disrupted gastrointestinal (GI) motility leading to stasis of luminal contents. Recent data show that SIBO is also found in children living in unsanitary conditions who do not have access to clean water. SIBO leads to impaired micronutrient absorption and increased GI permeability, both of which may contribute to growth stunting in children. SIBO also disrupts mucosal immunity and has been implicated in oral vaccination underperformance and the development of celiac disease. SIBO in the setting of the impoverished human habitats may be an under-recognized cause of pediatric morbidity and mortality in the developing world. PMID:25486880

  7. Diversity of the human intestinal microbial flora.

    PubMed

    Eckburg, Paul B; Bik, Elisabeth M; Bernstein, Charles N; Purdom, Elizabeth; Dethlefsen, Les; Sargent, Michael; Gill, Steven R; Nelson, Karen E; Relman, David A

    2005-06-10

    The human endogenous intestinal microflora is an essential "organ" in providing nourishment, regulating epithelial development, and instructing innate immunity; yet, surprisingly, basic features remain poorly described. We examined 13,355 prokaryotic ribosomal RNA gene sequences from multiple colonic mucosal sites and feces of healthy subjects to improve our understanding of gut microbial diversity. A majority of the bacterial sequences corresponded to uncultivated species and novel microorganisms. We discovered significant intersubject variability and differences between stool and mucosa community composition. Characterization of this immensely diverse ecosystem is the first step in elucidating its role in health and disease. PMID:15831718

  8. Cohabitation in the Intestine: Interactions among Helminth Parasites, Bacterial Microbiota, and Host Immunity.

    PubMed

    Reynolds, Lisa A; Finlay, B Brett; Maizels, Rick M

    2015-11-01

    Both intestinal helminth parasites and certain bacterial microbiota species have been credited with strong immunomodulatory effects. Recent studies reported that the presence of helminth infection alters the composition of the bacterial intestinal microbiota and, conversely, that the presence and composition of the bacterial microbiota affect helminth colonization and persistence within mammalian hosts. This article reviews recent findings on these reciprocal relationships, in both human populations and mouse models, at the level of potential mechanistic pathways and the implications these bear for immunomodulatory effects on allergic and autoimmune disorders. Understanding the multidirectional complex interactions among intestinal microbes, helminth parasites, and the host immune system allows for a more holistic approach when using probiotics, prebiotics, synbiotics, antibiotics, and anthelmintics, as well as when designing treatments for autoimmune and allergic conditions. PMID:26477048

  9. Cohabitation in the intestine: interactions between helminth parasites, bacterial microbiota and host immunity

    PubMed Central

    Reynolds, Lisa A.; Finlay, B. Brett; Maizels, Rick M.

    2015-01-01

    Both intestinal helminth parasites and certain bacterial microbiota species have been credited with strong immunomodulatory effects. Recent studies have reported that the presence of helminth infection alters the composition of the bacterial intestinal microbiota, and conversely that the presence and composition of the bacterial microbiota affects helminth colonisation and persistence within mammalian hosts. This article reviews recent findings on these reciprocal relationships, in both human populations and mouse models at the level of potential mechanistic pathways, and the implications these bear for immunomodulatory effects on allergic and autoimmune disorders. Understanding the multidirectional complex interactions between intestinal microbes, helminth parasites and the host immune system will allow for a more holistic approach when using pro-, pre-, synbiotics, antibiotics and anthelmintics, and when designing treatments for autoimmune and allergic conditions. PMID:26477048

  10. Effect of telavancin on human intestinal microflora.

    PubMed

    Rashid, Mamun-Ur; Weintraub, Andrej; Nord, Carl Erik

    2011-12-01

    Telavancin is a new lipoglycopeptide antibiotic for the treatment of Gram-positive infections. It has a dual mechanism of action by inhibiting bacterial cell wall synthesis and disrupting the bacterial plasma membrane. The purpose of the present study was to investigate the effect of administration of telavancin on the human intestinal microflora. Thirteen healthy subjects (six males and seven females; age range 18-40 years) received 10mg/kg body weight telavancin by intravenous infusion over a 60-min period once every 24h for 7 days. Plasma and urine were collected on Days 5, 6 and 7 for pharmacokinetic analysis of telavancin. Faecal samples were collected on Days -1 (pre-dose), 2, 5, 7, 9, 14 and 21. Faecal specimens were cultured on non-selective and selective media. Different colony types were counted, isolated in pure culture and identified to genus level. No measurable concentrations of telavancin were found in faeces. No significant effects on the number of Enterobacteriaceae, enterococci, Candida albicans, bifidobacteria, lactobacilli, clostridia and Bacteroides spp. were observed during the study period. No Clostridium difficile strains or toxins were found. No new colonising aerobic and anaerobic Gram-positive bacteria with telavancin minimum inhibitory concentrations of ≥ 2 mg/L were found. Based on the microbiological data, telavancin has no significant ecological impact on the human intestinal microflora. PMID:21982049

  11. Effect of cisapride on intestinal bacterial and endotoxin translocation in cirrhosis

    PubMed Central

    Zhang, Shun-Cai; Wang, Wei; Ren, Wei-Ying; He, Bo-Ming; Zhou, Kang; Zhu, Wu-Nan

    2003-01-01

    AIM: To investigate the effects of cisapride on intestinal bacterial overgrowth (IBO), bacterial and endotoxin translocation, intestinal transit and permeability in cirrhotic rats. METHODS: All animals were assessed with variables including bacterial and endotoxin translocation, intestinal bacterial overgrowth, intestinal transit and permeability. Bacterial translocation (BT) was assessed by bacterial culture of MLN, liver and spleen, IBO by a jejunal bacterial count of the specific organism, intestinal permeability by determination of the 24-hour urinary 99mTc-DTPA excretion and intestinal transit by measurement of the distribution of 51Cr in the intestine. RESULTS: Bacterial translocation (BT) and IBO was found in 48% and 80% cirrhotic rats respectively and none in control rats. Urinary excretion of 99mTc-DTPA in cirrhotic rats with BT (22.2 ± 7.8) was greater than these without BT (10.5 ± 2.9). Intestinal transit (geometric center ratio) was significantly delayed in cirrhotic rats (0.31 ± 0.06) and further more delayed in cirrhotic rats with BT (0.24 ± 0.06) than these without BT (0.38 ± 0.11). Cirrhotic rats with IBO had significantly higher rates of intestinal bacterial and endotoxin translocation, slower intestinal transit time and higher intestinal permeability than those without IBO. It was also found that BT was closely associated with IBO and the injury of intestinal barrier. Compared with the placebo group, cisapride-treated rats had lower rates of bacterial/endotoxin translocation and IBO, which was closely associated with increased intestinal transit and improved intestinal permeability by cisapride. CONCLUSION: These results indicate that endotoxin and bacterial translocation in cirrhotic rats may be attributed to IBO and increased intestinal permeability. Cisapride that accelerates intestinal transit and improve intestinal permeability might be helpful in preventing intestinal bacterial and endotoxin translocation. PMID:12632513

  12. [Microecological aspects of small intestinal bacterial overgrowth syndrome].

    PubMed

    Bondarenko, V M; Lykova, E A; Matsulevich, T V

    2006-01-01

    Small intestinal bacterial overgrowth syndrome (SIBOS) means chronic recurrent diarrhea with malabsorption, intoxication and increased risk of endogenous infection. This syndrome are accompanied by increase of overall bacterial burden in biotope >10(5) CFU/ml in adults and >10(4) CFU/ml in children, emergence of different species of enterobacteria, bacteroides, clostridia and fusobacteria et al. in small intestine. Such characteristics of the syndrome allow to consider it as syndrome of disturbances of intestinal microflora (dysbacteriosis). Microecological changes are accompanied by B12 vitamin deficiency anemia, hypovitaminosis, protein deficiency, translocation of bacteria and their toxins from intestine in blood, emergence of endotoxinemia and possible generalization of infection. SIBOS is diagnosed by concentration of hydrogen in expiratory flow (lactulosa load test) or by bacteriological study of aspirate from proximal part of small intestine. Complex treatment includes containing lacto- and bifidobacteria probiotics and, in more severe cases, antimicrobial agents (vancomycine, metronidazole, aminoglycosides, amoxicillin clavulanate, tetracycline, and cephalosporines of 2nd generation) with following correction of disturbed microbiocenosis by different probiotics. PMID:17163142

  13. Breath Testing for Small Intestinal Bacterial Overgrowth: Should We Bother?

    PubMed

    Pimentel, Mark

    2016-03-01

    The hydrogen breath test is based on following breath hydrogen levels after the administration of a carbohydrate (most commonly lactulose) to a patient with suspected small intestinal bacterial overgrowth. The test is based on the interaction between the administered carbohydrate and the intestinal bacteria. The resulting fermentation produces hydrogen. A positive breath test is based on a breath hydrogen rise prior to the expected arrival time in the highly microbial cecum. Despite renewed enthusiasm for breath testing in recent years due to associations with conditions such as irritable bowel syndrome, breath testing poses many challenges. In this argument against breath testing, several pitfalls that complicate breath testing will be described. PMID:26902227

  14. Enteric infection meets intestinal function: how bacterial pathogens cause diarrhoea

    PubMed Central

    Viswanathan, V. K.; Hodges, Kim; Hecht, Gail

    2012-01-01

    Infectious diarrhoea is a significant contributor to morbidity and mortality worldwide. In bacterium-induced diarrhoea, rapid loss of fluids and electrolytes results from inhibition of the normal absorptive function of the intestine as well as the activation of secretory processes. Advances in the past 10 years in the fields of gastrointestinal physiology, innate immunity and enteric bacterial virulence mechanisms highlight the multifactorial nature of infectious diarrhoea. This Review explores the various mechanisms that contribute to loss of fluids and electrolytes following bacterial infections, and attempts to link these events to specific virulence factors and toxins. PMID:19116615

  15. Analysis of Intestinal Bacterial Community Diversity of Adult Dastarcus helophoroides

    PubMed Central

    Zhang, Z. Q.; He, C.; Li, M. L.

    2014-01-01

    Polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE), and a culturedependent technique were used to study the diversity of the intestinal bacterial community in adult Dastarcus helophoroides (Fairmaire) (Coleoptera: Bothrideridae). Universal bacterial primers targeting 200 bp regions of the 16S rDNA gene were used in the PCR-DGGE assay, and 14 bright bands were obtained. The intestinal bacteria detected by PCR-DGGE were classified to Enterococcus (Lactobacillales: Enterococcaceae), Bacillus (Bacillales: Bacillaceae), Cellvibrio (Pseudomonadales: Pseudomonadaceae), Caulobacter (Caulobacterales: Caulobacteraceae), and uncultured bacteria, whereas those isolated by the culture-dependent technique belonged to Staphylococcus (Bacillales: Staphylococcaceae), Pectobacterium Enterobacteriales: Enterobacteriaceae), and Enterobacter (Enterobacteriales: Enterobacteriaceae). These intestinal bacteria represented the groups Lactobacillales (Enterococcus), Pseudomonadales (Cellvibrio), Caulobacterales (Caulobacter), Bacilli (Bacillus and Staphylococcus), and Gammaproteobacteria (Pectobacterium and Enterobacter). Our results demonstrated that PCR-DGGE analysis and the culture-dependent technique were useful in determining the intestinal bacteria of D. helophoroides and the two methods should be integrated to characterize the microbial community and diversity. PMID:25200108

  16. Bacterial DNA Content in the Intestinal Wall from Infants with Necrotizing Enterocolitis

    PubMed Central

    Bucher, Brian T.; McDuffie, Lucas A.; Shaikh, Nurmohammad; Tarr, Phillip I.; Warner, Barbara B.; Hamvas, Aaron; White, Francis V.; Erwin, Christopher R.; Warner, Brad W.

    2011-01-01

    PURPOSE The objectives of our study were to quantify mucosal bacterial DNA within specimens from neonates undergoing small bowel resection for necrotizing enterocolitis (NEC). METHODS We obtained clinical information and pathologic specimens from all infants diagnosed with NEC who underwent surgical treatment at our institution from 1999–2008. Bacterial and human DNA were isolated from paraffin-embedded surgical specimens and real-time PCR was used to amplify bacterial and human genes. Linear regression was used to quantify the amount of human and bacterial DNA in our specimens. RESULTS From a cohort of fifty infants, we identified twenty-three infants who underwent both surgical resection and subsequent intestinal reanastomosis. Thirteen (59%) of the neonates had Bell's Stage III NEC, and nine (41%) had Stage II. There was significantly more bacterial DNA in the resection specimens than in the reanastomosis specimens. This corresponds to a median (IQR) increase of 1.81 (1.11–4.69) fold bacterial DNA in the resection specimen compared to the reanastomosis specimen (p<0.05). CONCLUSION There is more bacterial DNA in infants with acute NEC compared with the same infants after the NEC had clinically resolved. These findings underscore the potential relevance of adherent or invasive bacteria across the bowel wall in the pathogenesis of NEC. PMID:21683193

  17. Metabolism of nitropolycyclic aromatic hydrocarbons by human intestinal microflora

    SciTech Connect

    Cerniglia, C.E.; Howard, P.C.; Fu, P.P.; Franklin, W.

    1984-08-30

    Anaerobic bacterial suspensions from human and rat feces and intestinal contents, and pure cultures of anaerobic bacteria metabolized 1-nitropyrene and 6-nitrobenzo(a)pyrene to 1-aminopyrene and 6-aminobenzo(a)pyrene, respectively. The metabolites were isolated by reversed-phase high performance liquid chromatography and identified by comparison of their chromatographic and mass spectral properties with those of authentic compounds. The results suggest that anaerobic intestinal bacteria could play a significant role in the metabolism of potentially carcinogenic nitropolycyclic aromatic hydrocarbons. 28 references, 4 figures, 1 table.

  18. Intestinal bacterial overgrowth after Roux-en-Y gastric bypass.

    PubMed

    Machado, Juliana Deh Carvalho; Campos, Camila Scalassara; Lopes Dah Silva, Carolina; Marques Suen, Vivian Miguel; Barbosa Nonino-Borges, Carla; Dos Santos, José Ernesto; Ceneviva, Reginaldo; Marchini, Júlio Sérgio

    2008-01-01

    The aim of the present study was to report the occurrence of serious subnutrition, associated to intestinal bacterial overgrowth, in two patients submitted to bariatric surgery. Two female patients (body mass index, 49 and 50 kg/m(2), respectively) were submitted to Y-en-Roux gastric bypass. The first patient evolved a 52% loss of body weight within 21 months after surgery; the other, a 34% loss of initial body weight within 15 months after surgery, results corresponding, respectively, to 62 and 45 kg weight losses. However, both patients reported asthenia, hair fallout, and edema, and one also reported diarrhea, but none was feverish. Their respective albuminemias were of 24 and 23 g/l. A respiratory hydrogen test suggested bacterial hyperproliferation. Thirty days after ciprofloxacin and tetracyclin treatments, they showed improved albumin levels and nutritional states, both confirmed by results of hydrogen breath tests. Bacterial overgrowth is an important complication that can compromise clinical evolution of patients submitted to intestinal surgery like gastroplasty with Y-Roux anastomosis. In cases of clinical suspicion or a confirmed diagnosis, adequate antibiotics, sometimes requiring to be cyclically repeated, should be administered. PMID:18080824

  19. Emerging insights on intestinal dysbiosis during bacterial infections☆

    PubMed Central

    Pham, Tu Anh N; Lawley, Trevor D

    2014-01-01

    Infection of the gastrointestinal tract is commonly linked to pathological imbalances of the resident microbiota, termed dysbiosis. In recent years, advanced high-throughput genomic approaches have allowed us to examine the microbiota in an unprecedented manner, revealing novel biological insights about infection-associated dysbiosis at the community and individual species levels. A dysbiotic microbiota is typically reduced in taxonomic diversity and metabolic function, and can harbour pathobionts that exacerbate intestinal inflammation or manifest systemic disease. Dysbiosis can also promote pathogen genome evolution, while allowing the pathogens to persist at high density and transmit to new hosts. A deeper understanding of bacterial pathogenicity in the context of the intestinal microbiota should unveil new approaches for developing diagnostics and therapies for enteropathogens. PMID:24581695

  20. Transfer of intestinal bacterial components to mammary secretions in the cow

    PubMed Central

    Young, Wayne; Hine, Brad C.; Wallace, Olivia A.M.; Callaghan, Megan

    2015-01-01

    Results from large multicentre epidemiological studies suggest an association between the consumption of raw milk and a reduced incidence of allergy and asthma in children. Although the underlying mechanisms for this association are yet to be confirmed, researchers have investigated whether bacteria or bacterial components that naturally occur in cow’s milk are responsible for modulating the immune system to reduce the risk of allergic diseases. Previous research in human and mice suggests that bacterial components derived from the maternal intestine are transported to breast milk through the bloodstream. The aim of our study was to assess whether a similar mechanism of bacterial trafficking could occur in the cow. Through the application of culture-independent methodology, we investigated the microbial composition and diversity of milk, blood and feces of healthy lactating cows. We found that a small number of bacterial OTUs belonging to the genera Ruminococcus and Bifidobacterium, and the Peptostreptococcaceae family were present in all three samples from the same individual animals. Although these results do not confirm the hypothesis that trafficking of intestinal bacteria into mammary secretions does occur in the cow, they support the existence of an endogenous entero-mammary pathway for some bacterial components during lactation in the cow. Further research is required to define the specific mechanisms by which gut bacteria are transported into the mammary gland of the cow, and the health implications of such bacteria being present in milk. PMID:25922791

  1. Transfer of intestinal bacterial components to mammary secretions in the cow.

    PubMed

    Young, Wayne; Hine, Brad C; Wallace, Olivia A M; Callaghan, Megan; Bibiloni, Rodrigo

    2015-01-01

    Results from large multicentre epidemiological studies suggest an association between the consumption of raw milk and a reduced incidence of allergy and asthma in children. Although the underlying mechanisms for this association are yet to be confirmed, researchers have investigated whether bacteria or bacterial components that naturally occur in cow's milk are responsible for modulating the immune system to reduce the risk of allergic diseases. Previous research in human and mice suggests that bacterial components derived from the maternal intestine are transported to breast milk through the bloodstream. The aim of our study was to assess whether a similar mechanism of bacterial trafficking could occur in the cow. Through the application of culture-independent methodology, we investigated the microbial composition and diversity of milk, blood and feces of healthy lactating cows. We found that a small number of bacterial OTUs belonging to the genera Ruminococcus and Bifidobacterium, and the Peptostreptococcaceae family were present in all three samples from the same individual animals. Although these results do not confirm the hypothesis that trafficking of intestinal bacteria into mammary secretions does occur in the cow, they support the existence of an endogenous entero-mammary pathway for some bacterial components during lactation in the cow. Further research is required to define the specific mechanisms by which gut bacteria are transported into the mammary gland of the cow, and the health implications of such bacteria being present in milk. PMID:25922791

  2. Indirect measurement of intestinal immune responses to an orally administered attenuated bacterial vaccine.

    PubMed Central

    Forrest, B D

    1992-01-01

    Intestinal fluid, saliva, circulating peripheral blood lymphocytes (PBL), and serum samples obtained from 81 human adult subjects who had been orally vaccinated with either Salmonella typhi Ty21a or one of its recombinant derivatives were examined to determine the value of indirect measurements of an antigen-specific intestinal-immunoglobulin A (IgA) response. Salivary IgA failed to provide consistent or correlative responses, and no evidence of a significant relationship was apparent with the intestinal-IgA responses. No significant correlation between the specific increase in responses in serum IgA and intestinal IgA was evident. While the magnitude of the serum IgG response significantly correlated with the intestinal-IgA response (P = 0.00064), it failed to detect 14.8% of the intestinal-IgA responses. The observation that 16.6% of the subjects had delayed serum IgA responses, with a peak occurring after day 23 compared with days 12 to 14, may have contributed to the inadequacy of the serum IgA response as a correlative indicator. The serum IgG responses in these subjects were also of a diminished magnitude. Specific IgA production by circulating PBL was found to be the most sensitive (92.6% response rate) and correlative (P = 0.00071) indicator of a specific intestinal-IgA immune response. However, its value in predicting protective efficacy is untried. These studies confirm that for the assessment of an enteric bacterial vaccine, determination of in vitro specific IgA production by circulating PBL may offer a single measurement of specific immunity which is as useful as serum and intestinal measurements combined. PMID:1563793

  3. Intestinal transit and bacterial translocation in obstructive pancreatitis.

    PubMed

    Moody, F G; Haley-Russell, D; Muncy, D M

    1995-08-01

    Pancreatic infection from gut-derived bacteria has emerged as the major cause of death in necrotizing pancreatitis. Bacterial overgrowth of indigenous enteric organisms as a consequence of guts stasis (ileus) represents a potential initial event in this process. The present study was designed to examine the interrelationships between intestinal transit, enteric bacteriology, and the translocation of bacteria from the gut lumen to mesenteric lymph nodes and splanchnic viscera during experimentally induced acute pancreatitis. Male rats underwent pancreaticobiliary duct ligation (PBDL) or sham surgery and were sacrificed after 24, 48, or 96 hr. Severity of pancreatitis was assessed with histology, tissue water content, and amylase and lipase levels. Intestinal transit was measured with fluorescent tracers. Blood, mesenteric lymph nodes (MLNs), splanchnic organs, and gut luminal contents were subjected to bacteriologic analysis. PBDL was followed by biochemical and histologic evidence of progressive pancreatic injury at each time interval. Enteric bacteria within the gut and in adjacent MLNs increased as intestinal transit decreased after PBDL-induced pancreatic inflammation. Surprisingly, all parameters returned to control levels by 96 hr in spite of progression of pancreatic inflammation. PMID:7648983

  4. Small intestinal bacterial overgrowth and warfarin dose requirement variability.

    PubMed

    Giuliano, Vittorio; Bassotti, Gabrio; Mourvaki, Evangelia; Castellani, Danilo; Filippucci, Esmeralda; Sabatino, Giuseppe; Gizzi, Stefania; Palmerini, Francesco; Galli, Francesco; Morelli, Olivia; Baldoni, Monia; Morelli, Antonio; Iorio, Alfonso

    2010-07-01

    The dose of warfarin needed to obtain a therapeutic anticoagulation level varies widely among patients and can undergo abrupt changes for unknown reasons. Drug interactions and genetic factors may partially explain these differences. Intestinal flora produces vitamin K2 (VK2) and patients with small intestinal bacterial overgrowth (SIBO) rarely present reduced INR values due to insufficient dietary vitamin K. The present study was undertaken to investigate whether SIBO occurrence may affect warfarin dose requirements in anticoagulated patients. Based on their mean weekly dose of warfarin while on stable anticoagulation, 3 groups of 10 patients each were defined: low dose (LD, or=70 mg/wk). Each patient underwent a lactulose breath test to diagnose SIBO. Plasma levels of warfarin and vitamin K-analogues were also assessed. Patients with an altered breath test were 50% in the VHD group, 10% in the HD group, and none in the LD group (P=0.01). Predisposing factors to SIBO were more frequent in the VHD group, while warfarin interfering variables were not. VHD patients were younger and had a higher plasma vitamin K1 (VK1) concentration (P>0.05). On the contrary, the plasma VK2 levels tended to be lower. This pilot study suggests that SIBO may increase a patient's warfarin dose requirement by increasing dietary VK1 absorption through the potentially damaged intestinal mucosa rather than increasing intestinal VK2 biosynthesis. Larger studies are needed to confirm these preliminary data and to evaluate the effects of SIBO decontamination on warfarin dosage. PMID:20051286

  5. Small Intestine Bacterial Overgrowth and Environmental Enteropathy in Bangladeshi Children

    PubMed Central

    Haque, Rashidul; Kirkpatrick, Beth D.; Alam, Masud; Lu, Miao; Kabir, Mamun; Kakon, Shahria Hafiz; Islam, Bushra Zarin; Afreen, Sajia; Musa, Abu; Khan, Shaila Sharmeen; Colgate, E. Ross; Carmolli, Marya P.; Ma, Jennie Z.

    2016-01-01

    ABSTRACT Recent studies suggest small intestine bacterial overgrowth (SIBO) is common among developing world children. SIBO’s pathogenesis and effect in the developing world are unclear. Our objective was to determine the prevalence of SIBO in Bangladeshi children and its association with malnutrition. Secondary objectives included determination of SIBO’s association with sanitation, diarrheal disease, and environmental enteropathy. We performed a cross-sectional analysis of 90 Bangladeshi 2-year-olds monitored since birth from an impoverished neighborhood. SIBO was diagnosed via glucose hydrogen breath testing, with a cutoff of a 12-ppm increase over baseline used for SIBO positivity. Multivariable logistic regression was performed to investigate SIBO predictors. Differences in concomitant inflammation and permeability between SIBO-positive and -negative children were compared with multiple comparison adjustment. A total of 16.7% (15/90) of the children had SIBO. The strongest predictors of SIBO were decreased length-for-age Z score since birth (odds ratio [OR], 0.13; 95% confidence interval [CI], 0.03 to 0.60) and an open sewer outside the home (OR, 4.78; 95% CI, 1.06 to 21.62). Recent or frequent diarrheal disease did not predict SIBO. The markers of intestinal inflammation fecal Reg 1β (116.8 versus 65.6 µg/ml; P = 0.02) and fecal calprotectin (1,834.6 versus 766.7 µg/g; P = 0.004) were elevated in SIBO-positive children. Measures of intestinal permeability and systemic inflammation did not differ between the groups. These findings suggest linear growth faltering and poor sanitation are associated with SIBO independently of recent or frequent diarrheal disease. SIBO is associated with intestinal inflammation but not increased permeability or systemic inflammation. PMID:26758185

  6. Infant intestinal Enterococcus faecalis down-regulates inflammatory responses in human intestinal cell lines

    PubMed Central

    Wang, Shugui; Ng, Lydia Hui Mei; Chow, Wai Ling; Lee, Yuan Kun

    2008-01-01

    AIM: To investigate the ability of Lactic acid bacteria (LAB) to modulate inflammatory reaction in human intestinal cell lines (Caco-2, HT-29 and HCT116). Different strains of LAB isolated from new born infants and fermented milk, together with the strains obtained from culture collections were tested. METHODS: LABs were treated with human intestinal cell lines. ELISA was used to detect IL-8 and TGF-? protein secretion. Cytokines and Toll like receptors (TLRs) gene expression were assessed using RT-PCR. Conditional medium, sonicated bacteria and UV killed bacteria were used to find the effecter molecules on the bacteria. Carbohydrate oxidation and protein digestion were applied to figure out the molecules residues. Adhesion assays were further carried out. RESULTS: It was found that Enterococcus faecalis is the main immune modulator among the LABs by downregulation of IL-8 secretion and upregulation of TGF-?. Strikingly, the effect was only observed in four strains of E. faecalis out of the 27 isolated and tested. This implies strain dependent immunomodulation in the host. In addition, E. faecalis may regulate inflammatory responses through TLR3, TLR4, TLR9 and TRAF6. Carbohydrates on the bacterial cell surface are involved in both its adhesion to intestinal cells and regulation of inflammatory responses in the host. CONCLUSION: These data provide a case for the modulation of intestinal mucosal immunity in which specific strains of E. faecalis have uniquely evolved to maintain colonic homeostasis and regulate inflammatory responses. PMID:18286689

  7. Link between hypothyroidism and small intestinal bacterial overgrowth.

    PubMed

    Patil, Anant D

    2014-05-01

    Altered gastrointestinal (GI) motility is seen in many pathological conditions. Reduced motility is one of the risk factors for development of a small intestinal bacterial overgrowth (SIBO). Hypothyroidism is associated with altered GI motility. The aim of this article was to study the link between hypothyroidism, altered GI motility and development of SIBO. Published literature was reviewed to study the association of altered GI motility, SIBO and hypothyroidism. Altered GI motility leads to SIBO. SIBO is common in patients with hypothyroidism. Patients with chronic GI symptoms in hypothyroidism should be evaluated for the possibility of SIBO. Both antibiotics and probiotics have been studied and found to be effective in management of SIBO. PMID:24944923

  8. Regulation of Bacterial Pathogenesis by Intestinal Short-Chain Fatty Acids

    PubMed Central

    Sun, Yvonne; O’Riordan, Mary X. D.

    2013-01-01

    The human gut microbiota is inextricably linked to health and disease. One important function of the commensal organisms living in the intestine is to provide colonization resistance against invading enteric pathogens. Because of the complex nature of the interaction between the microbiota and its host, multiple mechanisms likely contribute to resistance. In this review, we dissect the biological role of short-chain fatty acids (SCFA), which are fermentation end products of the intestinal microbiota, in host–pathogen interactions. SCFA exert an extensive influence on host physiology through nutritional, regulatory, and immunomodulatory functions and can also affect bacterial fitness as a form of acid stress. Moreover, SCFA act as a signal for virulence gene regulation in common enteric pathogens. Taken together, these studies highlight the importance of the chemical environment where the biology of the host, the microbiota, and the pathogen intersects, which provides a basis for designing effective infection prevention and control. PMID:23942149

  9. Blockage of protease-activated receptor 1 ameliorates heat-stress induced intestinal high permeability and bacterial translocation.

    PubMed

    Xu, Qiu-lin; Guo, Xiao-hua; Liu, Jing-xian; Chen, Bin; Liu, Zhi-feng; Su, Lei

    2015-04-01

    Accumulated evidences indicate intestinal lesions play an important role in the pathogenesis of heatstroke. However, the underlying mechanisms by which heat stress causes intestinal barrier dysfunction and bacterial translocation remain unclear. In this study, we investigated the role of protease-activated receptor 1 (PAR1) in heat stress-induced intestinal hyper-permeability and bacterial translocation. Intestinal permeability in heat stressed mouse was evaluated by determining plasma endotoxin concentration and urinal lactulose/mannitol (L/M) ratio with gastric administration of L/M solution. Venous blood, liver, spleen and mesenteric lymph node tissues were collected for bacterial load test. Real time PCR was used to determine ileum PAR1 mRNA expression. In vitro study, permeability was assessed by determining trans-epithelial electrical resistance (TEER) in human intestinal Caco-2 cell line. RWJ-58259, a selective antagonist of PAR1, was used both in vivo and in vitro studies. The results showed that heat stress could increase ileum PAR1 mRNA level, urinal L/M ratio, plasma endotoxin concentration and bacterial load in the blood, spleen and mesenteric lymph nodes. Blocking PAR1 with RWJ-58259 (10 mg/kg) pretreatment could significantly reduce heat stress-induced above changes, but have no role to PAR1 mRNA level. In Caco-2 cells, heat stress-induced high permeability could also be reduced by RWJ-58259 (5-20 µmol/L). In summary, our results demonstrated that PAR1 signaling pathway may play an important role in the heat stress-induced elevation of intestinal permeability, bacterial translocation and the occurrence of endotoxemia. PMID:25492552

  10. Transformation of trollioside and isoquercetin by human intestinal flora in vitro.

    PubMed

    Yuan, Ming; Shi, Duo-Zhi; Wang, Teng-Yu; Zheng, Shi-Qi; Liu, Li-Jia; Sun, Zhen-Xiao; Wang, Ru-Feng; Ding, Yi

    2016-03-01

    The present study was designed to determine the intestinal bacterial metabolites of trollioside and isoquercetin and their antibacterial activities. A systematic in vitro biotransformation investigation on trollioside and isoquercetin, including metabolite identification, metabolic pathway deduction, and time course, was accomplished using a human intestinal bacterial model. The metabolites were analyzed and identified by HPLC and HPLC-MS. The antibacterial activities of trollioside, isoquercetin, and their metabolites were evaluated using the broth microdilution method with berberine as a positive control, and their potency was measured as minimal inhibitory concentration (MIC). Our results indicated that trollioside and isoquercetin were metabolized by human intestinal flora through O-deglycosylation, yielding aglycones proglobeflowery acid and quercetin, respectively The antibacterial activities of both metabolites were more potent than that of their parent compounds. In conclusion, trollioside and isoquercetin are totally and rapidly transformed by human intestinal bacteria in vitro and the transformation favors the improvement of the antibacterial activities of the parent compounds. PMID:27025369

  11. Comparison of intestinal bacterial communities in grass carp, Ctenopharyngodon idellus, from two different habitats

    NASA Astrophysics Data System (ADS)

    Ni, Jiajia; Yu, Yuhe; Zhang, Tanglin; Gao, Lei

    2012-09-01

    The intestinal bacteria of vertebrates form a close relationship with their host. External and internal conditions of the host, including its habitat, affect the intestinal bacterial community. Similarly, the intestinal bacterial community can, in turn, influence the host, particularly with respect to disease resistance. We compared the intestinal bacterial communities of grass carp that were collected from farm-ponds or a lake. We conducted denaturing gradient gel electrophoresis of amplified 16S rRNA genes, from which 66 different operational taxonomic units were identified. Using both the unweighted pair-group method with arithmetic means clustering and principal component analysis ordination, we found that the intestinal bacterial communities from the two groups of pond fish were clustered together and inset into the clusters of wild fish, except for DF-7, and there was no significant correlation between genetic diversity of grass carp and their intestinal bacterial communities (Mantel one-tailed test, R=0.157, P=0.175). Cetobacterium appeared more frequently in the intestine of grass carp collected from pond. A more thorough understanding of the role played by intestinal microbiota on fish health would be of considerable benefit to the aquaculture industry.

  12. Evaluating and optimizing oral formulations of live bacterial vaccines using a gastro-small intestine model.

    PubMed

    de Barros, João M S; Costabile, Adele; Charalampopoulos, Dimitrios; Khutoryanskiy, Vitaliy V; Edwards, Alexander D

    2016-05-01

    Gastrointestinal (GI) models that mimic physiological conditions in vitro are important tools for developing and optimizing biopharmaceutical formulations. Oral administration of live attenuated bacterial vaccines (LBV) can safely and effectively promote mucosal immunity but new formulations are required that provide controlled release of optimal numbers of viable bacterial cells, which must survive gastrointestinal transit overcoming various antimicrobial barriers. Here, we use a gastro-small intestine gut model of human GI conditions to study the survival and release kinetics of two oral LBV formulations: the licensed typhoid fever vaccine Vivotif comprising enteric coated capsules; and an experimental formulation of the model vaccine Salmonella Typhimurium SL3261 dried directly onto cast enteric polymer films and laminated to form a polymer film laminate (PFL). Neither formulation released significant numbers of viable cells when tested in the complete gastro-small intestine model. The poor performance in delivering viable cells could be attributed to a combination of acid and bile toxicity plus incomplete release of cells for Vivotif capsules, and to bile toxicity alone for PFL. To achieve effective protection from intestinal bile in addition to effective acid resistance, bile adsorbent resins were incorporated into the PFL to produce a new formulation, termed BR-PFL. Efficient and complete release of 4.4×10(7) live cells per dose was achieved from BR-PFL at distal intestinal pH, with release kinetics controlled by the composition of the enteric polymer film, and no loss in viability observed in any stage of the GI model. Use of this in vitro GI model thereby allowed rational design of an oral LBV formulation to maximize viable cell release. PMID:26969261

  13. Breath testing for small intestinal bacterial overgrowth: maximizing test accuracy.

    PubMed

    Saad, Richard J; Chey, William D

    2014-12-01

    The diagnosis of small intestinal bacterial overgrowth (SIBO) has increased considerably owing to a growing recognition of its association with common bowel symptoms including chronic diarrhea, bloating, abdominal distention, and the irritable bowel syndrome. Ideally, an accurate and objective diagnosis of SIBO should be established before initiating antibiotic treatment. Unfortunately, no perfect test exists for the diagnosis of SIBO. The current gold standard, small-bowel aspiration and quantitative culture, is limited by its high cost, invasive nature, lack of standardization, sampling error, and need for dedicated infrastructure. Although not without shortcomings, hydrogen breath testing provides the simplest noninvasive and widely available diagnostic modality for suspected SIBO. Carbohydrates such as lactulose and glucose are the most widely used substrates in hydrogen breath testing, with glucose arguably providing greater testing accuracy. Lactose, fructose, and sorbitol should not be used as substrates in the assessment of suspected SIBO. The measurement of methane in addition to hydrogen can increase the sensitivity of breath testing for SIBO. Diagnostic accuracy of hydrogen breath testing in SIBO can be maximized by careful patient selection for testing, proper test preparation, and standardization of test performance as well as test interpretation. PMID:24095975

  14. Tipping elements in the human intestinal ecosystem

    PubMed Central

    Lahti, Leo; Salojärvi, Jarkko; Salonen, Anne; Scheffer, Marten; de Vos, Willem M.

    2014-01-01

    The microbial communities living in the human intestine can have profound impact on our well-being and health. However, we have limited understanding of the mechanisms that control this complex ecosystem. Here, based on a deep phylogenetic analysis of the intestinal microbiota in a thousand western adults, we identify groups of bacteria that exhibit robust bistable abundance distributions. These bacteria are either abundant or nearly absent in most individuals, and exhibit decreased temporal stability at the intermediate abundance range. The abundances of these bimodally distributed bacteria vary independently, and their abundance distributions are not affected by short-term dietary interventions. However, their contrasting alternative states are associated with host factors such as ageing and overweight. We propose that the bistable groups reflect tipping elements of the intestinal microbiota, whose critical transitions may have profound health implications and diagnostic potential. PMID:25003530

  15. The impact of hypoxia on intestinal epithelial cell functions: consequences for invasion by bacterial pathogens.

    PubMed

    Zeitouni, Nathalie E; Chotikatum, Sucheera; von Köckritz-Blickwede, Maren; Naim, Hassan Y

    2016-12-01

    The maintenance of oxygen homeostasis in human tissues is mediated by several cellular adaptations in response to low-oxygen stress, called hypoxia. A decrease in tissue oxygen levels is initially counteracted by increasing local blood flow to overcome diminished oxygenation and avoid hypoxic stress. However, studies have shown that the physiological oxygen concentrations in several tissues are much lower than atmospheric (normoxic) conditions, and the oxygen supply is finely regulated in individual cell types. The gastrointestinal tract has been described to subsist in a state of physiologically low oxygen level and is thus depicted as a tissue in the state of constant low-grade inflammation. The intestinal epithelial cell layer plays a vital role in the immune response to inflammation and infections that occur within the intestinal tissue and is involved in many of the adaptation responses to hypoxic stress. This is especially relevant in the context of inflammatory disorders, such as inflammatory bowel disease (IBD). Therefore, this review aims to describe the intestinal epithelial cellular response to hypoxia and the consequences for host interactions with invading gastrointestinal bacterial pathogens. PMID:27002817

  16. Human intestinal spirochetosis – a review

    PubMed Central

    Tsinganou, Efstathia; Gebbers, Jan-Olaf

    2010-01-01

    Human intestinal spirochetosis (IS) is a condition defined histologically by the presence of spirochetal microorganisms attached to the apical cell membrane of the colorectal epithelium. Intestinal spirochetes comprise a heterogeneous group of bacteria. In humans, Brachyspira aalborgi and Brachyspira pilosicoli predominate. Prevalence rates of IS are low where living standards are high, in contrast to poorly developed areas where IS is common. Homosexuals and HIV-infected individuals are at high risk of being colonized. Clinical significance in individual cases has remained unclear up to now. A review of the literature assumes that invasion of spirochetes beyond the surface epithelium may be associated with gastrointestinal symptoms which respond to antibiotic treatment (metronidazole), whereas individuals lacking this feature may be mostly asymptomatic. Of unknown reason, homosexual and HIV-positive men as well as children are more likely to be symptomatic irrespective of invasion. Rare cases of spirochetemia and multiple organ failure have been reported in critically ill patients with IS. PMID:20200654

  17. Probiotics prevent bacterial translocation and improve intestinal barrier function in rats following chronic psychological stress

    PubMed Central

    Zareie, M; Johnson‐Henry, K; Jury, J; Yang, P‐C; Ngan, B‐Y; McKay, D M; Soderholm, J D; Perdue, M H; Sherman, P M

    2006-01-01

    Background and aim Chronic psychological stress, including water avoidance stress (WAS), induces intestinal mucosal barrier dysfunction and impairs mucosal defences against luminal bacteria. The aim of this study was to determine the ability of a defined probiotic regimen to prevent WAS induced intestinal pathophysiology. Methods Male rats were subjected to either WAS or sham stress for one hour per day for 10 consecutive days. Additional animals received seven days of Lactobacillus helveticus and L rhamnosus in the drinking water prior to stress and remained on these probiotics for the duration of the study. Rats were then sacrificed, intestinal segments assessed in Ussing chambers, and mesenteric lymph nodes cultured to determine bacterial translocation. Results All animals remained healthy for the duration of the study. Chronic WAS induced excess ion secretion (elevated baseline short circuit current) and barrier dysfunction (increased conductance) in both the ileum and colon, associated with increased bacterial adhesion and penetration into surface epithelial cells. Approximately 70% of rats subjected to WAS had bacterial translocation to mesenteric lymph nodes while there was no bacterial translocation in controls. Probiotic pretreatment alone had no effect on intestinal barrier function. However, WAS induced increased ileal short circuit current was reduced with probiotics whereas there was no impact on altered conductance. Pretreatment of animals with probiotics also completely abrogated WAS induced bacterial adhesion and prevented translocation of bacteria to mesenteric lymph nodes. Conclusion These findings indicate that probiotics can prevent chronic stress induced intestinal abnormalities and, thereby, exert beneficial effects in the intestinal tract. PMID:16638791

  18. Probiotics prevent bacterial translocation and improve intestinal barrier function in rats following chronic psychological stress.

    TOXLINE Toxicology Bibliographic Information

    Zareie M; Johnson-Henry K; Jury J; Yang PC; Ngan BY; McKay DM; Soderholm JD; Perdue MH; Sherman PM

    2006-11-01

    BACKGROUND AND AIMS: Chronic psychological stress, including water avoidance stress (WAS), induces intestinal mucosal barrier dysfunction and impairs mucosal defences against luminal bacteria. The aim of this study was to determine the ability of a defined probiotic regimen to prevent WAS induced intestinal pathophysiology.METHODS: Male rats were subjected to either WAS or sham stress for one hour per day for 10 consecutive days. Additional animals received seven days of Lactobacillus helveticus and L rhamnosus in the drinking water prior to stress and remained on these probiotics for the duration of the study. Rats were then sacrificed, intestinal segments assessed in Ussing chambers, and mesenteric lymph nodes cultured to determine bacterial translocation.RESULTS: All animals remained healthy for the duration of the study. Chronic WAS induced excess ion secretion (elevated baseline short circuit current) and barrier dysfunction (increased conductance) in both the ileum and colon, associated with increased bacterial adhesion and penetration into surface epithelial cells. Approximately 70% of rats subjected to WAS had bacterial translocation to mesenteric lymph nodes while there was no bacterial translocation in controls. Probiotic pretreatment alone had no effect on intestinal barrier function. However, WAS induced increased ileal short circuit current was reduced with probiotics whereas there was no impact on altered conductance. Pretreatment of animals with probiotics also completely abrogated WAS induced bacterial adhesion and prevented translocation of bacteria to mesenteric lymph nodes.CONCLUSION: These findings indicate that probiotics can prevent chronic stress induced intestinal abnormalities and, thereby, exert beneficial effects in the intestinal tract.

  19. The human intestinal microbiome: a new frontier of human biology.

    PubMed

    Hattori, Masahira; Taylor, Todd D

    2009-02-01

    To analyze the vast number and variety of microorganisms inhabiting the human intestine, emerging metagenomic technologies are extremely powerful. The intestinal microbes are taxonomically complex and constitute an ecologically dynamic community (microbiota) that has long been believed to possess a strong impact on human physiology. Furthermore, they are heavily involved in the maturation and proliferation of human intestinal cells, helping to maintain their homeostasis and can be causative of various diseases, such as inflammatory bowel disease and obesity. A simplified animal model system has provided the mechanistic basis for the molecular interactions that occur at the interface between such microbes and host intestinal epithelia. Through metagenomic analysis, it is now possible to comprehensively explore the genetic nature of the intestinal microbiome, the mutually interacting system comprising the host cells and the residing microbial community. The human microbiome project was recently launched as an international collaborative research effort to further promote this newly developing field and to pave the way to a new frontier of human biology, which will provide new strategies for the maintenance of human health. PMID:19147530

  20. The Human Intestinal Microbiome: A New Frontier of Human Biology

    PubMed Central

    Hattori, Masahira; Taylor, Todd D.

    2009-01-01

    To analyze the vast number and variety of microorganisms inhabiting the human intestine, emerging metagenomic technologies are extremely powerful. The intestinal microbes are taxonomically complex and constitute an ecologically dynamic community (microbiota) that has long been believed to possess a strong impact on human physiology. Furthermore, they are heavily involved in the maturation and proliferation of human intestinal cells, helping to maintain their homeostasis and can be causative of various diseases, such as inflammatory bowel disease and obesity. A simplified animal model system has provided the mechanistic basis for the molecular interactions that occur at the interface between such microbes and host intestinal epithelia. Through metagenomic analysis, it is now possible to comprehensively explore the genetic nature of the intestinal microbiome, the mutually interacting system comprising the host cells and the residing microbial community. The human microbiome project was recently launched as an international collaborative research effort to further promote this newly developing field and to pave the way to a new frontier of human biology, which will provide new strategies for the maintenance of human health. PMID:19147530

  1. Intestinal Epithelial Serum Amyloid A Modulates Bacterial Growth In Vitro and Pro-Inflammatory Responses in Mouse Experimental Colitis

    PubMed Central

    2010-01-01

    Background Serum Amyloid A (SAA) is a major acute phase protein of unknown function. SAA is mostly expressed in the liver, but also in other tissues including the intestinal epithelium. SAA reportedly has anti-bacterial effects, and because inflammatory bowel diseases (IBD) result from a breakdown in homeostatic interactions between intestinal epithelia and bacteria, we hypothesized that SAA is protective during experimental colitis. Methods Intestinal SAA expression was measured in mouse and human samples. Dextran sodium sulfate (DSS) colitis was induced in SAA 1/2 double knockout (DKO) mice and in wildtype controls. Anti-bacterial effects of SAA1/2 were tested in intestinal epithelial cell lines transduced with adenoviral vectors encoding the CE/J SAA isoform or control vectors prior to exposure to live Escherichia coli. Results Significant levels of SAA1/SAA2 RNA and SAA protein were detected by in situ hybridization and immunohistochemistry in mouse colonic epithelium. SAA3 expression was weaker, but similarly distributed. SAA1/2 RNA was present in the ileum and colon of conventional mice and in the colon of germfree mice. Expression of SAA3 was strongly regulated by bacterial lipopolysaccharides in cultured epithelial cell lines, whereas SAA1/2 expression was constitutive and not LPS inducible. Overexpression of SAA1/2 in cultured epithelial cell lines reduced the viability of co-cultured E. coli. This might partially explain the observed increase in susceptibility of DKO mice to DSS colitis. SAA1/2 expression was increased in colon samples obtained from Crohn's Disease patients compared to controls. Conclusions Intestinal epithelial SAA displays bactericidal properties in vitro and could play a protective role in experimental mouse colitis. Altered expression of SAA in intestinal biopsies from Crohn's Disease patients suggests that SAA is involved in the disease process.. PMID:21067563

  2. Diagnosis and treatment of small intestinal bacterial overgrowth.

    PubMed

    Ponziani, Francesca Romana; Gerardi, Viviana; Gasbarrini, Antonio

    2016-02-01

    A huge number of bacteria are hosted in the gastrointestinal tract, following a gradient increasing towards the colon. Gastric acid secretion and intestinal clearance provide the qualitative and quantitative partitioning of intestinal bacteria; small intestinal bacteria overgrowth (SIBO) occurs when these barrier mechanisms fail. Diagnosis of SIBO is challenging due to the low specificity of symptoms, the frequent association with other diseases of the gastrointestinal tract and the absence of optimal objective diagnostic tests. The therapeutic approach to SIBO is oriented towards resolving predisposing conditions, and is supported by antibiotic treatment to restore the normal small intestinal microflora and by modifications of dietary habits for symptomatic relief. In the near future, metagenomics and metabolomics will help to overcome the uncertainties of SIBO diagnosis and the pitfalls of therapeutic management, allowing the design of a personalized strategy based on the direct insight into the small intestinal microbial community. PMID:26636484

  3. Robust bioengineered 3D functional human intestinal epithelium

    PubMed Central

    Chen, Ying; Lin, Yinan; Davis, Kimberly M.; Wang, Qianrui; Rnjak-Kovacina, Jelena; Li, Chunmei; Isberg, Ralph R.; Kumamoto, Carol A.; Mecsas, Joan; Kaplan, David L.

    2015-01-01

    Intestinal functions are central to human physiology, health and disease. Options to study these functions with direct relevance to the human condition remain severely limited when using conventional cell cultures, microfluidic systems, organoids, animal surrogates or human studies. To replicate in vitro the tissue architecture and microenvironments of native intestine, we developed a 3D porous protein scaffolding system, containing a geometrically-engineered hollow lumen, with adaptability to both large and small intestines. These intestinal tissues demonstrated representative human responses by permitting continuous accumulation of mucous secretions on the epithelial surface, establishing low oxygen tension in the lumen, and interacting with gut-colonizing bacteria. The newly developed 3D intestine model enabled months-long sustained access to these intestinal functions in vitro, readily integrable with a multitude of different organ mimics and will therefore ensure a reliable ex vivo tissue system for studies in a broad context of human intestinal diseases and treatments. PMID:26374193

  4. Composition, diversity, and origin of the bacterial community in grass carp intestine.

    PubMed

    Wu, Shangong; Wang, Guitang; Angert, Esther R; Wang, Weiwei; Li, Wenxiang; Zou, Hong

    2012-01-01

    Gut microbiota has become an integral component of the host, and received increasing attention. However, for many domestic animals, information on the microbiota is insufficient and more effort should be exerted to manage the gastrointestinal bacterial community. Understanding the factors that influence the composition of microbial community in the host alimentary canal is essential to manage or improve the microbial community composition. In the present study, 16S rRNA gene sequence-based comparisons of the bacterial communities in the grass carp (Ctenopharyngodon idellus) intestinal contents and fish culture-associated environments are performed. The results show that the fish intestinal microbiota harbors many cellulose-decomposing bacteria, including sequences related to Anoxybacillus, Leuconostoc, Clostridium, Actinomyces, and Citrobacter. The most abundant bacterial operational taxonomic units (OTUs) in the grass carp intestinal content are those related to feed digestion. In addition, the potential pathogens and probiotics are important members of the intestinal microbiota. Further analyses show that grass carp intestine holds a core microbiota composed of Proteobacteria, Firmicutes, and Actinobacteria. The comparison analyses reveal that the bacterial community in the intestinal contents is most similar to those from the culture water and sediment. However, feed also plays significant influence on the composition of gut microbiota. PMID:22363439

  5. Bacterial Population in Intestines of the Black Tiger Shrimp (Penaeus monodon) under Different Growth Stages

    PubMed Central

    Rungrassamee, Wanilada; Klanchui, Amornpan; Chaiyapechara, Sage; Maibunkaew, Sawarot; Tangphatsornruang, Sithichoke; Jiravanichpaisal, Pikul; Karoonuthaisiri, Nitsara

    2013-01-01

    Intestinal bacterial communities in aquaculture have been drawn to attention due to potential benefit to their hosts. To identify core intestinal bacteria in the black tiger shrimp (Penaeus monodon), bacterial populations of disease-free shrimp were characterized from intestines of four developmental stages (15-day-old post larvae (PL15), 1- (J1), 2- (J2), and 3-month-old (J3) juveniles) using pyrosequencing, real-time PCR and denaturing gradient gel electrophoresis (DGGE) approaches. A total of 25,121 pyrosequencing reads (reading length = 442±24 bases) were obtained, which were categorized by barcode for PL15 (7,045 sequences), J1 (3,055 sequences), J2 (13,130 sequences) and J3 (1,890 sequences). Bacteria in the phyla Bacteroides, Firmicutes and Proteobacteria were found in intestines at all four growth stages. There were 88, 14, 27, and 20 bacterial genera associated with the intestinal tract of PL15, J1, J2 and J3, respectively. Pyrosequencing analysis revealed that Proteobacteria (class Gammaproteobacteria) was a dominant bacteria group with a relative abundance of 89% for PL15 and 99% for J1, J2 and J3. Real-time PCR assay also confirmed that Gammaproteobacteria had the highest relative abundance in intestines from all growth stages. Intestinal bacterial communities from the three juvenile stages were more similar to each other than that of the PL shrimp based on PCA analyses of pyrosequencing results and their DGGE profiles. This study provides descriptive bacterial communities associated to the black tiger shrimp intestines during these growth development stages in rearing facilities. PMID:23577162

  6. Cd1d-dependent regulation of bacterial colonization in the intestine of mice.

    PubMed

    Nieuwenhuis, Edward E S; Matsumoto, Tetsuya; Lindenbergh, Dicky; Willemsen, Rob; Kaser, Arthur; Simons-Oosterhuis, Ytje; Brugman, Sylvia; Yamaguchi, Keizo; Ishikawa, Hiroki; Aiba, Yuji; Koga, Yasuhiro; Samsom, Janneke N; Oshima, Kenshiro; Kikuchi, Mami; Escher, Johanna C; Hattori, Masahira; Onderdonk, Andrew B; Blumberg, Richard S

    2009-05-01

    The accumulation of certain species of bacteria in the intestine is involved in both tissue homeostasis and immune-mediated pathologies. The host mechanisms involved in controlling intestinal colonization with commensal bacteria are poorly understood. We observed that under specific pathogen-free or germ-free conditions, intragastric administration of Pseudomonas aeruginosa, E. coli, Staphylococcus aureus, or Lactobacillus gasseri resulted in increased colonization of the small intestine and bacterial translocation in mice lacking Cd1d, an MHC class I-like molecule, compared with WT mice. In contrast, activation of Cd1d-restricted T cells (NKT cells) with alpha-galactosylceramide caused diminished intestinal colonization with the same bacterial strains. We also found prominent differences in the composition of intestinal microbiota, including increased adherent bacteria, in Cd1d-/- mice in comparison to WT mice under specific pathogen-free conditions. Germ-free Cd1d-/- mice exhibited a defect in Paneth cell granule ultrastructure and ability to degranulate after bacterial colonization. In vitro, NKT cells were shown to induce the release of lysozyme from intestinal crypts. Together, these data support a role for Cd1d in regulating intestinal colonization through mechanisms that include the control of Paneth cell function. PMID:19349688

  7. Comparative analysis of the composition of intestinal bacterial communities in Dastarcus helophoroides fed different diets.

    PubMed

    Wang, Wei-Wei; He, Cai; Cui, Jun; Wang, Hai-Dong; Li, Meng-Lou

    2014-01-01

    The diversity of the intestinal bacterial communities in Dastarcus helophoroides (Fairmaire) (Coleoptera: Bothrideridae) larvae and adults was assayed by PCR-DGGE to determine whether different artificial diets could influence these bacterial communities. Two diets were used for feeding the larvae and four for the adults. Escherichia, Desemzia, Staphylococcus, Asticcacaulis, Cellvibrio, Aurantimonas, and Planomicrobium were isolated from the gut of the adults, with Escherichia and Staphylococcus being the main bacterial communities, and the quantities of intestinal bacterial were different in the adults fed different diets. Specifically, the amount of intestinal bacteria from the adults fed different diets had the following ranking according to the major component of the diet: ant powder > darkling beetle pupa powder > cricket powder > silkworm pupa powder. Escherichia, Bacillus, Staphylococcus, Kurthia, Planococcaceae, Ralstonia, Leptothrix, Acinetobacter, and Pseudomonas were isolated from the gut of the larvae. The quantity of intestinal bacteria from the larvae fed the darkling beetle pupae was greater than that from the larvae fed other artificial diets. This study, for the first time, investigated the effect of artificial diets on the bacterial community and the intestinal microbial diversity of D. helophoroides. PMID:25373234

  8. Comparative Analysis of the Composition of Intestinal Bacterial Communities in Dastarcus helophoroides Fed Different Diets

    PubMed Central

    Wang, Wei-Wei; He, Cai; Cui, Jun; Wang, Hai-Dong; Li, Meng-Lou

    2014-01-01

    The diversity of the intestinal bacterial communities in Dastarcus helophoroides (Fairmaire) (Coleoptera: Bothrideridae) larvae and adults was assayed by PCR-DGGE to determine whether different artificial diets could influence these bacterial communities. Two diets were used for feeding the larvae and four for the adults. Escherichia, Desemzia, Staphylococcus, Asticcacaulis, Cellvibrio, Aurantimonas, and Planomicrobium were isolated from the gut of the adults, with Escherichia and Staphylococcus being the main bacterial communities, and the quantities of intestinal bacterial were different in the adults fed different diets. Specifically, the amount of intestinal bacteria from the adults fed different diets had the following ranking according to the major component of the diet: ant powder > darkling beetle pupa powder > cricket powder > silkworm pupa powder. Escherichia, Bacillus, Staphylococcus, Kurthia, Planococcaceae, Ralstonia, Leptothrix, Acinetobacter, and Pseudomonas were isolated from the gut of the larvae. The quantity of intestinal bacteria from the larvae fed the darkling beetle pupae was greater than that from the larvae fed other artificial diets. This study, for the first time, investigated the effect of artificial diets on the bacterial community and the intestinal microbial diversity of D. helophoroides. PMID:25199878

  9. Comparative analysis of the composition of intestinal bacterial communities in Dastarcus helophoroides fed different diets.

    PubMed

    Wang, Wei-Wei; He, Cai; Cui, Jun; Wang, Hai-Dong; Li, Meng-Lou

    2014-01-01

    The diversity of the intestinal bacterial communities in Dastarcus helophoroides (Fairmaire) (Coleoptera: Bothrideridae) larvae and adults was assayed by PCR-DGGE to determine whether different artificial diets could influence these bacterial communities. Two diets were used for feeding the larvae and four for the adults. Escherichia, Desemzia, Staphylococcus, Asticcacaulis, Cellvibrio, Aurantimonas, and Planomicrobium were isolated from the gut of the adults, with Escherichia and Staphylococcus being the main bacterial communities, and the quantities of intestinal bacterial were different in the adults fed different diets. Specifically, the amount of intestinal bacteria from the adults fed different diets had the following ranking according to the major component of the diet: ant powder > darkling beetle pupa powder > cricket powder > silkworm pupa powder. Escherichia, Bacillus, Staphylococcus, Kurthia, Planococcaceae, Ralstonia, Leptothrix, Acinetobacter, and Pseudomonas were isolated from the gut of the larvae. The quantity of intestinal bacteria from the larvae fed the darkling beetle pupae was greater than that from the larvae fed other artificial diets. This study, for the first time, investigated the effect of artificial diets on the bacterial community and the intestinal microbial diversity of D. helophoroides. PMID:25199878

  10. Intestinal permeability and bacterial translocation following small bowel transplantation in the rat

    SciTech Connect

    Grant, D.; Hurlbut, D.; Zhong, R.; Wang, P.Z.; Chen, H.F.; Garcia, B.; Behme, R.; Stiller, C.; Duff, J. )

    1991-08-01

    In addition to its role in absorbing nutrients, the intestinal mucosa provides an important barrier against toxins and bacteria in the bowel lumen. The present study evaluated gut barrier function following orthotopic (in continuity) intestinal grafting in rats. Graft histology, intestinal permeability, and bacterial translocation to the grafted mesenteric lymph nodes, the host's liver, and the host's spleen were assessed on the 3rd, 5th, and 7th postoperative days. The study group received no immunosuppression after allotransplantation. The two control groups included rats with isografts and rats with cyclosporine-treated allografts. On the 7th POD, the study animals had moderate transmural inflammation due to rejection, with normal histology in the isografts and CsA-treated allografts; increased intestinal permeability, measured by urinary excretion of oral 51Cr-EDTA (P less than 0.01); and increased number of bacteria in the MLN and spleen (P less than 0.05). The number of bacteria in the MLN and spleen of the study group positively correlated with the changes in intestinal permeability (P less than 0.05). Rejection of the orthotopic intestinal graft leads to increased intestinal permeability and bacterial translocation from the lumen of the graft to the host's reticuloendothelial system. Measures to improve gut barrier function and antibiotic therapy during rejection episodes may help reduce the incidence of septic complications after intestinal grafting.

  11. Alternative functional in vitro models of human intestinal epithelia

    PubMed Central

    Kauffman, Amanda L.; Gyurdieva, Alexandra V.; Mabus, John R.; Ferguson, Chrissa; Yan, Zhengyin; Hornby, Pamela J.

    2013-01-01

    Physiologically relevant sources of absorptive intestinal epithelial cells are crucial for human drug transport studies. Human adenocarcinoma-derived intestinal cell lines, such as Caco-2, offer conveniences of easy culture maintenance and scalability, but do not fully recapitulate in vivo intestinal phenotypes. Additional sources of renewable physiologically relevant human intestinal cells would provide a much needed tool for drug discovery and intestinal physiology. We compared two alternative sources of human intestinal cells, commercially available primary human intestinal epithelial cells (hInEpCs) and induced pluripotent stem cell (iPSC)-derived intestinal cells to Caco-2, for use in in vitro transwell monolayer intestinal transport assays. To achieve this for iPSC-derived cells, intestinal organogenesis was adapted to transwell differentiation. Intestinal cells were assessed by marker expression through immunocytochemical and mRNA expression analyses, monolayer integrity through Transepithelial Electrical Resistance (TEER) measurements and molecule permeability, and functionality by taking advantage the well-characterized intestinal transport mechanisms. In most cases, marker expression for primary hInEpCs and iPSC-derived cells appeared to be as good as or better than Caco-2. Furthermore, transwell monolayers exhibited high TEER with low permeability. Primary hInEpCs showed molecule efflux indicative of P-glycoprotein (Pgp) transport. Primary hInEpCs and iPSC-derived cells also showed neonatal Fc receptor-dependent binding of immunoglobulin G variants. Primary hInEpCs and iPSC-derived intestinal cells exhibit expected marker expression and demonstrate basic functional monolayer formation, similar to or better than Caco-2. These cells could offer an alternative source of human intestinal cells for understanding normal intestinal epithelial physiology and drug transport. PMID:23847534

  12. Bacterial Community Assembly and Turnover within the Intestines of Developing Zebrafish

    PubMed Central

    Yan, Qingyun; van der Gast, Christopher J.; Yu, Yuhe

    2012-01-01

    Background The majority of animal associated microorganisms are present in digestive tract communities. These intestinal communities arise from selective pressures of the gut habitats as well as host's genotype are regarded as an extra ‘organ’ regulate functions that have not evolved wholly on the host. They are functionally essential in providing nourishment, regulating epithelial development, and influencing immunity in the vertebrate host. As vertebrates are born free of microorganisms, what is poorly understood is how intestinal bacterial communities assemble and develop in conjunction with the development of the host. Methodology/Principal Findings Set within an ecological framework, we investigated the bacterial community assembly and turnover within the intestinal habitats of developing zebrafish (from larvae to adult animals). Spatial and temporal species-richness relationships and Mantel and partial Mantel tests revealed that turnover was low and that richness and composition was best predicted by time and not intestinal volume (habitat size) or changes in food diet. We also observed that bacterial communities within the zebrafish intestines were deterministically assembled (reflected by the observed low turnover) switching to stochastic assembly in the later stages of zebrafish development. Conclusions/Significance This study is of importance as it provides a novel insight into how intestinal bacterial communities assemble in tandem with the host's development (from early to adult stages). It is our hope that by studying intestinal microbiota of this vertebrate model with such or some more refined approaches in the future could well provide ecological insights for clinical benefit. In addition, this study also adds to our still fledgling knowledge of how spatial and temporal species-richness relationships are shaped and provides further mounting evidence that bacterial community assembly and dynamics are shaped by both deterministic and stochastic considerations. PMID:22276219

  13. Establishment of novel prediction system of intestinal absorption in humans using human intestinal tissues.

    PubMed

    Miyake, Masateru; Toguchi, Hajime; Nishibayashi, Toru; Higaki, Kazutaka; Sugita, Akira; Koganei, Kazutaka; Kamada, Nobuhiko; Kitazume, Mina T; Hisamatsu, Tadakazu; Sato, Toshiro; Okamoto, Susumu; Kanai, Takanori; Hibi, Toshifumi

    2013-08-01

    The objective of this study was to establish a novel prediction system of drug absorption in humans by utilizing human intestinal tissues. Based on the transport index (TI), a newly defined parameter, calculated by taking account of the change in drug concentrations because of precipitation on the apical side and the amounts accumulated in the tissue and transported to the basal side, the absorbability of drugs in rank order as well as the fraction of dose absorbed (Fa) in humans were estimated. Human intestinal tissues taken from ulcerative colitis or Crohn's disease patients were mounted in a mini-Ussing chamber and transport studies were performed to evaluate the permeation of drugs, including FD-4, a very low permeable marker, atenolol, a low permeable marker, and metoprolol, a high permeable marker. Although apparent permeability coefficients calculated by the conventional equation did not reflect human Fa values for FD-4, atenolol, and metoprolol, TI values were well correlated with Fa values, which are described by 100 · [1 - e (- f · (TI - α)) ]. Based on this equation, Fa values in humans for other test drugs were predicted successfully, indicating that our new system utilizing human intestinal tissues would be valuable for predicting oral drug absorption in humans. PMID:23686795

  14. Identification of a Core Bacterial Community within the Large Intestine of the Horse

    PubMed Central

    Dougal, Kirsty; de la Fuente, Gabriel; Harris, Patricia A.; Girdwood, Susan E.; Pinloche, Eric; Newbold, C. Jamie

    2013-01-01

    The horse has a rich and complex microbial community within its gastrointestinal tract that plays a central role in both health and disease. The horse receives much of its dietary energy through microbial hydrolysis and fermentation of fiber predominantly in the large intestine/hindgut. The presence of a possible core bacterial community in the equine large intestine was investigated in this study. Samples were taken from the terminal ileum and 7 regions of the large intestine from ten animals, DNA extracted and the V1-V2 regions of 16SrDNA 454-pyrosequenced. A specific group of OTUs clustered in all ileal samples and a distinct and different signature existed for the proximal regions of the large intestine and the distal regions. A core group of bacterial families were identified in all gut regions with clear differences shown between the ileum and the various large intestine regions. The core in the ileum accounted for 32% of all sequences and comprised of only seven OTUs of varying abundance; the core in the large intestine was much smaller (5-15% of all sequences) with a much larger number of OTUs present but in low abundance. The most abundant member of the core community in the ileum was Lactobacillaceae, in the proximal large intestine the Lachnospiraceae and in the distal large intestine the Prevotellaceae. In conclusion, the presence of a core bacterial community in the large intestine of the horse that is made up of many low abundance OTUs may explain in part the susceptibility of horses to digestive upset. PMID:24204908

  15. Human Enteroids/Colonoids and Intestinal Organoids Functionally Recapitulate Normal Intestinal Physiology and Pathophysiology.

    PubMed

    Zachos, Nicholas C; Kovbasnjuk, Olga; Foulke-Abel, Jennifer; In, Julie; Blutt, Sarah E; de Jonge, Hugo R; Estes, Mary K; Donowitz, Mark

    2016-02-19

    Identification of Lgr5 as the intestinal stem cell marker as well as the growth factors necessary to replicate adult intestinal stem cell division has led to the establishment of the methods to generate "indefinite" ex vivo primary intestinal epithelial cultures, termed "mini-intestines." Primary cultures developed from isolated intestinal crypts or stem cells (termed enteroids/colonoids) and from inducible pluripotent stem cells (termed intestinal organoids) are being applied to study human intestinal physiology and pathophysiology with great expectations for translational applications, including regenerative medicine. Here we discuss the physiologic properties of these cultures, their current use in understanding diarrhea-causing host-pathogen interactions, and potential future applications. PMID:26677228

  16. Plant innate immunity against human bacterial pathogens

    PubMed Central

    Melotto, Maeli; Panchal, Shweta; Roy, Debanjana

    2014-01-01

    Certain human bacterial pathogens such as the enterohemorrhagic Escherichia coli and Salmonella enterica are not proven to be plant pathogens yet. Nonetheless, under certain conditions they can survive on, penetrate into, and colonize internal plant tissues causing serious food borne disease outbreaks. In this review, we highlight current understanding on the molecular mechanisms of plant responses against human bacterial pathogens and discuss salient common and contrasting themes of plant interactions with phytopathogens or human pathogens. PMID:25157245

  17. The intestinal bacterial community in the food waste-reducing larvae of Hermetia illucens.

    PubMed

    Jeon, Hyunbum; Park, Soyoung; Choi, Jiyoung; Jeong, Gilsang; Lee, Sang-Beom; Choi, Youngcheol; Lee, Sung-Jae

    2011-05-01

    As it is known that food waste can be reduced by the larvae of Hermetia illucens (Black soldier fly, BSF), the scientific and commercial value of BSF larvae has increased recently. We hypothesised that the ability of catabolic degradation by BSF larvae might be due to intestinal microorganisms. Herein, we analysed the bacterial communities in the gut of BSF larvae by pyrosequencing of extracting intestinal metagenomic DNA from larvae that had been fed three different diets. The 16S rRNA sequencing results produced 9737, 9723 and 5985 PCR products from larval samples fed food waste, cooked rice and calf forage, respectively. A BLAST search using the EzTaxon program showed that the bacterial community in the gut of larvae fed three different diets was mainly composed of the four phyla with dissimilar proportions. Although the composition of the bacterial communities depended on the different nutrient sources, the identified bacterial strains in the gut of BSF larvae represented unique bacterial species that were unlike the intestinal microflora of other insects. Thus, our study analysed the structure of the bacterial communities in the gut of BSF larvae after three different feedings and assessed the application of particular bacteria for the efficient degradation of organic compounds. PMID:21267722

  18. Bacterial diversity in the intestine of young farmed puffer fish Takifugu rubripes

    NASA Astrophysics Data System (ADS)

    Li, Yanyu; Zhang, Tao; Zhang, Congyao; Zhu, Ying; Ding, Jianfeng; Ma, Yuexin

    2015-07-01

    The aim of the study was to examine the bacterial community associated with the intestinal mucus of young farmed puffer fish Takifugu rubripes. Polymerase chain reaction and partial 16S rDNA sequencing was performed on DNA from bacteria cultivated on Zobell 2216E medium. All the isolates were classified into two phyla—Proteobacteria and Firmicutes. Proteobacteria were the dominant, culturable intestinal microbiota (68.3%). At the genus level, Vibrio, Enterobacter, Bacillus, Pseudomonas, Exiguobacterium, Staphylococcus, Acinetobacter, Pseudoalteromonas and Shewanella were isolated from the intestine, with representatives of the genera Vibrio, Enterobacter and Bacillus accounting for 70.7% of the total. This is the first report of Enterobacter, Bacillus, Exiguobacterium and Staphylococcus as part of the intestinal bacterial microflora in T. rubripes. The profile of the culturable bacterial community differed between samples collected from the same tank at 2-month intervals, as indicated by Bray-Curtis and Sorensen indices, and the impact on the intestinal physiology and health of puffer fish requires further investigation.

  19. Normal and abnormal intestinal absorption by humans.

    PubMed

    Heizer, W D

    1979-12-01

    Adults eating a Western diet digest and absorb ingested food containing approximately 100 g fat, 350 g carbohydrate, and 75 g protein daily. Normal fat absorption requires adequate gastric, pancreatic, liver-biliary, mucosal, and lymphatic function. Carbohydrate and protein absorption is much less dependent on liver-biliary and lymphatic function. The intestine has a large reserve capacity for digestion and absorption of nutrients which is due to both excess function and to adaptive changes which increase function in one segment of the digestive-absorptive system when it is decreased or lost in another segment. The large reserve capacity explains why most of the prevalent intestinal diseases seldom cause clinically detectable changes in absorption. However, there are more than 30 less-common human diseases which cause malabsorption of one or more nutrients. Those that cause the malabsorption syndrome, i.e., steatorrhea and weight loss, can be conveniently categorized according to the major deficiency leading to the absorptive defect as follows: insufficient pancreatic enzyme activity, insufficient bile acid, disease of the small intestinal wall, multiple defects, mechanism unknown, and drug-induced malabsorption. A few diseases, most of which are congenital, cause malabsorption of only one or a few related nutrients such as lactose malabsorption in lactase deficiency. Most of the tests currently in use for detecting and diagnosing the cause of malabsorption are relatively insensitive and nonspecific. Chemical analysis of the fat in a three-day stool collection remains the single best test for diagnosing the malabsorption syndrome. However, a breath test using Triolein labeled with either the radioactive or stable isotope of carbon may be an important recent advance. Other breath tests are also currently being investigated for quantitating absorption or malabsorption of various substances including bile acids and various sugars. Studies of the function of the intestinal epithelial cells are usually best accomplished using tissue obtained by per oral biopsy. Biopsy specimens are used for many types of study including light and electron microscopic examination, chemical and enzymatic assays, tissue culture, and uptake of various radiolabeled compounds. PMID:540610

  20. Protective role of intestinal bacterial metabolism against baicalin-induced toxicity in HepG2 cell cultures.

    PubMed

    Khanal, Tilak; Kim, Hyung Gyun; Choi, Jae Ho; Park, Bong Hwan; Do, Minh Truong; Kang, Mi Jeong; Yeo, Hee Kyung; Kim, Dong Hyun; Kang, Wonku; Jeong, Tae Cheon; Jeong, Hye Gwang

    2012-01-01

    Baicalin, a glycoside present in Scutellaria baicalensis Georgi, is metabolized to its aglycone, baicalein, in intestine. In the present study, possible role of metabolism of baicalin by intestinal bacteria to baicalein in baicalin-induced toxicity was investigated in HepG2 cell cultures. As an intestinal bacterial metabolic system for baicalin, human fecal preparation containing intestinal microflora (fecalase) was employed. Initially, when cytotoxic effects of baicalin and baicalein were compared, baicalin was more cytotoxic than baicalein in HepG2 cells. When baicalin was incubated with fecalase, it was metabolized to baicalein. In addition, baicalin-incubated with fecalase reduced cytotoxicity of HepG2 cells in a concentration-dependent manner. Moreover, baicalin-incubated with fecalase significantly caused an increase in Bcl-2 expression together with a decrease in Bax expression and cleaved Caspase-3. Furthermore, anti-apoptotic effect by the incubation of baicalin with fecalase was also confirmed by the terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick-end labeling assay. Taken all together, the findings suggested that metabolism of baicalin by human fecalase to baicalein might have protective effects against baicalin-induced toxicity in HepG2 cells. PMID:22467027

  1. Common occurrence of antibacterial agents in human intestinal microbiota

    PubMed Central

    Drissi, Fatima; Buffet, Sylvain; Raoult, Didier; Merhej, Vicky

    2015-01-01

    Laboratory experiments have revealed many active mechanisms by which bacteria can inhibit the growth of other organisms. Bacteriocins are a diverse group of natural ribosomally synthesized antimicrobial peptides produced by a wide range of bacteria and which seem to play an important role in mediating competition within bacterial communities. In this study, we have identified and established the structural classification of putative bacteriocins encoded by 317 microbial genomes in the human intestine. On the basis of homologies to available bacteriocin sequences, mainly from lactic acid bacteria, we report the widespread occurrence of bacteriocins across the gut microbiota: 175 bacteriocins were found to be encoded in Firmicutes, 79 in Proteobacteria, 34 in Bacteroidetes, and 25 in Actinobacteria. Bacteriocins from gut bacteria displayed wide differences among phyla with regard to class distribution, net positive charge, hydrophobicity and secondary structure, but the α-helix was the most abundant structure. The peptide structures and physiochemical properties of bacteriocins produced by the most abundant bacteria in the gut, the Firmicutes and the Bacteroidetes, seem to ensure low antibiotic activity and participate in permanent intestinal host defense against the proliferation of harmful bacteria. Meanwhile, the potentially harmful bacteria, including the Proteobacteria, displayed highly effective bacteriocins, probably supporting the virulent character of diseases. These findings highlight the eventual role played by bacteriocins in gut microbial competition and their potential place in antibiotic therapy. PMID:25999943

  2. In vitro activity of rifaximin against isolates from patients with small intestinal bacterial overgrowth.

    PubMed

    Pistiki, Aikaterini; Galani, Irene; Pyleris, Emmanouel; Barbatzas, Charalambos; Pimentel, Mark; Giamarellos-Bourboulis, Evangelos J

    2014-03-01

    Rifaximin, a non-absorbable rifamycin derivative, has published clinical efficacy in the alleviation of symptoms in patients with irritable bowel syndrome (IBS). Small intestinal bacterial overgrowth (SIBO) is associated with the pathogenesis of IBS. This study describes for the first time the antimicrobial effect of rifaximin against SIBO micro-organisms from humans. Fluid was aspirated from the third part of the duodenum from 567 consecutive patients; quantitative cultures diagnosed SIBO in 117 patients (20.6%). A total of 170 aerobic micro-organisms were isolated and the in vitro efficacy of rifaximin was studied by (i) minimum inhibitory concentration (MIC) testing by a microdilution technique and (ii) time-kill assays using bile to simulate the small intestinal environment. At a breakpoint of 32 μg/mL, rifaximin inhibited in vitro 85.4% of Escherichia coli, 43.6% of Klebsiella spp., 34.8% of Enterobacter spp., 54.5% of other Enterobacteriaceae spp., 82.6% of non-Enterobacteriaceae Gram-negative spp., 100% of Enterococcus faecalis, 100% of Enterococcus faecium and 100% of Staphylococcus aureus. For the time-kill assays, 11 E. coli, 15 non-E. coli Gram-negative enterobacteria and three E. faecalis isolates were studied. Rifaximin produced a >3 log10 decrease in the starting inoculum against most of the tested isolates at 500 μg/mL after 24h of growth. The results indicate that rifaximin has a potent effect on specific small bowel flora associated with SIBO. This conclusion should be regarded in light of the considerable time-kill effect at concentrations lower than those achieved in the bowel lumen after administration of conventional doses in humans. PMID:24461710

  3. The effect of antimicrobial agents on the ecology of the human intestinal microflora.

    PubMed

    Nord, C E

    1993-06-01

    The most common and significant cause of disturbances in the normal intestinal microflora is the administration of antimicrobial agents. The microflora can be influenced by antimicrobial agents because of incomplete absorption of any orally administered antimicrobial agent, secretion of an antimicrobial agent in the bile, or secretion from the intestinal mucosa. Administration of these agents may seriously disturb the balance of the normal intestinal microflora. This disturbance can cause bacterial overgrowth and emergence of resistant microorganisms which may lead to serious infections and also encourage transfer of resistance factors among bacteria. The ecological effects of penicillins, cephalosporins, monobactams, carbapenems, macrolides, clindamycin, tetracyclines, nitroimidazoles and quinolones on the human intestinal microflora are presented in this review article. PMID:8212506

  4. Combinatorial QSAR modeling of human intestinal absorption.

    PubMed

    Suenderhauf, Claudia; Hammann, Felix; Maunz, Andreas; Helma, Christoph; Huwyler, Jörg

    2011-02-01

    Intestinal drug absorption in humans is a central topic in drug discovery. In this study, we use a broad selection of machine learning and statistical methods for the classification and numerical prediction of this key end point. Our data set is based on a selection of 458 small druglike compounds with FDA approval. Using easily available tools, we calculated one- to three-dimensional physicochemical descriptors and used various methods of feature selection (best-first backward selection, correlation analysis, and decision tree analysis). We then used decision tree induction (DTI), fragment-based lazy-learning (LAZAR), support vector machine classification, multilayer perceptrons, random forests, k-nearest neighbor and Naïve Bayes analysis to model absorption ratios and binary classification (well-absorbed and poorly absorbed compounds). Best performance for classification was seen with DTI using the chi-squared analysis interaction detector (CHAID) algorithm, yielding corrected classification rate of 88% (Matthews correlation coefficient of 75%). In numeric predictions, the multilayer perceptron performed best, achieving a root mean squared error of 25.823 and a coefficient of determination of 0.6. In line with current understanding is the importance of descriptors such as lipophilic partition coefficients (log P) and hydrogen bonding. However, we are able to highlight the utility of gravitational indices and moments of inertia, reflecting the role of structural symmetry in oral absorption. Our models are based on a diverse data set of marketed drugs representing a broad chemical space. These models therefore contribute substantially to the molecular understanding of human intestinal drug absorption and qualify for a generalized use in drug discovery and lead optimization. PMID:21142073

  5. A new approach to predict human intestinal absorption using porcine intestinal tissue and biorelevant matrices.

    PubMed

    Westerhout, Joost; van de Steeg, Evita; Grossouw, Dimitri; Zeijdner, Evelijn E; Krul, Cyrille A M; Verwei, Miriam; Wortelboer, Heleen M

    2014-10-15

    A reliable prediction of the oral bioavailability in humans is crucial and of high interest for pharmaceutical and food industry. The predictive value of currently used in silico methods, in vitro cell lines, ex vivo intestinal tissue and/or in vivo animal studies for human intestinal absorption, however, is often insufficient, especially when food-drug interactions are evaluated. Ideally, for this purpose healthy human intestinal tissue is used, but due to its limited availability there is a need for alternatives. The aim of this study was to evaluate the applicability of healthy porcine intestinal tissue mounted in a newly developed InTESTine™ system to predict human intestinal absorption of compounds with different chemical characteristics, and within biorelevant matrices. To that end, first, a representative set of compounds was chosen of which the apparent permeability (Papp) data in both Caco-2 cells and human intestinal tissue mounted in the Ussing chamber system, and absolute human oral bioavailability were reported. Thereafter, Papp values of the subset were determined in both porcine jejunal tissue and our own Caco-2 cells. In addition, the feasibility of this new approach to study regional differences (duodenum, jejunum, and ileum) in permeability of compounds and to study the effects of luminal factors on permeability was also investigated. For the latter, a comparison was made between the compatibility of porcine intestinal tissue, Caco-2 cells, and Caco-2 cells co-cultured with the mucin producing HT29-MTX cells with biorelevant samples as collected from an in vitro dynamic gastrointestinal model (TIM). The results demonstrated that for the paracellularly transported compounds atenolol, cimetidine, mannitol and ranitidine porcine Papp values are within 3-fold difference of human Papp values, whereas the Caco-2 Papp values are beyond 3-fold difference. Overall, the porcine intestinal tissue Papp values are more comparable to human Papp values (9 out of 12 are within 3-fold difference), compared to Caco-2 Papp values (4 out of 12 are within 3-fold difference). In addition, for the selected hydrophilic compounds a significant increase in the permeability was observed from duodenum to ileum. Finally, this study indicated that porcine jejunal tissue segments can be used with undiluted luminal samples to predict human intestinal permeability and the effect of biorelevant matrices on this. In conclusion, viable porcine intestinal tissue mounted in the InTESTine™ system can be applied as a reliable tool for the assessment of intestinal permeability in the absence and presence of biorelevant samples. This would enable an accessible opportunity for a reliable prediction of human intestinal absorption, and the effect of luminal compounds such as digested foods, early in drug development. PMID:25046168

  6. Bacterial dynamics in intestines of the black tiger shrimp and the Pacific white shrimp during Vibrio harveyi exposure.

    PubMed

    Rungrassamee, Wanilada; Klanchui, Amornpan; Maibunkaew, Sawarot; Karoonuthaisiri, Nitsara

    2016-01-01

    The intestinal microbiota play important roles in health of their host, contributing to maintaining the balance and resilience against pathogen. To investigate effects of pathogen to intestinal microbiota, the bacterial dynamics upon a shrimp pathogen, Vibrio harveyi, exposures were determined in two economically important shrimp species; the black tiger shrimp (BT) and the Pacific white shrimp (PW). Both shrimp species were reared under the same diet and environmental conditions. Shrimp survival rates after the V. harveyi exposure revealed that the PW shrimp had a higher resistance to the pathogen than the BT shrimp. The intestinal bacterial profiles were determined by denaturing gradient gel electrophoresis (DGGE) and barcoded pyrosequencing of the 16S rRNA sequences under no pathogen challenge control and under pathogenic V. harveyi challenge. The DGGE profiles showed that the presence of V. harveyi altered the intestinal bacterial patterns in comparison to the control in BT and PW intestines. This implies that bacterial balance in shrimp intestines was disrupted in the presence of V. harveyi. The barcoded pyrosequencing analysis showed the similar bacterial community structures in intestines of BT and PW shrimp under a normal condition. However, during the time course exposure to V. harveyi, the relative abundance of bacteria belong to Vibrio genus was higher in the BT intestines at 12h after the exposure, whereas relative abundance of vibrios was more stable in PW intestines. The principle coordinates analysis based on weighted-UniFrac analysis showed that intestinal bacterial population in the BT shrimp lost their ability to restore their bacterial balance during the 72-h period of exposure to the pathogen, while the PW shrimp were able to reestablish their bacterial population to resemble those seen in the unexposed control group. This observation of bacterial disruption might correlate to different mortality rates observed between the two shrimp species. Our findings provide evidence of intestinal bacterial population altered by a presence of the pathogen in shrimp intestines and intestinal bacterial stability might provide colonization resistance against the invading pathogen in the host shrimp. Hence, intestinal microbial ecology management may potentially contribute to disease prevention in aquaculture. PMID:26585302

  7. Generation of tissue-engineered small intestine using embryonic stem cell-derived human intestinal organoids.

    PubMed

    Finkbeiner, Stacy R; Freeman, Jennifer J; Wieck, Minna M; El-Nachef, Wael; Altheim, Christopher H; Tsai, Yu-Hwai; Huang, Sha; Dyal, Rachel; White, Eric S; Grikscheit, Tracy C; Teitelbaum, Daniel H; Spence, Jason R

    2015-01-01

    Short bowel syndrome (SBS) is characterized by poor nutrient absorption due to a deficit of healthy intestine. Current treatment practices rely on providing supportive medical therapy with parenteral nutrition; while life saving, such interventions are not curative and are still associated with significant co-morbidities. As approaches to lengthen remaining intestinal tissue have been met with only limited success and intestinal transplants have poor survival outcomes, new approaches to treating SBS are necessary. Human intestine derived from embryonic stem cells (hESCs) or induced pluripotent stem cells (iPSCs), called human intestinal organoids (HIOs), have the potential to offer a personalized and scalable source of intestine for regenerative therapies. However, given that HIOs are small three-dimensional structures grown in vitro, methods to generate usable HIO-derived constructs are needed. We investigated the ability of hESCs or HIOs to populate acellular porcine intestinal matrices and artificial polyglycolic/poly L lactic acid (PGA/PLLA) scaffolds, and examined the ability of matrix/scaffolds to thrive when transplanted in vivo. Our results demonstrate that the acellular matrix alone is not sufficient to instruct hESC differentiation towards an endodermal or intestinal fate. We observed that while HIOs reseed acellular porcine matrices in vitro, the HIO-reseeded matrices do not thrive when transplanted in vivo. In contrast, HIO-seeded PGA/PLLA scaffolds thrive in vivo and develop into tissue that looks nearly identical to adult human intestinal tissue. Our results suggest that HIO-seeded PGA/PLLA scaffolds are a promising avenue for developing the mucosal component of tissue engineered human small intestine, which need to be explored further to develop them into fully functional tissue. PMID:26459240

  8. Generation of tissue-engineered small intestine using embryonic stem cell-derived human intestinal organoids

    PubMed Central

    Finkbeiner, Stacy R.; Freeman, Jennifer J.; Wieck, Minna M.; El-Nachef, Wael; Altheim, Christopher H.; Tsai, Yu-Hwai; Huang, Sha; Dyal, Rachel; White, Eric S.; Grikscheit, Tracy C.; Teitelbaum, Daniel H.; Spence, Jason R.

    2015-01-01

    ABSTRACT Short bowel syndrome (SBS) is characterized by poor nutrient absorption due to a deficit of healthy intestine. Current treatment practices rely on providing supportive medical therapy with parenteral nutrition; while life saving, such interventions are not curative and are still associated with significant co-morbidities. As approaches to lengthen remaining intestinal tissue have been met with only limited success and intestinal transplants have poor survival outcomes, new approaches to treating SBS are necessary. Human intestine derived from embryonic stem cells (hESCs) or induced pluripotent stem cells (iPSCs), called human intestinal organoids (HIOs), have the potential to offer a personalized and scalable source of intestine for regenerative therapies. However, given that HIOs are small three-dimensional structures grown in vitro, methods to generate usable HIO-derived constructs are needed. We investigated the ability of hESCs or HIOs to populate acellular porcine intestinal matrices and artificial polyglycolic/poly L lactic acid (PGA/PLLA) scaffolds, and examined the ability of matrix/scaffolds to thrive when transplanted in vivo. Our results demonstrate that the acellular matrix alone is not sufficient to instruct hESC differentiation towards an endodermal or intestinal fate. We observed that while HIOs reseed acellular porcine matrices in vitro, the HIO-reseeded matrices do not thrive when transplanted in vivo. In contrast, HIO-seeded PGA/PLLA scaffolds thrive in vivo and develop into tissue that looks nearly identical to adult human intestinal tissue. Our results suggest that HIO-seeded PGA/PLLA scaffolds are a promising avenue for developing the mucosal component of tissue engineered human small intestine, which need to be explored further to develop them into fully functional tissue. PMID:26459240

  9. A Revised Model for Dosimetry in the Human Small Intestine

    SciTech Connect

    John Poston; Nasir U. Bhuiyan; R. Alex Redd; Neil Parham; Jennifer Watson

    2005-02-28

    A new model for an adult human gastrointestinal tract (GIT) has been developed for use in internal dose estimations to the wall of the GIT and to the other organs and tissues of the body from radionuclides deposited in the lumenal contents of the five sections of the GIT. These sections were the esophasgus, stomach, small intestine, upper large intestine, and the lower large intestine. The wall of each section was separated from its lumenal contents.

  10. IL-10 producing intestinal macrophages prevent excessive anti-bacterial innate immunity by limiting IL-23 synthesis

    PubMed Central

    Krause, Petra; Morris, Venetia; Greenbaum, Jason A.; Park, Yoon; Bjoerheden, Unni; Mikulski, Zbigniew; Muffley, Tracy; Shui, Jr-Wen; Kim, Gisen; Cheroutre, Hilde; Liu, Yun- Cai; Peters, Bjoern; Kronenberg, Mitchell; Murai, Masako

    2015-01-01

    Innate immune responses are regulated in the intestine to prevent excessive inflammation. Here we show that a subset of mouse colonic macrophages constitutively produce the anti-inflammatory cytokine IL-10. In mice infected with Citrobacter rodentium, a model for enteropathogenic Escherichia coli infection in humans, these macrophages are required to prevent intestinal pathology. IL-23 is significantly increased in infected mice with a myeloid cell-specific deletion of IL-10, and the addition of IL-10 reduces IL-23 production by intestinal macrophages. Furthermore, blockade of IL-23 leads to reduced mortality in the context of macrophage IL-10 deficiency. Transcriptome and other analyses indicate that IL-10-expressing macrophages receive an autocrine IL-10 signal. Interestingly, only transfer of the IL-10 positive macrophages could rescue IL-10 deficient infected mice. Therefore, these data indicate a pivotal role for intestinal macrophages that constitutively produce IL-10, in controlling excessive innate immune activation and preventing tissue damage after an acute bacterial infection. PMID:25959063

  11. Wingless homolog Wnt11 suppresses bacterial invasion and inflammation in intestinal epithelial cells

    PubMed Central

    Liu, Xingyin; Wu, Shaoping; Xia, Yinglin; Li, Xi Emma; Xia, Yuxuan; Zhou, Zhongren David

    2011-01-01

    Wnt11 plays an essential role in gastrointestinal epithelial proliferation, and previous investigations have focused on development and immune responses. However, the roles of how enteric bacteria regulate Wnt11 and how Wnt11 modulates the host response to pathogenic bacteria remain unexplored. This study investigated the effects of Salmonella infection on Wnt activation in intestinal epithelial cells. We found that Wnt11 mRNA and protein expression were elevated after Salmonella colonization. Wnt11 protein secretion in epithelial cells was also elevated after bacterial infection. Furthermore, we demonstrated that pathogenic Salmonella regulated Wnt11 expression and localization in vivo. We found a decrease in Salmonella invasion in cells with Wnt11 overexpression compared with cells with normal Wnt11 level. IL-8 mRNA in Wnt11-transfected cells was low; however, it was enhanced in cells with a low level of Wnt11 expression. Functionally, Wnt11 overexpression inhibited Salmonella-induced apoptosis. AvrA is a known bacterial effector protein that stabilizes β-catenin, the downstream regulator of Wnt signaling, and inhibits bacterially induced intestinal inflammation. We observed that Wnt11 expression, secretion, and transcriptional activity were regulated by Salmonella AvrA. Overall, Wnt11 is involved in the protection of the host intestinal cells by blocking the invasion of pathogenic bacteria, suppressing inflammation, and inhibiting apoptosis. Wnt11 is a novel and important contributor to intestinal homeostasis and host defense. PMID:21903761

  12. Supplemental Dietary Inulin of Variable Chain Lengths Alters Intestinal Bacterial Populations in Young Pigs123

    PubMed Central

    Patterson, Jannine K.; Yasuda, Koji; Welch, Ross M.; Miller, Dennis D.; Lei, Xin Gen

    2010-01-01

    Previously, we showed that supplementation of diets with short-chain inulin (P95), long-chain inulin (HP), and a 50:50 mixture of both (Synergy 1) improved body iron status and altered expression of the genes involved in iron homeostasis and inflammation in young pigs. However, the effects of these 3 types of inulin on intestinal bacteria remain unknown. Applying terminal restriction fragment length polymorphism analysis, we determined the abundances of luminal and adherent bacterial populations from 6 segments of the small and large intestines of pigs (n = 4 for each group) fed an iron-deficient basal diet (BD) or the BD supplemented with 4% of P95, Synergy 1, or HP for 5 wk. Compared with BD, all 3 types of inulin enhanced (P < 0.05) the abundance of beneficial bifidobacteria and lactobacilli in the microbiota adherent to intestinal mucus of various gut segments of pigs. These changes were seen as proximal as in the jejunum with P95 but did not appear until the distal ileum or cecum with HP. Similar effects of inulin on bacterial populations in the lumen contents were found. Meanwhile, all 3 types of inulin suppressed the less desirable bacteria Clostridium spp. and members of the Enterobacteriaceae in the lumen and mucosa of various gut segments. Our findings suggest that the ability of dietary inulin to alter intestinal bacterial populations may partially account for its iron bioavailability-promoting effect and possibly other health benefits. PMID:20980641

  13. Exploring food effects on indinavir absorption with human intestinal fluids in the mouse intestine.

    PubMed

    Holmstock, Nico; De Bruyn, Tom; Bevernage, Jan; Annaert, Pieter; Mols, Raf; Tack, Jan; Augustijns, Patrick

    2013-04-11

    Food can have a significant impact on the pharmacokinetics of orally administered drugs, as it may affect drug solubility as well as permeability. Since fed state conditions cannot easily be implemented in the presently available permeability tools, including the frequently used Caco-2 system, exploring food effects during drug development can be quite challenging. In this study, we investigated the effect of fasted and fed state conditions on the intestinal absorption of the HIV protease inhibitor indinavir using simulated and human intestinal fluids in the in situ intestinal perfusion technique in mice. Although the solubility of indinavir was 6-fold higher in fed state human intestinal fluids (FeHIF) as compared to fasted state HIF (FaHIF), the intestinal permeation of indinavir was 22-fold lower in FeHIF as compared to FaHIF. Dialysis experiments showed that only a small fraction of indinavir is accessible for absorption in FeHIF due to micellar entrapment, possibly explaining its low intestinal permeation. The presence of ritonavir, a known P-gp inhibitor, increased the intestinal permeation of indinavir by 2-fold in FaHIF, while there was no increase when using FeHIF. These data confirm that drug-food interactions form a complex interplay between solubility and permeability effects. The use of HIF in in situ intestinal perfusions holds great promise for biorelevant absorption evaluation as it allows to directly explore this complex solubility/permeability interplay on drug absorption. PMID:23402972

  14. Vitamin D Receptor Negatively Regulates Bacterial-Stimulated NF-κB Activity in Intestine

    PubMed Central

    Wu, Shaoping; Liao, Anne P.; Xia, Yinglin; Li, Yan Chun; Li, Jian-Dong; Sartor, R. Balfour; Sun, Jun

    2010-01-01

    Vitamin D receptor (VDR) plays an essential role in gastrointestinal inflammation. Most investigations have focused on the immune response; however, how bacteria regulate VDR and how VDR modulates the nuclear factor (NF)-κB pathway in intestinal epithelial cells remain unexplored. This study investigated the effects of VDR ablation on NF-κB activation in intestinal epithelia and the role of enteric bacteria on VDR expression. We found that VDR−/− mice exhibited a pro-inflammatory bias. After Salmonella infection, VDR−/− mice had increased bacterial burden and mortality. Serum interleukin-6 in noninfected VDR+/+ mice was undetectable, but was easily detectable in VDR−/− mice. NF-κB p65 formed a complex with VDR in noninfected wild-type mouse intestine. In contrast, deletion of VDR abolished VDR/P65 binding. P65 nuclear translocation occurred in colonic epithelial cells of untreated VDR−/− mice. VDR deletion also elevated NF-κB activity in intestinal epithelia. VDR was localized to the surface epithelia of germ-free mice, but to crypt epithelial cells in conventionalized mice. VDR expression, distribution, transcriptional activity, and target genes were regulated by Salmonella stimulation, independent of 1,25-dihydroxyvitamin D3. Our study demonstrates that commensal and pathogenic bacteria directly regulate colonic epithelial VDR expression and location in vivo. VDR negatively regulates bacterial-induced intestinal NF-κB activation and attenuates response to infection. Therefore, VDR is an important contributor to intestinal homeostasis and host protection from bacterial invasion and infection. PMID:20566739

  15. State of the art; microbiology in health and disease. Intestinal bacterial flora in autism.

    PubMed

    Finegold, Sydney M

    2011-12-01

    Autism of the regressive variety is selected as an example of the importance of intestinal bacterial microflora in disease other than classical infection. Our studies have indicated that intestinal bacteria play a role in this disease since it responds to oral vancomycin, a drug that is not absorbed from the GI tract. Pyrosequencing studies document an abnormal gut microflora in regressive autism subjects as compared to controls. Finally, we present preliminary evidence suggesting that Desulfovibrio may play a key role in this disease. PMID:21524713

  16. Identification of Population Bottlenecks and Colonization Factors during Assembly of Bacterial Communities within the Zebrafish Intestine

    PubMed Central

    Stephens, W. Zac; Wiles, Travis J.; Martinez, Emily S.; Jemielita, Matthew; Burns, Adam R.; Parthasarathy, Raghuveer; Bohannan, Brendan J. M.

    2015-01-01

    ABSTRACT The zebrafish, Danio rerio, is a powerful model for studying bacterial colonization of the vertebrate intestine, but the genes required by commensal bacteria to colonize the zebrafish gut have not yet been interrogated on a genome-wide level. Here we apply a high-throughput transposon mutagenesis screen to Aeromonas veronii Hm21 and Vibrio sp. strain ZWU0020 during their colonization of the zebrafish intestine alone and in competition with each other, as well as in different colonization orders. We use these transposon-tagged libraries to track bacterial population sizes in different colonization regimes and to identify gene functions required during these processes. We show that intraspecific, but not interspecific, competition with a previously established bacterial population greatly reduces the ability of these two bacterial species to colonize. Further, using a simple binomial sampling model, we show that under conditions of interspecific competition, genes required for colonization cannot be identified because of the population bottleneck experienced by the second colonizer. When bacteria colonize the intestine alone or at the same time as the other species, we find shared suites of functional requirements for colonization by the two species, including a prominent role for chemotaxis and motility, regardless of the presence of another species. PMID:26507229

  17. Influence of carp intestinal mucus molecular size and glycosylation on bacterial adhesion.

    PubMed

    Schroers, V; Van Der Marel, M; Steinhagen, D

    2008-08-27

    The first step of the pathogenesis of many infectious diseases is the colonisation of the mucosal surface by the pathogen. Bacterial colonisation of the mucosal surface is promoted by adherence to high molecular weight mucus glycoproteins. We examined the effect of carp intestinal mucus glycoproteins on the adhesion of different bacteria. The bacteria used were 3 strains of Aeromonas hydrophila, and A. salmonicida, Edwardsiella tarda and Yersinia ruckeri. All bacteria adhered to mucus, but at varying intensities. All tested bacteria adhered best to molecules of 670 to 2000 kDa in size, less to molecules larger than 2000 kDa and weakest to molecules of 30 to 670 kDa. In general, bacteria that showed a stronger adhesion to intestinal mucus were cytotoxic to cells in vitro, and bacteria that showed a weaker adhesion to intestinal mucus did not lead to alterations of monolayers of EPC-cells. Furthermore, the involvement of glycan side chains of the glycoproteins for bacterial adhesion was analysed for one A. hydrophila strain. After cleavage of terminal sugar residues by treatment of mucus glycoproteins with different glycosidases, binding of bacteria was modulated. When mannose was cleaved off, adhesion significantly increased. Blocking of glycan receptors by incubation of bacteria with different oligosaccharides had no clear effect on bacterial binding to mucus glycoproteins. Our results suggest that bacteria interact with carbohydrate side chains of mucus glycoproteins, and that the carbohydrates of the core region are involved in bacterial binding. PMID:18924378

  18. Transgenic milk containing recombinant human lactoferrin modulates the intestinal flora in piglets.

    PubMed

    Hu, Wenping; Zhao, Jie; Wang, Jianwu; Yu, Tian; Wang, Jing; Li, Ning

    2012-06-01

    Lactoferrin (LF) is a beneficial multifunctional protein in milk. The objective of this study was to determine whether bovine transgenic milk containing recombinant human lactoferrin (rhLF) can modulate intestinal flora in the neonatal pig as an animal model for the human infant. We fed 7-day-old piglets (i) ordinary whole milk (OM), (ii) a 1:1 mixture of OM and rhLF milk (MM), or (iii) rhLF milk (LFM). LFM provided better average daily mass gain than OM (P = 0.007). PCR-denaturing gradient gel electrophoresis and 16S rDNA sequencing analysis revealed that the LFM piglets exhibited more diversity of the intestinal flora than the OM group. Except for the colon in the LFM group, an increasing trend in microbial diversity occurred from the duodenum to the colon. Fecal flora was not different across different ages or different treatment groups, but a cluster analysis showed that the fecal flora of OM- and MM-fed piglets had a higher degree of similarity than that of LFM-fed piglets. Based on culture-based bacterial counts of intestinal content samples, concentrations of Salmonella spp. in the colon and of Escherichia coli throughout the intestine were reduced with LFM (P < 0.01). Concentrations of Bifidobacterium spp. in the ileum and of Lactobacillus spp. throughout the intestine were also increased with LFM (P ≤ 0.01). We suggest that rhLF can modulate the intestinal flora in piglets. PMID:22400985

  19. Intestinal behavior of the ester prodrug tenofovir DF in humans.

    PubMed

    Geboers, Sophie; Haenen, Steven; Mols, Raf; Brouwers, Joachim; Tack, Jan; Annaert, Pieter; Augustijns, Patrick

    2015-05-15

    Tenofovir-disoproxil-fumarate (TDF) is a double ester prodrug which enables intestinal uptake of tenofovir (TFV) after oral administration in humans. In this study, prodrug stability was monitored in situ in the human intestine and in vitro using biorelevant media. In fasted state human intestinal fluids, the prodrug was completely degraded within 90 min, resulting in the formation of the mono-ester intermediate and TFV; in fed state intestinal fluids, the degradation rate of TDF was slightly reduced and no TFV was formed. Intestinal fluid samples aspirated after administration of TDF confirmed extensive intraluminal degradation of TDF in fasted state conditions; a relatively fast absorption of TDF partly compensated for the degradation. Although food intake reduced intestinal degradation, the systemic exposure was not proportionally increased. The lower degradation in fed state conditions may be attributed to competing esterase substrates present in food, lower chemical degradation in the slightly more acidic environment and micellar entrapment, delaying exposure to the "degrading" intestinal environment. The results of this study demonstrate premature intestinal degradation of TDF and suggest that TFV may benefit from a more stable prodrug approach; however, fast absorption may compensate for fast degradation, indicating that prodrug selection should not be limited to stability assays. PMID:25747454

  20. Gastrointestinal complaints in runners are not due to small intestinal bacterial overgrowth

    PubMed Central

    2011-01-01

    Background Gastrointestinal complaints are common among long distance runners. We hypothesised that small intestinal bacterial overgrowth (SIBO) is present in long distance runners frequently afflicted with gastrointestinal complaints. Findings Seven long distance runners (5 female, mean age 29.1 years) with gastrointestinal complaints during and immediately after exercise without known gastrointestinal diseases performed Glucose hydrogen breath tests for detection of SIBO one week after a lactose hydrogen breath test checking for lactose intolerance. The most frequent symptoms were diarrhea (5/7, 71%) and flatulence (6/7, 86%). The study was conducted at a laboratory. In none of the subjects a pathological hydrogen production was observed after the intake of glucose. Only in one athlete a pathological hydrogen production was measured after the intake of lactose suggesting lactose intolerance. Conclusions Gastrointestinal disorders in the examined long distance runners were not associated with small intestinal bacterial overgrowth. PMID:21794099

  1. Rye affects bacterial translocation, intestinal viscosity, microbiota composition and bone mineralization in Turkey poults.

    PubMed

    Tellez, Guillermo; Latorre, Juan D; Kuttappan, Vivek A; Hargis, Billy M; Hernandez-Velasco, Xochitl

    2015-01-01

    Previously, we have reported that rye significantly increased both viscosity and Clostridium perfringens proliferation when compared with corn in an in vitro digestive model. Two independent trials were conducted to evaluate the effect of rye as a source of energy on bacterial translocation, intestinal viscosity, gut microbiota composition, and bone mineralization, when compared with corn in turkey poults. In each experiment, day-of-hatch, turkey poults were randomly assigned to either a corn or a rye diet (n = 0 /group). At 10 d of age, in both experiments, 12 birds/group were given an oral gavage dose of fluorescein isothiocyanate dextran (FITC-d). After 2.5 h of oral gavage, blood and liver samples were collected to evaluate the passage of FITC-d and bacterial translocation (BT) respectively. Duodenum, ileum and cecum gut sections were collected to evaluate intestinal viscosity and to enumerate gut microbiota. Tibias were collected for observation of bone parameters. Broilers fed with a rye diet showed increased (p<0.05) intestinal viscosity, BT, and serum FITC-d. Bacterial enumeration revealed that turkey poults fed with rye had increased the number of total lactic acid bacteria (LAB) in all three sections of the gastrointestinal tract evaluated when compared to turkey poults fed with corn. Turkey poults fed with rye also had significantly higher coliforms in duodenum and ileum but not in the ceca, whereas the total number of anaerobes increased only in duodenum. A significant reduction in bone strength and bone mineralization was observed in turkey poults fed with rye when compared with corn fed turkey poults. In conclusion, rye evoked mucosal damage in turkey poults that increased intestinal viscosity, increased leakage through the intestinal tract, and altered the microbiota composition and bone mineralization. Studies to evaluate dietary inclusion of selected Direct-Fed Microbial (DFM) candidates that produce exogenous enzymes in rye fed turkey poults are currently being evaluated. PMID:25849537

  2. Rye Affects Bacterial Translocation, Intestinal Viscosity, Microbiota Composition and Bone Mineralization in Turkey Poults

    PubMed Central

    Tellez, Guillermo; Latorre, Juan D.; Kuttappan, Vivek A.; Hargis, Billy M.; Hernandez-Velasco, Xochitl

    2015-01-01

    Previously, we have reported that rye significantly increased both viscosity and Clostridium perfringens proliferation when compared with corn in an in vitro digestive model. Two independent trials were conducted to evaluate the effect of rye as a source of energy on bacterial translocation, intestinal viscosity, gut microbiota composition, and bone mineralization, when compared with corn in turkey poults. In each experiment, day-of-hatch, turkey poults were randomly assigned to either a corn or a rye diet (n = 0 /group). At 10 d of age, in both experiments, 12 birds/group were given an oral gavage dose of fluorescein isothiocyanate dextran (FITC-d). After 2.5 h of oral gavage, blood and liver samples were collected to evaluate the passage of FITC-d and bacterial translocation (BT) respectively. Duodenum, ileum and cecum gut sections were collected to evaluate intestinal viscosity and to enumerate gut microbiota. Tibias were collected for observation of bone parameters. Broilers fed with a rye diet showed increased (p<0.05) intestinal viscosity, BT, and serum FITC-d. Bacterial enumeration revealed that turkey poults fed with rye had increased the number of total lactic acid bacteria (LAB) in all three sections of the gastrointestinal tract evaluated when compared to turkey poults fed with corn. Turkey poults fed with rye also had significantly higher coliforms in duodenum and ileum but not in the ceca, whereas the total number of anaerobes increased only in duodenum. A significant reduction in bone strength and bone mineralization was observed in turkey poults fed with rye when compared with corn fed turkey poults. In conclusion, rye evoked mucosal damage in turkey poults that increased intestinal viscosity, increased leakage through the intestinal tract, and altered the microbiota composition and bone mineralization. Studies to evaluate dietary inclusion of selected Direct-Fed Microbial (DFM) candidates that produce exogenous enzymes in rye fed turkey poults are currently being evaluated. PMID:25849537

  3. Efficient genetic engineering of human intestinal organoids using electroporation.

    PubMed

    Fujii, Masayuki; Matano, Mami; Nanki, Kosaku; Sato, Toshiro

    2015-10-01

    Gene modification in untransformed human intestinal cells is an attractive approach for studying gene function in intestinal diseases. However, because of the lack of practical tools, such studies have largely depended upon surrogates, such as gene-engineered mice or immortalized human cell lines. By taking advantage of the recently developed intestinal organoid culture method, we developed a methodology for modulating genes of interest in untransformed human colonic organoids via electroporation of gene vectors. Here we describe a detailed protocol for the generation of intestinal organoids by culture with essential growth factors in a basement membrane matrix. We also describe how to stably integrate genes via the piggyBac transposon, as well as precise genome editing using the CRISPR-Cas9 system. Beginning with crypt isolation from a human colon sample, genetically modified organoids can be obtained in 3 weeks. PMID:26334867

  4. Salmonella‐infected crypt‐derived intestinal organoid culture system for host–bacterial interactions

    PubMed Central

    Zhang, Yong‐Guo; Wu, Shaoping; Xia, Yinglin; Sun, Jun

    2014-01-01

    Abstract The in vitro analysis of bacterial–epithelial interactions in the intestine has been hampered by a lack of suitable intestinal epithelium culture systems. Here, we report a new experimental model using an organoid culture system to study pathophysiology of bacterial–epithelial interactions post Salmonella infection. Using crypt‐derived mouse intestinal organoids, we were able to visualize the invasiveness of Salmonella and the morphologic changes of the organoids. Importantly, we reported bacteria‐induced disruption of epithelial tight junctions in the infected organoids. In addition, we showed the inflammatory responses through activation of the NF‐κB pathway in the organoids. Moreover, our western blot, PCR, and immunofluorescence data demonstrated that stem cell markers (Lgr5 and Bmi1) were significantly decreased by Salmonella infection (determined using GFP‐labeled Lgr5 organoids). For the first time, we created a model system that recapitulated a number of observations from in vivo studies of the Salmonella‐infected intestine, including bacterial invasion, altered tight junctions, inflammatory responses, and decreased stem cells. We have demonstrated that the Salmonella‐infected organoid culture system is a new experimental model suitable for studying host–bacterial interactions. PMID:25214524

  5. Effect of Ceftaroline on Normal Human Intestinal Microflora▿

    PubMed Central

    Panagiotidis, Georgios; Bäckström, Tobias; Asker-Hagelberg, Charlotte; Jandourek, Alena; Weintraub, Andrej; Nord, Carl Erik

    2010-01-01

    Ceftaroline is a new broad-spectrum cephalosporin being developed for the treatment of serious bacterial infections, including those caused by aerobic Gram-positive and Gram-negative bacteria. The purpose of the present study was to investigate the effect of administration of ceftaroline on the intestinal flora of healthy subjects. Twelve healthy subjects (6 males and 6 females), 20 to 41 years of age, received ceftaroline (600 mg) by intravenous infusion every 12 h (q12h) for 7 days. Plasma and feces were collected for determination of ceftaroline concentration and analysis of fecal flora. Fecal specimens were cultured on nonselective and selective media. Different colony types were counted, isolated in pure culture, and identified to the genus level. All new strains of colonizing bacteria were tested for susceptibility to ceftaroline. The concentrations of ceftaroline in plasma were as follows: on day 2, 17.5 to 34.8 mg/liter; on day 5, 19.7 to 33.2 mg/liter; and on day 7, 18.0 to 29.8 mg/liter. No ceftaroline concentrations were found on day −1, 9, 14, or 21. No measurable concentrations in feces were found on day −1, 2, 5, 7, 9, 14, or 21. There was a minor impact on the numbers of Escherichia coli strains, while the numbers of enterococci and Candida albicans strains were not affected. There were moderate decreases in the numbers of bifidobacteria and lactobacilli during the first 7 days, while the numbers of clostridia increased during the same period. No impact on the numbers of Bacteroides bacteria was noticed. No new colonizing aerobic or anaerobic bacteria resistant to ceftaroline (MIC ≥ 4 mg/liter) were found. Ceftaroline had no significant ecological impact on the human intestinal microflora. PMID:20231399

  6. Nitroreduction and formation of hemoglobin adducts in rats with a human intestinal microflora.

    PubMed Central

    Scheepers, P T; Straetemans, M M; Koopman, J P; Bos, R P

    1994-01-01

    In the covalent binding of nitroarenes to macromolecules, nitroreduction is an important step. The intestinal microflora represents an enormous potential of bacterial nitroreductase activity. As a consequence, the in vivo nitroreduction of orally administered nitroarenes is primarily located in the intestine. In this study, we have investigated the nitroreduction of 2-nitrofluorene (2-NF) by a human microflora in female Wistar rats. Germ-free (GF) rats were equipped with a bacterial flora derived from human feces. Nontreated GF rats and GF animals equipped with a conventional rat flora were used as controls. The composition of the human and the conventional microflora isolated from the rats were consistent with the microflora of the administered feces. In the rats receiving only sunflower seed oil, no adducts were detected. The animals equipped with a human or rat microflora that received 2-aminofluorene (2-AF) formed 2-AF hemoglobin (Hb)-adducts at average levels (mean +/- SEM) of 5.3 +/- 0.3 and 6.7 +/- 0.7 mumole/g Hb, respectively. After 2-NF administration, the adduct levels were 0.022 +/- 0.003 and 0.043 +/- 0.010 mumole/g Hb, respectively. In the GF rats, an adduct level of 0.57 +/- 0.09 was determined after 2-AF administration and no adducts were detected after 2-NF administration. The results show that nitroreduction by an acquired human intestinal microflora and subsequent adduct formation can be studied in the rat in vivo. PMID:7889856

  7. Nitroreduction and formation of hemoglobin adducts in rats with a human intestinal microflora

    SciTech Connect

    Scheepers, P.T.J.; Straetemans, M.M.E.; Koopman, J.P.; Bos, R.P.

    1994-10-01

    In the covalent binding of nitroarenes to macromolecules, nitroreduction is an important step. The intestinal microflora represents an enormous potential of bacterial nitroreductase activity. As a consequence, the in vivo nitroreduction of orally administerednitroarenes is primarily located in the intestine. In this study, we have investigated the nitroreduction of 2-nitrofluorene (2-NF) by a human microflora in female Wistar rats. Germ-free (FG) rats were equipped with a bacterial flora derived from human feces. Nontreated GF rats and GF animals equipped with a conventional rat flora were used as controls. The composition of the human and the conventional microflora isolated from the rats were consistent with the microflora of the administered feces. In the rats receiving only sunflower seed oil, no adducts were detected. The animals equipped with a human or rat microflora that received 2-aminofluorene (2-AF) formed 2-AF hemoglobin (Hb)-adducts at average levels mean {+-} 0.003 and 0.043 {+-} 0.010 {mu}mole/g Hb, respectively. In the FG rats, an adduct level of 0.57 {+-} 0.09 was determined after 2-AF administration and non adducts were detected after 2-NF administration. The results show that nitroreduction by an acquired human intestinal microflora and subsequent adduct formation can be studied in the rate in vivo. 21 refs., 3 tabs.

  8. Enteric bacterial invasion of intestinal epithelial cells in vitro is dramatically enhanced using a vertical diffusion chamber model.

    PubMed

    Naz, Neveda; Mills, Dominic C; Wren, Brendan W; Dorrell, Nick

    2013-01-01

    The interactions of bacterial pathogens with host cells have been investigated extensively using in vitro cell culture methods. However as such cell culture assays are performed under aerobic conditions, these in vitro models may not accurately represent the in vivo environment in which the host-pathogen interactions take place. We have developed an in vitro model of infection that permits the coculture of bacteria and host cells under different medium and gas conditions. The Vertical Diffusion Chamber (VDC) model mimics the conditions in the human intestine where bacteria will be under conditions of very low oxygen whilst tissue will be supplied with oxygen from the blood stream. Placing polarized intestinal epithelial cell (IEC) monolayers grown in Snapwell inserts into a VDC creates separate apical and basolateral compartments. The basolateral compartment is filled with cell culture medium, sealed and perfused with oxygen whilst the apical compartment is filled with broth, kept open and incubated under microaerobic conditions. Both Caco-2 and T84 IECs can be maintained in the VDC under these conditions without any apparent detrimental effects on cell survival or monolayer integrity. Coculturing experiments performed with different C. jejuni wild-type strains and different IEC lines in the VDC model with microaerobic conditions in the apical compartment reproducibly result in an increase in the number of interacting (almost 10-fold) and intracellular (almost 100-fold) bacteria compared to aerobic culture conditions. The environment created in the VDC model more closely mimics the environment encountered by C. jejuni in the human intestine and highlights the importance of performing in vitro infection assays under conditions that more closely mimic the in vivo reality. We propose that use of the VDC model will allow new interpretations of the interactions between bacterial pathogens and host cells. PMID:24192850

  9. Burn Injury Alters the Intestinal Microbiome and Increases Gut Permeability and Bacterial Translocation

    PubMed Central

    Earley, Zachary M.; Akhtar, Suhail; Green, Stefan J.; Naqib, Ankur; Khan, Omair; Cannon, Abigail R.; Hammer, Adam M.; Morris, Niya L.; Li, Xiaoling; Eberhardt, Joshua M.; Gamelli, Richard L; Kennedy, Richard H.; Choudhry, Mashkoor A.

    2015-01-01

    Sepsis remains one of the leading causes of death in burn patients who survive the initial insult of injury. Disruption of the intestinal epithelial barrier has been shown after burn injury; this can lead to the translocation of bacteria or their products (e.g., endotoxin) from the intestinal lumen to the circulation, thereby increasing the risk for sepsis in immunocompromised individuals. Since the maintenance of the epithelial barrier is largely dependent on the intestinal microbiota, we examined the diversity of the intestinal microbiome of severely burned patients and a controlled mouse model of burn injury. We show that burn injury induces a dramatic dysbiosis of the intestinal microbiome of both humans and mice and allows for similar overgrowths of Gram-negative aerobic bacteria. Furthermore, we show that the bacteria increasing in abundance have the potential to translocate to extra-intestinal sites. This study provides an insight into how the diversity of the intestinal microbiome changes after burn injury and some of the consequences these gut bacteria can have in the host. PMID:26154283

  10. Three-Dimensional Coculture Of Human Small-Intestine Cells

    NASA Technical Reports Server (NTRS)

    Wolf, David; Spaulding, Glen; Goodwin, Thomas J.; Prewett, Tracy

    1994-01-01

    Complex three-dimensional masses of normal human epithelial and mesenchymal small-intestine cells cocultured in process involving specially designed bioreactors. Useful as tissued models for studies of growth, regulatory, and differentiation processes in normal intestinal tissues; diseases of small intestine; and interactions between cells of small intestine and viruses causing disease both in small intestine and elsewhere in body. Process used to produce other tissue models, leading to advances in understanding of growth and differentiation in developing organisms, of renewal of tissue, and of treatment of myriad of clinical conditions. Prior articles describing design and use of rotating-wall culture vessels include "Growing And Assembling Cells Into Tissues" (MSC-21559), "High-Aspect-Ratio Rotating Cell-Culture Vessel" (MSC-21662), and "In Vitro, Matrix-Free Formation Of Solid Tumor Spheroids" (MSC-21843).

  11. Active Transport of Phosphorylated Carbohydrates Promotes Intestinal Colonization and Transmission of a Bacterial Pathogen

    PubMed Central

    Sit, Brandon; Crowley, Shauna M.; Bhullar, Kirandeep; Lai, Christine Chieh-Lin; Tang, Calvin; Hooda, Yogesh; Calmettes, Charles; Khambati, Husain; Ma, Caixia; Brumell, John H.; Schryvers, Anthony B.; Vallance, Bruce A.; Moraes, Trevor F.

    2015-01-01

    Efficient acquisition of extracellular nutrients is essential for bacterial pathogenesis, however the identities and mechanisms for transport of many of these substrates remain unclear. Here, we investigate the predicted iron-binding transporter AfuABC and its role in bacterial pathogenesis in vivo. By crystallographic, biophysical and in vivo approaches, we show that AfuABC is in fact a cyclic hexose/heptose-phosphate transporter with high selectivity and specificity for a set of ubiquitous metabolites (glucose-6-phosphate, fructose-6-phosphate and sedoheptulose-7-phosphate). AfuABC is conserved across a wide range of bacterial genera, including the enteric pathogens EHEC O157:H7 and its murine-specific relative Citrobacter rodentium, where it lies adjacent to genes implicated in sugar sensing and acquisition. C. rodentium ΔafuA was significantly impaired in an in vivo murine competitive assay as well as its ability to transmit infection from an afflicted to a naïve murine host. Sugar-phosphates were present in normal and infected intestinal mucus and stool samples, indicating that these metabolites are available within the intestinal lumen for enteric bacteria to import during infection. Our study shows that AfuABC-dependent uptake of sugar-phosphates plays a critical role during enteric bacterial infection and uncovers previously unrecognized roles for these metabolites as important contributors to successful pathogenesis. PMID:26295949

  12. The murine lung microbiome in relation to the intestinal and vaginal bacterial communities

    PubMed Central

    2013-01-01

    Background This work provides the first description of the bacterial population of the lung microbiota in mice. The aim of this study was to examine the lung microbiome in mice, the most used animal model for inflammatory lung diseases such as COPD, cystic fibrosis and asthma. Bacterial communities from broncho-alveolar lavage fluids and lung tissue were compared to samples taken from fecal matter (caecum) and vaginal lavage fluid from female BALB/cJ mice. Results Using a customized 16S rRNA sequencing protocol amplifying the V3-V4 region our study shows that the mice have a lung microbiome that cluster separately from mouse intestinal microbiome (caecum). The mouse lung microbiome is dominated by Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes and Cyanobacteria overlapping the vaginal microbiome. We also show that removal of host tissue or cells from lung fluid during the DNA extraction step has an impact on the resulting bacterial community profile. Sample preparation needs to be considered when choosing an extraction method and interpreting data. Conclusions We have consistently amplified bacterial DNA from mouse lungs that is distinct from the intestinal microbiome in these mice. The gut microbiome has been extensively studied for its links to development of disease. Here we suggest that also the lung microbiome could be important in relation to inflammatory lung diseases. Further research is needed to understand the contribution of the lung microbiome and the gut-lung axis to the development of lung diseases such as COPD and asthma. PMID:24373613

  13. Over-starvation aggravates intestinal injury and promotes bacterial and endotoxin translocation under high-altitude hypoxic environment

    PubMed Central

    Zhou, Qi-Quan; Yang, Ding-Zhou; Luo, Yong-Jun; Li, Su-Zhi; Liu, Fu-Yu; Wang, Guan-Song

    2011-01-01

    AIM: To study whether over-starvation aggravates intestinal mucosal injury and promotes bacterial and endotoxin translocation in a high-altitude hypoxic environment. METHODS: Sprague-Dawley rats were exposed to hypobaric hypoxia at a simulated altitude of 7000 m for 72 h. Lanthanum nitrate was used as a tracer to detect intestinal injury. Epithelial apoptosis was observed with terminal deoxynucleotidyl transferase dUTP nick end labeling staining. Serum levels of diamino oxidase (DAO), malondialdehyde (MDA), glutamine (Gln), superoxide dismutase (SOD) and endotoxin were measured in intestinal mucosa. Bacterial translocation was detected in blood culture and intestinal homogenates. In addition, rats were given Gln intragastrically to observe its protective effect on intestinal injury. RESULTS: Apoptotic epithelial cells, exfoliated villi and inflammatory cells in intestine were increased with edema in the lamina propria accompanying effusion of red blood cells. Lanthanum particles were found in the intercellular space and intracellular compartment. Bacterial translocation to mesenteric lymph nodes (MLN) and spleen was evident. The serum endotoxin, DAO and MDA levels were significantly higher while the serum SOD, DAO and Gln levels were lower in intestine (P < 0.05). The bacterial translocation number was lower in the high altitude hypoxic group than in the high altitude starvation group (0.47 ± 0.83 vs 2.38 ± 1.45, P < 0.05). The bacterial translocation was found in each organ, especially in MLN and spleen but not in peripheral blood. The bacterial and endotoxin translocations were both markedly improved in rats after treatment with Gln. CONCLUSION: High-altitude hypoxia and starvation cause severe intestinal mucosal injury and increase bacterial and endotoxin translocation, which can be treated with Gln. PMID:21472125

  14. Role of metabolism by human intestinal microflora in geniposide-induced toxicity in HepG2 cells.

    PubMed

    Kang, Mi Jeong; Khanal, Tilak; Kim, Hyung Gyun; Lee, Dae Hun; Yeo, Hee Kyung; Lee, Yong Sup; Ahn, Young Tae; Kim, Dong Hyun; Jeong, Hye Gwang; Jeong, Tae Cheon

    2012-03-01

    Possible role of metabolism by the intestinal bacteria in geniposide-induced cytotoxicity was investigated in human hepatoma HepG2 cells. Initially, toxic effects of geniposide and its metabolite genipin were compared. Genipin, a deglycosylated form of geniposide, was cytotoxic at the concentrations that geniposide was not. As metabolic activation systems for geniposide, human intestinal bacterial cultures, fecal preparation (fecalase) and intestinal microbial enzyme mix were employed in the present study. When geniposide was incubated with human intestinal bacteria, either Bifidobacterium longum HY8001 or Bacteroides fragilis, for 24 h, the cultured media caused cytotoxicity in HepG2 cells. Fecalase and intestinal enzyme mix were also effective to metabolically activate geniposide to its cytotoxic metabolite. The present results indicated that genipin, a metabolite of geniposide, might be more toxic than geniposide, and that intestinal bacteria might have a role in biotransformation of geniposide to its toxic metabolite. In addition, among three activation systems tested, intestinal microbial enzyme mix would be convenient to use in detecting toxicants requiring metabolic activation by intestinal bacteria. PMID:22553067

  15. Distinct Human Stem Cell Populations in Small and Large Intestine

    PubMed Central

    Cramer, Julie M.; Thompson, Timothy; Geskin, Albert; LaFramboise, William; Lagasse, Eric

    2015-01-01

    The intestine is composed of an epithelial layer containing rapidly proliferating cells that mature into two regions, the small and the large intestine. Although previous studies have identified stem cells as the cell-of-origin for intestinal epithelial cells, no studies have directly compared stem cells derived from these anatomically distinct regions. Here, we examine intrinsic differences between primary epithelial cells isolated from human fetal small and large intestine, after in vitro expansion, using the Wnt agonist R-spondin 2. We utilized flow cytometry, fluorescence-activated cell sorting, gene expression analysis and a three-dimensional in vitro differentiation assay to characterize their stem cell properties. We identified stem cell markers that separate subpopulations of colony-forming cells in the small and large intestine and revealed important differences in differentiation, proliferation and disease pathways using gene expression analysis. Single cells from small and large intestine cultures formed organoids that reflect the distinct cellular hierarchy found in vivo and respond differently to identical exogenous cues. Our characterization identified numerous differences between small and large intestine epithelial stem cells suggesting possible connections to intestinal disease. PMID:25751518

  16. Distinct human stem cell populations in small and large intestine.

    PubMed

    Cramer, Julie M; Thompson, Timothy; Geskin, Albert; LaFramboise, William; Lagasse, Eric

    2015-01-01

    The intestine is composed of an epithelial layer containing rapidly proliferating cells that mature into two regions, the small and the large intestine. Although previous studies have identified stem cells as the cell-of-origin for intestinal epithelial cells, no studies have directly compared stem cells derived from these anatomically distinct regions. Here, we examine intrinsic differences between primary epithelial cells isolated from human fetal small and large intestine, after in vitro expansion, using the Wnt agonist R-spondin 2. We utilized flow cytometry, fluorescence-activated cell sorting, gene expression analysis and a three-dimensional in vitro differentiation assay to characterize their stem cell properties. We identified stem cell markers that separate subpopulations of colony-forming cells in the small and large intestine and revealed important differences in differentiation, proliferation and disease pathways using gene expression analysis. Single cells from small and large intestine cultures formed organoids that reflect the distinct cellular hierarchy found in vivo and respond differently to identical exogenous cues. Our characterization identified numerous differences between small and large intestine epithelial stem cells suggesting possible connections to intestinal disease. PMID:25751518

  17. The dual oxidase gene BdDuox regulates the intestinal bacterial community homeostasis of Bactrocera dorsalis.

    PubMed

    Yao, Zhichao; Wang, Ailin; Li, Yushan; Cai, Zhaohui; Lemaitre, Bruno; Zhang, Hongyu

    2016-05-01

    The guts of metazoans are in permanent contact with the microbial realm that includes beneficial symbionts, nonsymbionts, food-borne microbes and life-threatening pathogens. However, little is known concerning how host immunity affects gut bacterial community. Here, we analyze the role of a dual oxidase gene (BdDuox) in regulating the intestinal bacterial community homeostasis of the oriental fruit fly Bactrocera dorsalis. The results showed that knockdown of BdDuox led to an increased bacterial load, and to a decrease in the relative abundance of Enterobacteriaceae and Leuconostocaceae bacterial symbionts in the gut. The resulting dysbiosis, in turn, stimulates an immune response by activating BdDuox and promoting reactive oxygen species (ROS) production that regulates the composition and structure of the gut bacterial community to normal status by repressing the overgrowth of minor pathobionts. Our results suggest that BdDuox plays a pivotal role in regulating the homeostasis of the gut bacterial community in B. dorsalis. PMID:26565723

  18. Prebiotic effects of almonds and almond skins on intestinal microbiota in healthy adult humans.

    PubMed

    Liu, Zhibin; Lin, Xiuchun; Huang, Guangwei; Zhang, Wen; Rao, Pingfan; Ni, Li

    2014-04-01

    Almonds and almond skins are rich in fiber and other components that have potential prebiotic properties. In this study we investigated the prebiotic effects of almond and almond skin intake in healthy humans. A total of 48 healthy adult volunteers consumed a daily dose of roasted almonds (56 g), almond skins (10 g), or commercial fructooligosaccharides (8 g) (as positive control) for 6 weeks. Fecal samples were collected at defined time points and analyzed for microbiota composition and selected indicators of microbial activity. Different strains of intestinal bacteria had varying degrees of growth sensitivity to almonds or almond skins. Significant increases in the populations of Bifidobacterium spp. and Lactobacillus spp. were observed in fecal samples as a consequence of almond or almond skin supplementation. However, the populations of Escherichia coli did not change significantly, while the growth of the pathogen Clostridum perfringens was significantly repressed. Modification of the intestinal microbiota composition induced changes in bacterial enzyme activities, specifically a significant increase in fecal β-galactosidase activity and decreases in fecal β-glucuronidase, nitroreductase and azoreductase activities. Our observations suggest that almond and almond skin ingestion may lead to an improvement in the intestinal microbiota profile and a modification of the intestinal bacterial activities, which would induce the promotion of health beneficial factors and the inhibition of harmful factors. Thus we believe that almonds and almond skins possess potential prebiotic properties. PMID:24315808

  19. Depth of Bacterial Invasion in Resected Intestinal Tissue Predicts Mortality in Surgical Necrotizing Enterocolitis

    PubMed Central

    Remon, Juan I.; Amin, Sachin C.; Mehendale, Sangeeta R.; Rao, Rakesh; Luciano, Angel A.; Garzon, Steven A.; Maheshwari, Akhil

    2015-01-01

    Objective Up to a third of all infants who develop necrotizing enterocolitis (NEC) require surgical resection of necrotic bowel. We hypothesized that the histopathological findings in surgically-resected bowel can predict the clinical outcome of these infants. Study design We reviewed the medical records and archived pathology specimens from all patients who underwent bowel resection/autopsy for NEC at a regional referral center over a 10-year period. Pathology specimens were graded for the depth and severity of necrosis, inflammation, bacteria invasion, and pneumatosis, and histopathological findings were correlated with clinical outcomes. Results We performed clinico-pathological analysis on 33 infants with confirmed NEC, of which 18 (54.5%) died. Depth of bacterial invasion in resected intestinal tissue predicted death from NEC (odds ratio 5.39 per unit change in the depth of bacterial invasion, 95% confidence interval 1.33-21.73). The presence of transmural necrosis and bacteria in the surgical margins of resected bowel was also associated with increased mortality. Conclusions Depth of bacterial invasion in resected intestinal tissue predicts mortality in surgical NEC. PMID:25950918

  20. Hydrogen sulphide in exhaled breath: a potential biomarker for small intestinal bacterial overgrowth in IBS.

    PubMed

    Banik, Gourab Dutta; De, Anulekha; Som, Suman; Jana, Subhra; Daschakraborty, Sunil B; Chaudhuri, Sujit; Pradhan, Manik

    2016-01-01

    There is a pressing need to develop a novel early-detection strategy for the precise evolution of small intestinal bacterial overgrowth (SIBO) in irritable bowel syndrome (IBS) patients. The current method based on a hydrogen breath test (HBT) for the detection of SIBO is highly controversial. HBT has many limitations and drawbacks. It often fails to indentify SIBO when IBS individuals have 'non-hydrogen-producing' colonic bacteria. Here, we show that hydrogen sulphide (H2S) in exhaled breath is distinctly altered for diarrhea-predominant IBS individuals with positive and negative SIBO by the activity of intestinal sulphate-reducing bacteria. Subsequently, by analyzing the excretion kinetics of breath H2S, we found a missing link between breath H2S and SIBO when HBT often fails to diagnose SIBO. Moreover, breath H2S can track the precise evolution of SIBO, even after the eradication of bacterial overgrowth. Our findings suggest that the changes in H2S in the bacterial environment may contribute to the pathogenesis of SIBO and the breath H2S as a potential biomarker for non-invasive, rapid and precise assessment of SIBO without the endoscopy-based microbial culture of jejunal aspirates, and thus may open new perspectives into the pathophysiology of SIBO in IBS subjects. PMID:27163246

  1. In silico vs. in vivo human intestinal permeability.

    PubMed

    Idkaidek, N M; Najib, N

    2014-12-01

    The aim of this research is to calculate human intestinal permeability in silico and correlate results with those measured in vivo. Optimized human intestinal permeability values were calculated for 16 drugs by de-convolution of human plasma profiles using Parameter Estimation module of SimCYP program V13. Results showed high in silico-in vivo correlation coefficient of 0.89 for drugs with high/low permeability values. In silico permeability, if properly optimized, can be used as surrogate for in vivo permeability for BCS class I drugs and hence is suggested that such methodology could be employed as a support for waiver of in vivo studies. PMID:24515934

  2. Human intestinal sarcosporidiosis: report of six cases.

    PubMed

    Bunyaratvej, S; Bunyawongwiroj, P; Nitiyanant, P

    1982-01-01

    Specimens of resected small intestine from six patients aged 3 to 70 years with acute enteritis contained sexual forms of sarcosporidia. Histopathologically, the diagnoses were either segmental eosinophilic enteritis or segmental necrotizing enteritis. The presence of sarcosporidia in market beef (Bos indicus), and the patients' habit of eating the beef uncooked in the form of chili-hot dishes, suggest that the species is an ox-man parasite similar to Sarcocystis hominis (Railliet and Lucet, 1891) Dubey, 1976. Presence of numerous Gram-positive bacilli in segmental necrotizing enteritis suggests an interplay between two etiological agents in producing the hosts' inflammatory responses. Five patients recovered after resection, but one died due to extensive necrosis of the intestinal wall and leakage at the site of anastomosis. Only conventional antibiotics were given after the operations. None of the five surviving patients has had recurrent enteritis for at least 1 year. PMID:6800273

  3. Understanding drug resistance in human intestinal protozoa.

    PubMed

    El-Taweel, Hend Aly

    2015-05-01

    Infections with intestinal protozoa continue to be a major health problem in many areas of the world. The widespread use of a limited number of therapeutic agents for their management and control raises concerns about development of drug resistance. Generally, the use of any antimicrobial agent should be accompanied by meticulous monitoring of its efficacy and measures to minimize resistance formation. Evidence for the occurrence of drug resistance in different intestinal protozoa comes from case studies and clinical trials, sometimes with a limited number of patients. Large-scale field-based assessment of drug resistance and drug sensitivity testing of clinical isolates are needed. Furthermore, the association of drug resistance with certain geographic isolates or genotypes deserves consideration. Drug resistance has been triggered in vitro and has been linked to modification of pyruvate:ferredoxin oxidoreductase, nitroreductases, antioxidant defense, or cytoskeletal system. Further mechanistic studies will have important implications in the development of second generation therapeutic agents. PMID:25782683

  4. Role of small intestinal bacterial overgrowth in severe small intestinal damage in chronic non-steroidal anti-inflammatory drug users.

    PubMed

    Muraki, Motoko; Fujiwara, Yasuhiro; Machida, Hirohisa; Okazaki, Hirotoshi; Sogawa, Mitsue; Yamagami, Hirokazu; Tanigawa, Tetsuya; Shiba, Masatsugu; Watanabe, Kenji; Tominaga, Kazunari; Watanabe, Toshio; Arakawa, Tetsuo

    2014-03-01

    OBJECTIVE. Enteric bacteria play a significant role in the pathogenesis of non-steroidal anti-inflammatory drug (NSAID)-induced small intestinal damage. However, the association between small intestinal bacterial overgrowth (SIBO) and NSAID-induced small intestinal damage remains unclear. The aim of the study was to examine the association between SIBO and the presence of NSAID-induced severe small intestinal damage or its symptoms in chronic NSAID users. MATERIALS AND METHODS. Forty-three patients who had been using NSAIDs for over 3 months were enrolled. They were examined by capsule endoscopy and a lactulose hydrogen breath test (LHBT). We defined severe small intestinal damage as the presence of more than four small erosions or large erosions/ulcers. The LHBT result was considered positive if there was an increase in the level of breath hydrogen gas of >20 ppm above baseline. RESULTS. Out of 43 patients, 22 (51%) had severe small intestinal damage. The LHBT was positive in 5 of 21 patients (24%) without severe small intestinal damage and in 13 of 21 patients (59%) with severe small intestinal damage. Multiple logistic regression analysis showed that an LHBT-positive result was significantly associated with increased odds ratio for severe small intestinal damage (OR, 6.54; 95% CI, 1.40-30.50). There was no significant difference in the presence of symptoms between the LHBT-positive and LHBT-negative patients with severe small intestinal damage. CONCLUSION. SIBO might have a role in the development of severe small intestinal damage in chronic NSAID users. PMID:24417613

  5. Intestine.

    PubMed

    Smith, J M; Skeans, M A; Horslen, S P; Edwards, E B; Harper, A M; Snyder, J J; Israni, A K; Kasiske, B L

    2016-01-01

    Intestine and intestine-liver transplant plays an important role in the treatment of intestinal failure, despite decreased morbidity associated with parenteral nutrition. In 2014, 210 new patients were added to the intestine transplant waiting list. Among prevalent patients on the list at the end of 2014, 65% were waiting for an intestine transplant and 35% were waiting for an intestine-liver transplant. The pretransplant mortality rate decreased dramatically over time for all age groups. Pretransplant mortality was highest for adult candidates, at 22.1 per 100 waitlist years compared with less than 3 per 100 waitlist years for pediatric candidates, and notably higher for candidates for intestine-liver transplant than for candidates for intestine transplant without a liver. Numbers of intestine transplants without a liver increased from a low of 51 in 2013 to 67 in 2014. Intestine-liver transplants increased from a low of 44 in 2012 to 72 in 2014. Short-gut syndrome (congenital and other) was the main cause of disease leading to both intestine and intestine-liver transplant. Graft survival improved over the past decade. Patient survival was lowest for adult intestine-liver recipients and highest for pediatric intestine recipients. PMID:26755265

  6. Increased Bacterial Translocation in Gluten-Sensitive Mice Is Independent of Small Intestinal Paracellular Permeability Defect

    PubMed Central

    Jury, Jennifer; Sanz, Yolanda; Wiepjes, Michelle; Huang, Xianxi; Murray, Joseph A.; David, Chella S.; Fasano, Alessio; Verd, Elena F.

    2012-01-01

    Aim We investigated whether treatment with gliadin induces a paracellular permeability defect that enhances bacterial translocation to mesenteric lymph nodes (MLN) via resident dendritic cells (DC) expressing TLR-2 or 4 in HCD4/HLA-DQ8 transgenic mice. Methods HLA-DQ8 transgenic mice were sensitized and subsequently gavaged with gliadin, in the presence or absence of AT1001 (paracellular permeability inhibitor). Non-sensitized mice were gavaged with indomethacin (permeability inducer) or rice cereal. CD11c and CD103 (DC markers) and TLR-2 and 4 were investigated by immunostaining. Intestinal permeability was assessed by paracellular flux of 51Cr-EDTA in Ussing chambers. Bacterial translocation to MLN was performed by plate counting on aerobic and anaerobic conditions. Results In gliadin-treated mice, both 51Cr-EDTA flux in jejunal mucosa and aerobic and anaerobic bacterial counts in MLN were increased (p < 0.05) compared to indomethacin-treated mice and controls. The inhibitor AT1001 normalized 51Cr-EDTA flux, but had no effect on bacterial translocation in gliadin-treated mice. In addition, changes in mucosal DC marker distribution such as increased (p < 0.05) trans-epithelial CD103+ cells and reduction (p < 0.05) of CD11c immunostaining were detected in gliadin-treated mice. Moreover, changes in DC markers and TLR-2 or 4 immunophenotypes were not associated. Conclusions Pharmacological restoration of paracellular permeability was not sufficient to prevent bacterial translocation in gluten-sensitive mice. We hypothesize that transcellular mechanisms involving CD103+DC and CD11c+DC may explain in gluten-sensitive HCD4/HLA-DQ8 transgenic mice the sustained increased bacterial translocation observed in the absence of a significant inflammatory response. PMID:21822909

  7. In vitro alterations of intestinal bacterial microbiota in fecal samples during storage.

    PubMed

    Ott, Stephan J; Musfeldt, Meike; Timmis, Kenneth N; Hampe, Jochen; Wenderoth, Dirk F; Schreiber, Stefan

    2004-12-01

    The human gastrointestinal tract harbors an extremely diverse and complex microbial ecosystem. Most of the existent data about the enteric microflora have been generated using stool samples, but the collection and storage of fecal samples are often problematic. The influence of the storage of stool samples on the bacterial diversity and the degradation of bacterial DNA was analysed in this study. Stool samples from 5 healthy volunteers were exposed to different storage temperatures and durations. The bacterial diversity and the amount of intact bacterial DNA were analysed by single-stranded conformation polymorphism analysis (SSCP) and real-time polymerase chain reaction (PCR), both using a 16S rDNA approach. Additionally, biopsy specimens were taken from 3 of the 5 individuals to compare fecal and mucosal flora. The bacterial diversity of the fecal flora and the total number of bacteria were significantly reduced after 8 and 24 hours at both room temperature and 4 degrees C. The mucosa-associated bacterial microflora showed substantial differences compared with the fecal flora. The observed alterations of fecal flora during storage point to the difficulty of the molecular analysis of the bacterial diversity and the enumeration of bacterial cells in fecal samples. PMID:15582296

  8. Large intestine bacterial flora of nonhibernating and hibernating leopard frogs (Rana pipiens).

    PubMed Central

    Gossling, J; Loesche, W J; Nace, G W

    1982-01-01

    The bacteria in the large intestines of 10 northern leopard frogs (Rana pipiens) were enumerated and partially characterized. Four nonhibernating frogs were collected in the summer, four hibernating frogs were collected in the winter, and two frogs just emerged from hibernation were collected in the spring. All frogs had about 10(10) bacteria per g (wet weight) of intestinal contents and about 10(9) bacteria per g (wet weight) of mucosal scraping, although the counts from the winter frogs were slightly less than those from the other two groups of frogs. Another group of 14 summer frogs, after treatment to induce hibernation, showed a drop in bacterial counts accompanied by a change in the composition of the flora. In most frogs, Bacteroides was the dominant organism. Other bacteria repeatedly isolated at high dilutions were strict anaerobes, including butyrigenic and acetogenic helically coiled bacteria; fusobacteria; and acetogenic, small, gram-positive bacilli. These data indicate that the intestinal flora of frogs is similar to that of mammals and birds and that this flora can be maintained at temperatures close to freezing. PMID:6982025

  9. How to Test and Treat Small Intestinal Bacterial Overgrowth: an Evidence-Based Approach.

    PubMed

    Rezaie, Ali; Pimentel, Mark; Rao, Satish S

    2016-02-01

    Small intestinal bacterial overgrowth (SIBO) is characterized by an excessive amount of bacteria in the small intestine and a constellation of symptoms that include bloating, pain, gas, and diarrhea. Although known for many decades, there is a lack of consensus and clarity regarding the natural history and methods for its diagnosis. Several tests have been proposed, including the glucose breath test, lactulose breath test, small intestinal aspiration and culture, and others. However, there is a lack of standardization of these tests and their interpretation. Treatment of SIBO remains empirical; generally, broad spectrum antibiotics are recommended for 2 weeks (amoxicillin, rifaximin, ciprofloxacin, etc.) but evidence for their use is fair. Clearly, there is a strong need to develop a systematic approach for the management of SIBO and to perform multicenter clinical trials for the treatment of SIBO. In this review, we will discuss the current evidence for the diagnosis and treatment of SIBO, which includes (1) elimination/modification of the underlying causes, (2) induction of remission (antibiotics and elemental diet), and (3) maintenance of remission (promotility drugs, dietary modifications, repeat or cyclical antibiotics). PMID:26780631

  10. Intestinal-fatty acid binding protein and lipid transport in human intestinal epithelial cells

    SciTech Connect

    Montoudis, Alain; Delvin, Edgard; Menard, Daniel

    2006-01-06

    Intestinal-fatty acid binding protein (I-FABP) is a 14-15 kDa cytoplasmic molecule highly expressed in the enterocyte. Although different functions have been proposed for various FABP family members, the specific function of I-FABP in human intestine remains unclear. Here, we studied the role of I-FABP in molecularly modified normal human intestinal epithelial cells (HIEC-6). cDNA transfection resulted in 90-fold I-FABP overexpression compared to cells treated with empty pQCXIP vector. The high-resolution immunogold technique revealed labeling mainly in the cytosol and confirmed the marked phenotype abundance of I-FABP in cDNA transfected cells. I-FABP overexpression was not associated with alterations in cell proliferation and viability. Studies using these transfected cells cultured with [{sup 14}C]oleic acid did not reveal higher efficiency in de novo synthesis or secretion of triglycerides, phospholipids, and cholesteryl esters compared to cells treated with empty pQCXIP vector only. Similarly, the incubation with [{sup 35}S]methionine did not disclose a superiority in the biogenesis of apolipoproteins (apo) A-I, A-IV, B-48, and B-100. Finally, cells transfected with I-FABP did not exhibit an increased production of chylomicrons, VLDL, LDL, and HDL. Our observations establish that I-FABP overexpression in normal HIEC-6 is not related to cell proliferation, lipid esterification, apo synthesis, and lipoprotein assembly, and, therefore, exclude its role in intestinal fat transport.

  11. Host-Microbe Interactions in the Neonatal Intestine: Role of Human Milk Oligosaccharides123

    PubMed Central

    Donovan, Sharon M.; Wang, Mei; Li, Min; Friedberg, Iddo; Schwartz, Scott L.; Chapkin, Robert S.

    2012-01-01

    The infant intestinal microbiota is shaped by genetics and environment, including the route of delivery and early dietary intake. Data from germ-free rodents and piglets support a critical role for the microbiota in regulating gastrointestinal and immune development. Human milk oligosaccharides (HMO) both directly and indirectly influence intestinal development by regulating cell proliferation, acting as prebiotics for beneficial bacteria and modulating immune development. We have shown that the gut microbiota, the microbial metatranscriptome, and metabolome differ between porcine milk–fed and formula-fed (FF) piglets. Our goal is to define how early nutrition, specifically HMO, shapes host-microbe interactions in breast-fed (BF) and FF human infants. We an established noninvasive method that uses stool samples containing intact sloughed epithelial cells to quantify intestinal gene expression profiles in human infants. We hypothesized that a systems biology approach, combining i) HMO composition of the mother’s milk with the infant’s gut gene expression and fecal bacterial composition, ii) gene expression, and iii short-chain fatty acid profiles would identify important mechanistic pathways affecting intestinal development of BF and FF infants in the first few months of life. HMO composition was analyzed by HLPC Chip/time-of-flight MS and 3 HMO clusters were identified using principle component analysis. Initial findings indicated that both host epithelial cell mRNA expression and the microbial phylogenetic profiles provided strong feature sets that distinctly classified the BF and FF infants. Ongoing analyses are designed to integrate the host transcriptome, bacterial phylogenetic profiles, and functional metagenomic data using multivariate statistical analyses. PMID:22585924

  12. Biotransformation of luteoloside by a newly isolated human intestinal bacterium using UHPLC-Q-TOF/MS.

    PubMed

    Tao, Jin-hua; Wang, Dong-geng; Yang, Chi; Huang, Jin-hua; Qiu, Wen-qian; Zhao, Xi

    2015-06-01

    To explore the metabolic pathways and metabolites of luteoloside yielded by the isolated human intestinal bacteria from healthy human feces and characterize the β-d-glucosidase activity of the specific strain which catalyzed the breakdown of luteoloside, a preculture bacterial GAM broth and luteoloside were mixed incubated together for 48h. UHPLC-Q-TOF/MS was used for analysis of the metabolites of luteoloside in the corresponding supernatant fractions from fermentation. Aliquots of the reactive solutions were collected at different times and were measured with a microplate reader at 405nm to evaluate the enzymatic activity. Three metabolites (acetylated luteoloside, luteolin and deoxygenated luteolin) were detected in the fractions isolated from the bacterial samples. The variation of β-d-glucosidase activity inside the bacterium was in coincidence with the changes in luteolin generation or luteoloside degradation in different time periods. PMID:25899973

  13. Bacterial protein toxins in human cancers.

    PubMed

    Rosadi, Francesca; Fiorentini, Carla; Fabbri, Alessia

    2016-02-01

    Many bacteria causing persistent infections produce toxins whose mechanisms of action indicate that they could have a role in carcinogenesis. Some toxins, like CDT and colibactin, directly attack the genome by damaging DNA whereas others, as for example CNF1, CagA and BFT, impinge on key eukaryotic processes, such as cellular signalling and cell death. These bacterial toxins, together with other less known toxins, mimic carcinogens and tumour promoters. The aim of this review is to fulfil an up-to-date analysis of toxins with carcinogenic potential that have been already correlated to human cancers. Bacterial toxins-induced carcinogenesis represents an emerging aspect in bacteriology, and its significance is increasingly recognized. PMID:26534910

  14. Colonic bacterial metabolites and human health.

    PubMed

    Russell, Wendy R; Hoyles, Lesley; Flint, Harry J; Dumas, Marc-Emmanuel

    2013-06-01

    The influence of the microbial-mammalian metabolic axis is becoming increasingly important for human health. Bacterial fermentation of carbohydrates (CHOs) and proteins produces short-chain fatty acids (SCFA) and a range of other metabolites including those from aromatic amino acid (AAA) fermentation. SCFA influence host health as energy sources and via multiple signalling mechanisms. Bacterial transformation of fibre-related phytochemicals is associated with a reduced incidence of several chronic diseases. The 'gut-liver axis' is an emerging area of study. Microbial deconjugation of xenobiotics and release of aromatic moieties into the colon can have a wide range of physiological consequences. In addition, the role of the gut microbiota in choline deficiency in non-alcoholic fatty liver disease (NAFLD) and insulin resistance is receiving increased attention. PMID:23880135

  15. Small intestinal mucosal cell proliferation and bacterial flora in the conventionalization of the germfree mouse.

    PubMed

    Khoury, K A; Floch, M H; Hersh, T

    1969-09-01

    The relationship between intestinal colonization and the small bowel mucosal cellular proliferation rate during conventionalization of the germfree mouse was examined. 16 mice were maintained under standard germfree conditions, and 54 others were conventionalized. Migration of the small bowel epithelial cells was followed by radioautography with administration of tritiated thymidine. Colonization was followed by qualitative and quantitative bacteriological fecal analyses. The percentages of the villi labeled (as determined by cell count) 24, 48, and 72 hr following thymidine administration showed immediate progression in the conventionalized animals from the germfree villus migration time (4 days) toward the conventional villus migration time (2 days). The epithelial migration rate of animals conventionalized for 8 days was comparable to that of conventional animals. After conventionalization, aerobic and anaerobic organisms undergo a period of extensive multiplication; however, 72 hr later the number of these microorganisms cultured in the stool decrease and are similar to those recovered from normal animals. Coliforms and streptococci are recovered in large numbers only in the first days after conventionalization, while the Bacteroides are first recovered in significant numbers on the fifth day of conventionalization. Except for smaller numbers of Bacteroides, the bacterial populations in the stools of the conventionalized animals are qualitatively and quantitatively similar by the eighth day of conventionalization to those of true conventional mice. Adaptive balance between cell proliferation and sloughing, and thus migration rate, begins immediately after conventionalization of germfree animals as bacterial populations establish themselves throughout the gastrointestinal tract, and results in a doubling of the mucosal cell turnover after 8 days. At this time both the small intestinal epithelial cell migration rate and the intestinal microflora are similar to those of conventional animals. PMID:4896909

  16. Impact of enrofloxacin on the human intestinal microbiota revealed by comparative molecular analysis.

    PubMed

    Kim, Bong-Soo; Kim, Jong Nam; Yoon, Seok-Hwan; Chun, Jongsik; Cerniglia, Carl E

    2012-06-01

    The indigenous human intestinal microbiota could be disrupted by residues of antibiotics in foods as well as therapeutically administered antibiotics to humans. These disruptions may lead to adverse health outcomes. To observe the possible impact of residues of antibiotics at concentrations below therapeutic levels on human intestinal microbiota, we performed studies using in vitro cultures of fecal suspensions from three individuals with 10 different concentrations (0, 0.1, 0.5, 1, 5, 10, 15, 25, 50 and 150 μg/ml) of the fluoroquinolone, enrofloxacin. The bacterial communities of the control and enrofloxacin dosed fecal samples were analyzed by denaturing gradient gel electrophoresis (DGGE) and pyrosequencing. In addition, changes of functional gene expression were analyzed by a pyrosequencing-based random whole-community mRNA sequencing method. Although each individual had a unique microbial composition, the communities of all individuals were affected by enrofloxacin. The proportions of two phyla, namely, Bacteroidetes and Proteobacteria, were significantly reduced with increasing concentrations of enrofloxacin exposure, while the proportion of Firmicutes increased. Principal Coordinate Analysis (PCoA) using the Fast UniFrac indicated that the community structures of intestinal microbiota were shifted by enrofloxacin. Most of the mRNA transcripts and the anti-microbial drug resistance genes increased with increasing concentrations of enrofloxacin. 16S rRNA gene pyrosequencing of control and enrofloxacin treated fecal suspensions provided valuable information of affected bacterial taxa down to the species level, and the community transcriptomic analyses using mRNA revealed the functional gene expression responses of the changed bacterial communities by enrofloxacin. PMID:22321759

  17. Intestinal fluid and electrolyte transport in human cholera

    PubMed Central

    Banwell, John G.; Pierce, Nathaniel F.; Mitra, Rupak C.; Brigham, Kenneth L.; Caranasos, George J.; Keimowitz, Robert I.; Fedson, David S.; Thomas, Jacob; Gorbach, Sherwood L.; Sack, R. Bradley; Mondal, Arabindo

    1970-01-01

    The site, nature, magnitude, and duration of fluid and electrolyte loss into the small intestine during the acute and recovery phase of human cholera was defined in 27 Indian patients. 11 subjects without cholera served as controls. The marker perfusion technique employed was shown, in preliminary experiments, to measure accurately jejunal and ileal fluid and electrolyte transmucosal transport rates under conditions of cholera diarrhea. Fluid loss into the lumen occurred from jejunal and ileal mucosa. The fluid was isotonic in both regions. Bicarbonate concentration was significantly higher in ileal than jejunal fluid during all phases of the disease. Bicarbonate concentration in both regions was significantly higher in acute cholera than during convalescence. Fluid loss into the intestinal lumen ranged from 0.07 to 10.9 ml/hr per cm. Losses were significantly greater from jejunum than ileum. Net ileal absorption was recorded in five of 10 acute cholera studies. During the acute phase of the disease, net jejunal fluid transport showed a positive correlation with fasting intestinal flow rate and stool output. Stool output was also positively correlated with jejunal fasting intestinal flow rates. Recovery of normal fluid and electrolyte absorptive function was usually complete in both jejunum and ileum by the sixth day after admission. These findings in human cholera validate the animal models of choleraic diarrhea and suggest that similar measurements of small intestinal secretory function in other nonspecific diarrheal diseases using the marker perfusion technique may be rewarding. PMID:5409804

  18. Dendritic cells transmit HIV-1 through human small intestinal mucosa

    PubMed Central

    Shen, Ruizhong; Smythies, Lesley E.; Clements, Ronald H.; Novak, Lea; Smith, Phillip D.

    2010-01-01

    To dissect the early events in the transmission of HIV-1 from mother to child, we investigated whether DCs participate in HIV-1 entry into human small intestinal mucosa. We isolated human MNLs from jejunal lamina propria and identified a subpopulation of CD11c+HLA-DR+ MNLs that expressed DC-SIGN, CD83, CD86, CD206, and CCR7, indicating a DC phenotype. Jejunal DCs also expressed the HIV-1 receptor CD4 and coreceptors CCR5 and CXCR4 and in suspension rapidly took up cell-free HIV-1. HIV-1 inoculated onto the apical surface of explanted jejunum was transported by lamina propria DCs through the mucosa and transmitted in trans to blood and intestinal lymphocytes. These findings indicate that in addition to intestinal epithelial cells, which we showed previously transcytose infectious HIV-1 to indicator cells, intestinal DCs play an important role in transporting HIV-1 through the intestinal mucosa and the subsequent transmission to T cells. PMID:20007245

  19. Species-specific oligonucleotide probes for five Bifidobacterium species detected in human intestinal microflora.

    PubMed Central

    Yamamoto, T; Morotomi, M; Tanaka, R

    1992-01-01

    Portions of the 16S rRNA from closely related species of the genus Bifidobacterium that are found in the human intestinal microflora were sequenced in order to design species-specific oligonucleotide probes. Five oligonucleotide probes ranging from 16 to 19 bases in length and complementary to 16S rRNA sequences from Bifidobacterium adolescentis, B. bifidum, B. breve, B. infantis, and B. longum were synthesized. With crude high-molecular-weight RNA preparations as targets, these probes showed the desired species specificity, even down to a 1-nucleotide difference. For the practical evaluation of these probes, their specificity and sensitivity were tested against seven strains of the same species and 54 strains of heterologous bacteria with fixed whole cells as targets. The probes for B. adolescentis, B. breve, and B. longum showed efficient and specific hybridization. Although the probes for B. bifidum and B. infantis cross-reacted with a few bacterial strains not isolated from humans, these probes showed species specificity for human intestinal bacteria. These 16S rRNA probes should prove valuable for the identification and detection of human intestinal Bifidobacterium species. Images PMID:1282315

  20. Quantitation of small intestinal permeability during normal human drug absorption

    PubMed Central

    2013-01-01

    Background Understanding the quantitative relationship between a drug’s physical chemical properties and its rate of intestinal absorption (QSAR) is critical for selecting candidate drugs. Because of limited experimental human small intestinal permeability data, approximate surrogates such as the fraction absorbed or Caco-2 permeability are used, both of which have limitations. Methods Given the blood concentration following an oral and intravenous dose, the time course of intestinal absorption in humans was determined by deconvolution and related to the intestinal permeability by the use of a new 3 parameter model function (“Averaged Model” (AM)). The theoretical validity of this AM model was evaluated by comparing it to the standard diffusion-convection model (DC). This analysis was applied to 90 drugs using previously published data. Only drugs that were administered in oral solution form to fasting subjects were considered so that the rate of gastric emptying was approximately known. All the calculations are carried out using the freely available routine PKQuest Java (http://www.pkquest.com) which has an easy to use, simple interface. Results Theoretically, the AM permeability provides an accurate estimate of the intestinal DC permeability for solutes whose absorption ranges from 1% to 99%. The experimental human AM permeabilities determined by deconvolution are similar to those determined by direct human jejunal perfusion. The small intestinal pH varies with position and the results are interpreted in terms of the pH dependent octanol partition. The permeability versus partition relations are presented separately for the uncharged, basic, acidic and charged solutes. The small uncharged solutes caffeine, acetaminophen and antipyrine have very high permeabilities (about 20 x 10-4 cm/sec) corresponding to an unstirred layer of only 45 μm. The weak acid aspirin also has a large AM permeability despite its low octanol partition at pH 7.4, suggesting that it is nearly completely absorbed in the first part of the intestine where the pH is about 5.4. Conclusions The AM deconvolution method provides an accurate estimate of the human intestinal permeability. The results for these 90 drugs should provide a useful benchmark for evaluating QSAR models. PMID:23800230

  1. Comparative analysis of the intestinal bacterial and RNA viral communities from sentinel birds placed on selected broiler chicken farms.

    PubMed

    Day, J Michael; Oakley, Brian B; Seal, Bruce S; Zsak, Laszlo

    2015-01-01

    There is a great deal of interest in characterizing the complex microbial communities in the poultry gut, and in understanding the effects of these dynamic communities on poultry performance, disease status, animal welfare, and microbes with human health significance. Investigations characterizing the poultry enteric virome have identified novel poultry viruses, but the roles these viruses play in disease and performance problems have yet to be fully characterized. The complex bacterial community present in the poultry gut influences gut development, immune status, and animal health, each of which can be an indicator of overall performance. The present metagenomic investigation was undertaken to provide insight into the colonization of specific pathogen free chickens by enteric microorganisms under field conditions and to compare the pre-contact intestinal microbiome with the altered microbiome following contact with poultry raised in the field. Analysis of the intestinal virome from contact birds ("sentinels") placed on farms revealed colonization by members of the Picornaviridae, Picobirnaviridae, Reoviridae, and Astroviridae that were not present in pre-contact birds or present in proportionally lower numbers. Analysis of the sentinel gut bacterial community revealed an altered community in the post-contact birds, notably by members of the Lachnospiracea/Clostridium and Lactobacillus families and genera. Members of the avian enteric Reoviridae and Astroviridae have been well-characterized and have historically been implicated in poultry enteric disease; members of the Picobirnaviridae and Picornaviridae have only relatively recently been described in the poultry and avian gut, and their roles in the recognized disease syndromes and in poultry performance in general have not been determined. This metagenomic analysis has provided insight into the colonization of the poultry gut by enteric microbes circulating in commercial broiler flocks, and has identified enteric viruses and virus communities that warrant further study in order to understand their role(s) in avian gut health and disease. PMID:25635690

  2. Comparative Analysis of the Intestinal Bacterial and RNA Viral Communities from Sentinel Birds Placed on Selected Broiler Chicken Farms

    PubMed Central

    Day, J. Michael; Oakley, Brian B.; Seal, Bruce S.; Zsak, Laszlo

    2015-01-01

    There is a great deal of interest in characterizing the complex microbial communities in the poultry gut, and in understanding the effects of these dynamic communities on poultry performance, disease status, animal welfare, and microbes with human health significance. Investigations characterizing the poultry enteric virome have identified novel poultry viruses, but the roles these viruses play in disease and performance problems have yet to be fully characterized. The complex bacterial community present in the poultry gut influences gut development, immune status, and animal health, each of which can be an indicator of overall performance. The present metagenomic investigation was undertaken to provide insight into the colonization of specific pathogen free chickens by enteric microorganisms under field conditions and to compare the pre-contact intestinal microbiome with the altered microbiome following contact with poultry raised in the field. Analysis of the intestinal virome from contact birds (“sentinels”) placed on farms revealed colonization by members of the Picornaviridae, Picobirnaviridae, Reoviridae, and Astroviridae that were not present in pre-contact birds or present in proportionally lower numbers. Analysis of the sentinel gut bacterial community revealed an altered community in the post-contact birds, notably by members of the Lachnospiracea/Clostridium and Lactobacillus families and genera. Members of the avian enteric Reoviridae and Astroviridae have been well-characterized and have historically been implicated in poultry enteric disease; members of the Picobirnaviridae and Picornaviridae have only relatively recently been described in the poultry and avian gut, and their roles in the recognized disease syndromes and in poultry performance in general have not been determined. This metagenomic analysis has provided insight into the colonization of the poultry gut by enteric microbes circulating in commercial broiler flocks, and has identified enteric viruses and virus communities that warrant further study in order to understand their role(s) in avian gut health and disease. PMID:25635690

  3. Diet and the development of the human intestinal microbiome

    PubMed Central

    Voreades, Noah; Kozil, Anne; Weir, Tiffany L.

    2014-01-01

    The important role of the gut microbiome in maintaining human health has necessitated a better understanding of the temporal dynamics of intestinal microbial communities as well as the host and environmental factors driving these dynamics. Genetics, mode of birth, infant feeding patterns, antibiotic usage, sanitary living conditions and long term dietary habits contribute to shaping the composition of the gut microbiome. This review focuses primarily on diet, as it is one of the most pivotal factors in the development of the human gut microbiome from infancy to the elderly. The infant gut microbiota is characterized by a high degree of instability, only reaching a state similar to that of adults by 2–3 years of age; consistent with the establishment of a varied solid food diet. The diet-related factors influencing the development of the infant gut microbiome include whether the child is breast or formula-fed as well as how and when solid foods are introduced. In contrast to the infant gut, the adult gut microbiome is resilient to large shifts in community structure. Several studies have shown that dietary changes induce transient fluctuations in the adult microbiome, sometimes in as little as 24 h; however, the microbial community rapidly returns to its stable state. Current knowledge of how long-term dietary habits shape the gut microbiome is limited by the lack of long-term feeding studies coupled with temporal gut microbiota characterization. However, long-term weight loss studies have been shown to alter the ratio of the Bacteroidetes and Firmicutes, the two major bacterial phyla residing in the human gastrointestinal tract. With aging, diet-related factors such as malnutrition are associated with microbiome shifts, although the cause and effect relationship between these factors has not been established. Increased pharmaceutical usage is also more prevalent in the elderly and can contribute to reduced gut microbiota stability and diversity. Foods containing prebiotic oligosaccharide components that nurture beneficial commensals in the gut community and probiotic supplements are being explored as interventions to manipulate the gut microbiome, potentially improving health status. PMID:25295033

  4. Diet and the development of the human intestinal microbiome.

    PubMed

    Voreades, Noah; Kozil, Anne; Weir, Tiffany L

    2014-01-01

    The important role of the gut microbiome in maintaining human health has necessitated a better understanding of the temporal dynamics of intestinal microbial communities as well as the host and environmental factors driving these dynamics. Genetics, mode of birth, infant feeding patterns, antibiotic usage, sanitary living conditions and long term dietary habits contribute to shaping the composition of the gut microbiome. This review focuses primarily on diet, as it is one of the most pivotal factors in the development of the human gut microbiome from infancy to the elderly. The infant gut microbiota is characterized by a high degree of instability, only reaching a state similar to that of adults by 2-3 years of age; consistent with the establishment of a varied solid food diet. The diet-related factors influencing the development of the infant gut microbiome include whether the child is breast or formula-fed as well as how and when solid foods are introduced. In contrast to the infant gut, the adult gut microbiome is resilient to large shifts in community structure. Several studies have shown that dietary changes induce transient fluctuations in the adult microbiome, sometimes in as little as 24 h; however, the microbial community rapidly returns to its stable state. Current knowledge of how long-term dietary habits shape the gut microbiome is limited by the lack of long-term feeding studies coupled with temporal gut microbiota characterization. However, long-term weight loss studies have been shown to alter the ratio of the Bacteroidetes and Firmicutes, the two major bacterial phyla residing in the human gastrointestinal tract. With aging, diet-related factors such as malnutrition are associated with microbiome shifts, although the cause and effect relationship between these factors has not been established. Increased pharmaceutical usage is also more prevalent in the elderly and can contribute to reduced gut microbiota stability and diversity. Foods containing prebiotic oligosaccharide components that nurture beneficial commensals in the gut community and probiotic supplements are being explored as interventions to manipulate the gut microbiome, potentially improving health status. PMID:25295033

  5. Human Ghrelin Mitigates Intestinal Injury and Mortality after Whole Body Irradiation in Rats

    PubMed Central

    Wang, Zhimin; Yang, Weng Lang; Jacob, Asha; Aziz, Monowar; Wang, Ping

    2015-01-01

    Widespread use of ionizing radiation has led to the realization of the danger associated with radiation exposure. Although studies in radiation countermeasures were initiated a half century ago, an effective therapy for a radiomitigator has not been identified. Ghrelin is a gastrointestinal hormone, and administration of ghrelin is protective in animal models of injuries including radiation combined injury. To test whether ghrelin can be protective in whole body irradiaton (WBI) alone, male Sprague Dawley (SD) rats were treated with human ghrelin (20 nmol/rat) daily for 6 days starting at either 24 h or 48 h after 10 Gray (Gy) WBI and survival outcome was examined. The 10 Gy WBI produced a LD70/30 model in SD rats (30% survival in 30 days). The survival rate in rats treated with ghrelin starting at 24 h was significantly improved to 63% and when treatment was initiated at 48 h, the survival remained at 61%. At 7 days post WBI, plasma ghrelin was significantly reduced from the control value. Ghrelin treatment starting at 24 h after WBI daily for 6 days improved histological appearance of the intestine, reduced gut permeability, serum endotoxin levels and bacterial translocation to the liver by 38%, 42% and 61%, respectively at day 7 post WBI. Serum glucose and albumin were restored to near control levels with treatment. Ghrelin treatment also attenuated WBI-induced intestinal apoptosis by 62% as evidenced by TUNEL staining. The expression of anti-apoptotic cell regulator Bcl-xl was decreased by 38% in the vehicle and restored to 75% of the control with ghrelin treatment. Increased expression of intestinal CD73 and pAkt were observed with ghrelin treatment, indicating protection of the intestinal epithelium after WBI. These results indicate that human ghrelin attenuates intestinal injury and mortality after WBI. Thus, human ghrelin can be developed as a novel mitigator for radiation injury. PMID:25671547

  6. Bacterial biogeography of the human digestive tract

    PubMed Central

    Stearns, Jennifer C.; Lynch, Michael D. J.; Senadheera, Dilani B.; Tenenbaum, Howard C.; Goldberg, Michael B.; Cvitkovitch, Dennis G.; Croitoru, Kenneth; Moreno-Hagelsieb, Gabriel; Neufeld, Josh D.

    2011-01-01

    We present bacterial biogeography as sampled from the human gastrointestinal tract of four healthy subjects. This study generated >32 million paired-end sequences of bacterial 16S rRNA genes (V3 region) representing >95,000 unique operational taxonomic units (OTUs; 97% similarity clusters), with >99% Good's coverage for all samples. The highest OTU richness and phylogenetic diversity was found in the mouth samples. The microbial communities of multiple biopsy sites within the colon were highly similar within individuals and largely distinct from those in stool. Within an individual, OTU overlap among broad site definitions (mouth, stomach/duodenum, colon and stool) ranged from 32–110 OTUs, 25 of which were common to all individuals and included OTUs affiliated with Faecalibacterium prasnitzii and the TM7 phylum. This first comprehensive characterization of the abundant and rare microflora found along the healthy human digestive tract represents essential groundwork to investigate further how the human microbiome relates to health and disease. PMID:22355685

  7. Propolis reduces bacterial translocation and intestinal villus atrophy in experimental obstructive jaundice

    PubMed Central

    Sabuncuoglu, Mehmet Zafer; Kismet, Kemal; Kilicoglu, Sibel Serin; Kilicoglu, Bulent; Erel, Serap; Muratoglu, Sabahattin; Sunay, Asli Elif; Erdemli, Esra; Akkus, Mehmet Ali

    2007-01-01

    AIM: To investigate the effects of propolis on bacterial translocation and ultrastructure of intestinal morphology in experimental obstructive jaundice. METHODS: Thirty Wistar-Albino male rats were randomly divided into three groups, each including 10 animals: groupI, sham-operated; group II, ligation and division of the common bile duct (BDL); group III, BDL followed by oral supplementation of propolis 100 mg/kg per day. Liver, blood, spleen, mesenteric lymph nodes, and ileal samples were taken for microbiological, light and transmission electron microscopic examination on postoperative 7th d after sacrification. RESULTS: The mean number of villi per centimeter and mean mucosal height of the propolis group were significantly different in the BDL group (P = 0.001 and 0.012, respectively). The electron microscopic changes were also different between these groups. Sham and BDL + propolis groups had similar incidence of bacterial translocation (BT). The BDL group had significantly higher rates of BT as compared with sham and BDL + propolis groups. BT was predominantly detected in MLNs and the most commonly isolated bacteria was Escherichia coli. CONCLUSION: Propolis showed a significant protective effect on ileal mucosa and reduced bacterial translocation in the experimental obstructive jaundice model. Further studies should be carried out to explain the mechanisms of these effects. PMID:17876893

  8. Role of Ankaferd on bacterial translocation and inflammatory response in an experimental rat model of intestinal obstruction

    PubMed Central

    Şen, Velat; Uluca, Ünal; Ece, Aydın; Güneş, Ali; Zeytun, Hikmet; Arslan, Serkan; Kaplan, İbrahim; Türkçü, Gül; Tekin, Recep

    2014-01-01

    Intestinal obstruction (IO) is an important risk factor for the development of bacteria translocation (BT), a serious condition associated with sepsis and potential mortality. Ankaferd is an herbal extract that is reported to exert anti-hemorrhagic, anti-oxidant, anti-microbial, and anti-inflammatory, effects in the intestine. In this study, we employed an animal model of intestinal obstruction to evaluate the effects of Ankaferd in the prevention of bacterial translocation and the suppression of the inflammatory response. Thirty male Wistar Albino rats were allocated randomly to three groups: Group 1 (sham) underwent ileal manipulation alone; Group 2 (intestinal obstruction, IO) underwent complete ileal ligation; Group 3 (intestinal obstruction + Ankaferd blood stopper, ABS) underwent complete ileal ligation and intraperitoneal Ankaferd injection. All rats were euthanized after 24 hours. Blood samples were collected for the measurement of serum oxidative stress parameters and cytokine expression. In addition, liver, mesenteric lymph node (MLN), spleen, and ileal specimens were obtained for microbiological culture to determine the rate of bacterial translocation. Liver and ileal tissues were collected for histopathological examination. A reduction in oxidative damage, inflammatory cytokine expression and bacterial translocation was observed in the ABS treatment group relative to the IO group (p<0.05). Furthermore, histopathological examination demonstrated a reduction in obstruction-induced mucosal injury in Ankaferd-treated rats. Data derived from this study provided the first evidence that Ankaferd treatment limits bacterial translocation and enhances intestinal barrier function in mice undergoing intestinal obstruction. Ankaferd may be useful in the prevention of BT associated with IO. PMID:25356125

  9. Role of Ankaferd on bacterial translocation and inflammatory response in an experimental rat model of intestinal obstruction.

    PubMed

    Sen, Velat; Uluca, Unal; Ece, Aydın; Güneş, Ali; Zeytun, Hikmet; Arslan, Serkan; Kaplan, Ibrahim; Türkçü, Gül; Tekin, Recep

    2014-01-01

    Intestinal obstruction (IO) is an important risk factor for the development of bacteria translocation (BT), a serious condition associated with sepsis and potential mortality. Ankaferd is an herbal extract that is reported to exert anti-hemorrhagic, anti-oxidant, anti-microbial, and anti-inflammatory, effects in the intestine. In this study, we employed an animal model of intestinal obstruction to evaluate the effects of Ankaferd in the prevention of bacterial translocation and the suppression of the inflammatory response. Thirty male Wistar Albino rats were allocated randomly to three groups: Group 1 (sham) underwent ileal manipulation alone; Group 2 (intestinal obstruction, IO) underwent complete ileal ligation; Group 3 (intestinal obstruction + Ankaferd blood stopper, ABS) underwent complete ileal ligation and intraperitoneal Ankaferd injection. All rats were euthanized after 24 hours. Blood samples were collected for the measurement of serum oxidative stress parameters and cytokine expression. In addition, liver, mesenteric lymph node (MLN), spleen, and ileal specimens were obtained for microbiological culture to determine the rate of bacterial translocation. Liver and ileal tissues were collected for histopathological examination. A reduction in oxidative damage, inflammatory cytokine expression and bacterial translocation was observed in the ABS treatment group relative to the IO group (p<0.05). Furthermore, histopathological examination demonstrated a reduction in obstruction-induced mucosal injury in Ankaferd-treated rats. Data derived from this study provided the first evidence that Ankaferd treatment limits bacterial translocation and enhances intestinal barrier function in mice undergoing intestinal obstruction. Ankaferd may be useful in the prevention of BT associated with IO. PMID:25356125

  10. Molecular Epidemiology of Human Intestinal Amoebas in Iran

    PubMed Central

    Hooshyar, H; Rostamkhani, P; Rezaian, M

    2012-01-01

    Many microscopic-based epidemiological surveys on the prevalence of human intestinal pathogenic and non-pathogenic protozoa including intestinal amoeba performed in Iran show a high prevalence of human intestinal amoeba in different parts of Iran. Such epidemiological studies on amoebiasis are confusing, mainly due to recently appreciated distinction between the Entamoeba histolytica, E. dispar and E. moshkovskii. Differential diagnosis can be done by some methods such as PCR-based methods, monoclonal antibodies and the analysis of isoenzyme typing, however the molecular study of these protozoa in Iran is low. Based on molecular studies, it seems that E. dispar is predominant species especially in the central and northern areas of Iran and amoebiasis due to E. histolytica is a rare infection in the country. It is suggested that infection with E. moshkovskii may be common among Iranians. Considering the importance of molecular epidemiology of amoeba in Iran and also the current data, the present study reviews the data currently available on the molecular distribution of intestinal human amoeba in Iran. PMID:23193500

  11. Molecular epidemiology of human intestinal amoebas in iran.

    PubMed

    Hooshyar, H; Rostamkhani, P; Rezaian, M

    2012-01-01

    Many microscopic-based epidemiological surveys on the prevalence of human intestinal pathogenic and non-pathogenic protozoa including intestinal amoeba performed in Iran show a high prevalence of human intestinal amoeba in different parts of Iran. Such epidemiological studies on amoebiasis are confusing, mainly due to recently appreciated distinction between the Entamoeba histolytica, E. dispar and E. moshkovskii. Differential diagnosis can be done by some methods such as PCR-based methods, monoclonal antibodies and the analysis of isoenzyme typing, however the molecular study of these protozoa in Iran is low. Based on molecular studies, it seems that E. dispar is predominant species especially in the central and northern areas of Iran and amoebiasis due to E. histolytica is a rare infection in the country. It is suggested that infection with E. moshkovskii may be common among Iranians. Considering the importance of molecular epidemiology of amoeba in Iran and also the current data, the present study reviews the data currently available on the molecular distribution of intestinal human amoeba in Iran. PMID:23193500

  12. Solubility profiling of HIV protease inhibitors in human intestinal fluids.

    PubMed

    Wuyts, Benjamin; Brouwers, Joachim; Mols, Raf; Tack, Jan; Annaert, Pieter; Augustijns, Patrick

    2013-10-01

    The present study pursued to profile the intestinal solubility of nine HIV protease inhibitors (PIs) in fasted- and fed-state human intestinal fluids (FaHIF, FeHIF) aspirated from four volunteers. In addition, the ability of fasted- and fed-state simulated intestinal fluids (FaSSIF, FeSSIF) to predict the intestinal solubility was evaluated. All PIs were poorly soluble in FaHIF (from 7 μM for ritonavir to 327 μM for darunavir) and FeHIF (from 15 μM for atazanavir to 409μM for darunavir). For four of nine PIs, food intake significantly enhanced the solubilizing capacity of intestinal fluids (up to 18.4-fold increase for ritonavir). The intersubject variability (average coefficient of variance CVfed = 60.6%, CVfasted = 40.4%) was higher as compared with the intrasubject variability (CVfed = 41.3%, CVfasted = 20.5%). PI solubilities correlated reasonably well between FaSSIF and FaHIF (R = 0.817), but not between FeSSIF and FeHIF (R = 0.617). To conclude, postprandial conditions increased the inter- and intrasubject variability of the PIs. The inability of FeSSIF to accurately predict the FeHIF solubility emphasizes the need for a multivariate approach to determine solubility profiles, taking into account solid-state characteristics, pH, mixed bile acid/phospholipid micelles, and digestive products. PMID:23939880

  13. Human Carboxymethylenebutenolidase as a Bioactivating Hydrolase of Olmesartan Medoxomil in Liver and Intestine

    PubMed Central

    Ishizuka, Tomoko; Fujimori, Izumi; Kato, Mitsunori; Noji-Sakikawa, Chisa; Saito, Motoko; Yoshigae, Yasushi; Kubota, Kazuishi; Kurihara, Atsushi; Izumi, Takashi; Ikeda, Toshihiko; Okazaki, Osamu

    2010-01-01

    Olmesartan medoxomil (OM) is a prodrug type angiotensin II type 1 receptor antagonist widely prescribed as an antihypertensive agent. Herein, we describe the identification and characterization of the OM bioactivating enzyme that hydrolyzes the prodrug and converts to its pharmacologically active metabolite olmesartan in human liver and intestine. The protein was purified from human liver cytosol by successive column chromatography and was identified by mass spectrometry to be a carboxymethylenebutenolidase (CMBL) homolog. Human CMBL, whose endogenous function has still not been reported, is a human homolog of Pseudomonas dienelactone hydrolase involved in the bacterial halocatechol degradation pathway. The ubiquitous expression of human CMBL gene transcript in various tissues was observed. The recombinant human CMBL expressed in mammalian cells was clearly shown to activate OM. By comparing the enzyme kinetics and chemical inhibition properties between the recombinant protein and human tissue preparations, CMBL was demonstrated to be the primary OM bioactivating enzyme in the liver and intestine. The recombinant CMBL also converted other prodrugs having the same ester structure as OM, faropenem medoxomil and lenampicillin, to their active metabolites. CMBL exhibited a unique sensitivity to chemical inhibitors, thus, being distinguishable from other known esterases. Site-directed mutagenesis on the putative active residue Cys132 of the recombinant CMBL caused a drastic reduction of the OM-hydrolyzing activity. We report for the first time that CMBL serves as a key enzyme in the bioactivation of OM, hydrolyzing the ester bond of the prodrug type xenobiotics. PMID:20177059

  14. Human carboxymethylenebutenolidase as a bioactivating hydrolase of olmesartan medoxomil in liver and intestine.

    PubMed

    Ishizuka, Tomoko; Fujimori, Izumi; Kato, Mitsunori; Noji-Sakikawa, Chisa; Saito, Motoko; Yoshigae, Yasushi; Kubota, Kazuishi; Kurihara, Atsushi; Izumi, Takashi; Ikeda, Toshihiko; Okazaki, Osamu

    2010-04-16

    Olmesartan medoxomil (OM) is a prodrug type angiotensin II type 1 receptor antagonist widely prescribed as an antihypertensive agent. Herein, we describe the identification and characterization of the OM bioactivating enzyme that hydrolyzes the prodrug and converts to its pharmacologically active metabolite olmesartan in human liver and intestine. The protein was purified from human liver cytosol by successive column chromatography and was identified by mass spectrometry to be a carboxymethylenebutenolidase (CMBL) homolog. Human CMBL, whose endogenous function has still not been reported, is a human homolog of Pseudomonas dienelactone hydrolase involved in the bacterial halocatechol degradation pathway. The ubiquitous expression of human CMBL gene transcript in various tissues was observed. The recombinant human CMBL expressed in mammalian cells was clearly shown to activate OM. By comparing the enzyme kinetics and chemical inhibition properties between the recombinant protein and human tissue preparations, CMBL was demonstrated to be the primary OM bioactivating enzyme in the liver and intestine. The recombinant CMBL also converted other prodrugs having the same ester structure as OM, faropenem medoxomil and lenampicillin, to their active metabolites. CMBL exhibited a unique sensitivity to chemical inhibitors, thus, being distinguishable from other known esterases. Site-directed mutagenesis on the putative active residue Cys(132) of the recombinant CMBL caused a drastic reduction of the OM-hydrolyzing activity. We report for the first time that CMBL serves as a key enzyme in the bioactivation of OM, hydrolyzing the ester bond of the prodrug type xenobiotics. PMID:20177059

  15. Metabolism of anthocyanins by human gut microflora and their influence on gut bacterial growth.

    PubMed

    Hidalgo, Maria; Oruna-Concha, M Jose; Kolida, Sofia; Walton, Gemma E; Kallithraka, Stamatina; Spencer, Jeremy P E; de Pascual-Teresa, Sonia

    2012-04-18

    Consumption of anthocyanins has been related with beneficial health effects. However, bioavailability studies have shown low concentration of anthocyanins in plasma and urine. In this study, we have investigated the bacterial-dependent metabolism of malvidin-3-glucoside, gallic acid and a mixture of anthocyanins using a pH-controlled, stirred, batch-culture fermentation system reflective of the distal human large intestine conditions. Most anthocyanins have disappeared after 5 h incubation while gallic acid remained constant through the first 5 h and was almost completely degraded following 24 h of fermentation. Incubation of malvidin-3-glucoside with fecal bacteria mainly resulted in the formation of syringic acid, while the mixture of anthocyanins resulted in formation of gallic, syringic and p-coumaric acids. All the anthocyanins tested enhanced significantly the growth of Bifidobacterium spp. and Lactobacillus-Enterococcus spp. These results suggest that anthocyanins and their metabolites may exert a positive modulation of the intestinal bacterial population. PMID:22439618

  16. Localization of human intestinal defensin 5 in Paneth cell granules.

    PubMed Central

    Porter, E M; Liu, L; Oren, A; Anton, P A; Ganz, T

    1997-01-01

    Antibiotic peptides of higher animals include the defensins, first discovered in phagocytic cells but recently also found to be produced by epithelial cells. We biosynthesized recombinant human intestinal defensin 5 (rHD-5) using the baculovirus-insect cell expression system. Since insect cells process defensin incompletely and secrete the precursor proHD-5, we substituted a methionine for an alanine at a likely processing site to allow selective chemical cleavage with cyanogen bromide, and rHD-5 was used to elicit polyclonal antibodies. By the immunoperoxidase-staining technique, the antibodies selectively stained Paneth cells of the normal adult small intestine. Immunogold electron microscopy further localized HD-5 to the Paneth cell secretory granules. Since some defensins exert activity cytotoxic to mammalian cells, we assayed the effect of rHD-5 on the human intestinal cell lines Caco2 and Int407. proHD-5 did not exert cytotoxic activity, and rHD-5 showed only minimal activity against Int407 and was inert against Caco2. Since Paneth cells release their granules adjacent to the mitotic cells of the intestinal crypts, HD could protect this cell population against invasion and parasitization by microbes. PMID:9169779

  17. Intestinal REG3 Lectins Protect against Alcoholic Steatohepatitis by Reducing Mucosa-Associated Microbiota and Preventing Bacterial Translocation.

    PubMed

    Wang, Lirui; Fouts, Derrick E; Stärkel, Peter; Hartmann, Phillipp; Chen, Peng; Llorente, Cristina; DePew, Jessica; Moncera, Kelvin; Ho, Samuel B; Brenner, David A; Hooper, Lora V; Schnabl, Bernd

    2016-02-10

    Approximately half of all deaths from liver cirrhosis, the tenth leading cause of mortality in the United States, are related to alcohol use. Chronic alcohol consumption is accompanied by intestinal dysbiosis and bacterial overgrowth, yet little is known about the factors that alter the microbial composition or their contribution to liver disease. We previously associated chronic alcohol consumption with lower intestinal levels of the antimicrobial-regenerating islet-derived (REG)-3 lectins. Here, we demonstrate that intestinal deficiency in REG3B or REG3G increases numbers of mucosa-associated bacteria and enhances bacterial translocation to the mesenteric lymph nodes and liver, promoting the progression of ethanol-induced fatty liver disease toward steatohepatitis. Overexpression of Reg3g in intestinal epithelial cells restricts bacterial colonization of mucosal surfaces, reduces bacterial translocation, and protects mice from alcohol-induced steatohepatitis. Thus, alcohol appears to impair control of the mucosa-associated microbiota, and subsequent breach of the mucosal barrier facilitates progression of alcoholic liver disease. PMID:26867181

  18. The bacterial flora of neonates with congenital abnormalities of the gastro-intestinal tract

    PubMed Central

    Rotimi, V. O.; Duerden, B. I.

    1982-01-01

    The development of the bacterial flora of neonates with congenital abnormalities of the gastro-intestinal tract was studied in 31 infants during the first 10 days of life. Specimens were collected from the umbilicus, mouth and gastro-intestinal tract on the pre-operative day, at operation and on post-operative days 1, 2, 3, 5, 7 and 10. Bacteria were isolated semi-quantitatively on a variety of plain and selective media and identified by conventional methods. Staphylococcus albus was the predominant species isolated from the umbilicus; it was recovered from 24 of the 31 babies. The viridans group of streptococci and Streptococcus salivarius were the commonest species isolated from the mouth; there were no differences between the babies with different abnormalities and treatment with antibiotics had no effect on the bacterial flora. Ten babies were colonized by each species on the pre-operative day, and 25 and 19 respectively by the tenth post-operative day. Anaerobic gram-positive cocci were the predominant oral anaerobes. Bacteria were not isolated from the rectal swabs of babies with tracheo-oesophageal fistula (TOF) or small bowel atresia on the pre-operative days. Post-operatively the predominant faecal isolates from babies with TOF were Str. faecalis, Escherichia coli and Clostridium perfringens. About 80% of the babies with small bowel atresia were colonized by Str. faecalis and Bacteroides vulgatus, 60% each by E. coli, Klebsiella aerogenes and Str. faecium. The five babies with necrotizing enterocolitis were colonized by Str. faecalis, E. coli, Cl. perfringens and Cl. difficile; Bacteroides spp. were not recovered from any of them. The commonest facultative species recovered from babies with large bowel obstruction were Str. faecalis and E. coli. B. vulgatus, Cl. perfringens and Bifidobacterium spp. were the commonest anaerobes and anaerobes outnumbered aerobes. No significant isolates were recovered from the wound swabs and none of the babies developed post-surgical sepsis. PMID:7057028

  19. Small intestinal bacterial overgrowth mimicking acute flare as a pitfall in patients with Crohn's Disease

    PubMed Central

    2009-01-01

    Background Small intestinal bacterial overgrowth (SIBO) is characterized by excessive proliferation of colonic bacterial species in the small bowel. Potential causes of SIBO include fistulae, strictures or motility disturbances. Hence, patients with Crohn's Disease (CD) are especially predisposed to develop SIBO. As result, CD patients may experience malabsorption and report symptoms such as weight loss, watery diarrhea, meteorism, flatulence and abdominal pain, mimicking acute flare in these patients. Methods One-hundred-fifty patients with CD reporting increased stool frequency, meteorism and/or abdominal pain were prospectively evaluated for SIBO with the Hydrogen Glucose Breath Test (HGBT). Results Thirty-eight patients (25.3%) were diagnosed with SIBO based on positive findings at HGBT. SIBO patients reported a higher rate of abdominal complaints and exhibited increased stool frequency (5.9 vs. 3.7 bowel movements/day, p = 0.003) and lower body weight (63.6 vs 70.4 kg, p = 0.014). There was no correlation with the Crohn's Disease Activity Index. SIBO was significantly more frequent in patients with partial resection of the colon or multiple intestinal surgeries; there was also a clear trend in patients with ileocecal resection that did not reach statistical significance. SIBO rate was also higher in patients with affection of both the colon and small bowel, while inflammation of the (neo)terminal ileum again showed only tendential association with the development of SIBO. Conclusion SIBO represents a frequently ignored yet clinically relevant complication in CD, often mimicking acute flare. Because symptoms of SIBO are often difficult to differentiate from those caused by the underlying disease, targeted work-up is recommended in patients with corresponding clinical signs and predisposing factors. PMID:19643023

  20. Small Intestinal Bacterial Overgrowth Diagnosed by Glucose Hydrogen Breath Test in Post-cholecystectomy Patients

    PubMed Central

    Sung, Hea Jung; Paik, Chang-Nyol; Chung, Woo Chul; Lee, Kang-Moon; Yang, Jin-Mo; Choi, Myung-Gyu

    2015-01-01

    Background/Aims Patients undergoing cholecystectomy may have small intestinal bacterial overgrowth (SIBO). We investigated the prevalence and characteristics of SIBO in patients with intestinal symptoms following cholecystectomy. Methods Sixty-two patients following cholecystectomy, 145 with functional gastrointestinal diseases (FGIDs), and 30 healthy controls undergoing hydrogen (H2)-methane (CH4) glucose breath test (GBT) were included in the study. Before performing GBT, all patients were interrogated using bowel symptom questionnaire. The positivity to GBT indicating the presence of SIBO, gas types and bowel symptoms were surveyed. Results Post-cholecystectomy patients more often had SIBO as evidenced by a positive (+) GBT than those with FGID and controls (29/62, 46.8% vs 38/145, 26.2% vs 4/30, 13.3%, respectively; P = 0.010). In the gas types, the GBT (H2) + post-cholecystectomy patients was significantly higher than those in FGIDs patients (P = 0.017). Especially, positivity to fasting GBT (H2) among the GBT (H2)+ post-cholecystectomy patients was high, as diagnosed by elevated fasting H2 level. The GBT+ group had higher symptom scores of significance or tendency in abdominal discomfort, bloating, chest discomfort, early satiety, nausea, and tenesmus than those of the GBT negative group. The status of cholecystectomy was the only significant independent factor for predicting SIBO. Conclusions The SIBO with high levels of baseline H2 might be the important etiologic factor of upper GI symptoms for post-cholecystectomy patients. PMID:26351251

  1. Transmucosal passage of bacteria across rat intestinal epithelium in the Ussing chamber: effect of nutritional factors and bacterial virulence.

    PubMed

    Kurkchubasche, A G; Cardona, M; Watkins, S C; Smith, S D; Albanese, C T; Simmons, R L; Rowe, M I; Ford, H R

    1998-02-01

    Transmucosal passage of bacteria across the intestine, the essential and prerequisite step for bacterial translocation, cannot be effectively studied using in vivo models of translocation. We have adapted the Ussing chamber into a fresh, sterile organ culture system that can facilitate the study of bacterial-epithelial interactions. Intestinal membranes were mounted in the Ussing chamber and perfused with a solution rich in putative mucosal micronutrients. The transmembrane potential difference was constantly monitored as a marker of intestinal integrity. Transmucosal passage of various bacteria across the normal intestinal epithelium was quantitated, and the mucosal membrane was examined by light and transmission electron microscopy. The addition of potassium cyanide to the mucosal perfusate resulted in an irreversible loss of potential difference. Oxygen deprivation also led to a precipitous drop in potential difference, but it was reversible with prompt reoxygenation. In contrast, intestinal membranes perfused with a solution consisting of Dulbecco's modified Eagle's medium + 20 mM glutamine maintained their potential difference for a sustained period (>180 min). Both the viability and structural integrity of the ileal intestinal membrane were maintained in culture ex vivo using this perfusate. Qualitative differences were observed in the mechanism of transmucosal passage of mild to moderately virulent bacteria such as Escherichia coli C-25 and Proteus mirabilis M-13, which pass through the intestinal epithelium without causing overt damage to the mucosa, and more virulent organisms such as Salmonella typhimurium, which cause extensive mucosal damage by light and transmission electron microscopy. The Ussing system should provide a useful model of intact organ culture for the study of the mechanisms of bacterial translocation and the pathogenesis of enteric infections. PMID:9488257

  2. Bacterial Respiratory Infections Complicating Human Immunodeficiency Virus.

    PubMed

    Feldman, Charles; Anderson, Ronald

    2016-04-01

    Opportunistic bacterial and fungal infections of the lower respiratory tract, most commonly those caused by Streptococcus pneumoniae (the pneumococcus), Mycobacterium tuberculosis, and Pneumocystis jirovecii, remain the major causes of mortality in those infected with human immunodeficiency virus (HIV). Bacterial respiratory pathogens most prevalent in those infected with HIV, other than M. tuberculosis, represent the primary focus of the current review with particular emphasis on the pneumococcus, the leading cause of mortality due to HIV infection in the developed world. Additional themes include (1) risk factors; (2) the predisposing effects of HIV-mediated suppression on pulmonary host defenses, possibly intensified by smoking; (3) clinical and laboratory diagnosis, encompassing assessment of disease severity and outcome; and (4) antibiotic therapy. The final section addresses current recommendations with respect to pneumococcal immunization in the context of HIV infection, including an overview of the rationale underpinning the current "prime-boost" immunization strategy based on sequential administration of pneumococcal conjugate vaccine 13 and pneumococcal polysaccharide vaccine 23. PMID:26974299

  3. Development of the Human Infant Intestinal Microbiota

    PubMed Central

    Palmer, Chana; Bik, Elisabeth M; DiGiulio, Daniel B; Relman, David A; Brown, Patrick O

    2007-01-01

    Almost immediately after a human being is born, so too is a new microbial ecosystem, one that resides in that person's gastrointestinal tract. Although it is a universal and integral part of human biology, the temporal progression of this process, the sources of the microbes that make up the ecosystem, how and why it varies from one infant to another, and how the composition of this ecosystem influences human physiology, development, and disease are still poorly understood. As a step toward systematically investigating these questions, we designed a microarray to detect and quantitate the small subunit ribosomal RNA (SSU rRNA) gene sequences of most currently recognized species and taxonomic groups of bacteria. We used this microarray, along with sequencing of cloned libraries of PCR-amplified SSU rDNA, to profile the microbial communities in an average of 26 stool samples each from 14 healthy, full-term human infants, including a pair of dizygotic twins, beginning with the first stool after birth and continuing at defined intervals throughout the first year of life. To investigate possible origins of the infant microbiota, we also profiled vaginal and milk samples from most of the mothers, and stool samples from all of the mothers, most of the fathers, and two siblings. The composition and temporal patterns of the microbial communities varied widely from baby to baby. Despite considerable temporal variation, the distinct features of each baby's microbial community were recognizable for intervals of weeks to months. The strikingly parallel temporal patterns of the twins suggested that incidental environmental exposures play a major role in determining the distinctive characteristics of the microbial community in each baby. By the end of the first year of life, the idiosyncratic microbial ecosystems in each baby, although still distinct, had converged toward a profile characteristic of the adult gastrointestinal tract. PMID:17594176

  4. Changing bacterial ecology during a five-year period of selective intestinal decontamination.

    PubMed

    Lingnau, W; Berger, J; Javorsky, F; Fille, M; Allerberger, F; Benzer, H

    1998-07-01

    The development of bacterial resistance during selective decontamination of the digestive tract (SDD) is controversial. We studied effects on bacterial resistance one year before and during a randomized, placebo-controlled trial of SDD in a surgical intensive care unit. We randomized patients within two different topical regimens (PTA, PCA) or placebo, administered four-times daily to both the oropharynx and gastrointestinal tract. All patients received intravenous ciprofloxacin (200 mg b.d.) for four days. Both SDD regimens successfully reduced aerobic Gram-negative intestinal colonization. There was no increase in resistance of Enterobacteriaceae or Pseudomonas aeruginosa. Acinetobacter calcoaceticus developed multi-resistance over one year, but differences between groups were not significant. We detected a shift towards Gram-positive organisms. Oxacillin-resistant Staphylococcus aureus increased in concert with ciprofloxacin resistance, from 17 to 80.7%, and frequencies of resistance were significantly higher in SDD patients (P < 0.001). Resistance of coagulase-negative staphylococci (CNS) to oxacillin increased initially (25 to 66.9%), but values returned to baseline in controls. Ciprofloxacin resistance in CNS remained higher (P < 0.001) in SDD-treated patients (52.5 vs. 23.3%). The incidence of late respiratory tract infections was unaltered by the prophylactic regimen (SDD 35.2%; Placebo 41.2%; n.s.). We cannot recommend SDD as a prophylactic tool in critically ill patients. PMID:9699139

  5. Effects of Enteromyxum leei (Myxozoa) infection on gilthead sea bream (Sparus aurata) (Teleostei) intestinal mucus: glycoprotein profile and bacterial adhesion.

    PubMed

    Estensoro, Itziar; Jung-Schroers, Verena; Álvarez-Pellitero, Pilar; Steinhagen, Dieter; Sitjà-Bobadilla, Ariadna

    2013-02-01

    The intestinal myxosporean parasite Enteromyxum leei causes severe desquamative enteritis in gilthead sea bream (Sparus aurata) (Teleostei) that impairs nutrient absorption causing anorexia and cachexia. In fish, as in terrestrial vertebrates, intestinal goblet cells are responsible for the adherent mucus secretion overlying epithelial cells, which constitutes a first line of innate immune defense against offending microorganisms but serves also as substrate and nutrient source for the commensal microflora. The secreted intestinal mucus of parasitized (n = 6) and unexposed (n = 8) gilthead sea bream was isolated, concentrated, and subjected to downward gel chromatography. Carbohydrate and protein contents (via PAS and Bradford stainings), terminal glycosylation (via lectin ELISA), and Aeromonas hydrophila and Vibrio alginolyticus adhesion were analyzed for the isolated intestinal mucins. Parasitized fish, compared with unexposed fish, presented intestinal mucus mucins with a lower glycoprotein content and glycosylation degree at the anterior and middle intestine, whereas both glycoprotein content and glycosylation degree increased at the posterior intestine section, though only significantly for the total carbohydrate content. Additionally, a slight molecular size increase was detected in the mucin glycoproteins of parasitized fish. Terminal glycosylation of the mucus glycoproteins in parasitized fish pointed to an immature mucin secretion (N-acetyl-α-D-galactosamine increase, α-L-fucose, and neuraminic-acid-α-2-6-galactose reduction). Bacterial adhesion to large-sized mucus glycoproteins (>2,000 kDa) of parasitized fish was significantly lower than in unexposed fish. PMID:23086443

  6. [Establishment of the intestinal microflora and regulation of bacterial translocation after caffeine citrate treatment during postnatal period in rat].

    PubMed

    Moumen Chentouf, W; Tir Touil Meddah, A; Léké, A; Mullié, C; Krim, G; Canarelli, J-P; Meddah, B

    2012-10-01

    To relieve respiratory problems such as apnea in newborns, caffeine citrate is the drug of choice because of its good tolerance and therapeutic index. However, its impact on the intestinal microbial ecosystem and on bacterial translocation in the neonatal period remains insufficiently investigated. Therefore, the objective of this study was to evaluate the effects of caffeine citrate on the establishment of the intestinal microflora and bacterial translocation in rats from birth to the 30th day of life. Newborn Wistar rats were divided into four groups of 14 animals, each subdivided into a control group receiving a placebo (12mL tap water/kg/day) and another treated with caffeine citrate (12mg/kg/day). The animals were nursed by their mothers and weighed daily. A group of 14 rats was killed at birth and after 10, 20, or 30 days of life. Organs in which translocation was assessed (liver, lungs, spleen, and kidneys) and various fragments of intestine (duodenum, jejunum, ileum, and colon) were surgically removed. The bacteriological analysis performed involved enumeration of the total microflora, staphylococci, enterobacteria, and lactobacilli. From the 10th day, caffeine was shown to significantly decrease the weight of treated animals as compared with controls (P<0.05). However, caffeine treatment did not drastically alter the kinetics of establishment of the intestinal microflora as only enterobacteria were found to be significantly lower in any intestinal segment of the treated group (P<0.05). Moreover, from the 20th day of life, caffeine citrate significantly downregulated bacterial translocation of both Gram-positive and -negative bacteria (P<0.05). This preliminary study on the effects of treatment with caffeine citrate may open opportunities in clinical pediatrics; the treatment will remain partially effective in preventing bacterial translocation in the neonatal period. PMID:22920890

  7. Biotransformation of 1-nitropyrene to 1-aminopyrene and N-formyl-1-aminopyrene by the human intestinal microbiota

    SciTech Connect

    Manning, B.W.; Cerniglia, C.E.; Federle, T.W.

    1986-01-01

    The nitropolycyclic aromatic hydrocarbon 1-nitropyrene (1-NP) is an environmental pollutant, a potent bacterial and mammalian mutagen, and a carcinogen. The metabolism of 1-NP by the human intestinal microbiota was studied using a semicontinuous culture system that simulates the colonic lumen. (/sup 3/H)-1-Nitropyrene was metabolized by the intestinal microbiota to 1-aminopyrene (1-AP) and N-formyl-1-aminopyrene (FAP) as determined by high-performance liquid chromatography (HPLC) and mass spectrometry. Twenty-four hours after the addition of (/sup 3/H)-1-NP, the formylated compound and 1-AP accounted for 20 and 80% of the total metabolism respectively. This percentage increased to 66% for FAP after 24 h following 10 d of chronic exposure to unlabeled 1-NP, suggesting metabolic adaptation to 1-NP by the microbiota. Both 1-AP and FAP have been shown to be nonmutagenic towards Salmonella typhimurium TA98, which indicates that the intestinal microflora may potentially detoxify 1-NP.

  8. Advancing the use of Lactobacillus acidophilus surface layer protein A for the treatment of intestinal disorders in humans.

    PubMed

    Sahay, Bikash; Ge, Yong; Colliou, Natacha; Zadeh, Mojgan; Weiner, Chelsea; Mila, Ashley; Owen, Jennifer L; Mohamadzadeh, Mansour

    2015-01-01

    Intestinal immunity is subject to complex and fine-tuned regulation dictated by interactions of the resident microbial community and their gene products with host innate cells. Deterioration of this delicate process may result in devastating autoinflammatory diseases, including inflammatory bowel disease (IBD), which primarily comprises Crohn's disease (CD) and ulcerative colitis (UC). Efficacious interventions to regulate proinflammatory signals, which play critical roles in IBD, require further scientific investigation. We recently demonstrated that rebalancing intestinal immunity via the surface layer protein A (SlpA) from Lactobacillus acidophilus NCFM potentially represents a feasible therapeutic approach to restore intestinal homeostasis. To expand on these findings, we established a new method of purifying bacterial SlpA, a new SlpA-specific monoclonal antibody, and found no SlpA-associated toxicity in mice. Thus, these data may assist in our efforts to determine the immune regulatory efficacy of SlpA in humans. PMID:26647142

  9. Chloride dependent amino acid transport in the human small intestine.

    PubMed Central

    Munck, L K

    1995-01-01

    Carriers of beta amino acids and imino acids in the small intestine of rabbits and guinea pigs are chloride dependent, and a cotransport of chloride, sodium, and 2-methyl-aminoisobutyric acid has been shown. This study examines the chloride dependence of amino acid transport in the human small intestine. The steady state tissue uptake of amino acids, given as the ratio between substrate concentration in intracellular and extracellular water after 35 minutes incubation at 37 degrees C, was determined in mucosal biopsy specimens from the duodenum of patients undergoing diagnostic upper endoscopy and compared using one way analysis of variance. Uptake of leucine and alpha-methyl-D-glucoside in the duodenum and the distal ileum did not differ. The accumulation of all substrates was sodium dependent. In the absence of mucosal chloride the uptake of taurine, glycine, and 2-methyl-aminoisobutyric acid was significantly reduced while that of leucine and alpha-methyl-D-glucoside was unaffected and the reduction of beta alanine uptake not statistically significant. Uptake of 2-methyl-aminoisobutyric acid and proline showed mutual inhibition. Leucine did not reduce uptake of the beta amino acids. In conclusion, chloride dependent transport processes for 2-methyl-amino-isobutyric acid, taurine, and glycine are present in the human small intestine. PMID:7883220

  10. Sequential cancer mutations in cultured human intestinal stem cells.

    PubMed

    Drost, Jarno; van Jaarsveld, Richard H; Ponsioen, Bas; Zimberlin, Cheryl; van Boxtel, Ruben; Buijs, Arjan; Sachs, Norman; Overmeer, René M; Offerhaus, G Johan; Begthel, Harry; Korving, Jeroen; van de Wetering, Marc; Schwank, Gerald; Logtenberg, Meike; Cuppen, Edwin; Snippert, Hugo J; Medema, Jan Paul; Kops, Geert J P L; Clevers, Hans

    2015-05-01

    Crypt stem cells represent the cells of origin for intestinal neoplasia. Both mouse and human intestinal stem cells can be cultured in medium containing the stem-cell-niche factors WNT, R-spondin, epidermal growth factor (EGF) and noggin over long time periods as epithelial organoids that remain genetically and phenotypically stable. Here we utilize CRISPR/Cas9 technology for targeted gene modification of four of the most commonly mutated colorectal cancer genes (APC, P53 (also known as TP53), KRAS and SMAD4) in cultured human intestinal stem cells. Mutant organoids can be selected by removing individual growth factors from the culture medium. Quadruple mutants grow independently of all stem-cell-niche factors and tolerate the presence of the P53 stabilizer nutlin-3. Upon xenotransplantation into mice, quadruple mutants grow as tumours with features of invasive carcinoma. Finally, combined loss of APC and P53 is sufficient for the appearance of extensive aneuploidy, a hallmark of tumour progression. PMID:25924068

  11. Intestinal Epithelial CD98 Directly Modulates the Innate Host Response to Enteric Bacterial Pathogens

    PubMed Central

    Laroui, Hamed; Liu, Hongchun; Viennois, Emilie; Ayyadurai, Saravanan; Xiao, Bo; Ingersoll, Sarah A.; Kalman, Daniel; Merlin, Didier

    2013-01-01

    CD98 is a type II transmembrane glycoprotein whose expression increases in intestinal epithelial cells (IECs) during intestinal inflammation. Enteropathogenic Escherichia coli (EPEC) is a food-borne human pathogen that attaches to IECs and injects effector proteins directly into the host cells, thus provoking an inflammatory response. In the present study, we investigated CD98 and EPEC interactions in vitro and ex vivo and examined FVB wild-type (WT) and villin-CD98 transgenic mice overexpressing human CD98 in IECs (hCD98 Tg mice) and infected with Citrobacter rodentium as an in vivo model. In vivo studies indicated that CD98 overexpression, localized to the apical domain of colonic cells, increased the attachment of C. rodentium in mouse colons and resulted in increased expression of proinflammatory markers and decreased expression of anti-inflammatory markers. The proliferative markers Ki-67 and cyclin D1 were significantly increased in the colonic tissue of C. rodentium-infected hCD98 Tg mice compared to that of WT mice. Ex vivo studies correlate with the in vivo data. Small interfering RNA (siRNA) studies with Caco2-BBE cells showed a decrease in adherence of EPEC to Caco2 cells in which CD98 expression was knocked down. In vitro surface plasmon resonance (SPR) experiments showed direct binding between recombinant hCD98 and EPEC/C. rodentium proteins. We also demonstrated that the partial extracellular loop of hCD98 was sufficient for direct binding to EPEC/C. rodentium. These findings demonstrate the importance of the extracellular loop of CD98 in the innate host defense response to intestinal infection by attaching and effacing (A/E) pathogens. PMID:23297381

  12. In Vitro Expansion of Human Gastric Epithelial Stem Cells and Their Responses to Bacterial Infection

    PubMed Central

    Bartfeld, Sina; Bayram, Tülay; van de Wetering, Marc; Huch, Meritxell; Begthel, Harry; Kujala, Pekka; Vries, Robert; Peters, Peter J; Clevers, Hans

    2014-01-01

    Background & Aims We previously established systems for long-term, 3-dimensional (3D) culture of organoids from mouse tissues (intestine, stomach, pancreas, and liver) and human intestine and pancreas. We describe conditions required for long-term 3D cultures of human gastric stem cells. The technology can be applied to study the epithelial response to infection with Helicobacter pylori. Methods We generated organoids from surgical samples of human gastric corpus. Culture conditions were developed based on those for the mouse gastric and human intestinal systems. We used microinjection to infect the organoids with H pylori. Epithelial responses were measured using microarray and quantitative PCR analyses. Results Human gastric cells were expanded indefinitely in 3D matrigel cultures. We cultured cells from healthy gastric tissues, single-sorted stem cells, or tumor tissues. Organoids maintained many characteristics of their respective tissues, based on their histology, expression of markers, and euploidy. Organoids from healthy tissue expressed markers of 4 lineages of the stomach and self-organized into gland and pit domains. They could be directed to specifically express either lineages of the gastric gland, or the gastric pit, by addition of nicotinamide and withdrawal of WNT. Whereas gastric pit lineages had only marginal reactions to bacterial infection, gastric gland lineages mounted a strong inflammatory response. Conclusion We developed a system to culture human gastric organoids. This system can be used to study H pylori infection and other gastric pathologies. PMID:25307862

  13. The Modulatory Effect of Anthocyanins from Purple Sweet Potato on Human Intestinal Microbiota in Vitro.

    PubMed

    Zhang, Xin; Yang, Yang; Wu, Zufang; Weng, Peifang

    2016-03-30

    In order to investigate the modulatory effect of purple sweet potato anthocyanins (PSPAs) on human intestinal microbiota, PSPAs were prepared by column chromatography and their influence on intestinal microbiota was analyzed by monitoring the bacterial populations and analyzing short-chain fatty acid (SCFA) concentrations at different time points. The numbers (log10 cell/mL) of Bifidobacterium and Lactobacillus/Enterococcus spp., Bacteroides-Prevotella, Clostridium histolyticum, and total bacteria after 24 h of culture in anaerobic fermentation broth containing PSPAs were 8.44 ± 0.02, 8.30 ± 0.01, 7.80 ± 0.03, 7.60 ± 0.03, and 9.00 ± 0.02, respectively, compared with 8.21 ± 0.03, 8.12 ± 0.02, 7.95 ± 0.02, 7.77 ± 0.02, and 9.01 ± 0.03, respectively, in the controls. The results showed that PSPAs induced the proliferation of Bifidobacterium and Lactobacillus/Enterococcus spp., inhibited the growth of Bacteroides-Prevotella and Clostridium histolyticum, and did not affect the total bacteria number. Total SCFA concentrations in the cultures with PSPAs were significantly higher than in the controls (P < 0.05). Moreover, during the fermentation, the PSPAs were partially fragmented to phenolic acids, which may exert a better effect on intestinal microecology, suggesting that PSPAs may have prebiotic-like activity by generating SCFAs and modulating the intestinal microbiota, contributing to improvements in human health. PMID:26975278

  14. Commensal Streptococcus salivarius Modulates PPARγ Transcriptional Activity in Human Intestinal Epithelial Cells

    PubMed Central

    Couvigny, Benoît; de Wouters, Tomas; Kaci, Ghalia; Jacouton, Elsa; Delorme, Christine; Doré, Joël; Renault, Pierre; Blottière, Hervé M.

    2015-01-01

    The impact of commensal bacteria in eukaryotic transcriptional regulation has increasingly been demonstrated over the last decades. A multitude of studies have shown direct effects of commensal bacteria from local transcriptional activity to systemic impact. The commensal bacterium Streptococcus salivarius is one of the early bacteria colonizing the oral and gut mucosal surfaces. It has been shown to down-regulate nuclear transcription factor (NF-кB) in human intestinal cells, a central regulator of the host mucosal immune system response to the microbiota. In order to evaluate its impact on a further important transcription factor shown to link metabolism and inflammation in the intestine, namely PPARγ (peroxisome proliferator-activated receptor), we used human intestinal epithelial cell-lines engineered to monitor PPARγ transcriptional activity in response to a wide range of S. salivarius strains. We demonstrated that different strains from this bacterial group share the property to inhibit PPARγ activation independently of the ligand used. First attempts to identify the nature of the active compounds showed that it is a low-molecular-weight, DNase-, proteases- and heat-resistant metabolite secreted by S. salivarius strains. Among PPARγ-targeted metabolic genes, I-FABP and Angptl4 expression levels were dramatically reduced in intestinal epithelial cells exposed to S. salivarius supernatant. Both gene products modulate lipid accumulation in cells and down-regulating their expression might consequently affect host health. Our study shows that species belonging to the salivarius group of streptococci impact both host inflammatory and metabolic regulation suggesting a possible role in the host homeostasis and health. PMID:25946041

  15. Human intestinal potential difference: recording method and biophysical implications.

    PubMed Central

    Gustke, R F; McCormick, P; Ruppin, H; Soergel, K H; Whalen, G E; Wood, C M

    1981-01-01

    1. The transmural electrical potential difference (PD) of the intact human small intestine was recorded with close attention to electrical symmetry, shielding from electro-magnetic waves and correction for junction potentials. 2. The PD is -12 mV (mucosa-negative) in the fasting jejunum and ileum and does not change during perfusion with isotonic NaCl. 3. Absorption of Na and Cl appears to be non-electrogenic and the 'resting' PD is probably generated by active anion secretion of fasting intestinal contents. 4. Diffusion potentials during isotonic D-mannitol perfusion indicated higher cation selectivity in the ileum than in the jejunum. 5. The calculated contribution of a free-solution path to total paracellular permeability is 55% in the jejunum but only 15% in the ileum. 6. No 'streaming' potential was detected during osmotic water flow, suggesting that the cation-selectivity of the channels is temporarily inactivated during dilatation of the lateral intercellular space. PMID:6802960

  16. Genome sequence of Victivallis vadensis ATCC BAA-548, an anaerobic bacterium from the phylum Lentisphaerae, isolated from the human gastro-intestinal tract

    SciTech Connect

    Van Passel, Mark W.J.; Kant, Ravi; Palva, Airi; Lucas, Susan; Copeland, A; Lapidus, Alla L.; Glavina Del Rio, Tijana; Dalin, Eileen; Tice, Hope; Bruce, David; Goodwin, Lynne A.; Pitluck, Sam; Davenport, Karen W.; Sims, David; Detter, J. Chris; Han, Cliff; Larimer, Frank W; Land, Miriam L; Hauser, Loren John; Kyrpides, Nikos C; Ovchinnikova, Galina; Richardson, Paul; De Vos, Willem M.; Smidt, Hauke; Zoetendal, Erwin G.

    2011-01-01

    Victivallis vadensis ATCC BAA-548 represents the first cultured representative from the novel phylum Lentisphaerae, a deep-branching bacterial lineage. Few cultured bacteria from this phylum are known, and V. vadensis therefore represents an important organism for evolutionary studies. V. vadensis is a strictly anaerobic sugar-fermenting isolate from the human gastro-intestinal tract.

  17. Survivability of Kudoa septempunctata in human intestinal conditions.

    PubMed

    Ohnishi, Takahiro; Fujiwara, Marina; Tomaru, Akiko; Yoshinari, Tomoya; Sugita-Konishi, Yoshiko

    2016-06-01

    To elucidate whether Kudoa septempunctata was able to live in the human intestine, we assessed viability of K. septempunctata sporoplasms under conditions that mimicked human and ragworm digestive tracts. To study the effect of osmotic pressure on viability, sporoplasms were incubated in 0.9 or 3.4 % sodium chloride solutions, which roughly corresponded to the osmotic pressure in human or ragworm tissues, respectively. While viability in 3.4 % sodium chloride did not change after 72 h, it dropped to 21 % in 0.9 % sodium chloride. To study the effect of temperature on viability, sporoplasms were incubated at 37, 15, or 25 °C, which were representative of human, winter ragworm, or summer ragworm temperatures, respectively. Viability decreased sharply to 8.4 % after 48 h at 37 °C, but remained essentially unchanged at 15 and 25 °C. In addition, sporoplasms showed strong susceptibility to bile. These results indicate that K. septempunctata could not live in the human intestine for a long time. PMID:27038250

  18. Intestinal Dysbiosis and Bacterial Enteroinvasion in a Murine Model of Hirschsprung’s Disease

    PubMed Central

    Pierre, Joseph F.; Barlow-Anacker, Amanda J.; Erickson, Christopher S.; Heneghan, Aaron F.; Leverson, Glen E.; Dowd, Scot E.; Epstein, Miles L.; Kudsk, Kenneth A.; Gosain, Ankush

    2014-01-01

    Background/Purpose Hirschsprung’s disease (HSCR), characterized by the absence of ganglia in the distal colon, results in functional obstruction. Despite surgical resection of the aganglionic segment, around 40% of patients suffer recurrent life threatening Hirschsprung’s-associated enterocolitis (HAEC). The aim of this study was to investigate whether gut microbiota and intestinal immunity changes contribute to the HAEC risk in a HSCR model. Methods Mice with neural crest conditional deletion of Endothelin receptor B (EdnrB) and their littermate controls were used (EdnrB-null and EdnrB-het). Bacterial DNA was prepared from cecal contents of P16–18 and P21–24 animals and pyrosequencing employed for microbiome analysis. Ileal tissue was isolated and secretory phospholipase A2 (sPLA2) expression and activity determined. Enteroinvasion of E. coli into ileal explants was measured using an ex vivo organ culture system. Results EdnrB-het and EdnrB-nulls displayed similar flora, sPLA2 expression and activity at P16–18. However, by P21–24, EdnrB-hets demonstrated increased Lactobacillus and decreased Bacteroides and Clostridium, while EdnrB-nulls exhibited reciprocal changes. EdnrB-nulls also showed reduced sPLA2 expression and luminal activity at this stage. Functionally, EdnrB-nulls were more susceptible to enteroinvasion with E. coli ex vivo and released less sPLA2 than EdnrB-hets. Conclusions Initially, EdnrB-het and EdnrB-nulls contain similar cecal flora but then undergo reciprocal changes. EdnrB-nulls display dysbiosis, demonstrate impaired mucosal defense, decreased luminal sPLA2 and increased enteroinvasion of E. coli just prior to robust colonic inflammation and death. These findings suggest a role for the intestinal microbiome in the development of HAEC. PMID:25092084

  19. Phylogenetic diversity of the intestinal bacterial community in the termite Reticulitermes speratus.

    PubMed Central

    Ohkuma, M; Kudo, T

    1996-01-01

    The phylogenetic diversity of the intestinal microflora of a lower termite, Reticulitermes speratus, was examined by a strategy which does not rely on cultivation of the resident microorganisms. Small-subunit rRNA genes (16S rDNAs) were directly amplified from the mixed-population DNA of the termite gut by the PCR and were clonally isolated. Analysis of partial 16S rDNA sequences showed the existence of well-characterized genera as well as the presence of bacterial species for which no 16S rDNA sequence data are available. Of 55 clones sequenced, 45 were phylogenetically affiliated with four of the major groups of the domain Bacteria: the Proteobacteria, the spirochete group, the Bacteroides group, and the low-G+C-content gram-positive bacteria. Within the Proteobacteria, the 16S rDNA clones showed a close relationship to those of cultivated species of enteric bacteria and sulfate-reducing bacteria, while the 16S rDNA clones in the remaining three groups showed only distant relationships to those of known organisms in these groups. Of the remaining 10 clones, among which 8 clones formed a cluster, there was only very low sequence similarity to known 16S rRNA sequences. None of these clones were affiliated with any of the major groups within the domain Bacteria. The 16S rDNA gene sequence data show that the majority of the intestinal microflora of R. speratus consists of new, uncultured species previously unknown to microbiologists. PMID:8593049

  20. Characteristics of human intestinal Escherichia coli with changing environments.

    PubMed

    Skurnik, David; Bonnet, Daniel; Bernède-Bauduin, Claire; Michel, Rémy; Guette, Christian; Becker, Jean-Marie; Balaire, Corinne; Chau, Françoise; Mohler, Jacqueline; Jarlier, Vincent; Boutin, Jean-Paul; Moreau, Brigitte; Guillemot, Didier; Denamur, Erick; Andremont, Antoine; Ruimy, Raymond

    2008-08-01

    To investigate if the characteristics of human intestinal Escherichia coli are changing with the environment of the host, we studied intestinal E. coli from subjects having recently migrated from a temperate to a tropical area. We determined the phylogenetic group, the prevalence of the antibiotic resistance, the presence of integrons and the strain diversity in faecal isolates from 25 subjects originally from metropolitan France and expatriated to French Guyana. These characteristics were compared with those of 25 previously studied Wayampi Amerindian natives of French Guyana and from 25 metropolitan French residents. The three groups of subjects were matched for age and sex, had not taken antibiotics for at least 1 month, nor had been hospitalized within the past year. In all, the characteristics of intestinal E. coli from Expatriates were intermediate between those found in residents from metropolitan France and those found in natives of French Guyana. Prevalence of carriage of resistant Gram-negative bacteria in Expatriates was intermediate between French residents and Wayampi as were the prevalence of integrons in E. coli (12.3% versus 16.3% and 7.8% respectively), and the intra-host diversity of E. coli (2.3 strains/subject versus 1.9 and 3.1, respectively); lastly, in Expatriates, the prevalence of carriage of phylogenetic group B2 strains was lower than in French residents (16% versus 56%, P = 0.005), while carriage of phylogenetic group A strains was lower than in Wayampi (56% versus 88%, P = 0.03). Our results suggest that the composition of the commensal intestinal flora of humans is not static but changes dynamically in response to new environmental conditions. PMID:18459976

  1. Protective effects of terminal ileostomy against bacterial translocation in a rat model of intestinal ischemia/reperfusion injury

    PubMed Central

    Lin, Zhi-Liang; Yu, Wen-Kui; Tan, Shan-Jun; Duan, Kai-Peng; Dong, Yi; Bai, Xiao-Wu; Xu, Lin; Li, Ning

    2014-01-01

    AIM: To investigate the effects of terminal ileostomy on bacterial translocation (BT) and systemic inflammation after intestinal ischemia/reperfusion (I/R) injury in rats. METHODS: Thirty-two rats were assigned to either the sham-operated group, I/R group, I/R + resection and anastomosis group, or the I/R + ileostomy group. The superior mesenteric artery was occluded for 60 min. After 4 h, tissue samples were collected for analysis. BT was assessed by bacteriologic cultures, intestinal permeability and serum levels of endotoxin; systemic inflammation was assessed by serum levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-10, as well as by the activity of myeloperoxidase (MPO) and by intestinal histopathology. RESULTS: Intestinal I/R injury not only caused morphologic damage to ileal mucosa, but also induced BT, increased MPO activity and promoted the release of TNF-α, IL-6, and IL-10 in serum. BT and ileal mucosa injuries were significantly improved and levels of TNF-α and IL-6 in serum were decreased in the I/R + ileostomy group compared with the I/R + resection and anastomosis group. CONCLUSION: Terminal ileostomy can prevent the detrimental effects of intestinal I/R injury on BT, intestinal tissue, and inflammation. PMID:25548488

  2. The relationship between intestinal Campylobacter species isolated from animals and humans as determined by BRENDA.

    PubMed Central

    Kakoyiannis, C. K.; Winter, P. J.; Marshall, R. B.

    1988-01-01

    Intestinal thermophilic Campylobacter species produce stable patterns when subjected to bacterial restriction endonuclease DNA analysis (BRENDA); this technique is therefore of considerable value in epidemiological studies. BRENDA was used to examine thermophilic Campylobacter species from humans, wild and domestic animals. One hundred and ninety-four (61%) of 316 isolates of Campylobacter jejuni from humans had BRENDA patterns which could be matched to those of animal isolates. Poultry appear to be a major source of infection for C. jejuni in humans with nearly half (49.7%) of the human isolates giving patterns which were indistinguishable from those isolated from poultry. A total of 60 BRENDA types were identified from 316 human isolates and 11 of these had the same pattern as those isolated from poultry. One of the three Campylobacter coli BRENDA types recovered from poultry was indistinguishable from a human isolate type. Pigs appear to be only a minor source of C. coli infection for humans in New Zealand. Rats were found to be infected with strains of C. jejuni with BRENDA patterns indistinguishable from those infecting humans, poultry and a horse. None of the 102 isolates of Campylobacter species from wild birds gave BRENDA patterns similar to those of isolates from humans. Images Fig. 1 Fig. 2 PMID:2837404

  3. Functional Metagenomic Investigations of the Human Intestinal Microbiota

    PubMed Central

    Moore, Aimee M.; Munck, Christian; Sommer, Morten O. A.; Dantas, Gautam

    2011-01-01

    The human intestinal microbiota encode multiple critical functions impacting human health, including metabolism of dietary substrate, prevention of pathogen invasion, immune system modulation, and provision of a reservoir of antibiotic resistance genes accessible to pathogens. The complexity of this microbial community, its recalcitrance to standard cultivation, and the immense diversity of its encoded genes has necessitated the development of novel molecular, microbiological, and genomic tools. Functional metagenomics is one such culture-independent technique, used for decades to study environmental microorganisms, but relatively recently applied to the study of the human commensal microbiota. Metagenomic functional screens characterize the functional capacity of a microbial community, independent of identity to known genes, by subjecting the metagenome to functional assays in a genetically tractable host. Here we highlight recent work applying this technique to study the functional diversity of the intestinal microbiota, and discuss how an approach combining high-throughput sequencing, cultivation, and metagenomic functional screens can improve our understanding of interactions between this complex community and its human host. PMID:22022321

  4. Age-associated modifications of intestinal permeability and innate immunity in human small intestine.

    PubMed

    Man, Angela L; Bertelli, Eugenio; Rentini, Silvia; Regoli, Mari; Briars, Graham; Marini, Mario; Watson, Alastair J M; Nicoletti, Claudio

    2015-10-01

    The physical and immunological properties of the human intestinal epithelial barrier in aging are largely unknown. Ileal biopsies from young (7-12 years), adult (20-40 years) and aging (67-77 years) individuals not showing symptoms of gastrointestinal (GI) pathologies were used to assess levels of inflammatory cytokines, barrier integrity and cytokine production in response to microbial challenges. Increased expression of interleukin (IL)-6, but not interferon (IFN)γ, tumour necrosis factor (TNF)-α and IL-1β was observed during aging; further analysis showed that cluster of differentiation (CD)11c(+) dendritic cells (DCs) are one of the major sources of IL-6 in the aging gut and expressed higher levels of CD40. Up-regulated production of IL-6 was accompanied by increased expression of claudin-2 leading to reduced transepithelial electric resistance (TEER); TEER could be restored in in vitro and ex vivo cultures by neutralizing anti-IL-6 antibody. In contrast, expression of zonula occludens-1 (ZO-1), occludin and junctional-adhesion molecule-A1 did not vary with age and overall permeability to macromolecules was not affected. Finally, cytokine production in response to different microbial stimuli was assessed in a polarized in vitro organ culture (IVOC). IL-8 production in response to flagellin declined progressively with age although the expression and distribution of toll-like receptor (TLR)-5 on intestinal epithelial cells (IECs) remained unchanged. Also, flagellin-induced production of IL-6 was less pronounced in aging individuals. In contrast, TNF-α production in response to probiotics (VSL#3) did not decline with age; however, in our experimental model probiotics did not down-regulate the production of IL-6 and expression of claudin-2. These data suggested that aging affects properties of the intestinal barrier likely to impact on age-associated disturbances, both locally and systemically. PMID:25948052

  5. Ultrastructural study of adhesion of enterotoxigenic Escherichia coli to erythrocytes and human intestinal epithelial cells.

    PubMed

    Knutton, S; Lloyd, D R; Candy, D C; McNeish, A S

    1984-05-01

    The adhesion to erythrocytes and human intestinal epithelial cells of enterotoxigenic Escherichia coli strains H10407, B2C, and H10407P, expressing colonization factor antigen I (CFA/I), CFA/II, and type 1 fimbriae, respectively, was examined by electron microscopy. CFA and type 1 fimbriae were visualized by negative staining in thin sections after en bloc staining with ruthenium red and by immune labeling with antisera raised against purified fimbriae. By negative and ruthenium red staining, CFA/I, CFA/II, and type 1 fimbriae were indistinguishable and appeared as approximately 7-nm-diameter hollow cylindrical structures up to 1.5 micron in length; strain B2C also produced 2- to 3-nm-diameter flexible fibrillar fimbriae. Bacteria producing CFA/I, CFA/II, and type 1 fimbriae adhered to and agglutinated human, bovine, and guinea pig erythrocytes, respectively; CFA/I and CFA/II also mediated attachment of bacteria to the brush border of isolated human duodenal enterocytes. Electron microscopy of agglutinated erythrocytes and enterocytes with adherent bacteria showed, in each case, that bacterial adhesion involved the formation of many interactions between the tips of fimbriae and receptors on the erythrocyte or enterocyte brush border membrane. Immune labeling allowed different fimbrial antigens mediating bacterial attachment to human enterocytes to be identified. PMID:6143731

  6. Human milk hyaluronan enhances innate defense of the intestinal epithelium.

    PubMed

    Hill, David R; Rho, Hyunjin K; Kessler, Sean P; Amin, Ripal; Homer, Craig R; McDonald, Christine; Cowman, Mary K; de la Motte, Carol A

    2013-10-01

    Breast-feeding is associated with enhanced protection from gastrointestinal disease in infants, mediated in part by an array of bioactive glycan components in milk that act through molecular mechanisms to inhibit enteric pathogen infection. Human milk contains hyaluronan (HA), a glycosaminoglycan polymer found in virtually all mammalian tissues. We have shown that synthetic HA of a specific size range promotes expression of antimicrobial peptides in intestinal epithelium. We hypothesize that hyaluronan from human milk also enhances innate antimicrobial defense. Here we define the concentration of HA in human milk during the first 6 months postpartum. Importantly, HA isolated from milk has a biological function. Treatment of HT-29 colonic epithelial cells with human milk HA at physiologic concentrations results in time- and dose-dependent induction of the antimicrobial peptide human β-defensin 2 and is abrogated by digestion of milk HA with a specific hyaluronidase. Milk HA induction of human β-defensin 2 expression is also reduced in the presence of a CD44-blocking antibody and is associated with a specific increase in ERK1/2 phosphorylation, suggesting a role for the HA receptor CD44. Furthermore, oral administration of human milk-derived HA to adult, wild-type mice results in induction of the murine Hβ D2 ortholog in intestinal mucosa and is dependent upon both TLR4 and CD44 in vivo. Finally, treatment of cultured colonic epithelial cells with human milk HA enhances resistance to infection by the enteric pathogen Salmonella typhimurium. Together, our observations suggest that maternally provided HA stimulates protective antimicrobial defense in the newborn. PMID:23950179

  7. Human Milk Hyaluronan Enhances Innate Defense of the Intestinal Epithelium*

    PubMed Central

    Hill, David R.; Rho, Hyunjin K.; Kessler, Sean P.; Amin, Ripal; Homer, Craig R.; McDonald, Christine; Cowman, Mary K.; de la Motte, Carol A.

    2013-01-01

    Breast-feeding is associated with enhanced protection from gastrointestinal disease in infants, mediated in part by an array of bioactive glycan components in milk that act through molecular mechanisms to inhibit enteric pathogen infection. Human milk contains hyaluronan (HA), a glycosaminoglycan polymer found in virtually all mammalian tissues. We have shown that synthetic HA of a specific size range promotes expression of antimicrobial peptides in intestinal epithelium. We hypothesize that hyaluronan from human milk also enhances innate antimicrobial defense. Here we define the concentration of HA in human milk during the first 6 months postpartum. Importantly, HA isolated from milk has a biological function. Treatment of HT-29 colonic epithelial cells with human milk HA at physiologic concentrations results in time- and dose-dependent induction of the antimicrobial peptide human β-defensin 2 and is abrogated by digestion of milk HA with a specific hyaluronidase. Milk HA induction of human β-defensin 2 expression is also reduced in the presence of a CD44-blocking antibody and is associated with a specific increase in ERK1/2 phosphorylation, suggesting a role for the HA receptor CD44. Furthermore, oral administration of human milk-derived HA to adult, wild-type mice results in induction of the murine Hβ D2 ortholog in intestinal mucosa and is dependent upon both TLR4 and CD44 in vivo. Finally, treatment of cultured colonic epithelial cells with human milk HA enhances resistance to infection by the enteric pathogen Salmonella typhimurium. Together, our observations suggest that maternally provided HA stimulates protective antimicrobial defense in the newborn. PMID:23950179

  8. Bifidobacteria isolated from infants and cultured on human milk oligosaccharides affect intestinal epithelial function

    PubMed Central

    Chichlowski, Maciej; De Lartigue, Guillaume; German, J. Bruce; Raybould, Helen E.; Mills, David A.

    2012-01-01

    Objectives Human milk oligosaccharides (HMO) are the third most abundant component of breast milk. Our laboratory has previously revealed gene clusters specifically linked to HMO metabolism in select bifidobacteria isolated from fecal samples of infants. Our objective was to test the hypothesis that growth of select bifidobacteria on HMO stimulates the intestinal epithelium. Methods Caco-2 and HT-29 cells were incubated with lactose (LAC) or HMO-grown Bifidobacterium longum subsp. infantis (B. infantis) or B. bifidum. Bacterial adhesion and translocation was measured by real-time quantitative PCR. Expression of pro- and anti-inflammatory cytokines and tight junction proteins was analyzed by real time reverse transcriptase. Distribution of tight junction proteins was measured using immunofluorescent microscopy. Results We showed that HMO-grown B. infantis had significantly higher rate of adhesion to HT-29 cells compared to B. bifidum. B. infantis also induced expression of a cell membrane glycoprotein, P-selectin glycoprotein ligand -1. Both B. infantis and B. bifidum grown on HMO caused less occludin relocalization and higher expression of anti-inflammatory cytokine, interleukin (IL)-10 compared to LAC-grown bacteria in Caco-2 cells. B. bifidum grown on HMO showed higher expression of junctional adhesion molecule and occludin in Caco-2 cell and HT-29 cells. There were no significant differences between LAC or HMO treatments in bacterial translocation. Conclusions This study provides evidence for the specific relationship between HMO-grown bifidobacteria and intestinal epithelial cells. To our knowledge, this is the first study describing HMO-induced changes in the bifidobacteria-intestinal cells interaction. PMID:22383026

  9. Nonsteroidal antiinflammatory drug-induced intestinal inflammation in humans

    SciTech Connect

    Bjarnason, I.; Zanelli, G.; Smith, T.; Prouse, P.; Williams, P.; Smethurst, P.; Delacey, G.; Gumpel, M.J.; Levi, A.J.

    1987-09-01

    This study examines the effects of nonsteroidal antiinflammatory drugs on the small intestine in humans. Using an /sup 111/In-leukocyte technique in patients with rheumatoid arthritis (n = 90) and osteoarthritis (n = 7), it appears that nonsteroidal antiinflammatory drugs cause small intestinal inflammation in two-thirds of patients on long-term treatment and on discontinuation, the inflammation may persist for up to 16 mo. The prevalence and magnitude of the intestinal inflammation was unrelated to the type and dose of nonsteroidal drugs and previous or concomitant second-line drug treatment. There was a significant inverse correlation (r = -0.29, p less than 0.05) between fecal /sup 111/In excretion and hemoglobin levels in patients treated with nonsteroidal antiinflammatory drugs. The kinetics of fecal indium 111 excretion in patients treated with nonsteroidal antiinflammatory drugs was almost identical to that of patients with small bowel Crohn's disease. Eighteen patients on nonsteroidal antiinflammatory drugs underwent a radiologic examination of the small bowel and 3 were found to have asymptomatic ileal disease with ulceration and strictures. Nineteen patients on nonsteroidal antiinflammatory drugs, 20 healthy controls, and 13 patients with Crohn's ileitis underwent a dual radioisotopic ileal function test with tauro 23 (/sup 75/Se) selena-25-homocholic acid and cobalt 58-labeled cyanocobalamine. On day 4, more than half of the patients with rheumatoid arthritis had evidence of bile acid malabsorption, but the ileal dysfunction was much milder than seen in patients with Crohn's ileitis.

  10. Intestinal microbiota modulates gluten-induced immunopathology in humanized mice.

    PubMed

    Galipeau, Heather J; McCarville, Justin L; Huebener, Sina; Litwin, Owen; Meisel, Marlies; Jabri, Bana; Sanz, Yolanda; Murray, Joseph A; Jordana, Manel; Alaedini, Armin; Chirdo, Fernando G; Verdu, Elena F

    2015-11-01

    Celiac disease (CD) is an immune-mediated enteropathy triggered by gluten in genetically susceptible individuals. The recent increase in CD incidence suggests that additional environmental factors, such as intestinal microbiota alterations, are involved in its pathogenesis. However, there is no direct evidence of modulation of gluten-induced immunopathology by the microbiota. We investigated whether specific microbiota compositions influence immune responses to gluten in mice expressing the human DQ8 gene, which confers moderate CD genetic susceptibility. Germ-free mice, clean specific-pathogen-free (SPF) mice colonized with a microbiota devoid of opportunistic pathogens and Proteobacteria, and conventional SPF mice that harbor a complex microbiota that includes opportunistic pathogens were used. Clean SPF mice had attenuated responses to gluten compared to germ-free and conventional SPF mice. Germ-free mice developed increased intraepithelial lymphocytes, markers of intraepithelial lymphocyte cytotoxicity, gliadin-specific antibodies, and a proinflammatory gliadin-specific T-cell response. Antibiotic treatment, leading to Proteobacteria expansion, further enhanced gluten-induced immunopathology in conventional SPF mice. Protection against gluten-induced immunopathology in clean SPF mice was reversed after supplementation with a member of the Proteobacteria phylum, an enteroadherent Escherichia coli isolated from a CD patient. The intestinal microbiota can both positively and negatively modulate gluten-induced immunopathology in mice. In subjects with moderate genetic susceptibility, intestinal microbiota changes may be a factor that increases CD risk. PMID:26456581

  11. Identification and Treatment of New Inflammatory Triggers for Complex Regional Pain Syndrome: Small Intestinal Bacterial Overgrowth and Obstructive Sleep Apnea.

    PubMed

    Weinstock, Leonard B; Myers, Trisha L; Walters, Arthur S; Schwartz, Oscar A; Younger, Jarred W; Chopra, Pradeep J; Guarino, Anthony H

    2016-05-01

    Complex regional pain syndrome (CRPS) is evoked by conditions that may be associated with local and/or systemic inflammation. We present a case of long-standing CRPS in a patient with Ehlers-Danlos syndrome in which prolonged remission was attained by directing therapy toward concomitant small intestinal bacterial overgrowth, obstructive sleep apnea, and potential increased microglia activity. We theorize that cytokine production produced by small intestinal bacterial overgrowth and obstructive sleep apnea may act as stimuli for ongoing CRPS symptoms. CRPS may also benefit from the properties of low-dose naltrexone that blocks microglia Toll-like receptors and induces production of endorphins that regulate and reduce inflammation. PMID:26867023

  12. Human milk and infant intestinal mucosal glycans guide succession of the neonatal intestinal microbiota.

    PubMed

    Newburg, David S; Morelli, Lorenzo

    2015-01-01

    Infants begin acquiring intestinal microbiota at parturition. Initial colonization by pioneer bacteria is followed by active succession toward a dynamic ecosystem. Keystone microbes engage in reciprocal transkingdom communication with the host, which is essential for human homeostasis and health; therefore, these bacteria should be considered mutualists rather than commensals. This review discusses the maternal role in providing infants with functional and stable microbiota. The initial fecal inoculum of microbiota results from the proximity of the birth canal and anus; the biological significance of this anatomic proximity could underlie observed differences in microbiota between vaginal and cesarean birth. Secondary sources of inocula include mouths and skin of kin, animals and objects, and the human milk microbiome, but guiding microbial succession may be a primary role of human milk. The unique glycans of human milk cannot be digested by the infant, but are utilized by mutualist bacteria. These prebiotic glycans support expansion of mutualist microbiota, which manifests as differences in microbiota among breastfed and artificially fed infants. Human milk glycans vary by maternal genotype. Milks of genetically distinct mothers and variations in infant mucosal glycan expression support discrete microbiota. Early colonization may permanently influence microbiota composition and function, with ramifications for health. PMID:25356747

  13. Irritable bowel syndrome and small intestinal bacterial overgrowth: meaningful association or unnecessary hype.

    PubMed

    Ghoshal, Uday C; Srivastava, Deepakshi

    2014-03-14

    Irritable bowel syndrome (IBS) is a common condition characterized by abdominal pain or discomfort, bloating, and altered stool form and passage. Small intestinal bacterial overgrowth (SIBO) is a condition in which there is overgrowth of bacteria in small bowel in excess of 10⁵ colony forming units per milliliter on culture of the upper gut aspirate. Frequency of SIBO varied from 4%-78% among patients with IBS and from 1%-40% among controls. Higher frequency in some studies might be due to fallacious criteria [post-lactulose breath-hydrogen rise 20 PPM above basal within 90 min (early-peak)]. Glucose hydrogen breath test (GHBT) has a low sensitivity to diagnose SIBO. Hence, studies based on GHBT might have under-estimated frequency of SIBO. Therefore, it is important to analyze these studies carefully to evaluate whether the reported association between IBS and SIBO is over or under-projected. This review evaluates studies on association between SIBO and IBS, discordance between different studies, their strength and weakness including methodological issues and evidence on therapeutic manipulation of gut flora on symptoms of IBS. PMID:24627585

  14. Comparison of intestinal bacterial populations between two dairy cattle herds colonized or not by Campylobacter jejuni.

    PubMed

    Ward, Pierre; Guévremont, Evelyne

    2014-12-01

    Campylobacter jejuni is an important foodborne pathogen. It can be isolated from bovine feces and its presence is influenced by farm characteristics and management practices. The impact of the bovine gut microbiota on the presence of C. jejuni is poorly documented. Two herds of lactating cows were selected: one where C. jejuni was not detected in 20 animals and the other where 55% of the sampled animals (11/20) were contaminated by C. jejuni. The bacterial diversity of bovine feces from these two herds was analyzed by terminal restriction fragment length polymorphism. The full-length 16S rRNA gene was amplified using fluorescently labeled primers and subsequently digested with HaeIII. Terminal restriction fragments profiles comparison showed a similarity level >79% between microbial populations from both herds. As profiles containing or not C. jejuni were clustered together, it is proposed that the presence of C. jejuni is not linked to a particular profile from the recovered intestinal bovine microbiota. PMID:25405278

  15. Small intestinal bacterial overgrowth in inactive Crohn’s disease: Influence of thiopurine and biological treatment

    PubMed Central

    Sánchez-Montes, Cristina; Ortiz, Vicente; Bastida, Guillermo; Rodríguez, Ester; Yago, María; Beltrán, Belén; Aguas, Mariam; Iborra, Marisa; Garrigues, Vicente; Ponce, Julio; Nos, Pilar

    2014-01-01

    AIM: To investigate the influence of thiopurines and biological drugs on the presence of small intestinal bacterial overgrowth (SIBO) in patients with inactive Crohn’s disease (CD). METHODS: This was a prospective study in patients with CD in remission and without corticosteroid treatment, included consecutively from 2004 to 2010. SIBO was investigated using the hydrogen glucose breath test. RESULTS: One hundred and seven patients with CD in remission were included. Almost 58% of patients used maintenance immunosuppressant therapy and 19.6% used biological therapy. The prevalence of SIBO was 16.8%. No association was observed between SIBO and the use of thiopurine Immunosuppressant (12/62 patients), administration of biological drugs (2/21 patients), or with double treatment with an anti-tumor necrosis factor drugs plus thiopurine (1/13 patients). Half of the patients had symptoms that were suggestive of SIBO, though meteorism was the only symptom that was significantly associated with the presence of SIBO on univariate analysis (P < 0.05). Multivariate analysis revealed that the presence of meteorism and a fistulizing pattern were associated with the presence of SIBO (P < 0.05). CONCLUSION: Immunosuppressants and/or biological drugs do not induce SIBO in inactive CD. Fistulizing disease pattern and meteorism are associated with SIBO. PMID:25320539

  16. Small Intestinal Bacterial Overgrowth in Patients with Refractory Functional Gastrointestinal Disorders

    PubMed Central

    Shimura, Shino; Ishimura, Norihisa; Mikami, Hironobu; Okimoto, Eiko; Uno, Goichi; Tamagawa, Yuji; Aimi, Masahito; Oshima, Naoki; Sato, Shuichi; Ishihara, Shunji; Kinoshita, Yoshikazu

    2016-01-01

    Background/Aims Small intestinal bacterial overgrowth (SIBO) is considered to be involved in the pathogenesis of functional gastrointestinal disorders (FGID). However, the prevalence and clinical conditions of SIBO in patients with FGID remain to be fully elucidated. Here, we examined the frequency of SIBO in patients with refractory FGID. Methods We prospectively enrolled patients with refractory FGID based on Rome III criteria. A glucose hydrogen breath test (GHBT) was performed using a gas analyzer after an overnight fast, with breath hydrogen concentration measured at baseline and every 15 minutes after administration of glucose for a total of 3 hours. A peak hydrogen value ≥ 10 ppm above the basal value between 60 and 120 minutes after administration of glucose was diagnosed as SIBO. Results A total of 38 FGID patients, including 11 with functional dyspepsia (FD), 10 with irritable bowel syndrome (IBS), and 17 with overlapping with FD and IBS, were enrolled. Of those, 2 (5.3%) were diagnosed with SIBO (one patient diagnosed with FD; the other with overlapping FD and IBS). Their symptoms were clearly improved and breath hydrogen levels decreased to normal following levofloxacin administration for 7 days. Conclusions Two patients initially diagnosed with FD and IBS were also diagnosed with SIBO as assessed by GHBT. Although the frequency of SIBO is low among patients with FGID, it may be important to be aware of SIBO as differential diagnosis when examining patients with refractory gastrointestinal symptoms, especially bloating, as a part of routine clinical care. PMID:26554916

  17. Irritable bowel syndrome and small intestinal bacterial overgrowth: Meaningful association or unnecessary hype

    PubMed Central

    Ghoshal, Uday C; Srivastava, Deepakshi

    2014-01-01

    Irritable bowel syndrome (IBS) is a common condition characterized by abdominal pain or discomfort, bloating, and altered stool form and passage. Small intestinal bacterial overgrowth (SIBO) is a condition in which there is overgrowth of bacteria in small bowel in excess of 105 colony forming units per milliliter on culture of the upper gut aspirate. Frequency of SIBO varied from 4%-78% among patients with IBS and from 1%-40% among controls. Higher frequency in some studies might be due to fallacious criteria [post-lactulose breath-hydrogen rise 20 PPM above basal within 90 min (early-peak)]. Glucose hydrogen breath test (GHBT) has a low sensitivity to diagnose SIBO. Hence, studies based on GHBT might have under-estimated frequency of SIBO. Therefore, it is important to analyze these studies carefully to evaluate whether the reported association between IBS and SIBO is over or under-projected. This review evaluates studies on association between SIBO and IBS, discordance between different studies, their strength and weakness including methodological issues and evidence on therapeutic manipulation of gut flora on symptoms of IBS. PMID:24627585

  18. Human intestinal epithelial cells express IL-10 through Toll-like receptor 4 (TLR4)-mediated epithelial-macrophage crosstalk

    PubMed Central

    Hyun, Jinhee; Romero, Laura; Riveron, Reldy; Flores, Claudia; Kanagavelu, Saravana; Chung, Kristina D.; Alonso, Ana; Sotolongo, John; Ruiz, Jose; Manukyan, Armine; Chun, Sally; Singh, Gaurav; Pedro, Salas; Targan, Stephan R.; Fukata, Masayuki

    2015-01-01

    In the intestine, interaction between epithelial cells and macrophages creates a unique immunoregulatory microenvironment necessary to maintain local immune and tissue homeostasis. Human intestinal epithelial cells (IECs) have been shown to express IL-10, which keeps epithelial integrity. We have demonstrated that bacterial signaling through TLR4 induces 15-Deoxy-Delta-12,14-prostaglandin J2 (15d-PGJ2) synthesis in intestinal macrophages by Cox-2 expression. Here we show that TLR4 signaling generates crosstalk between IECs and macrophages that enhances IL-10 expression in IECs. Direct stimulation of TLR4 leads to the expression of IL-10 in IECs, while the presence of macrophages in a transwell system induces another peak of IL-10 in IECs at a later time point. The second peak of the IL-10 expression is two times greater than the first peak. This late induction of IL-10 depends on a nuclear receptor peroxisome proliferator-activated receptor (PPAR)γ that is accumulated in IECs by TLR4-mediated inhibition of the ubiquitin-proteasomal pathway. TLR4 signaling in macrophages in turn synthesizes 15d-PGJ2 through p38 and ERK activation and Cox-2 induction, which activates PPARγ in IECs. These results suggest that TLR4 signaling maintains IL-10 production in IECs by generating epithelial-macrophage crosstalk, which is an important mechanism in maintenance of intestinal homeostasis mediated through host-bacterial interactions. PMID:25171731

  19. The involvement of Aeromonas salmonicida virulence factors in bacterial translocation across the rainbow trout, Oncorhynchus mykiss (Walbaum), intestine.

    PubMed

    Jutfelt, F; Sundh, H; Glette, J; Mellander, L; Thrandur Björnsson, B; Sundell, K

    2008-02-01

    The pathogenic bacterium Aeromonas salmonicida is the causative agent of furunculosis, a lethal disease in salmonids. The mode of lateral transmission has not been conclusively defined, but A. salmonicida is able to translocate across the intestinal epithelium of salmonids, making the intestinal route a probable candidate. This study investigated some of the virulence mechanisms used by the bacteria to promote translocation. Intestinal segments were placed in modified Ussing chambers to investigate epithelial functions during exposure to bacterial factors. The factors were: extracellular products (ECP), lipopolysaccharide (LPS) or live or heat-inactivated A. salmonicida. Fluorescein isothiocynate (FITC)-labelling enabled detection of translocated bacteria by fluorometry. Live A. salmonicida translocated to a greater degree than heat-inactivated bacteria, suggesting that the bacteria utilize a heat sensitive surface-bound virulence factor which promotes translocation. The epithelium was negatively affected by ECP, manifested as decreased net ion transport, indicating a disturbance in ion channels or cell metabolism. LPS did not affect the epithelium in vitro when administered on the luminal side of the intestinal segment, but significantly increased epithelial translocation of fluorescent bacterial-sized microspheres when administered on the serosal side. This is suggested to be caused by increased transcellular transport, as the paracellular permeability was unaffected indicating maintained epithelial integrity. PMID:18234022

  20. HUIEC, Human intestinal epithelial cell line with differentiated properties: process of isolation and characterisation.

    PubMed

    Gradisnik, Lidija; Trapecar, Martin; Rupnik, Marjan Slak; Velnar, Tomaz

    2015-12-01

    The intestinal epithelium is composed of diverse cell types, most abundant being the enterocytes. Among other functions, they maintain the intestinal barrier and play a critical role in the absorption of nutrients, drugs and toxins. This study describes the development and characterization of human intestinal epithelial cells (HUIEC), a spontaneously arising cell line established by selective trypsinization and cloning of the intestinal epithelium, resulting in a uniform population of highly epithelial cells with a strong growth potential. PMID:25821058

  1. [The role of vasoactive intestinal peptide in human body].

    PubMed

    Zdrojewicz, Z; Sztuka-Pietkiewicz, A; Pietkiewicz, W

    1999-01-01

    The quick progress of medical sciences changed somewhat our point of view on the role of Vasoactive Intestinal Peptide in human body. In the following article we have tried to gather all the latest information concerning VIP and its regulatory function. The role in menstrual cycle regulation, in prolactine and in hypothalamo-pituitary-adrenal axis secretion as well as in pancreas' hormones secretion has been described. We also emphasized the role in maintaining the blood pressure. The influence on the digestion, hematopoiesis, cell growth and differentiation was also discussed. PMID:10540588

  2. A Novel Method for the Culture and Polarized Stimulation of Human Intestinal Mucosa Explants

    PubMed Central

    Tsilingiri, Katerina; Sonzogni, Angelica; Caprioli, Flavio; Rescigno, Maria

    2013-01-01

    Few models currently exist to realistically simulate the complex human intestine's micro-environment, where a variety of interactions take place. Proper homeostasis directly depends on these interactions, as they shape an entire immunological response inducing tolerance against food antigens while at the same time mounting effective immune responses against pathogenic microbes accidentally ingested with food. Intestinal homeostasis is preserved also through various complex interactions between the microbiota (including food-associated beneficial bacterial strains) and the host, that regulate the attachment/degradation of mucus, the production of antimicrobial peptides by the epithelial barrier, and the "education" of epithelial cells' that controls the tolerogenic or immunogenic phenotype of unique, gut-resident lymphoid cells' populations. These interactions have been so far very difficult to reproduce with in vitro assays using either cultured cell lines or peripheral blood mononuclear cells. In addition, mouse models differ substantially in components of the intestinal mucosa (mucus layer organization, commensal bacteria community) with respect to the human gut. Thus, studies of a variety of treatments to be brought in the clinics for important stress-related or pathological conditions such as irritable bowel syndrome, inflammatory bowel disease or colorectal cancer have been difficult to carry out. To address these issues, we developed a novel system that enables us to stimulate explants of human intestinal mucosa that retain their in situ conditioning by the host microbiota and immune response, in a polarized fashion. Polarized apical stimulation is of great importance for the outcome of the elicited immune response. It has been repeatedly shown that the same stimuli can produce completely different responses when they bypass the apical face of the intestinal epithelium, stimulating epithelial cells basolaterally or coming into direct contact with lamina propria components, switching the phenotype from tolerogenic to immunogenic and causing unnecessary and excessive inflammation in the area. We achieved polarized stimulation by gluing a cave cylinder which delimited the area of stimulation on the apical face of the mucosa as will be described in the protocol. We used this model to examine, among others, differential effects of three different Lactobacilli strains. We show that this model system is very powerful to assess the immunomodulatory properties of probiotics in healthy and disease conditions. PMID:23666550

  3. [Human intestinal parasitosis: role of Dientamoeba fragilis in human infections].

    PubMed

    Crotti, D; D'Annibale, M L

    2007-01-01

    The Authors report prevalences of intestinal parasitosis among home children and adults during 2002-2004, as in O&P as in acute or prolonged diarrhoea, with particular attention to the role of Dientamoeba fragilis, because often undervalued. Among 3139 subjects, 116 cases of dientamoebiasis (3.7%) and 62 of giardiasis (2.0%) were observed; not typical pathogenic protozoa were reported in 71 cases (2.3%); helminths were identified only in 8 cases (0.5%). Particularly, inside O&P group D. fragilis prevailed in 5.2% of cases (7.8% in adults and 0.5% in children) and G. duodenalis in 2.7% (3.5% and 1.3% respectively); inside acute diarrhoeas D. fragilis prevailed in 1.6% (3.9% and 0.3%) and G. duodenalis in 0.6% (1.3% and 0. 1%); inside prolonged diarrhoeas D. fragilis prevailed in 3.5 % (2.6% and 5.4%) and G. duodenalis in 3.9% (5.8% in adults and never in children). D. fragilis was more often observed among adults (6.3% of all) than among children (0.6%), like G. duodenalis (3.1% versus 0.6%). So, 107 strains of D. fragilis (92.2%) and 53 strains of G. duodenalis (85.5%) were identified in adults. D. fragilis was more frequent among females (24/39 cases, 61.5%, in the last year) while G. duodenalis was more frequent in males (13/23 cases, 56.5%). The Authors conclude underlining the importance of a permanent stain, as Giemsa stain, for a good and complete diagnosis of protozoal intestinal infections, particularly for D. fragilis. PMID:17405510

  4. Human intestinal epithelial cells produce proinflammatory cytokines in response to infection in a SCID mouse-human intestinal xenograft model of amebiasis.

    PubMed Central

    Seydel, K B; Li, E; Swanson, P E; Stanley, S L

    1997-01-01

    The protozoan parasite Entamoeba histolytica causes amebic dysentery and amebic liver abscess, diseases associated with significant morbidity and mortality worldwide. E. histolytica infection appears to involve the initial attachment of amebic trophozoites to intestinal epithelial cells, followed by lysis of these cells and subsequent invasion into the submucosa. A recent in vitro study (L. Eckmann, S. L. Reed, J. R. Smith, and M. F. Kagnoff, J. Clin. Invest. 96:1269-1279, 1995) demonstrated that incubation of E. histolytica trophozoites with epithelial cell lines results in epithelial cell production of inflammatory cytokines, including interleukin-1 (IL-1) and IL-8, suggesting that intestinal epithelial cell production of cytokines might play a role in the inflammatory response and tissue damage seen in intestinal amebiasis. To determine whether intestinal epithelial cell production of IL-1 and IL-8 occurs in response to E. histolytica infection in vivo and as an approach to studying the specific interactions between amebic trophozoites and human intestine, we used a SCID mouse-human intestinal xenograft (SCID-HU-INT) model of disease, where human intestinal xenografts were infected with virulent E. histolytica trophozoites. Infection of xenografts with E. histolytica trophozoites resulted in extensive tissue damage, which was associated with the development of an early inflammatory response composed primarily of neutrophils. Using oligonucleotide primers that specifically amplify human IL-1beta and IL-8, we could demonstrate by reverse transcription PCR that mRNA for both IL-1beta and IL-8 is produced by human intestinal xenografts in response to amebic infection. The increase in human intestinal IL-1beta and IL-8 in response to invasive amebiasis was confirmed by enzyme-linked immunosorbent assays specific for human IL-1beta and IL-8. Using immunohistochemistry, we confirmed that human intestinal epithelial cells were the source of IL-8 in infected xenografts and established that IL-8 production can occur at sites distal to areas of intestinal mucosal damage. These results demonstrate that human intestinal epithelial cells can produce inflammatory cytokines in response to infection in vivo and establish the SCID-HU-INT model as a system for studying the interactions between E. histolytica and human intestine. PMID:9125540

  5. Multiscale analysis of the murine intestine for modeling human diseases.

    PubMed

    Lyons, Jesse; Herring, Charles A; Banerjee, Amrita; Simmons, Alan J; Lau, Ken S

    2015-07-01

    When functioning properly, the intestine is one of the key interfaces between the human body and its environment. It is responsible for extracting nutrients from our food and excreting our waste products. It provides an environment for a host of healthful microbes and serves as a first defense against pathogenic ones. These processes require tight homeostatic controls, which are provided by the interactions of a complex mix of epithelial, stromal, neural and immune cells, as well as the resident microflora. This homeostasis can be disrupted by invasive microbes, genetic lesions, and carcinogens, resulting in diseases such Clostridium difficile infection, inflammatory bowel disease (IBD) and cancer. Enormous strides have been made in understanding how this important organ functions in health and disease using everything from cell culture systems to animal models to human tissue samples. This has resulted in better therapies for all of these diseases, but there is still significant room for improvement. In the United States alone, 14,000 people per year die of C. difficile, up to 1.6 million people suffer from IBD, and more than 50,000 people die every year from colon cancer. Because these and other intestinal diseases arise from complex interactions between the different components of the gut ecosystem, we propose that systems approaches that address this complexity in an integrative manner may eventually lead to improved therapeutics that deliver lasting cures. This review will discuss the use of systems biology for studying intestinal diseases in vivo with particular emphasis on mouse models. Additionally, it will focus on established experimental techniques that have been used to drive this systems-level analysis, and emerging techniques that will push this field forward in the future. PMID:26040649

  6. Multiscale analysis of the murine intestine for modeling human diseases

    PubMed Central

    Lyons, Jesse; Herring, Charles A.; Banerjee, Amrita; Simmons, Alan J.

    2015-01-01

    When functioning properly, the intestine is one of the key interfaces between the human body and its environment. It is responsible for extracting nutrients from our food and excreting our waste products. It provides an environment for a host of healthful microbes and serves as a first defense against pathogenic ones. These processes require tight homeostatic controls, which are provided by the interactions of a complex mix of epithelial, stromal, neural and immune cells, as well as the resident microflora. This homeostasis can be disrupted by invasive microbes, genetic lesions, and carcinogens, resulting in diseases such Clostridium difficile infection, inflammatory bowel disease (IBD) and cancer. Enormous strides have been made in understanding how this important organ functions in health and disease using everything from cell culture systems to animal models to human tissue samples. This has resulted in better therapies for all of these diseases, but there is still significant room for improvement. In the United States alone, 14000 people per year die of C. difficile, up to 1.6 million people suffer from IBD, and more than 50000 people die every year from colon cancer. Because these and other intestinal diseases arise from complex interactions between the different components of the gut ecosystem, we propose that systems approaches that address this complexity in an integrative manner may eventually lead to improved therapeutics that deliver lasting cures. This review will discuss the use of systems biology for studying intestinal diseases in vivo with particular emphasis on mouse models. Additionally, it will focus on established experimental techniques that have been used to drive this systems-level analysis, and emerging techniques that will push this field forward in the future. PMID:26040649

  7. Herbal Therapy Is Equivalent to Rifaximin for the Treatment of Small Intestinal Bacterial Overgrowth

    PubMed Central

    Chedid, Victor; Dhalla, Sameer; Clarke, John O.; Roland, Bani Chander; Dunbar, Kerry B.; Koh, Joyce; Justino, Edmundo; Tomakin, Eric

    2014-01-01

    Objective: Patients with small intestine bacterial overgrowth (SIBO) have chronic intestinal and extraintestinal symptomatology which adversely affects their quality of life. Present treatment of SIBO is limited to oral antibiotics with variable success. A growing number of patients are interested in using complementary and alternative therapies for their gastrointestinal health. The objective was to determine the remission rate of SIBO using either the antibiotic rifaximin or herbals in a tertiary care referral gastroenterology practice. Design: One hundred and four patients who tested positive for newly diagnosed SIBO by lactulose breath testing (LBT) were offered either rifaximin 1200 mg daily vs herbal therapy for 4 weeks with repeat LBT post-treatment. Results: Three hundred ninety-six patients underwent LBT for suspected SIBO, of which 251 (63.4%) were positive 165 underwent treatment and 104 had a follow-up LBT. Of the 37 patients who received herbal therapy, 17 (46%) had a negative follow-up LBT compared to 23/67 (34%) of rifaximin users (P=.24). The odds ratio of having a negative LBT after taking herbal therapy as compared to rifaximin was 1.85 (CI=0.77-4.41, P=.17) once adjusted for age, gender, SIBO risk factors and IBS status. Fourteen of the 44 (31.8%) rifaximin non-responders were offered herbal rescue therapy, with 8 of the 14 (57.1%) having a negative LBT after completing the rescue herbal therapy, while 10 non-responders were offered triple antibiotics with 6 responding (60%, P=.89). Adverse effects were reported among the rifaximin treated arm including 1 case of anaphylaxis, 2 cases of hives, 2 cases of diarrhea and 1 case of Clostridium difficile. Only one case of diarrhea was reported in the herbal therapy arm, which did not reach statistical significance (P=.22). Conclusion: SIBO is widely prevalent in a tertiary referral gastroenterology practice. Herbal therapies are at least as effective as rifaximin for resolution of SIBO by LBT. Herbals also appear to be as effective as triple antibiotic therapy for SIBO rescue therapy for rifaximin non-responders. Further, prospective studies are needed to validate these findings and explore additional alternative therapies in patients with refractory SIBO. PMID:24891990

  8. Carbon Monoxide and Heme Oxygenase-1 Prevent Intestinal Inflammation in Mice by Promoting Bacterial Clearance

    PubMed Central

    Onyiah, Joseph C.; Sheikh, Shehzad Z.; Maharshak, Nitsan; Steinbach, Erin C.; Russo, Steven M.; Kobayashi, Taku; Mackey, Lantz C.; Hansen, Jonathan J.; Moeser, Adam J.; Rawls, John F.; Borst, Luke B.; Otterbein, Leo E.; Plevy, Scott E.

    2013-01-01

    BACKGROUND & AIMS Heme oxygenase-1 (HO-1) and its metabolic by-product, carbon monoxide (CO), protect against intestinal inflammation in experimental models of colitis, but little is known about their intestinal immune mechanisms. We investigated the interactions among CO, HO-1, and the enteric microbiota in mice and zebrafish. METHODS Germ-free, wild-type, and Il10−/− mice and germ free zebrafish embryos were colonized with pathogen-free (SPF). Germ-free or SPF-raised wild-type and Il10−/− mice were given intraperitoneal injections of cobalt protoporphyrin (CoPP), which upregulates HO-1, the CO releasing molecule ALF186, or saline (control). Colitis was induced in wild-type mice housed in SPF conditions by infection with S. typhimurium. RESULTS In colons of germ-free, wild-type mice, SPF microbiota induced production of HO-1 via activation of Nrf2–, IL-10–, and toll-like receptor–dependent pathways; similar observations were made in zebrafish. SPF microbiota did not induce HO-1 in colons of germ-free Il10−/− mice. Administration of CoPP to Il10−/− mice before transition from germ-free to SPF conditions reduced their development of colitis. In Il10−/− mice, CO and CoPP reduced levels of enteric bacterial genomic DNA in mesenteric lymph nodes (MLN). In mice with S. typhimurium-induced enterocolitis, CoPP reduced the numbers of live S. typhimurium recovered from the lamina propria, MLN, spleen, and liver. Knockdown of HO-1 in mouse macrophages impaired their bactericidal activity against E. coli, E. faecalis, and S. typhimurium, whereas exposure to CO or overexpression of HO-1 increased their bactericidal activity. HO-1 induction and CO increased acidification of phagolysosomes. CONCLUSIONS Colonic HO-1 prevents colonic inflammation in mice. HO-1 is induced by the enteric microbiota and its homeostatic function is mediated, in part, by promoting bactericidal activities of macrophages. PMID:23266559

  9. Effects of enrofloxacin on the human intestinal microbiota in vitro.

    TOXLINE Toxicology Bibliographic Information

    Chen T; Yuan J; Feng X; Wei H; Hua W

    2011-06-01

    An anaerobic, continuous-flow culture method has been developed to assess the effects of different levels of enrofloxacin (ENR) on the human intestinal microbiota. Chemostats containing human faecal flora were exposed to 1.25, 12.5 and 125 μg/mL ENR. Before and during drug exposure, samples aspirated from culture vessels were analysed using viable cell counting and denaturing gradient gel electrophoresis (DGGE). In addition, the colonisation resistance (CR) of the microbiota to Candida albicans SC5314 was evaluated. When exposed to 1.25 μg/mL ENR, total counts of aerobic bacteria, anaerobic bacteria, Lactobacillus, enterococci, Escherichia coli and Bacteroides fragilis were similar to the control group, except for Bifidobacterium; when exposed to 12.5 μg/mL and 125μg/mL ENR, numbers of categorised microorganisms changed significantly, except for B. fragilis. DGGE indicated that although 1.25 μg/mL ENR had little effect on the total number of microbiota, several bands representing dominant bacteria disappeared. The bands disappeared more quickly when exposed to 12.5 μg/mL and 125 μg/mL ENR. In addition to their influence on microbial diversity, different levels of ENR reduced the CR of the intestinal microbiota to C. albicans SC5314.

  10. Effects of enrofloxacin on the human intestinal microbiota in vitro.

    PubMed

    Chen, Tingtao; Yuan, Jing; Feng, Xu; Wei, Hong; Hua, Wei

    2011-06-01

    An anaerobic, continuous-flow culture method has been developed to assess the effects of different levels of enrofloxacin (ENR) on the human intestinal microbiota. Chemostats containing human faecal flora were exposed to 1.25, 12.5 and 125 μg/mL ENR. Before and during drug exposure, samples aspirated from culture vessels were analysed using viable cell counting and denaturing gradient gel electrophoresis (DGGE). In addition, the colonisation resistance (CR) of the microbiota to Candida albicans SC5314 was evaluated. When exposed to 1.25 μg/mL ENR, total counts of aerobic bacteria, anaerobic bacteria, Lactobacillus, enterococci, Escherichia coli and Bacteroides fragilis were similar to the control group, except for Bifidobacterium; when exposed to 12.5 μg/mL and 125μg/mL ENR, numbers of categorised microorganisms changed significantly, except for B. fragilis. DGGE indicated that although 1.25 μg/mL ENR had little effect on the total number of microbiota, several bands representing dominant bacteria disappeared. The bands disappeared more quickly when exposed to 12.5 μg/mL and 125 μg/mL ENR. In addition to their influence on microbial diversity, different levels of ENR reduced the CR of the intestinal microbiota to C. albicans SC5314. PMID:21420834

  11. Transgenic Expression of Human Lysophosphatidic Acid Receptor LPA2 in Mouse Intestinal Epithelial Cells Induces Intestinal Dysplasia

    PubMed Central

    Yoshida, Michihiro; He, Peijian; Yun, C. Chris

    2016-01-01

    Lysophosphatidic acid (LPA) acts on LPA2 receptor to mediate multiple pathological effects that are associated with tumorigenesis. The absence of LPA2 attenuates tumor progression in rodent models of colorectal cancer, but whether overexpression of LPA2 alone can lead to malignant transformation in the intestinal tract has not been studied. In this study, we expressed human LPA2 in intestinal epithelial cells (IECs) under control of the villin promoter. Less than 4% of F1-generation mice had germline transmission of transgenic (TG) human LPA2; as such only 3 F1 mice out of 72 genotyped had TG expression. These TG mice appeared anemic with hematochezia and died shortly after birth. TG mice were smaller in size compared with the wild type mouse of the same age and sex. Morphological analysis showed that TG LPA2 colon had hyper-proliferation of IECs resulting in increased colonic crypt depth. Surprisingly, TG small intestine had villus blunting and decreased IEC proliferation and dysplasia. In both intestine and colon, TG expression of LPA2 compromised the terminal epithelial differentiation, consistent with epithelial dysplasia. Furthermore, we showed that epithelial dysplasia was observed in founder mouse intestine, correlating LPA2 overexpression with epithelial dysplasia. The current study demonstrates that overexpression of LPA2 alone can lead to intestinal dysplasia. PMID:27124742

  12. Effects of laxative and N-acetylcysteine on mucus accumulation, bacterial load, transit, and inflammation in the cystic fibrosis mouse small intestine.

    PubMed

    De Lisle, Robert C; Roach, Eileen; Jansson, Kyle

    2007-09-01

    The accumulation of mucus in affected organs is characteristic of cystic fibrosis (CF). The CF mouse small intestine has dramatic mucus accumulation and exhibits slower interdigestive intestinal transit. These factors are proposed to play cooperative roles that foster small intestinal bacterial overgrowth (SIBO) and contribute to the innate immune response of the CF intestine. It was hypothesized that decreasing the mucus accumulation would reduce SIBO and might improve other aspects of the CF intestinal phenotype. To test this, solid chow-fed CF mice were treated with an osmotic laxative to improve gut hydration or liquid-fed mice were treated orally with N-acetylcysteine (NAC) to break mucin disulfide bonds. Treatment with laxative or NAC reduced mucus accumulation by 43% and 50%, respectively, as measured histologically as dilation of the intestinal crypts. Laxative and NAC also reduced bacterial overgrowth in the CF intestine by 92% and 63%, respectively. Treatment with laxative normalized small intestinal transit in CF mice, whereas NAC did not. The expression of innate immune response-related genes was significantly reduced in laxative-treated CF mice, whereas there was no significant effect in NAC-treated CF mice. In summary, laxative and NAC treatments of CF mice reduced mucus accumulation to a similar extent, but laxative was more effective than NAC at reducing bacterial load. Eradication of bacterial overgrowth by laxative treatment was associated with normalized intestinal transit and a reduction in the innate immune response. These results suggest that both mucus accumulation and slowed interdigestive small intestinal transit contribute to SIBO in the CF intestine. PMID:17615175

  13. Comparison of DNA extraction kits for PCR-DGGE analysis of human intestinal microbial communities from fecal specimens

    PubMed Central

    2010-01-01

    Background The influence of diet on intestinal microflora has been investigated mainly using conventional microbiological approaches. Although these studies have advanced knowledge on human intestinal microflora, it is imperative that new methods are applied to facilitate scientific progress. Culture-independent molecular fingerprinting method of Polymerase Chain Reaction and Denaturing Gradient Gel Electrophoresis (PCR-DGGE) has been used to study microbial communities in a variety of environmental samples. However, these protocols must be optimized prior to their application in order to enhance the quality and accuracy of downstream analyses. In this study, the relative efficacy of four commercial DNA extraction kits (Mobio Ultra Clean Fecal DNA Isolation Kit, M; QIAamp DNA Stool Mini Kit, Q; FastDNA SPIN Kit, FSp; FastDNA SPIN Kit for Soil, FSo) were evaluated. Further, PCR-DGGE technique was also assessed for its feasibility in detecting differences in human intestinal bacterial fingerprint profiles. Method Total DNA was extracted from varying weights of human fecal specimens using four different kits, followed by PCR amplification of bacterial 16S rRNA genes, and DGGE separation of the amplicons. Results Regardless of kit, maximum DNA yield was obtained using 10 to 50 mg (wet wt) of fecal specimens and similar DGGE profiles were obtained. However, kits FSp and FSo extracted significantly larger amounts of DNA per g dry fecal specimens and produced more bands on their DGGE profiles than kits M and Q due to their use of bead-containing lysing matrix and vigorous shaking step. DGGE of 16S rRNA gene PCR products was suitable for capturing the profiles of human intestinal microbial community and enabled rapid comparative assessment of inter- and intra-subject differences. Conclusion We conclude that extraction kits that incorporated bead-containing lysing matrix and vigorous shaking produced high quality DNA from human fecal specimens (10 to 50 mg, wet wt) that can be resolved as bacterial community fingerprints using PCR-DGGE technique. Subsequently, PCR-DGGE technique can be applied for studying variations in human intestinal microbial communities. PMID:20492702

  14. Utilization of rye as energy source affects bacterial translocation, intestinal viscosity, microbiota composition, and bone mineralization in broiler chickens.

    PubMed

    Tellez, Guillermo; Latorre, Juan D; Kuttappan, Vivek A; Kogut, Michael H; Wolfenden, Amanda; Hernandez-Velasco, Xochitl; Hargis, Billy M; Bottje, Walter G; Bielke, Lisa R; Faulkner, Olivia B

    2014-01-01

    Two independent trials were conducted to evaluate the utilization of rye as energy source on bacterial translocation (BT), intestinal viscosity, gut integrity, gut microbiota composition, and bone mineralization, when compared with a traditional cereal (corn) in broiler chickens. In each experiment, day-of-hatch, broiler chickens were randomly assigned to either a corn or a rye diet (n = 20 chickens/group). At 10 d of age, in both experiments, 12 chickens/group were randomly selected, and given an oral gavage dose of fluorescein isothiocyanate dextran (FITC-d). After 2.5 h of oral gavage, blood samples were collected to determine the passage of FITC-d. The liver was collected from each bird to evaluate BT. Duodenum, ileum, and cecum gut sections were collected to evaluate intestinal viscosity and to enumerate gut microbiota. Tibias were collected for observation of bone parameters. Broilers fed with rye showed increased (p < 0.05) intestinal viscosity, BT, and serum FITC-d. Bacterial enumeration revealed that chickens fed with rye had increased the number of total lactic acid bacteria in all three sections of the gastrointestinal tract evaluated when compared to chickens fed with corn. Chickens fed with rye also had significantly higher coliforms in duodenum and ileum, whereas the total number of anaerobes increased only in duodenum. A significant reduction in bone strength and bone mineralization was observed in chickens fed with rye when compared with corn fed chickens. In conclusion, rye evoked mucosal damage in chickens that alter the intestinal viscosity, increased leakage through the intestinal tract, and altered the microbiota composition as well as bone mineralization. Studies to evaluate dietary inclusion of selected DFM candidates that produce exogenous enzymes in rye fed chickens are currently being evaluated. PMID:25309584

  15. Utilization of rye as energy source affects bacterial translocation, intestinal viscosity, microbiota composition, and bone mineralization in broiler chickens

    PubMed Central

    Tellez, Guillermo; Latorre, Juan D.; Kuttappan, Vivek A.; Kogut, Michael H.; Wolfenden, Amanda; Hernandez-Velasco, Xochitl; Hargis, Billy M.; Bottje, Walter G.; Bielke, Lisa R.; Faulkner, Olivia B.

    2014-01-01

    Two independent trials were conducted to evaluate the utilization of rye as energy source on bacterial translocation (BT), intestinal viscosity, gut integrity, gut microbiota composition, and bone mineralization, when compared with a traditional cereal (corn) in broiler chickens. In each experiment, day-of-hatch, broiler chickens were randomly assigned to either a corn or a rye diet (n = 20 chickens/group). At 10 d of age, in both experiments, 12 chickens/group were randomly selected, and given an oral gavage dose of fluorescein isothiocyanate dextran (FITC-d). After 2.5 h of oral gavage, blood samples were collected to determine the passage of FITC-d. The liver was collected from each bird to evaluate BT. Duodenum, ileum, and cecum gut sections were collected to evaluate intestinal viscosity and to enumerate gut microbiota. Tibias were collected for observation of bone parameters. Broilers fed with rye showed increased (p < 0.05) intestinal viscosity, BT, and serum FITC-d. Bacterial enumeration revealed that chickens fed with rye had increased the number of total lactic acid bacteria in all three sections of the gastrointestinal tract evaluated when compared to chickens fed with corn. Chickens fed with rye also had significantly higher coliforms in duodenum and ileum, whereas the total number of anaerobes increased only in duodenum. A significant reduction in bone strength and bone mineralization was observed in chickens fed with rye when compared with corn fed chickens. In conclusion, rye evoked mucosal damage in chickens that alter the intestinal viscosity, increased leakage through the intestinal tract, and altered the microbiota composition as well as bone mineralization. Studies to evaluate dietary inclusion of selected DFM candidates that produce exogenous enzymes in rye fed chickens are currently being evaluated. PMID:25309584

  16. Use of Stable Isotopes To Measure the Metabolic Activity of the Human Intestinal Microbiota▿

    PubMed Central

    Reichardt, Nicole; Barclay, Andrew R.; Weaver, Lawrence T.; Morrison, Douglas J.

    2011-01-01

    The human intestinal microbiota is a complex biological system comprising a vast repertoire of microbes with considerable metabolic activity relevant to both bacterial growth and host health. Greater strides have been made in the analysis of microbial diversity than in the measurement of functional activity, particularly in vivo. Stable isotope probing offers a new approach by coupling measurements of metabolic activity with microbial identification. Using a low-enrichment labeling strategy in vitro, this study has identified metabolically active bacterial groups via magnetic-bead capture methodology and stable isotope ratio analysis. Using five probes (EUB338, Bac303, Bif164, EREC482, and Clep866), changes in the activities of key intestinal microbial groups were successfully measured by exploiting tracers of de novo RNA synthesis. Perturbation of the nutrient source with oligofructose generated changes in the activity of bifidobacteria as expected, but also in the Bacteroides-Prevotella group, the Eubacterium rectale-Clostridium coccoides group, and the Clostridium leptum subgroup. Changes in activity were also observed in response to the medium type. This study suggests that changes in the functional activity of the gut microbiota can be assessed using tracers of de novo nucleic acid synthesis combined with measurement of low isotopic enrichment in 16S rRNA. Such tracers potentially limit substrate bias because they are universally available to bacteria. This low-enrichment labeling approach does not depend on the commercial availability of specific labeled substrates and can be easily translated to in vivo probing experiments of the functional activity of the microbiota in the human gut. PMID:21948826

  17. An in vivo model of human small intestine using pluripotent stem cells.

    PubMed

    Watson, Carey L; Mahe, Maxime M; Múnera, Jorge; Howell, Jonathan C; Sundaram, Nambirajan; Poling, Holly M; Schweitzer, Jamie I; Vallance, Jefferson E; Mayhew, Christopher N; Sun, Ying; Grabowski, Gregory; Finkbeiner, Stacy R; Spence, Jason R; Shroyer, Noah F; Wells, James M; Helmrath, Michael A

    2014-11-01

    Differentiation of human pluripotent stem cells (hPSCs) into organ-specific subtypes offers an exciting avenue for the study of embryonic development and disease processes, for pharmacologic studies and as a potential resource for therapeutic transplant. To date, limited in vivo models exist for human intestine, all of which are dependent upon primary epithelial cultures or digested tissue from surgical biopsies that include mesenchymal cells transplanted on biodegradable scaffolds. Here, we generated human intestinal organoids (HIOs) produced in vitro from human embryonic stem cells (ESCs) or induced pluripotent stem cells (iPSCs) that can engraft in vivo. These HIOs form mature human intestinal epithelium with intestinal stem cells contributing to the crypt-villus architecture and a laminated human mesenchyme, both supported by mouse vasculature ingrowth. In vivo transplantation resulted in marked expansion and maturation of the epithelium and mesenchyme, as demonstrated by differentiated intestinal cell lineages (enterocytes, goblet cells, Paneth cells, tuft cells and enteroendocrine cells), presence of functional brush-border enzymes (lactase, sucrase-isomaltase and dipeptidyl peptidase 4) and visible subepithelial and smooth muscle layers when compared with HIOs in vitro. Transplanted intestinal tissues demonstrated digestive functions as shown by permeability and peptide uptake studies. Furthermore, transplanted HIO-derived tissue was responsive to systemic signals from the host mouse following ileocecal resection, suggesting a role for circulating factors in the intestinal adaptive response. This model of the human small intestine may pave the way for studies of intestinal physiology, disease and translational studies. PMID:25326803

  18. Carriage of ? Latent Virus Is Costly for Its Bacterial Host due to Frequent Reactivation in Monoxenic Mouse Intestine.

    PubMed

    De Paepe, Marianne; Tournier, Laurent; Moncaut, Elisabeth; Son, Olivier; Langella, Philippe; Petit, Marie-Agns

    2016-02-01

    Temperate phages, the bacterial viruses able to enter in a dormant prophage state in bacterial genomes, are present in the majority of bacterial strains for which the genome sequence is available. Although these prophages are generally considered to increase their hosts' fitness by bringing beneficial genes, studies demonstrating such effects in ecologically relevant environments are relatively limited to few bacterial species. Here, we investigated the impact of prophage carriage in the gastrointestinal tract of monoxenic mice. Combined with mathematical modelling, these experimental results provided a quantitative estimation of key parameters governing phage-bacteria interactions within this model ecosystem. We used wild-type and mutant strains of the best known host/phage pair, Escherichia coli and phage ?. Unexpectedly, ? prophage caused a significant fitness cost for its carrier, due to an induction rate 50-fold higher than in vitro, with 1 to 2% of the prophage being induced. However, when prophage carriers were in competition with isogenic phage susceptible bacteria, the prophage indirectly benefited its carrier by killing competitors: infection of susceptible bacteria led to phage lytic development in about 80% of cases. The remaining infected bacteria were lysogenized, resulting overall in the rapid lysogenization of the susceptible lineage. Moreover, our setup enabled to demonstrate that rare events of phage gene capture by homologous recombination occurred in the intestine of monoxenic mice. To our knowledge, this study constitutes the first quantitative characterization of temperate phage-bacteria interactions in a simplified gut environment. The high prophage induction rate detected reveals DNA damage-mediated SOS response in monoxenic mouse intestine. We propose that the mammalian gut, the most densely populated bacterial ecosystem on earth, might foster bacterial evolution through high temperate phage activity. PMID:26871586

  19. Carriage of λ Latent Virus Is Costly for Its Bacterial Host due to Frequent Reactivation in Monoxenic Mouse Intestine

    PubMed Central

    De Paepe, Marianne; Tournier, Laurent; Moncaut, Elisabeth; Son, Olivier; Langella, Philippe; Petit, Marie-Agnès

    2016-01-01

    Temperate phages, the bacterial viruses able to enter in a dormant prophage state in bacterial genomes, are present in the majority of bacterial strains for which the genome sequence is available. Although these prophages are generally considered to increase their hosts’ fitness by bringing beneficial genes, studies demonstrating such effects in ecologically relevant environments are relatively limited to few bacterial species. Here, we investigated the impact of prophage carriage in the gastrointestinal tract of monoxenic mice. Combined with mathematical modelling, these experimental results provided a quantitative estimation of key parameters governing phage-bacteria interactions within this model ecosystem. We used wild-type and mutant strains of the best known host/phage pair, Escherichia coli and phage λ. Unexpectedly, λ prophage caused a significant fitness cost for its carrier, due to an induction rate 50-fold higher than in vitro, with 1 to 2% of the prophage being induced. However, when prophage carriers were in competition with isogenic phage susceptible bacteria, the prophage indirectly benefited its carrier by killing competitors: infection of susceptible bacteria led to phage lytic development in about 80% of cases. The remaining infected bacteria were lysogenized, resulting overall in the rapid lysogenization of the susceptible lineage. Moreover, our setup enabled to demonstrate that rare events of phage gene capture by homologous recombination occurred in the intestine of monoxenic mice. To our knowledge, this study constitutes the first quantitative characterization of temperate phage-bacteria interactions in a simplified gut environment. The high prophage induction rate detected reveals DNA damage-mediated SOS response in monoxenic mouse intestine. We propose that the mammalian gut, the most densely populated bacterial ecosystem on earth, might foster bacterial evolution through high temperate phage activity. PMID:26871586

  20. Parenteral Nutrition Decreases Paneth cell function and Intestinal Bactericidal Activity while Increasing Susceptibility to Bacterial Enteroinvasion

    PubMed Central

    Tandee, Kanokwan; Shanmuganayagam, Dhanansayan; Wang, Xinying; Reed, Jess D.; Steele, James L; Kudsk, Kenneth A

    2016-01-01

    Introduction Parenteral nutrition (PN) increases the risk of infection in patients with contraindication to enteral feeding. Paneth cells produce and secrete antimicrobial products that protect the mucosa from pathogens. Their loss is associated with increased host-pathogen interactions, mucosal inflammation, and altered microbiome composition. Hypothesis We hypothesized that PN reduces Paneth cell product expression, and these changes would reduce bactericidal properties of tissue secretions following cholinergic stimulation, increase mucosal enteroinvasion, and shift the intestinal microbiome. Method Expt 1: Male ICR mice were randomized to Chow (n=8) or PN (n=8). Ileum tissue was collected for Paneth cell antimicrobial expression using RT-PCR, stimulated with a cholinergic agonist degranulate Paneth cells bactericidal activity, or used to assess bacterial enteroinvasion in EVISC. Expt 2. Mice were randomized to Chow (n=11) or PN (n=8) and ileum washing was collected for 16s pyrosequencing analysis. Results Compared to Chow, PN decreased tissue expression of REGIII-γ (p < 0.002), lysozyme (p < 0.002), and cryptdin-4 (p < 0.03). At the phylum level, PN decreased total Firmicutes but increased total Bacteroidetes, and Proteobacteria. Functionally, secretions from PN tissue was less bactericidal (p < 0.03) and demonstrated increased susceptibility to enteroinvasion by E. coli (p < 0.02). Conclusion PN without enteral nutrition impairs innate mucosal immune function. Tissue expression of Paneth cell antimicrobial proteins decreases associated with compositional shifts to the microbiome, decreased bactericidal activity of mucosal secretions and greater susceptibility of to enteroinvasion by E. coli. These changes may explain in-part the increased risk of infection in parenterally fed patients. PMID:23894173

  1. Prevalence and treatment of small intestinal bacterial overgrowth in postoperative patients with colorectal cancer

    PubMed Central

    DENG, LIHUA; LIU, YANG; ZHANG, DONGSHENG; LI, YUAN; XU, LIN

    2016-01-01

    To investigate the prevalence of small intestinal bacterial overgrowth (SIBO) in patients with colorectal cancer (CRC) after surgical treatment and observe whether gastrointestinal symptoms may improve with rifaximin, 43 postoperative CRC patients (CRC group) and 30 healthy individuals (normal group) were subjected to the glucose hydrogen breath test (GHBT). All the patients were asked to evaluate the gastrointestinal symptoms using the visual analogue scale (VAS). SIBO-positive patients were administered rifaximin for 10 days on the basis of the original treatment. After the treatment, the patients were asked to undergo GHBT and re-evaluate the gastrointestinal symptoms score (GISS). The results demonstrated that 18 of the 43 postoperative patients with CRC were SIBO-positive (41.86%), which was significantly higher compared with the incidence in normal controls (6.67%) (P<0.05). GISS was higher in SIBO-positive patients (P<0.05). Following rifaximin treatment, 6 of the 18 (33.33%) SIBO-positive patients had improved, as evaluated by GHBT and VAS. Additionally, the GISS in the SIBO-turned-negative group had improved significantly compared with that in the non-turned-negative group (P<0.05). The symptoms of all 18 SIBO-positive patients following rifaximin treatment improved notably, particularly diarrhea (P<0.05). In conclusion, postoperative CRC patients are more likely to develop SIBO compared with healthy individuals, and SIBO may aggravate digestive symptoms. The administration of rifaximin improved the overall gastrointestinal symptoms, particularly diarrhea, in SIBO-positive patients. PMID:27123301

  2. Human and mouse tissue-engineered small intestine both demonstrate digestive and absorptive function.

    PubMed

    Grant, Christa N; Mojica, Salvador Garcia; Sala, Frederic G; Hill, J Ryan; Levin, Daniel E; Speer, Allison L; Barthel, Erik R; Shimada, Hiroyuki; Zachos, Nicholas C; Grikscheit, Tracy C

    2015-04-15

    Short bowel syndrome (SBS) is a devastating condition in which insufficient small intestinal surface area results in malnutrition and dependence on intravenous parenteral nutrition. There is an increasing incidence of SBS, particularly in premature babies and newborns with congenital intestinal anomalies. Tissue-engineered small intestine (TESI) offers a therapeutic alternative to the current standard treatment, intestinal transplantation, and has the potential to solve its biggest challenges, namely donor shortage and life-long immunosuppression. We have previously demonstrated that TESI can be generated from mouse and human small intestine and histologically replicates key components of native intestine. We hypothesized that TESI also recapitulates native small intestine function. Organoid units were generated from mouse or human donor intestine and implanted into genetically identical or immunodeficient host mice. After 4 wk, TESI was harvested and either fixed and paraffin embedded or immediately subjected to assays to illustrate function. We demonstrated that both mouse and human tissue-engineered small intestine grew into an appropriately polarized sphere of intact epithelium facing a lumen, contiguous with supporting mesenchyme, muscle, and stem/progenitor cells. The epithelium demonstrated major ultrastructural components, including tight junctions and microvilli, transporters, and functional brush-border and digestive enzymes. This study demonstrates that tissue-engineered small intestine possesses a well-differentiated epithelium with intact ion transporters/channels, functional brush-border enzymes, and similar ultrastructural components to native tissue, including progenitor cells, whether derived from mouse or human cells. PMID:25573173

  3. Intestinal Short Chain Fatty Acids and their Link with Diet and Human Health

    PubMed Central

    Ríos-Covián, David; Ruas-Madiedo, Patricia; Margolles, Abelardo; Gueimonde, Miguel; de los Reyes-Gavilán, Clara G.; Salazar, Nuria

    2016-01-01

    The colon is inhabited by a dense population of microorganisms, the so-called “gut microbiota,” able to ferment carbohydrates and proteins that escape absorption in the small intestine during digestion. This microbiota produces a wide range of metabolites, including short chain fatty acids (SCFA). These compounds are absorbed in the large bowel and are defined as 1-6 carbon volatile fatty acids which can present straight or branched-chain conformation. Their production is influenced by the pattern of food intake and diet-mediated changes in the gut microbiota. SCFA have distinct physiological effects: they contribute to shaping the gut environment, influence the physiology of the colon, they can be used as energy sources by host cells and the intestinal microbiota and they also participate in different host-signaling mechanisms. We summarize the current knowledge about the production of SCFA, including bacterial cross-feedings interactions, and the biological properties of these metabolites with impact on the human health. PMID:26925050

  4. Intestinal Short Chain Fatty Acids and their Link with Diet and Human Health.

    PubMed

    Ríos-Covián, David; Ruas-Madiedo, Patricia; Margolles, Abelardo; Gueimonde, Miguel; de Los Reyes-Gavilán, Clara G; Salazar, Nuria

    2016-01-01

    The colon is inhabited by a dense population of microorganisms, the so-called "gut microbiota," able to ferment carbohydrates and proteins that escape absorption in the small intestine during digestion. This microbiota produces a wide range of metabolites, including short chain fatty acids (SCFA). These compounds are absorbed in the large bowel and are defined as 1-6 carbon volatile fatty acids which can present straight or branched-chain conformation. Their production is influenced by the pattern of food intake and diet-mediated changes in the gut microbiota. SCFA have distinct physiological effects: they contribute to shaping the gut environment, influence the physiology of the colon, they can be used as energy sources by host cells and the intestinal microbiota and they also participate in different host-signaling mechanisms. We summarize the current knowledge about the production of SCFA, including bacterial cross-feedings interactions, and the biological properties of these metabolites with impact on the human health. PMID:26925050

  5. Regulatory T cells promote a protective Th17-associated immune response to intestinal bacterial infection with C. rodentium.

    PubMed

    Wang, Z; Friedrich, C; Hagemann, S C; Korte, W H; Goharani, N; Cording, S; Eberl, G; Sparwasser, T; Lochner, M

    2014-11-01

    Intestinal infection with the mouse pathogen Citrobacter rodentium induces a strong local Th17 response in the colon. Although this inflammatory immune response helps to clear the pathogen, it also induces inflammation-associated pathology in the gut and thus, has to be tightly controlled. In this project, we therefore studied the impact of Foxp3(+) regulatory T cells (Treg) on the infectious and inflammatory processes elicited by the bacterial pathogen C. rodentium. Surprisingly, we found that depletion of Treg by diphtheria toxin in the Foxp3(DTR) (DEREG) mouse model resulted in impaired bacterial clearance in the colon, exacerbated body weight loss, and increased systemic dissemination of bacteria. Consistent with the enhanced susceptibility to infection, we found that the colonic Th17-associated T-cell response was impaired in Treg-depleted mice, suggesting that the presence of Treg is crucial for the establishment of a functional Th17 response after the infection in the gut. As a consequence of the impaired Th17 response, we also observed less inflammation-associated pathology in the colons of Treg-depleted mice. Interestingly, anti-interleukin (IL)-2 treatment of infected Treg-depleted mice restored Th17 induction, indicating that Treg support the induction of a protective Th17 response during intestinal bacterial infection by consumption of local IL-2. PMID:24646939

  6. In vitro analysis of the impact of enrofloxacin residues on the human intestinal microbiota using H-NMR spectroscopy.

    PubMed

    Ahn, Youngbeom; Jung, Ji Young; Chung, Yong Hyun; Chae, Minho; Jeon, Che Ok; Cerniglia, Carl E

    2012-01-01

    Exposure of humans to antimicrobial residues in food-producing animals may alter the intestinal microbiota which could result in a potential risk to human health. To determine the effect of enrofloxacin on the human intestinal microbiota, fecal suspensions (25%) were cultured in the presence of 0.06-5 µg/ml enrofloxacin. The bacterial community was analyzed by plating on selective culture media, pyrosequencing and nuclear magnetic resonance (NMR) spectroscopy. Pyrosequencing analysis of 16S rRNA genes and viable counts on Bacteroides sp., Enterococcus sp., and Bifidobacterium sp. selection medium indicated that there were no significant changes in the bacteria numbers at the selected enrofloxacin concentrations (0.06, 0.1, and 1 µg/ml) relative to the control samples after a 48 h incubation. NMR analysis showed remarkably similar spectra in cultures treated with 0.06, 0.1, and 1 µg/ml enrofloxacin, with some slight differences in peak heights. However, hierarchical clustering analysis indicated significant differences in metabolite concentrations between the control and those samples treated with 1 µg/ml enrofloxacin. Leucine, phenylalanine, proline, and 2-oxovalerate were positively correlated with the concentration of enrofloxacin. NMR analysis is a potentially useful tool to monitor changes of the human intestinal microbiota, in addition to traditional culture methods and pyrosequencing. PMID:23221505

  7. Difficult case of Cronkhite-Canada syndrome with small intestinal bacterial overgrowth, Clostridium difficile infection and polymyalgia rheumatica.

    PubMed

    Traussnigg, Stefan; Dolak, Werner; Trauner, Michael; Kazemi-Shirazi, Lili

    2016-01-01

    A 64-year-old woman presented with heavy diarrhoea, nausea and weight loss accompanied by alopecia and dystrophic fingernails and toenails. The preceding diagnosis of an inflammatory bowel disease, a common pitfall, was excluded by endoscopic work up. Instead, Cronkhite-Canada syndrome (CCS), a rare polyposis condition, was identified as the reason for this almost pathognomonic combination of diagnostic findings including various polyps throughout the entire intestine and ectodermal abnormalities. This case exemplifies common risks and complications in terms of gastrointestinal malabsorption, infections and small intestinal bacterial overgrowth (SIBO), including its treatment as well as a hereto unreported association with polymyalgia rheumatica. In CCS, long-term immunosuppressive therapy and close endoscopic cancer screening of the patient is essential. The treatment of vitamin deficiency and recurring SIBO helps to reduce symptoms. PMID:26818813

  8. A comprehensive metatranscriptome analysis pipeline and its validation using human small intestine microbiota datasets

    PubMed Central

    2013-01-01

    Background Next generation sequencing (NGS) technologies can be applied in complex microbial ecosystems for metatranscriptome analysis by employing direct cDNA sequencing, which is known as RNA sequencing (RNA-seq). RNA-seq generates large datasets of great complexity, the comprehensive interpretation of which requires a reliable bioinformatic pipeline. In this study, we focus on the development of such a metatranscriptome pipeline, which we validate using Illumina RNA-seq datasets derived from the small intestine microbiota of two individuals with an ileostomy. Results The metatranscriptome pipeline developed here enabled effective removal of rRNA derived sequences, followed by confident assignment of the predicted function and taxonomic origin of the mRNA reads. Phylogenetic analysis of the small intestine metatranscriptome datasets revealed a strong similarity with the community composition profiles obtained from 16S rDNA and rRNA pyrosequencing, indicating considerable congruency between community composition (rDNA), and the taxonomic distribution of overall (rRNA) and specific (mRNA) activity among its microbial members. Reproducibility of the metatranscriptome sequencing approach was established by independent duplicate experiments. In addition, comparison of metatranscriptome analysis employing single- or paired-end sequencing methods indicated that the latter approach does not provide improved functional or phylogenetic insights. Metatranscriptome functional-mapping allowed the analysis of global, and genus specific activity of the microbiota, and illustrated the potential of these approaches to unravel syntrophic interactions in microbial ecosystems. Conclusions A reliable pipeline for metatransciptome data analysis was developed and evaluated using RNA-seq datasets obtained for the human small intestine microbiota. The set-up of the pipeline is very generic and can be applied for (bacterial) metatranscriptome analysis in any chosen niche. PMID:23915218

  9. Dysmotility and ppi use are independent risk factors for small intestinal bacterial and/or fungal overgrowth

    PubMed Central

    Jacobs, C; Coss Adame, E; Attaluri, A; Valestin, J; Rao, SSC

    2013-01-01

    Introduction Whether intestinal dysmotility and proton pump inhibitor (PPI) use either independently or together contributes to small intestinal bacterial overgrowth (SIBO), and/or small intestinal fungal overgrowth (SIFO) is not known. Aim Investigate the role of dysmotility and PPI use in patients with persistent gastrointestinal complaints. Methods Patients with unexplained gastrointestinal symptoms and negative endoscopy/radiology tests completed a validated symptom questionnaire and underwent 24-hour ambulatory antro-duodeno-jejunal manometry (ADJM). Simultaneously, duodenal aspirate was obtained for aerobic, anaerobic and fungal culture. Dysmotility was diagnosed by (> 2): absent phase III MMC, absent/diminished postprandial response, diminished amplitude of antral/intestinal phasic activity, impaired antro-duodenal coordination. Bacterial growth ≥103 CFU/mL or fungal growth was considered evidence for SIBO/SIFO. PPI use was documented. Correlation of symptoms with presence of SIBO or SIFO were assessed. Results 150 subjects (M/F=47/103) were evaluated; 94/150 (63%) had overgrowth: 38/94 (40%) had SIBO, 24/94 (26%) had SIFO, and 32/94 (34%) had mixed SIBO/SIFO. SIBO was predominately due to Streptococcus, Enterococcus, Klebsiella, and E. coli. SIFO was due to Candida. 80/150 (53%) patients had dysmotility and 65/150 (43%) used PPI. PPI use (p=.0063) and Dysmotility (p=.0003) were independent significant risk factors (p<0.05) for overgrowth, but together did not pose additional risk. Symptom profiles were similar between those with or without SIBO/SIFO. Conclusions Dysmotility and PPI use were independent risk factors for SIBO or SIFO and were present in over 50% of subjects with unexplained gastrointestinal symptoms. Diagnosis of overgrowth requires testing because symptoms were poor predictors of overgrowth. PMID:23574267

  10. Quantitative prediction of intestinal metabolism in humans from a simplified intestinal availability model and empirical scaling factor.

    PubMed

    Kadono, Keitaro; Akabane, Takafumi; Tabata, Kenji; Gato, Katsuhiko; Terashita, Shigeyuki; Teramura, Toshio

    2010-07-01

    This study aimed to establish a practical and convenient method of predicting intestinal availability (F(g)) in humans for highly permeable compounds at the drug discovery stage, with a focus on CYP3A4-mediated metabolism. We constructed a "simplified F(g) model," described using only metabolic parameters, assuming that passive diffusion is dominant when permeability is high and that the effect of transporters in epithelial cells is negligible. Five substrates for CYP3A4 (alprazolam, amlodipine, clonazepam, midazolam, and nifedipine) and four for both CYP3A4 and P-glycoprotein (P-gp) (nicardipine, quinidine, tacrolimus, and verapamil) were used as model compounds. Observed fraction of drug absorbed (F(a)F(g)) values for these compounds were calculated from in vivo pharmacokinetic (PK) parameters, whereas in vitro intestinal intrinsic clearance (CL(int,intestine)) was determined using human intestinal microsomes. The CL(int,intestine) for the model compounds corrected with that of midazolam was defined as CL(m,index) and incorporated into a simplified F(g) model with empirical scaling factor. Regardless of whether the compound was a P-gp substrate, the F(a)F(g) could be reasonably fitted by the simplified F(g) model, and the value of the empirical scaling factor was well estimated. These results suggest that the effects of P-gp on F(a) and F(g) are substantially minor, at least in the case of highly permeable compounds. Furthermore, liver intrinsic clearance (CL(int,liver)) can be used as a surrogate index of intestinal metabolism based on the relationship between CL(int,liver) and CL(m,index). F(g) can be easily predicted using a simplified F(g) model with the empirical scaling factor, enabling more confident selection of drug candidates with desirable PK profiles in humans. PMID:20354105

  11. Human in vivo regional intestinal permeability: quantitation using site-specific drug absorption data.

    PubMed

    Sjögren, Erik; Dahlgren, David; Roos, Carl; Lennernäs, Hans

    2015-06-01

    Application of information on regional intestinal permeability has been identified as a key aspect of successful pharmaceutical product development. This study presents the results and evaluation of an approach for the indirect estimation of site-specific in vivo intestinal effective permeability (Peff) in humans. Plasma concentration-time profiles from 15 clinical studies that administered drug solutions to specific intestinal regions were collected and analyzed. The intestinal absorption rate for each drug was acquired by deconvolution, using historical intravenous data as reference, and used with the intestinal surface area and the dose remaining in the lumen to estimate the Peff. Forty-three new Peff values were estimated (15 from the proximal small intestine, 11 from the distal small intestine, and 17 from the large intestine) for 14 active pharmaceutical ingredients representing a wide range of biopharmaceutical properties. A good correlation (r(2) = 0.96, slope = 1.24, intercept = 0.030) was established between these indirect jejunal Peff estimates and jejunal Peff measurements determined directly using the single-pass perfusion double balloon technique. On average, Peff estimates from the distal small intestine and large intestine were 90% and 40%, respectively, of those from the proximal small intestine. These results support the use of the evaluated deconvolution method for indirectly estimating regional intestinal Peff in humans. This study presents the first comprehensive data set of estimated human regional intestinal permeability values for a range of drugs. These biopharmaceutical data can be used to improve the accuracy of gastrointestinal absorption predictions used in drug development decision-making. PMID:25919764

  12. Bats as Reservoir Hosts of Human Bacterial Pathogen, Bartonella mayotimonensis

    PubMed Central

    Veikkolainen, Ville; Vesterinen, Eero J.; Lilley, Thomas M.

    2014-01-01

    A plethora of pathogenic viruses colonize bats. However, bat bacterial flora and its zoonotic threat remain ill defined. In a study initially conducted as a quantitative metagenomic analysis of the fecal bacterial flora of the Daubenton’s bat in Finland, we unexpectedly detected DNA of several hemotrophic and ectoparasite-transmitted bacterial genera, including Bartonella. Bartonella spp. also were either detected or isolated from the peripheral blood of Daubenton's, northern, and whiskered bats and were detected in the ectoparasites of Daubenton's, northern, and Brandt's bats. The blood isolates belong to the Candidatus-status species B. mayotimonensis, a recently identified etiologic agent of endocarditis in humans, and a new Bartonella species (B. naantaliensis sp. nov.). Phylogenetic analysis of bat-colonizing Bartonella spp. throughout the world demonstrates a distinct B. mayotimonensis cluster in the Northern Hemisphere. The findings of this field study highlight bats as potent reservoirs of human bacterial pathogens. PMID:24856523

  13. Helicobacter pylori infection but not small intestinal bacterial overgrowth may play a pathogenic role in rosacea

    PubMed Central

    Federico, A; Ruocco, E; Lo Schiavo, A; Masarone, M; Tuccillo, C; Peccerillo, F; Miranda, A; Romano, L; de Sio, C; de Sio, I; Persico, M; Ruocco, V; Riegler, G; Loguercio, C; Romano, M

    2015-01-01

    Background and aims Recent studies suggest a potential relationship between rosacea and Helicobacter pylori (H. pylori) infection or small intestinal bacterial overgrowth (SIBO), but there is no firm evidence of an association between rosacea and H. pylori infection or SIBO. We performed a prospective study to assess the prevalence of H. pylori infection and/or SIBO in patients with rosacea and evaluated the effect of H. pylori or SIBO eradication on rosacea. Methods We enrolled 90 patients with rosacea from January 2012 to January 2013 and a control group consisting of 90 patients referred to us because of mapping of nevi during the same period. We used the 13C Urea Breath Test and H. pylori stool antigen (HpSA) test to assess H. pylori infection and the glucose breath test to assess SIBO. Patients infected by H. pylori were treated with clarithromycin-containing sequential therapy. Patients positive for SIBO were treated with rifaximin. Results We found that 44/90 (48.9%) patients with rosacea and 24/90 (26.7%) control subjects were infected with H. pylori (p = 0.003). Moreover, 9/90 (10%) patients with rosacea and 7/90 (7.8%) subjects in the control group had SIBO (p = 0.6). Within 10 weeks from the end of antibiotic therapy, the skin lesions of rosacea disappeared or decreased markedly in 35/36 (97.2%) patients after eradication of H. pylori and in 3/8 (37.5%) patients who did not eradicate the infection (p < 0.0001). Rosacea skin lesions decreased markedly in 6/7 (85.7%) after eradication of SIBO whereas of the two patients who did not eradicate SIBO, one (50%) showed an improvement in rosacea (p = 0.284). Conclusions Prevalence of H. pylori infection was significantly higher in patients with rosacea than control group, whereas SIBO prevalence was comparable between the two groups. Eradication of H. pylori infection led to a significant improvement of skin symptoms in rosacea patients. PMID:25653855

  14. A bacterial homologue of the human iron exporter ferroportin.

    PubMed

    Bonaccorsi di Patti, Maria Carmela; Polticelli, Fabio; Tortosa, Valentina; Furbetta, Pier Antonio; Musci, Giovanni

    2015-12-21

    A bacterial homologue of the human iron exporter ferroportin found in the predatory Gram-negative bacterium Bdellovibrio bacteriovorus has been investigated. Molecular modelling, expression in recombinant form and iron binding and transport assays demonstrate that B. bacteriovorus ferroportin (bdFpn) is indeed an orthologue of human ferroportin. Key residues corresponding to those essential for iron binding and transport in human ferroportin are conserved in the bacterial homologue and are predicted to be correctly clustered in the central cavity of the protein. Mutation of these residues grossly affects the iron binding and transport ability of bdFpn. PMID:26608034

  15. Cdx2 modulates proliferation in normal human intestinal epithelial crypt cells

    SciTech Connect

    Escaffit, Fabrice; Pare, Frederic; Gauthier, Remy; Rivard, Nathalie; Boudreau, Francois; Beaulieu, Jean-Francois . E-mail: Jean-Francois.Beaulieu@USherbrooke.ca

    2006-03-31

    The homeobox gene Cdx2 is involved in the regulation of the expression of intestine specific markers such as sucrase-isomaltase and lactase-phlorizin hydrolase. Previous studies performed with immortalized or transformed intestinal cell lines have provided evidence that Cdx2 can promote morphological and functional differentiation in these experimental models. However, no data exist concerning the implication of this factor in normal human intestinal cell physiology. In the present work, we have investigated the role of Cdx2 in normal human intestinal epithelial crypt (HIEC) cells that lack this transcription factor. The establishment of HIEC cells expressing Cdx2 in an inducible manner shows that forced expression of Cdx2 significantly alters the proliferation of intestinal crypt cells and stimulates dipeptidylpeptidase IV expression but is not sufficient to trigger intestinal terminal differentiation. These observations suggest that Cdx2 requires additional factors to activate the enterocyte differentiation program in normal undifferentiated cells.

  16. Human blood group activity of human and canine intestinal glycolipids containing fucose

    PubMed Central

    Smith, E. L.; Bowdler, A. J.; Bull, R. W.; McKibbin, J. M.

    1973-01-01

    A number of fucose-containing glycolipids (fuco-lipids), which are similar in composition to those of human normal and malignant gastrointestinal tissue, have been isolated from whole small intestines of individual dogs. Dogs from which these fuco-lipids were isolated fell into two types according to the qualitative sugar composition of their fuco-lipids. Glycolipids from type I dogs contained glucose, galactose, glucosamine, galactosamine and fucose, while those from type II dogs contained the same sugars but lacked galactosamine. Fucolipids isolated from type I and II dogs were tested for both canine blood group and human A, B, H and Lea and Leb blood group activity. At the concentrations tested, only human blood group A activity was found in significant amounts, and only in those fuco-lipids which contained galactosamine (type I dogs). Of the fuco-lipids with human blood group A activity, some had activity comparable to that of glycoprotein blood group substances, while others had lower, but significant, activity. These latter fuco-lipids also had marked chromatographic differences, indicating that they are of several different structural types, a finding similar to the A active glycolipids of human red cell stroma. None of the isolated intestinal fuco-lipids had canine blood group activity. A fuco-lipid with Lea activity was also isolated in relatively large amounts from a normal human whole small intestine. PMID:4753403

  17. Fermentation in the human large intestine: its physiologic consequences and the potential contribution of prebiotics.

    PubMed

    Macfarlane, George T; Macfarlane, Sandra

    2011-11-01

    The human large intestine harbors a complex microbiota containing many hundreds of different bacterial species. Although structure/function relationships between different components of the microbiota are unclear, this complex multicellular entity plays an important role in maintaining homeostasis in the body. Many of the physiologic properties of the microbiota can be attributed to fermentation and the production of short-chain fatty acids (SCFAs), particularly acetate, propionate, and butyrate. In healthy people, fermentation processes are largely controlled by the amounts and different types of substrate, particularly complex carbohydrates that are accessible to bacteria in the colonic ecosystem. However, other factors impact on bacterial metabolism in the large gut, including large bowel transit time, the availability of inorganic terminal electron acceptors, such as nitrate and sulfate, and gut pH. They all affect the types and levels of SCFA that can be formed by the microbiota. This is important because to a large extent, acetate, propionate, and butyrate have varying physiologic effects in different body tissues. Prebiotics such as galactooligosaccharides together with inulins and their fructooligosaccharide derivatives have been shown to modify the species composition of the colonic microbiota, and in various degrees, to manifest several health-promoting properties related to enhanced mineral absorption, laxation, potential anticancer properties, lipid metabolism, and anti-inflammatory and other immune effects, including atopic disease. Many of these phenomena can be linked to their digestion and SCFA production by bacteria in the large gut. PMID:21992950

  18. Metabolism of green tea catechins by the human small intestine.

    PubMed

    Schantz, Markus; Erk, Thomas; Richling, Elke

    2010-10-01

    Numerous studies have shown that green tea polyphenols can be degraded in the colon, and there is abundant knowledge about the metabolites of these substances that appear in urine and plasma after green tea ingestion. However, there is very little information on the extent and nature of intestinal degradation of green tea catechins in humans. Therefore, the aim of this study was to examine in detail the microbial metabolism and chemical stability of these polyphenols in the small intestine using a well-established ex vivo model. For this purpose, fresh ileostomy fluids from two probands were incubated for 24 h under anaerobic conditions with (+)-catechin (C), (-)-epicatechin (EC), (-)-epicatechin 3-O-gallate (ECG), (-)-epigallocatechin (EGC), (-)-epigallocatchin 3-O-gallate (EGCG) and gallic acid (GA). After lyophilisation and extraction, metabolites were separated, identified and quantified by high performance liquid chromatography-photodiode array detection (HPLC-DAD) and HPLC-ESI-tandem mass spectrometry. Two metabolites of EC and C (3', 4', 5'-trihydroxyphenyl-γ-valerolactone and 3', 4'-dihydroxyphenyl-γ-valerolactone) were identified. In addition, 3', 4', 5'-trihydroxyphenyl-γ-valerolactone was detected as a metabolite of EGC, and (after 24-h incubation) pyrogallol as a degradation product of GA. Cleavage of the GA esters of EGCG and ECG was also observed, with variations dependent on the sources (probands) of the ileal fluids, which differed substantially microbiotically. The results provide new information about the degradation of green tea catechins in the gastrointestinal tract, notably that microbiota-dependent liberation of GA esters may occur before these compounds reach the colon. PMID:20931601

  19. Bacterial vaginosis and human immunodeficiency virus infection

    PubMed Central

    Spear, Gregory T; St John, Elizabeth; Zariffard, M Reza

    2007-01-01

    Epidemiologic studies indicate that bacterial vaginosis (BV), a common alteration of lower genital tract flora in women, is associated with increased susceptibility to HIV infection. Other recent studies show that HIV is detected more frequently and at higher levels in the lower genital tract of HIV-seropositive women with BV. In vitro studies show that genital tract secretions from women with BV or flora associated with BV induce HIV expression in infected cells. The increased HIV expression appears to be due at least in part to activation through Toll-like receptors (TLR), specifically TLR2. Further research is needed to elucidate how BV contributes to HIV acquisition and transmission. PMID:17953761

  20. Garlic inhibits microsomal triglyceride transfer protein gene expression in human liver and intestinal cell lines and in rat intestine.

    PubMed

    Lin, Marie C; Wang, Er-Jia; Lee, Catherine; Chin, K T; Liu, Depei; Chiu, Jen-Fu; Kung, Hsiang-Fu

    2002-06-01

    Epidemiologic studies have suggested that fresh garlic has lipid-lowering activity. Because the microsomal triglyceride transfer protein (MTP) plays a pivotal role in the assembly and secretion of apolipoprotein B (apoB)-containing lipoproteins, we evaluated the effect of garlic on the expression of the MTP gene in vitro in cell lines and in vivo in rats. Fresh garlic extract (FGE) reduced MTP mRNA levels in both the human hepatoma HepG2 and intestinal carcinoma Caco-2 cells in dose-dependent fashion; significant reductions were detected with 3 g/L FGE. Maximal 72 and 59% reductions, respectively, were observed with 6 g/L FGE. To evaluate the in vivo effect of garlic on MTP gene expression, rats were given a single oral dose of fresh garlic homogenate (FGH), with hepatic and intestinal MTP mRNA measured 3 h after dosing. Rats fed FGH had significantly (46% of the control) lower intestinal MTP mRNA levels compared with the control rats, whereas hepatic MTP mRNA levels were not affected. These results suggest a new mechanism for the hypolipidemic effect of fresh garlic. Long-term dietary supplementation of fresh garlic may exert a lipid-lowering effect partly through reducing intestinal MTP gene expression, thus suppressing the assembly and secretion of chylomicrons from intestine to the blood circulation. PMID:12042427

  1. Mechanism of intestinal lipoprotein overproduction in insulin resistant humans.

    PubMed

    Duez, Hélène; Pavlic, Mirjana; Lewis, Gary F

    2008-09-01

    Triglyceride-rich lipoproteins (TRLs) derived from the intestine are increased in insulin resistant states both in the post-prandial and fasted state and are associated with increased cardiovascular risk. Impaired clearance has long been invoked to explain this accumulation of intestinal TRLs, but more recent studies have highlighted the fact that the production rate of apolipoprotein (apo) B-48-containing particles is also increased in insulin resistance and Type 2 diabetes. Recent data also indicate that the enterocyte, similar to the hepatocyte, overproduces lipoprotein particles in response to an elevation of plasma free fatty acids. It is not yet clear precisely how much this overproduction of intestinal lipoprotein particles contributes to the hypertriglyceridemia of insulin resistant states. We speculate that chronic intestinal overproduction of apoB-48 primes the intestine to rapidly and efficiently facilitate the absorption of ingested fat, enhancing the assembly and secretion of intestinal TRL, and hence contributing to post-prandial lipemia. PMID:18676184

  2. Altered Virome and Bacterial Microbiome in Human Immunodeficiency Virus-Associated Acquired Immunodeficiency Syndrome.

    PubMed

    Monaco, Cynthia L; Gootenberg, David B; Zhao, Guoyan; Handley, Scott A; Ghebremichael, Musie S; Lim, Efrem S; Lankowski, Alex; Baldridge, Megan T; Wilen, Craig B; Flagg, Meaghan; Norman, Jason M; Keller, Brian C; Luévano, Jesús Mario; Wang, David; Boum, Yap; Martin, Jeffrey N; Hunt, Peter W; Bangsberg, David R; Siedner, Mark J; Kwon, Douglas S; Virgin, Herbert W

    2016-03-01

    Human immunodeficiency virus (HIV) infection is associated with increased intestinal translocation of microbial products and enteropathy as well as alterations in gut bacterial communities. However, whether the enteric virome contributes to this infection and resulting immunodeficiency remains unknown. We characterized the enteric virome and bacterial microbiome in a cohort of Ugandan patients, including HIV-uninfected or HIV-infected subjects and those either treated with anti-retroviral therapy (ART) or untreated. Low peripheral CD4 T cell counts were associated with an expansion of enteric adenovirus sequences and this increase was independent of ART treatment. Additionally, the enteric bacterial microbiome of patients with lower CD4 T counts exhibited reduced phylogenetic diversity and richness with specific bacteria showing differential abundance, including increases in Enterobacteriaceae, which have been associated with inflammation. Thus, immunodeficiency in progressive HIV infection is associated with alterations in the enteric virome and bacterial microbiome, which may contribute to AIDS-associated enteropathy and disease progression. PMID:26962942

  3. The Human Microbiome during Bacterial Vaginosis.

    PubMed

    Onderdonk, Andrew B; Delaney, Mary L; Fichorova, Raina N

    2016-04-01

    Bacterial vaginosis (BV) is the most commonly reported microbiological syndrome among women of childbearing age. BV is characterized by a shift in the vaginal flora from the dominant Lactobacillus to a polymicrobial flora. BV has been associated with a wide array of health issues, including preterm births, pelvic inflammatory disease, increased susceptibility to HIV infection, and other chronic health problems. A number of potential microbial pathogens, singly and in combinations, have been implicated in the disease process. The list of possible agents continues to expand and includes members of a number of genera, including Gardnerella, Atopobium, Prevotella, Peptostreptococcus, Mobiluncus, Sneathia, Leptotrichia, Mycoplasma, and BV-associated bacterium 1 (BVAB1) to BVAB3. Efforts to characterize BV using epidemiological, microscopic, microbiological culture, and sequenced-based methods have all failed to reveal an etiology that can be consistently documented in all women with BV. A careful analysis of the available data suggests that what we term BV is, in fact, a set of common clinical signs and symptoms that can be provoked by a plethora of bacterial species with proinflammatory characteristics, coupled to an immune response driven by variability in host immune function. PMID:26864580

  4. Human colostrum oligosaccharides modulate major immunologic pathways of immature human intestine

    PubMed Central

    He, YingYing; Liu, ShuBai; Leone, Serena; Newburg, David S.

    2014-01-01

    The immature neonatal intestinal immune system hyperreacts to newly colonizing unfamiliar bacteria. The hypothesis that human milk oligosaccharides from colostrum (cHMOS) can directly modulate the signaling pathways of the immature mucosa was tested. Modulation of cytokine immune signaling by HMOS was measured ex vivo in intact immature (fetal) human intestinal mucosa. From the genes whose transcription was modulated by colostrum HMOS (cHMOS), Ingenuity Pathway Analysis identified networks controlling immune cell communication, intestinal mucosal immune system differentiation, and homeostasis. cHMOS attenuate pathogen-associated molecular pattern (PAMP)-stimulated acute phase inflammatory cytokine protein levels (IL-8, IL-6, MCP-1/2, IL-1β), while elevating cytokines involved in tissue repair and homeostasis. 3’-, 4-, and 6’-galactosyllactoses of cHMOS account for specific immunomodulation of PIC-induced IL-8 levels. cHMOS attenuate mucosal responses to surface inflammatory stimuli during early development, while enhancing signals that support maturation of the intestinal mucosal immune system. PMID:24691111

  5. Vasoactive intestinal polypeptide (VIP) innervation of the human eyelid glands.

    PubMed

    Seifert, P; Spitznas, M

    1999-06-01

    This study was conducted to obtain morphological proof of innervating nerve fibres in the glands of the human eyelid (accessory lacrimal glands of Wolfring, meibomian glands, goblet cells, glands of Zeis, glands of Moll, sweat glands, glands of lanugo hair follicles) and identification of the secretomotorically active neuropeptide vasoactive intestinal polypeptide (VIP) as a common transmitter. Epoxy-embedded ultrathin sections of tissue samples from human eyelids were studied using electron microscopy. Paraffin sections fixed in Bouin-Hollande solution were immunostained with rabbit antiserum against VIP. With the electron microscope we were able to identify nerves in the glandular stroma of all the glands examined with the exception of goblet cells. Intraepithelial single axons were only seen in the parenchyma of Wolfring glands. The morphological findings corresponded with the immunological finding of VIP-positive, nerve-like structures in the same locations, with the exception of lanugo hair follicle glands, and goblet cells. Our findings indicate that the glands of the eyelids and main lacrimal gland represent a functional unit with VIP as a possible common stimulating factor. PMID:10375432

  6. Initial insights into bacterial succession during human decomposition.

    PubMed

    Hyde, Embriette R; Haarmann, Daniel P; Petrosino, Joseph F; Lynne, Aaron M; Bucheli, Sibyl R

    2015-05-01

    Decomposition is a dynamic ecological process dependent upon many factors such as environment, climate, and bacterial, insect, and vertebrate activity in addition to intrinsic properties inherent to individual cadavers. Although largely attributed to microbial metabolism, very little is known about the bacterial basis of human decomposition. To assess the change in bacterial community structure through time, bacterial samples were collected from several sites across two cadavers placed outdoors to decompose and analyzed through 454 pyrosequencing and analysis of variable regions 3-5 of the bacterial 16S ribosomal RNA (16S rRNA) gene. Each cadaver was characterized by a change in bacterial community structure for all sites sampled as time, and decomposition, progressed. Bacteria community structure is variable at placement and before purge for all body sites. At bloat and purge and until tissues began to dehydrate or were removed, bacteria associated with flies, such as Ignatzschineria and Wohlfahrtimonas, were common. After dehydration and skeletonization, bacteria associated with soil, such as Acinetobacter, were common at most body sites sampled. However, more cadavers sampled through multiple seasons are necessary to assess major trends in bacterial succession. PMID:25431049

  7. Use of molecular typing to investigate bacterial translocation from the intestinal tract in malnourished children with Gram-negative bacteremia.

    PubMed

    Youssef, Mohammad; Al Shurman, Abdallah; Chachaty, Elisabeth; Bsoul, Abder-Rahman; Andremont, Antoine

    1998-02-01

    OBJECTIVE: To investigate whether translocation of intestinal Enterobacteriaceae was a likely source of bacteremia in children of 2 years or less hospitalized for fever and moderate malnutrition. METHODS: Blood and fecal cultures were obtained from 198 such children admitted in the Princess Basma Hospital (Irbid, Jordan). Enterobacteriaceae isolated from blood cultures were compared with those present in fecal cultures by genomic typing using pulsed-field gel electrophoresis. The characteristics of children whose blood and fecal strain typing patterns were not distinguishable, i.e. with documented translocation, were compared to those of children without documented translocation. RESULTS: Bacterial translocation was documented in 12 of 19 children (63%) with Enterobacteriaceae bacteremia for whom paired blood and fecal strains were available for genomic typing, and was thus the major source of these bacteremias. The clinical or biological signs of malnutrition were not significantly more pronounced in the bacteremic children with documented translocation than in those without. CONCLUSIONS: We demonstrated that bacterial translocation from the intestinal tract was the most common source of Gram-negative bacteremia in the population studied. PMID:11864289

  8. Low dietary iron intake restrains the intestinal inflammatory response and pathology of enteric infection by food-borne bacterial pathogens.

    PubMed

    Kortman, Guus A M; Mulder, Michelle L M; Richters, Thijs J W; Shanmugam, Nanda K N; Trebicka, Estela; Boekhorst, Jos; Timmerman, Harro M; Roelofs, Rian; Wiegerinck, Erwin T; Laarakkers, Coby M; Swinkels, Dorine W; Bolhuis, Albert; Cherayil, Bobby J; Tjalsma, Harold

    2015-09-01

    Orally administrated iron is suspected to increase susceptibility to enteric infections among children in infection endemic regions. Here we investigated the effect of dietary iron on the pathology and local immune responses in intestinal infection models. Mice were held on iron-deficient, normal iron, or high iron diets and after 2 weeks they were orally challenged with the pathogen Citrobacter rodentium. Microbiome analysis by pyrosequencing revealed profound iron- and infection-induced shifts in microbiota composition. Fecal levels of the innate defensive molecules and markers of inflammation lipocalin-2 and calprotectin were not influenced by dietary iron intervention alone, but were markedly lower in mice on the iron-deficient diet after infection. Next, mice on the iron-deficient diet tended to gain more weight and to have a lower grade of colon pathology. Furthermore, survival of the nematode Caenorhabditis elegans infected with Salmonella enterica serovar Typhimurium was prolonged after iron deprivation. Together, these data show that iron limitation restricts disease pathology upon bacterial infection. However, our data also showed decreased intestinal inflammatory responses of mice fed on high iron diets. Thus additionally, our study indicates that the effects of iron on processes at the intestinal host-pathogen interface may highly depend on host iron status, immune status, and gut microbiota composition. PMID:26046550

  9. Evolution of Bacterial Pathogens within the Human Host

    PubMed Central

    Bliven, Kimberly A.; Maurelli, Anthony T.

    2015-01-01

    Selective pressures within the human host, including interactions with innate and adaptive immune responses, exposure to medical interventions such as antibiotics, and competition with commensal microbiota all facilitate the evolution of bacterial pathogens. In this chapter, we present examples of pathogen strategies which emerged as a result of selective pressures within the human host niche, and discuss the resulting co-evolutionary ‘arms race’ between these organisms. In bacterial pathogens, many of the genes responsible for these strategies are encoded on mobile pathogenicity islands (PAIs) or plasmids, underscoring the importance of horizontal gene transfer (HGT) in the emergence of virulent microbial species. PMID:26999399

  10. Protective Capacity of Resveratrol, a Natural Polyphenolic Compound, against Deoxynivalenol-Induced Intestinal Barrier Dysfunction and Bacterial Translocation.

    PubMed

    Ling, Ka-Ho; Wan, Murphy Lam Yim; El-Nezami, Hani; Wang, Mingfu

    2016-05-16

    Contamination of food/feedstuffs by mycotoxins is a serious problem worldwide, causing severe economic losses and serious health problems in animals/humans. Deoxynivalenol (DON) is a major mycotoxin contaminant and is known to impair intestinal barrier function. Grapes and red wine are rich in polyphenols, such as resveratrol (RES), which has striking antioxidant and anti-inflammatory activities. RES is a food-derived component; therefore, it may be simultaneously present with DON in the gastrointestinal tract. The aim of this study was to explore in vitro protective effects of RES against DON-induced intestinal damage. The results showed that RES could protect DON-induced bacteria translocation because of enhanced of intestinal barrier function by restoring the DON-induced decrease in transepithelial electrical resistance and increase in paracellular permeability. Further mechanistic studies demonstrated that RES protects against DON-induced barrier dysfunction by promoting the assembly of claudin-4 in the tight junction complex. This is probably mediated through modulation of IL-6 and IL-8 secretion via mitogen-activated protein kinase-dependent pathways. Our results imply that RES can protect against DON-induced intestinal damage and that RES may be used as a novel dietary intervention strategy to reduce DON toxicity in animals/humans. PMID:27058607

  11. Melatonin reduces bacterial translocation by preventing damage to the intestinal mucosa in an experimental severe acute pancreatitis rat model

    PubMed Central

    SUN, XUECHENG; SHAO, YINGYING; JIN, YIN; HUAI, JIAPING; ZHOU, QIONG; HUANG, ZHIMING; WU, JIANSHENG

    2013-01-01

    Recent studies have demonstrated that melatonin significantly decreased all studied acute pancreatitis-associated inflammatory parameters, in addition to reducing apoptosis and necrosis associated with pancreatic injury. However, the effect of melatonin on gut barrier dysfunction and bacterial translocation has not been fully elucidated. This study aimed to investigate the protective effects of melatonin on intestinal integrity in a rat model of severe acute pancreatitis (SAP) to evaluate whether melatonin prevented intestine barrier dysfunction and reduced bacterial translocation. Forty male Sprague Dawley (SD) rats were randomly divided into three groups, with 8 rats in the sham operation (SO) group, 18 rats in the SAP group and 14 SAP rats in the melatonin treatment (MT) group. SAP was induced by retrograde injection of 4% taurocholate into the biliopancreatic duct. Melatonin was administered 30 min prior to taurocholate injection in the melatonin-treated rats. All rats were sacrificed 24 h subsequent to pancreatitis induction. Real-time fluorescence quantitative polymerase chain reaction was used to detect and quantify Escherichia coli (E. coli) O157 in postcava blood. The microvilli structure was also analyzed with transmission electron microscopy. The level of E. coli DNA in the MT group was significantly lower than in rats in the SAP group. No E. coli DNA was detected in the control group. Villus height and crypt depth in the ileum were significantly higher in the MT and control groups compared to the SAP group, and were significantly higher in the MT group than in the SAP group. These results suggested that melatonin prevented gut barrier dysfunction and reduced bacterial translocation, resulting in reduced pancreatic-associated infections and decreased early mortality rates. PMID:24255660

  12. Escherichia coli diversity in the lower intestinal tract of humans.

    PubMed

    Gordon, David M; O'Brien, Claire L; Pavli, Paul

    2015-08-01

    Previous studies examining the clonal diversity of Escherichia coli populations within humans have been based on faecal isolates. In this study E. coli were isolated from biopsies taken from the terminal ileum, ascending, transverse and descending colon, and rectum of 69 individuals. Multiple isolates from each biopsy were characterized using Rep-PCR. An average of 3.5 genotypes were recovered per host, and in hosts with two or more strains, the phylogroup membership of the second most abundant strain was significantly more likely to be the same as the dominant strain. There was no indication of a non-random distribution of E. coli phylogroups among the regions of the lower intestine. In hosts with multiple genotypes, as defined by Repetitive extragenic palindromic-PCR, genotypes were non-randomly distributed among gut regions in over half the individuals. The phylogroup membership of an individual's numerically dominant strain explained some of the variation in the extent to which strains within an individual were heterogeneously distributed, with most heterogeneity observed when the numerically dominant strain belonged to phylogroups E or F, and the least when the dominant strain belonged to phylogroup B2. The results of this study support previous studies on pigs that demonstrated faecal sampling underestimates the genotype diversity present within a host. PMID:26034010

  13. Protective effect of glutamine on intestinal injury and bacterial community in rats exposed to hypobaric hypoxia environment

    PubMed Central

    Xu, Chun-Lan; Sun, Rui; Qiao, Xiang-Jin; Xu, Cui-Cui; Shang, Xiao-Ya; Niu, Wei-Ning

    2014-01-01

    AIM: To investigate the protective effect of glutamine (Gln) on intestinal injury and the bacterial community in rats exposed to hypobaric hypoxia environment. METHODS: Sprague-Dawley rats were divided into control, hypobaric hypoxia (HH), and hypobaric hypoxia + Gln (5.0 g/kg BW·d) (HG) groups. On the first 3 d, all rats were placed in a normal environment. After the third day, the HH and HG groups were transferred into a hypobaric chamber at a simulated elevation of 7000 m for 5 d. The rats in the HG group were given Gln by gavage daily for 8 d. The rats in the control and HH groups were treated with the same volume of saline. The intestinal morphology, serum levels of malondialdehyde (MDA), superoxide dismutase (SOD), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interferon-gamma (IFN-γ) and diamino oxidase (DAO) were examined. We also evaluated the expression levels of occludin, toll-like receptor 4 (TLR4), nuclear factor-κB p65 (NF-κB p65) and myeloid differentiation factor 88 (MyD88), and examined the bacterial community in caecal contents. RESULTS: Hypobaric hypoxia induced the enlargement of the heart, liver, lung and kidney, and caused spleen atrophy. Intestinal villi damage was also observed in the HH group. Supplementation with Gln significantly alleviated hypobaric-induced damage to main organs including the intestine, increased serum SOD (1.14 ± 0.03 vs 0.88 ± 0.04, P < 0.05) and MDA (8.35 ± 1.60, P < 0.01) levels and decreased serum IL-6 (1172.13±30.49 vs 1407.05 ± 34.36, P < 0.05), TNF-α (77.46 ± 0.78 vs 123.70 ± 3.03, P < 0.001), IFN-γ (1355.42 ± 72.80 vs 1830.16 ± 42.07, P < 0.01) and DAO (629.30 ± 9.15 vs 524.10 ± 13.34, P < 0.001) levels. Moreover, Gln significantly increased occludin (0.72 ± 0.05 vs 0.09 ± 0.01, P < 0.001), TLR4 (0.15 ± 0.05 vs 0.30 ±0.09, P < 0.05), MyD88 (0.32 ± 0.08 vs 0.71 ± 0.06, P < 0.01), and NF-κB p65 (0.16 ± 0.04 vs 0.44 ± 0.03, P < 0.01) expression levels and improved the intestinal bacterial community. CONCLUSION: Gln treatment protects from intestinal injury and regulates the gut flora imbalance in hypoxia environment. These effects may be related to the TLR4/MyD88/NF-κB signaling pathway. PMID:24782618

  14. Bacterial scissors to edit human embryos?

    PubMed

    Gross, Michael

    2015-06-01

    A recently discovered gene editing tool raises the possibility of precisely targeted changes to human genes, even in the germline. The nascent debate over the ethics and limitations of its use has already been overtaken by events. Is this a whole new Pandora’s box for bioethics? PMID:26230009

  15. Human intestinal parasites in primary school children in Kampala, Uganda.

    PubMed

    Kabatereine, N B; Kemijumbi, J; Kazibwe, F; Onapa, A W

    1997-05-01

    A cross sectional survey on intestinal parasite infections was carried out in 5,313 pupils between the ages of ten and fifteen years in 98 primary schools in Kampala. The aim was to identify the types and distribution of intestinal parasites and to estimate the prevalence in school children. Trichuris trichiura (28%), Ascaris lumbricoides (17%) and hookworms (12.9%) were common infections among the children. Other less commonly found parasites were S.mansoni, Strongyloides stercolaris, Taenia sp, Enterobius vermicularis, Giardia lamblia, Entamoeba coli and E. histolytica. Refuse dumps are probably a significant source of transmission of intestinal helminthic infections in Kampala. PMID:9337010

  16. The metabolic profile of acteoside produced by human or rat intestinal bacteria or intestinal enzyme in vitro employed UPLC-Q-TOF-MS.

    PubMed

    Cui, Qingling; Pan, Yingni; Xu, Xiaotong; Zhang, Wenjie; Wu, Xiao; Qu, Shouhe; Liu, Xiaoqiu

    2016-03-01

    Acteoside, the main and representative phenylethanoid glycosides of Herba Cistanches, possesses wide bioactivities but low oral bioavailability. It may serve as the prodrug and be converted into the active forms in gastrointestinal tract, which mainly occurred in intestinal tract composed of intestinal bacteria and intestinal enzyme. Intestinal bacteria, a new drug target, take a significant role on exerting pharmacological effects of drugs by oral administration. In this paper, acteoside was incubated with human or rat intestinal bacteria or rat intestinal enzyme for 36h to seek metabolites responsible for pharmacodynamics. The samples were analyzed by ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. Besides the parent compound, 14 metabolites were detected and identified based on their retention times and fragmentation patterns in their MS spectra including 8 degradation metabolites, 2 isomers in intestinal bacteria and intestinal enzyme samples and 4 parent metabolites only found in intestinal enzymes. The metabolic pathway of acteoside was thus proposed. Identification of these metabolites of acteoside by the intestinal bacteria or intestinal enzyme gave an insight to clarify pharmacological mechanism of traditional Chinese medicines and identify the real active molecules. PMID:26705842

  17. Insights into bacterial protein glycosylation in human microbiota.

    PubMed

    Zhu, Fan; Wu, Hui

    2016-01-01

    The study of human microbiota is an emerging research topic. The past efforts have mainly centered on studying the composition and genomic landscape of bacterial species within the targeted communities. The interaction between bacteria and hosts is the pivotal event in the initiation and progression of infectious diseases. There is a great need to identify and characterize the molecules that mediate the bacteria-host interaction. Bacterial surface exposed proteins play an important role in the bacteria- host interaction. Numerous surface proteins are glycosylated, and the glycosylation is crucial for their function in mediating the bacterial interaction with hosts. Here we present an overview of surface glycoproteins from bacteria that inhabit three major mucosal environments across human body: oral, gut and skin. We describe the important enzymes involved in the process of protein glycosylation, and discuss how the process impacts the bacteria-host interaction. Emerging molecular details underlying glycosylation of bacterial surface proteins may lead to new opportunities for designing anti-infective small molecules, and developing novel vaccines in order to treat or prevent bacterial infection. PMID:26712033

  18. Clostridium difficile-mediated effects on human intestinal epithelia: Modelling host-pathogen interactions in a vertical diffusion chamber.

    PubMed

    Jafari, Nazila V; Kuehne, Sarah A; Minton, Nigel P; Allan, Elaine; Bajaj-Elliott, Mona

    2016-02-01

    Clostridium difficile infection is one of the leading causes of healthcare associated diarrhoea in the developed world. Although the contribution of C.difficile toxins to disease pathogenesis is now well understood, many facets of host-pathogen interactions between the human intestinal epithelia and the C.difficile bacterium that may contribute to asymptomatic carriage and/or clinical disease remain less clear. Herein, we tested the hypothesis that C.difficile strains mediate intestinal epithelial cell (IEC) antimicrobial immunity via toxin dependent and independent means and that the 'anaerobic' environment has a significant impact on bacterial-IEC interactions. Crosstalk between three C.difficile PCR ribotypes (RT) [RT027 (strain R20291), RT012 (strain 630) and RT017 (strains M68 and CF5)] and IEC cell-lines were investigated. All RTs showed significant engagement with human Toll-like receptors (TLR)-5, TLR2-CD14 and TLR2/6 as measured by IL-8 release from TLR-transfected HEK cells. Co-culture studies indicated minimal impact of R20291 and 630 TcdA and TcdB on bacterial adherence to Caco-2cells. An apical anaerobic environment had a major effect on C.difficile-T84 crosstalk as significantly greater cytokine immunity and trans-epithelial electrical resistance (TEER) dysfunction was recorded when co-cultures were performed in an Ussing chamber system compared to standard 5% CO2 conditions. Overall, this study suggests that anaerobic C.difficile engagement with human IECs is a complex interplay that involves bacterial and toxin-mediated cellular events. PMID:26708704

  19. Modulation of rainbow trout (Oncorhynchus mykiss) intestinal immune gene expression following bacterial challenge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The mucosal immune system of fish is still poorly understood, and defined models for studying natural host-pathogen interaction are lacking. The objective of this study was to evaluate different challenge paradigms and pathogens to examine the magnitude of change in intestinal immune gene expressio...

  20. Human intestinal macrophages display profound inflammatory anergy despite avid phagocytic and bacteriocidal activity.

    PubMed

    Smythies, Lesley E; Sellers, Marty; Clements, Ronald H; Mosteller-Barnum, Meg; Meng, Gang; Benjamin, William H; Orenstein, Jan M; Smith, Phillip D

    2005-01-01

    Intestinal macrophages, which are thought to orchestrate mucosal inflammatory responses, have received little investigative attention compared with macrophages from other tissues. Here we show that human intestinal macrophages do not express innate response receptors, including the receptors for LPS (CD14), Fcalpha (CD89), Fcgamma (CD64, CD32, CD16), CR3 (CD11b/CD18), and CR4 (CD11c/CD18); the growth factor receptors IL-2 (CD25) and IL-3 (CD123); and the integrin LFA-1 (CD11a/CD18). Moreover, resident intestinal macrophages also do not produce proinflammatory cytokines, including IL-1, IL-6, IL-10, IL-12, RANTES, TGF-beta, and TNF-alpha, in response to an array of inflammatory stimuli but retain avid phagocytic and bacteriocidal activity. Thus, intestinal macrophages are markedly distinct in phenotype and function from blood monocytes, although intestinal macrophages are derived from blood monocytes. To explain this paradox, we show that intestinal stromal cell-derived products downregulate both monocyte receptor expression and, via TGF-beta, cytokine production but not phagocytic or bacteriocidal activity, eliciting the phenotype and functional profile of intestinal macrophages. These findings indicate a mechanism in which blood monocytes recruited to the intestinal mucosa retain avid scavenger and host defense functions but acquire profound "inflammatory anergy," thereby promoting the absence of inflammation characteristic of normal intestinal mucosa despite the close proximity of immunostimulatory bacteria. PMID:15630445

  1. Adhesion of human bifidobacterial strains to cultured human intestinal epithelial cells and inhibition of enteropathogen-cell interactions.

    PubMed Central

    Bernet, M F; Brassart, D; Neeser, J R; Servin, A L

    1993-01-01

    Thirteen human bifidobacterial strains were tested for their abilities to adhere to human enterocyte-like Caco-2 cells in culture. The adhering strains were also tested for binding to the mucus produced by the human mucus-secreting HT29-MTX cell line in culture. A high level of calcium-independent adherence was observed for Bifidobacterium breve 4, for Bifidobacterium infantis 1, and for three fresh human isolates from adults. As observed by scanning electron microscopy, adhesion occurs to the apical brush border of the enterocytic Caco-2 cells and to the mucus secreted by the HT29-MTX mucus-secreting cells. The bacteria interacted with the well-defined apical microvilli of Caco-2 cells without cell damage. The adhesion to Caco-2 cells of bifidobacteria did not require calcium and was mediated by a proteinaceous adhesion-promoting factor which was present both in the bacterial whole cells and in the spent supernatant of bifidobacterium culture. This adhesion-promoting factor appeared species specific, as are the adhesion-promoting factors of lactobacilli. We investigated the inhibitory effect of adhering human bifidobacterial strains against intestinal cell monolayer colonization by a variety of diarrheagenic bacteria. B. breve 4, B. infantis 1, and fresh human isolates were shown to inhibit cell association of enterotoxigenic, enteropathogenic, diffusely adhering Escherichia coli and Salmonella typhimurium strains to enterocytic Caco-2 cells in a concentration-dependent manner. Moreover, B. breve 4 and B. infantis 1 strains inhibited, dose dependently, Caco-2 cell invasion by enteropathogenic E. coli, Yersinia pseudotuberculosis, and S. typhimurium strains. Images PMID:8285709

  2. Plagiarized bacterial genes in the human book of life.

    PubMed

    Ponting, C P

    2001-05-01

    The initial analysis of the human genome draft sequence reveals that our 'book of life' is multi-authored. A small but significant proportion of our genes owes their heritage not to antecedent eukaryotes but instead to bacteria. The publicly funded Human Genome Project study indicates that about 0.5% of all human genes were copied into the genome from bacterial sources. Detailed sequence analyses point to these 'horizontal gene transfer' events having occurred relatively recently. So how did the human 'book of life' evolve to be a chimaera, part animal and part bacterium? And what was the probable evolutionary impact of such gene plagiarism? PMID:11335018

  3. Congruent Strain Specific Intestinal Persistence of Lactobacillus plantarum in an Intestine-Mimicking In Vitro System and in Human Volunteers

    PubMed Central

    van Bokhorst-van de Veen, Hermien; van Swam, Iris; Wels, Michiel; Bron, Peter A.; Kleerebezem, Michiel

    2012-01-01

    Background An important trait of probiotics is their capability to reach their intestinal target sites alive to optimally exert their beneficial effects. Assessment of this trait in intestine-mimicking in vitro model systems has revealed differential survival of individual strains of a species. However, data on the in situ persistence characteristics of individual or mixtures of strains of the same species in the gastrointestinal tract of healthy human volunteers have not been reported to date. Methodology/Principal Findings The GI-tract survival of individual L. plantarum strains was determined using an intestine mimicking model system, revealing substantial inter-strain differences. The obtained data were correlated to genomic diversity of the strains using comparative genome hybridization (CGH) datasets, but this approach failed to discover specific genetic loci that explain the observed differences between the strains. Moreover, we developed a next-generation sequencing-based method that targets a variable intergenic region, and employed this method to assess the in vivo GI-tract persistence of different L. plantarum strains when administered in mixtures to healthy human volunteers. Remarkable consistency of the strain-specific persistence curves were observed between individual volunteers, which also correlated significantly with the GI-tract survival predicted on basis of the in vitro assay. Conclusion The survival of individual L. plantarum strains in the GI-tract could not be correlated to the absence or presence of specific genes compared to the reference strain L. plantarum WCFS1. Nevertheless, in vivo persistence analysis in the human GI-tract confirmed the strain-specific persistence, which appeared to be remarkably similar in different healthy volunteers. Moreover, the relative strain-specific persistence in vivo appeared to be accurately and significantly predicted by their relative survival in the intestine-mimicking in vitro assay, supporting the use of this assay for screening of strain-specific GI persistence. PMID:22970257

  4. Biovolatilization of metal(loid)s by intestinal microorganisms in the simulator of the human intestinal microbial ecosystem.

    PubMed

    Diaz-Bone, Roland A; van de Wiele, Tom R

    2009-07-15

    Methylation and hydrogenation of metal(loid)s by microorganisms are widespread and well-known processes in the environment by which mobility and in most cases toxicity are significantly enhanced in comparison to inorganic species. The human gut contains highly diverse and active microbiocenosis, yet little is known about the occurrence and importance of microbial metal(loid) methylation and hydrogenation. In this study, an in vitro gastrointestinal model, the Simulator of the Human Intestinal Microbial Ecosystem (SHIME),was used for investigating volatilization of metal(loid)s by intestinal microbiota. Suspensions from different compartments of the SHIME system analogous to different parts of the human intestinal tract were incubated with different concentrations of inorganic Ge, As, Se, Sn, Sb, Te, Hg, Pb, and Bi and analyzed by gas chromatography and inductively coupled plasma mass spectrometry (GC-ICP-MS). Significant volatilization was found for Se, As, and Te (maximal hourly production rates relative to the amount spiked; 0.6, 2, and 9 ng/mg/h, respectively). In addition, volatile species of Sb and Bi were detected. The occurrence of AsH3 and (CH3)2Te was toxicologically important. Furthermore, mixed Se/S and mixed As/S metabolites were detected in significant amounts in the gas phase of the incubation experiments of which two metabolites, (CH3)2AsSSCH3 and CH3As(SCH3)2, are described for the first time in environmental matrices. The toxicology of these species is unknown. These data show that the intestinal microbiota may increase the mobility of metal(loid)s, suggesting a significant modulation of their toxicity. Our research warrants further studies to investigate the extent of this process as well as the availability of metal(loid)s from different sources for microbial transformations. PMID:19708349

  5. Do dietary betaine and the antibiotic florfenicol influence the intestinal autochthonous bacterial community in hybrid tilapia (Oreochromis niloticus ♀ × O. aureus ♂)?

    PubMed

    He, Suxu; Zhou, Zhigang; Liu, Yuchun; Cao, Yanan; Meng, Kun; Shi, Penjun; Yao, Bin; Ringø, Einar

    2012-03-01

    The attractant betaine and the antibiotic growth promoter florfenicol are commonly used together in Chinese fresh water aquaculture, but there is no information about the effect of these two feed additive on the intestinal autochthonous bacterial community in hybrid tilapia (Oreochromis nilotica ♀ × O. aureas ♂). Hybrid tilapia (240 fish in total; 20 fish per net cage; three cages per group) were divided into four dietary groups: control group, no betaine or florfenical addition (CK); betaine group, 0.1% betaine added (B); florfenicol group, 0.002% florfenicol added (F); and combination group, 0.1% betaine and 0.002% florfenicol added together (BF). After 8 weeks of feeding, six fish from each cage were chosen randomly, the guts were sampled and pooled, and their intestinal autochthonous bacterial communities were analyzed by 16S rDNA-denaturing gradient gel electrophoresis. Enumeration of total gut autochthonous bacteria was analyzed by quantitative PCR with rpoB as the endogenous control. The results showed that the fish intestinal bacteria of group B were more diverse than that of CK, and that of F and BF groups was reduced in the total numbers and limited to certain bacterial species or genera (P < 0.05). This study revealed that betaine can promote some intestinal autochthonous bacteria, and florfenicol play a depressor role. When combined together, florfenicol may overshadow the effect of betaine on the predominant intestinal bacteria of tilapia. PMID:22805797

  6. Sampling of intestinal microbiota and targeted amplification of bacterial 16S rRNA genes for microbial ecologic analysis

    PubMed Central

    Tong, Maomeng; Jacobs, Jonathan P.; McHardy, Ian H.; Braun, Jonathan

    2015-01-01

    Dysbiosis of host-associated commensal microbiota is emerging as an important factor in risk and phenotype of immunologic, metabolic, and behavioral diseases. Appropriate collection and pre-processing of biospecimens from humans or mice is necessary for accurate analysis of microbial composition and functional state. Methods to sample intestinal luminal and mucosal microbiota from humans and mice, and to profile microbial phylogenetic composition using 16S rRNA sequencing are presented here. Data generated using this protocol can be used for downstream quantitative analysis of microbial ecology. PMID:25367129

  7. Butyrate produced by commensal bacteria potentiates phorbol esters induced AP-1 response in human intestinal epithelial cells.

    PubMed

    Nepelska, Malgorzata; Cultrone, Antonietta; Bguet-Crespel, Fabienne; Le Roux, Karine; Dor, Jol; Arulampalam, Vermulugesan; Blottire, Herv M

    2012-01-01

    The human intestine is a balanced ecosystem well suited for bacterial survival, colonization and growth, which has evolved to be beneficial both for the host and the commensal bacteria. Here, we investigated the effect of bacterial metabolites produced by commensal bacteria on AP-1 signaling pathway, which has a plethora of effects on host physiology. Using intestinal epithelial cell lines, HT-29 and Caco-2, stably transfected with AP-1-dependent luciferase reporter gene, we tested the effect of culture supernatant from 49 commensal strains. We observed that several bacteria were able to activate the AP-1 pathway and this was correlated to the amount of short chain fatty acids (SCFAs) produced. Besides being a major source of energy for epithelial cells, SCFAs have been shown to regulate several signaling pathways in these cells. We show that propionate and butyrate are potent activators of the AP-1 pathway, butyrate being the more efficient of the two. We also observed a strong synergistic activation of AP-1 pathway when using butyrate with PMA, a PKC activator. Moreover, butyrate enhanced the PMA-induced expression of c-fos and ERK1/2 phosphorylation, but not p38 and JNK. In conclusion, we showed that SCFAs especially butyrate regulate the AP-1 signaling pathway, a feature that may contribute to the physiological impact of the gut microbiota on the host. Our results provide support for the involvement of butyrate in modulating the action of PKC in colon cancer cells. PMID:23300800

  8. The intestinal archaea Methanosphaera stadtmanae and Methanobrevibacter smithii activate human dendritic cells.

    PubMed

    Bang, Corinna; Weidenbach, Katrin; Gutsmann, Thomas; Heine, Holger; Schmitz, Ruth A

    2014-01-01

    The methanoarchaea Methanosphaera stadtmanae and Methanobrevibacter smithii are known to be part of the indigenous human gut microbiota. Although the immunomodulatory effects of bacterial gut commensals have been studied extensively in the last decade, the impact of methanoarchaea in human's health and disease was rarely examined. Consequently, we studied and report here on the effects of M. stadtmanae and M. smithii on human immune cells. Whereas exposure to M. stadtmanae leads to substantial release of proinflammatory cytokines in monocyte-derived dendritic cells (moDCs), only weak activation was detected after incubation with M. smithii. Phagocytosis of M. stadtmanae by moDCs was demonstrated by confocal microscopy as well as transmission electronic microscopy (TEM) and shown to be crucial for cellular activation by using specific inhibitors. Both strains, albeit to different extents, initiate a maturation program in moDCs as revealed by up-regulation of the cell-surface receptors CD86 and CD197 suggesting additional activation of adaptive immune responses. Furthermore, M. stadtmanae and M. smithii were capable to alter the gene expression of antimicrobial peptides in moDCs to different extents. Taken together, our findings strongly argue that the archaeal gut inhabitants M. stadtmanae and M. smithii are specifically recognized by the human innate immune system. Moreover, both strains are capable of inducing an inflammatory cytokine response to different extents arguing that they might have diverse immunomodulatory functions. In conclusion, we propose that the impact of intestinal methanoarchaea on pathological conditions involving the gut microbiota has been underestimated until now. PMID:24915454

  9. A simple and rapid method for extracting bacterial DNA from intestinal microflora for ERIC-PCR detection

    PubMed Central

    Yang, Jin-Long; Wang, Ming-Shu; Cheng, An-Chun; Pan, Kang-Cheng; Li, Chuan-Feng; Deng, Shu-Xuan

    2008-01-01

    AIM: To develop a simple and convenient method for extracting genomic DNA from intestinal microflora for enterobacterial repetitive intergenic consensus (ERIC)-PCR detection. METHODS: Five methods of extracting bacterial DNA, including Tris-EDTA buffer, chelex-100, ultrapure water, 2% sodium dodecyl sulfate and 10% Triton-100 with and without sonication, were compared with the commercial fecal DNA extraction kit method, which is considered as the gold standard for DNA extraction. The comparison was based on the yield and purity of DNA and the indexes of the structure and property of micro-organisms that were reflected by ERIC-PCR. RESULTS: The yield and purity of DNA obtained by the chelex method was similar to that obtained with the fecal DNA kit. The ERIC-PCR results obtained for the DNA extracted by the chelex method and those obtained for DNA extracted with the fecal DNA kit were basically the same. CONCLUSION: The chelex method is recommended for ERIC-PCR experiments in view of its simplicity and cost-effectiveness; and it is suitable for extracting total DNA from intestinal micro-organisms, particularly for handling a large number of samples. PMID:18473413

  10. Long-term changes of bacterial and viral compositions in the intestine of a recovered Clostridium difficile patient after fecal microbiota transplantation.

    PubMed

    Broecker, Felix; Klumpp, Jochen; Schuppler, Markus; Russo, Giancarlo; Biedermann, Luc; Hombach, Michael; Rogler, Gerhard; Moelling, Karin

    2016-01-01

    Fecal microbiota transplantation (FMT) is an effective treatment for recurrent Clostridium difficile infections (RCDIs). However, long-term effects on the patients' gut microbiota and the role of viruses remain to be elucidated. Here, we characterized bacterial and viral microbiota in the feces of a cured RCDI patient at various time points until 4.5 yr post-FMT compared with the stool donor. Feces were subjected to DNA sequencing to characterize bacteria and double-stranded DNA (dsDNA) viruses including phages. The patient's microbial communities varied over time and showed little overall similarity to the donor until 7 mo post-FMT, indicating ongoing gut microbiota adaption in this time period. After 4.5 yr, the patient's bacteria attained donor-like compositions at phylum, class, and order levels with similar bacterial diversity. Differences in the bacterial communities between donor and patient after 4.5 yr were seen at lower taxonomic levels. C. difficile remained undetectable throughout the entire timespan. This demonstrated sustainable donor feces engraftment and verified long-term therapeutic success of FMT on the molecular level. Full engraftment apparently required longer than previously acknowledged, suggesting the implementation of year-long patient follow-up periods into clinical practice. The identified dsDNA viruses were mainly Caudovirales phages. Unexpectedly, sequences related to giant algae-infecting Chlorella viruses were also detected. Our findings indicate that intestinal viruses may be implicated in the establishment of gut microbiota. Therefore, virome analyses should be included in gut microbiota studies to determine the roles of phages and other viruses-such as Chlorella viruses-in human health and disease, particularly during RCDI. PMID:27148577

  11. Long-term changes of bacterial and viral compositions in the intestine of a recovered Clostridium difficile patient after fecal microbiota transplantation

    PubMed Central

    Broecker, Felix; Klumpp, Jochen; Schuppler, Markus; Russo, Giancarlo; Biedermann, Luc; Hombach, Michael; Rogler, Gerhard; Moelling, Karin

    2016-01-01

    Fecal microbiota transplantation (FMT) is an effective treatment for recurrent Clostridium difficile infections (RCDIs). However, long-term effects on the patients’ gut microbiota and the role of viruses remain to be elucidated. Here, we characterized bacterial and viral microbiota in the feces of a cured RCDI patient at various time points until 4.5 yr post-FMT compared with the stool donor. Feces were subjected to DNA sequencing to characterize bacteria and double-stranded DNA (dsDNA) viruses including phages. The patient's microbial communities varied over time and showed little overall similarity to the donor until 7 mo post-FMT, indicating ongoing gut microbiota adaption in this time period. After 4.5 yr, the patient's bacteria attained donor-like compositions at phylum, class, and order levels with similar bacterial diversity. Differences in the bacterial communities between donor and patient after 4.5 yr were seen at lower taxonomic levels. C. difficile remained undetectable throughout the entire timespan. This demonstrated sustainable donor feces engraftment and verified long-term therapeutic success of FMT on the molecular level. Full engraftment apparently required longer than previously acknowledged, suggesting the implementation of year-long patient follow-up periods into clinical practice. The identified dsDNA viruses were mainly Caudovirales phages. Unexpectedly, sequences related to giant algae–infecting Chlorella viruses were also detected. Our findings indicate that intestinal viruses may be implicated in the establishment of gut microbiota. Therefore, virome analyses should be included in gut microbiota studies to determine the roles of phages and other viruses—such as Chlorella viruses—in human health and disease, particularly during RCDI. PMID:27148577

  12. Beta adrenergic modulation of human upper intestinal propulsive forces.

    PubMed Central

    Ahluwalia, N K; Thompson, D G; Barlow, J; Heggie, L

    1994-01-01

    beta Adrenoceptor blockade is known to accelerate transit through the small intestine without changing either the number or pattern of intestinal contractions. This study therefore tested the hypothesis that an increase in intraluminal aboral propulsive force may contribute to this transit acceleration. Twenty paired studies were performed, in 10 healthy volunteers, after oral administration of either 100 mg atenolol (a selective beta 1 antagonist) or matched dummy tablets according to a double blind, randomised protocol. The frequency of occurrence of, and the propulsive force exerted by, traction events related to intestinal contractions were measured, using a combined traction force detector and manometry assembly. After atenolol, a consistent increase in the force generated per traction event was noted, both for propagating contractions mean (SEM) (12.0 (1.8) g v control 5.9 (0.07) g; p < 0.05) and for stationary (11.6 (1.4) g v control 7.0 (0.7) g; p < 0.05). In contrast no change in the number of traction events was noted (control v atenolol = 1.6 (0.3) v 1.64 (0.4) per min for propagating and 0.7 (0.1) v 0.85 (0.16) per min for stationary contraction; p > 0.05). beta Adrenoceptor blockade thus increases the propulsive force generated by intestinal contractions, possibly by removing a sympathetic neural inhibition of intestinal tone. PMID:7959185

  13. Intraepithelial lymphocytes in normal human intestine do not express proteins associated with cytolytic function.

    PubMed Central

    Chott, A.; Gerdes, D.; Spooner, A.; Mosberger, I.; Kummer, J. A.; Ebert, E. C.; Blumberg, R. S.; Balk, S. P.

    1997-01-01

    Human small intestine contains a very large population of intraepithelial T lymphocytes (IELs) that are oligoclonal, appear functionally to be cytolytic T cells, and may contribute to the normal and pathological turnover of intestinal epithelial cells. This report addresses the cytolytic function of IELs in normal small intestine by examining their expression of molecules that carry out cell-mediated cytolysis. Immunohistochemical analyses of granzyme B, perforin, Fas ligand, and tumor necrosis factor-alpha demonstrated these proteins were not expressed by small intestinal IELs in situ. These proteins also were not expressed by colonic IELs or by lamina propria lymphocytes in the small or large intestine. Granzyme A, however, was expressed by a large fraction of IELs. In contrast to these in situ results, isolated and in vitro activated IELs were shown to express effector proteins consistent with cytolytic T cells, including granzyme B, Fas ligand, tumor necrosis factor-alpha, and interferon-gamma. These results are most consistent with the vast majority of IELs in normal human small intestine being resting cytolytic T cells and suggest that these cells do not contribute to the apoptotic cell death of epithelial cells in normal intestine. Images Figure 1 Figure 2 Figure 3 PMID:9250156

  14. Orchestration of Neutrophil Movement by Intestinal Epithelial Cells in Response to Salmonella typhimurium Can Be Uncoupled from Bacterial Internalization

    PubMed Central

    Gewirtz, Andrew T.; Siber, Andrew M.; Madara, James L.; McCormick, Beth A.

    1999-01-01

    Intestinal epithelial cells respond to Salmonella typhimurium by internalizing this pathogen and secreting, in a polarized manner, an array of chemokines which direct polymorphonuclear leukocyte (PMN) movement. Notably, interleukin-8 (IL-8) is secreted basolaterally and directs PMN through the lamina propria, whereas pathogen-elicited epithelial chemoattractant (PEEC) is secreted apically and directs PMN migration across the epithelial monolayer to the intestinal lumen. While most studies of S. typhimurium pathogenicity have focused on the mechanism by which this bacterium invades its host, the enteritis characteristically associated with salmonellosis appears to be more directly attributable to the PMN movement that occurs in response to this pathogen. Therefore, we sought to better understand the relationship between S. typhimurium invasion and epithelial promotion of PMN movement. First, we investigated whether S. typhimurium becoming intracellular was necessary or sufficient to induce epithelial promotion of PMN movement. Blocking S. typhimurium invasion by preventing, with cytochalasin D, the epithelial cytoskeletal rearrangements which mediate internalization did not reduce the epithelial promotion of PMN movement. Conversely, bacterial attainment of an intracellular position was not sufficient to induce model epithelia to direct PMN transmigration, since neither basolateral invasion by S. typhimurium nor apical internalization of an invasion-deficient mutant (achieved by inducing membrane ruffling with epidermal growth factor) induced this epithelial cell response. These results indicate that specific interactions between the apical surface of epithelial cells and S. typhimurium, rather than simply bacterial invasion, mediate the epithelial direction of PMN transmigration. To further investigate the means by which S. typhimurium induces epithelia to direct PMN movement, we investigated whether the same signaling pathways regulate secretion of IL-8 and PEEC. IL-8 secretion, but not PEEC secretion, was activated by phorbol myristate acetate and blocked by an inhibitor (mg-132) of the proteosome which mediates NF-κβ activation. Further, secretion of IL-8, but not PEEC, was activated by an entry-deficient (HilΔ) S. typhimurium mutant or by basolateral invasion of a wild-type strain. Together, these results indicate that distinct signaling pathways mediate S. typhimurium invasion, induction of IL-8 secretion, and induction of PEEC secretion in model intestinal epithelia. PMID:9916066

  15. Orchestration of neutrophil movement by intestinal epithelial cells in response to Salmonella typhimurium can be uncoupled from bacterial internalization.

    PubMed

    Gewirtz, A T; Siber, A M; Madara, J L; McCormick, B A

    1999-02-01

    Intestinal epithelial cells respond to Salmonella typhimurium by internalizing this pathogen and secreting, in a polarized manner, an array of chemokines which direct polymorphonuclear leukocyte (PMN) movement. Notably, interleukin-8 (IL-8) is secreted basolaterally and directs PMN through the lamina propria, whereas pathogen-elicited epithelial chemoattractant (PEEC) is secreted apically and directs PMN migration across the epithelial monolayer to the intestinal lumen. While most studies of S. typhimurium pathogenicity have focused on the mechanism by which this bacterium invades its host, the enteritis characteristically associated with salmonellosis appears to be more directly attributable to the PMN movement that occurs in response to this pathogen. Therefore, we sought to better understand the relationship between S. typhimurium invasion and epithelial promotion of PMN movement. First, we investigated whether S. typhimurium becoming intracellular was necessary or sufficient to induce epithelial promotion of PMN movement. Blocking S. typhimurium invasion by preventing, with cytochalasin D, the epithelial cytoskeletal rearrangements which mediate internalization did not reduce the epithelial promotion of PMN movement. Conversely, bacterial attainment of an intracellular position was not sufficient to induce model epithelia to direct PMN transmigration, since neither basolateral invasion by S. typhimurium nor apical internalization of an invasion-deficient mutant (achieved by inducing membrane ruffling with epidermal growth factor) induced this epithelial cell response. These results indicate that specific interactions between the apical surface of epithelial cells and S. typhimurium, rather than simply bacterial invasion, mediate the epithelial direction of PMN transmigration. To further investigate the means by which S. typhimurium induces epithelia to direct PMN movement, we investigated whether the same signaling pathways regulate secretion of IL-8 and PEEC. IL-8 secretion, but not PEEC secretion, was activated by phorbol myristate acetate and blocked by an inhibitor (mg-132) of the proteosome which mediates NF-kappabeta activation. Further, secretion of IL-8, but not PEEC, was activated by an entry-deficient (HilDelta) S. typhimurium mutant or by basolateral invasion of a wild-type strain. Together, these results indicate that distinct signaling pathways mediate S. typhimurium invasion, induction of IL-8 secretion, and induction of PEEC secretion in model intestinal epithelia. PMID:9916066

  16. Bacterial community structure in the intestinal ecosystem of rainbow trout (Oncorhynchus mykiss) as revealed by pyrosequencing-based analysis of 16S rRNA genes.

    PubMed

    Etyemez, Miray; Balcázar, José Luis

    2015-06-01

    In this study, we determined the diversity and composition of bacterial communities within the intestinal ecosystem of farmed rainbow trout (Oncorhynchus mykiss). Healthy rainbow trout, weighing between 520 and 750 g, were fed a commercial diet. Subsequently, genomic DNA was isolated from the intestinal mucus (n = 16 fish samples) and combined into groups of four fish samples each for pyrosequencing analysis of bacterial 16S rRNA genes. The results revealed that the most abundant operational taxonomic units (OTUs) were affiliated to the genera Acinetobacter, Cetobacterium, Pseudomonas, and Psychrobacter, and to a lesser extent, the genera Aeromonas, Clostridium, Deefgea, Flavobacterium, Neptuniibacter, and Mycoplasma. These findings could be used as a baseline for further studies about the role of bacterial communities in normal and altered host physiological states. PMID:25843896

  17. Association between the ABO blood group and the human intestinal microbiota composition

    PubMed Central

    2012-01-01

    Background The mucus layer covering the human intestinal epithelium forms a dynamic surface for host-microbial interactions. In addition to the environmental factors affecting the intestinal equilibrium, such as diet, it is well established that the microbiota composition is individually driven, but the host factors determining the composition have remained unresolved. Results In this study, we show that ABO blood group is involved in differences in relative proportion and overall profiles of intestinal microbiota. Specifically, the microbiota from the individuals harbouring the B antigen (secretor B and AB) differed from the non-B antigen groups and also showed higher diversity of the Eubacterium rectale-Clostridium coccoides (EREC) and Clostridium leptum (CLEPT) -groups in comparison with other blood groups. Conclusions Our novel finding indicates that the ABO blood group is one of the genetically determined host factors modulating the composition of the human intestinal microbiota, thus enabling new applications in the field of personalized nutrition and medicine. PMID:22672382

  18. Postoperative Changes in Fecal Bacterial Communities and Fermentation Products in Obese Patients Undergoing Bilio-Intestinal Bypass.

    PubMed

    Patrone, Vania; Vajana, Elia; Minuti, Andrea; Callegari, Maria L; Federico, Alessandro; Loguercio, Carmela; Dallio, Marcello; Tolone, Salvatore; Docimo, Ludovico; Morelli, Lorenzo

    2016-01-01

    We assessed the gut microbial ecology of 11 severely obese patients before and after bilio-intestinal bypass (BIB). Fecal samples were evaluated for microbial communities using 16S rDNA Illumina sequencing, real-time PCR targeting functional genes, and gas chromatography of short chain fatty acids (SCFAs). At 6 months after surgery, subjects exhibited significant improvements in metabolic markers (body weight, glucose, and lipid metabolism) compared with baseline. The fecal microbiota of post-surgery individuals was characterized by an overall decrease of bacterial diversity, with a significant reduction in Lachnospiraceae, Clostridiaceae, Ruminococcaceae, Eubacteriaceae, and Coriobacteriaceae. On the contrary, there were significant increases of genera Lactobacillus, Megasphaera, and Acidaminococcus and the family Enterobacteriaceae. The pH was decreased in fecal samples from patients after BIB and SCFA profiles were altered, with lower percentages of acetate and propionate and higher levels of valerate and hexanoate. Some changes in the bacterial populations were associated with variations in the patients' metabolic health parameters, namely Gemmiger and glucose, Lactobacillus and glucose, and Faecalibacterium and triglycerides. The results from this study of BIB patients furthers our understanding of the composition of gut microbiota and the functional changes that may be involved in improving obesity-related conditions following weight-loss surgery. PMID:26941724

  19. Postoperative Changes in Fecal Bacterial Communities and Fermentation Products in Obese Patients Undergoing Bilio-Intestinal Bypass

    PubMed Central

    Patrone, Vania; Vajana, Elia; Minuti, Andrea; Callegari, Maria L.; Federico, Alessandro; Loguercio, Carmela; Dallio, Marcello; Tolone, Salvatore; Docimo, Ludovico; Morelli, Lorenzo

    2016-01-01

    We assessed the gut microbial ecology of 11 severely obese patients before and after bilio-intestinal bypass (BIB). Fecal samples were evaluated for microbial communities using 16S rDNA Illumina sequencing, real-time PCR targeting functional genes, and gas chromatography of short chain fatty acids (SCFAs). At 6 months after surgery, subjects exhibited significant improvements in metabolic markers (body weight, glucose, and lipid metabolism) compared with baseline. The fecal microbiota of post-surgery individuals was characterized by an overall decrease of bacterial diversity, with a significant reduction in Lachnospiraceae, Clostridiaceae, Ruminococcaceae, Eubacteriaceae, and Coriobacteriaceae. On the contrary, there were significant increases of genera Lactobacillus, Megasphaera, and Acidaminococcus and the family Enterobacteriaceae. The pH was decreased in fecal samples from patients after BIB and SCFA profiles were altered, with lower percentages of acetate and propionate and higher levels of valerate and hexanoate. Some changes in the bacterial populations were associated with variations in the patients' metabolic health parameters, namely Gemmiger and glucose, Lactobacillus and glucose, and Faecalibacterium and triglycerides. The results from this study of BIB patients furthers our understanding of the composition of gut microbiota and the functional changes that may be involved in improving obesity-related conditions following weight-loss surgery. PMID:26941724

  20. Maternal 18:3n-3 favors piglet intestinal passage of LPS and promotes intestinal anti-inflammatory response to this bacterial ligand.

    PubMed

    Desaldeleer, Cécile; Ferret-Bernard, Stéphanie; de Quelen, Francine; Le Normand, Laurence; Perrier, Cécile; Savary, Gérard; Romé, Véronique; Michel, Catherine; Mourot, Jacques; Le Huërou-Luron, Isabelle; Boudry, Gaëlle

    2014-10-01

    We recently observed that maternal 18:3n-3 increases piglet jejunal permeability. We hypothesized that this would favor intestinal lipopolysaccharide (LPS) passage and alter gut immune system education toward this bacterial ligand. Sows were fed 18:3n-3 or 18:2n-6 diets throughout gestation and lactation. In each litter, two piglets were given oral Gram-negative spectrum antibiotic from post-natal day (PND) 14 to 28. All piglets were weaned on a regular diet at PND28. 18:3n-3 piglets exhibited greater jejunal permeability to FITC-LPS at PND28. Levels of 18:3n-3 but neither 20:5n-3 nor 20:4n-6 were greater in mesenteric lymph nodes (MLN) of 18:3n-3 piglets. Jejunal explant or MLN cell cytokine responses to LPS were not influenced by the maternal diet. Antibiotic increased jejunal permeability to FITC-LPS and lowered the level of 20:5n-3 in MLN, irrespective of the maternal diet. At PND52, no long-lasting effect of the maternal diet or antibiotic treatment on jejunal permeability was noticed. 18:3n-3 and 20:4n-6 levels were greater and lower, respectively, in MLN of 18:3n-3 compared to 18:2n-6 piglets. IL-10 production by MLN cells in response to LPS was greater in the 18:3n-3 group, irrespective of the neonatal antibiotic treatment. IL-8 secretion by jejunal explants in response to LPS was lower in antibiotic-treated 18:3n-3 compared to 18:2n-6 piglets. Finally, proportion of MHC class II(+) antigen-presenting cells was greater in 18:3n-3 than 18:2n-6 MLN cells. In conclusion, maternal 18:3n-3 directs the intestinal immune response to LPS toward an anti-inflammatory profile beyond the breastfeeding period; microbiota involvement seems dependent of the immune cells considered. PMID:25087993

  1. Development of Functional Microfold (M) Cells from Intestinal Stem Cells in Primary Human Enteroids

    PubMed Central

    Rouch, Joshua D.; Scott, Andrew; Lei, Nan Ye; Solorzano-Vargas, R. Sergio; Wang, Jiafang; Hanson, Elaine M.; Kobayashi, Masae; Lewis, Michael; Stelzner, Matthias G.; Dunn, James C. Y.; Eckmann, Lars; Martín, Martín G.

    2016-01-01

    Background & Aims Intestinal microfold (M) cells are specialized epithelial cells that act as gatekeepers of luminal antigens in the intestinal tract. They play a critical role in the intestinal mucosal immune response through transport of viruses, bacteria and other particles and antigens across the epithelium to immune cells within Peyer’s patch regions and other mucosal sites. Recent studies in mice have demonstrated that M cells are generated from Lgr5+ intestinal stem cells (ISCs), and that infection with Salmonella enterica serovar Typhimurium increases M cell formation. However, it is not known whether and how these findings apply to primary human small intestinal epithelium propagated in an in vitro setting. Methods Human intestinal crypts were grown as monolayers with growth factors and treated with recombinant RANKL, and assessed for mRNA transcripts, immunofluorescence and uptake of microparticles and S. Typhimurium. Results Functional M cells were generated by short-term culture of freshly isolated human intestinal crypts in a dose- and time-dependent fashion. RANKL stimulation of the monolayer cultures caused dramatic induction of the M cell-specific markers, SPIB, and Glycoprotein-2 (GP2) in a process primed by canonical WNT signaling. Confocal microscopy demonstrated a pseudopod phenotype of GP2-positive M cells that preferentially take up microparticles. Furthermore, infection of the M cell-enriched cultures with the M cell-tropic enteric pathogen, S. Typhimurium, led to preferential association of the bacteria with M cells, particularly at lower inoculum sizes. Larger inocula caused rapid induction of M cells. Conclusions Human intestinal crypts containing ISCs can be cultured and differentiate into an epithelial layer with functional M cells with characteristic morphological and functional properties. This study is the first to demonstrate that M cells can be induced to form from primary human intestinal epithelium, and that S. Typhimurium preferentially infect these cells in an in vitro setting. We anticipate that this model can be used to generate large numbers of M cells for further functional studies of these key cells of intestinal immune induction and their impact on controlling enteric pathogens and the intestinal microbiome. PMID:26820624

  2. Bacterial expression of human cysteine proteinase inhibitor stefin A.

    PubMed

    Fong, D; Kartasova, T; Sloane, B F; Chan, M M

    1989-10-23

    Stefin A, a cysteine proteinase inhibitor of the cystatin superfamily, has been found to be most abundant in epidermal cells. In order to determine its cellular function, we have expressed human stefin A in Escherichia coli using plasmid expression vectors under the control of bacteriophage T7 RNA polymerase. The heat-stable, antibody-positive bacterial product was isolated using a papain-Sepharose affinity column and was shown to inhibit two cysteine proteinases, papain and human cathepsin B. Recombinant stefin A may have commercial and therapeutic potential in situations requiring inhibition of cysteine proteinase activities, and in cosmetics, as an ingredient in skin creams. PMID:2680606

  3. Induction of Human Regulatory T Cells with Bacterial Superantigens.

    PubMed

    Caserta, Stefano; Taylor, Amanda L; Terrazzini, Nadia; Llewelyn, Martin J

    2016-01-01

    Regulatory T cells (Tregs) that suppress the activation of immune effector cells limit immunopathology and are fast emerging as therapeutic targets for autoimmune and cancer disease. Tools enabling Treg in vitro-induction, expansion, and characterization and manipulation will help future clinical developments. In this chapter, we describe in detail how to use bacterial superantigens to induce human Tregs efficiently from peripheral blood mononuclear cells. How to assess human Treg phenotype and suppressive capacity are also described. Technical details, variations, and alternative experimental conditions are provided. PMID:26676048

  4. A Comparative Study of Bacterial and Parasitic Intestinal Infections in India

    PubMed Central

    Uppal, Beena; Perween, Naz; Kumar, Shyam Kishor

    2015-01-01

    Background: Infectious diarrhea causes a major health problem in developing countries with significant morbidity and mortality. Very often, rehydration therapy alone does not suffice, mandating the use of antimicrobial agents. However, rapidly decreasing antimicrobial susceptibility is complicating the matters. Materials and Methods: The study aimed to determine the prevalent bacterial and parasitic agents of diarrhea in India. A cross-sectional study was done at Maulana Azad Medical College and associated Lok Nayak Hospital, New Delhi, during 2012-14. Stool samples were received from patients of all age groups and processed for bacteriological and parasitological identification by microscopy, bacterial culture, biochemical identification, serotyping and antimicrobial susceptibility tests. The study also aimed to identify the recent papers (after year 2000) reporting aetiology of infectious diarrhea in India involving the general population as a whole and compare them with present findings. Results: Out of 6527 samples, 581 (8.90%) were positive for bacterial pathogens. A total of 280 samples (of 3823 under-five year children) were positive for diarrheagenic Escherichia coli. Other organisms like Vibrio cholera were found in 159 (2.44%) cases, Shigella spp. in 126 (1.93%), Salmonella Typhi in 7 (0.11%), Salmonella Typhimurium in 6 (0.10%), Aeromonas hydrophila in 3 (0.05%) cases. Levels of resistance to nalidixic acid, amoxicillin and ciprofloxacin were alarmingly high. Third generation cephalosporins were seen to be moderately active except against E. coli. Parasites were identified in 312 (4.78%) cases. Giardia intestinalis, Ascaris lumbricoides and Entamoeba histolytica were identified in 2.27%, 1.15% and 0.64% cases respectively. Conclusion: Analysis of recent nationwide studies revealed V. cholerae was the most common bacterial/parasitic agent of diarrhea across all populations, being followed by diarrheagenic E. coli and Giardia intestinalis. Periodic laboratory monitoring of antimicrobial susceptibility pattern is essential, as is formulation of effective antibiotic use policy. PMID:25954615

  5. Bacterial communities on classroom surfaces vary with human contact

    PubMed Central

    2014-01-01

    Background Humans can spend the majority of their time indoors, but little is known about the interactions between the human and built-environment microbiomes or the forces that drive microbial community assembly in the built environment. We sampled 16S rRNA genes from four different surface types throughout a university classroom to determine whether bacterial assemblages on each surface were best predicted by routine human interactions or by proximity to other surfaces within the classroom. We then analyzed our data with publicly-available datasets representing potential source environments. Results Bacterial assemblages from the four surface types, as well as individual taxa, were indicative of different source pools related to the type of human contact each surface routinely encounters. Spatial proximity to other surfaces in the classroom did not predict community composition. Conclusions Our results indicate that human-associated microbial communities can be transferred to indoor surfaces following contact, and that such transmission is possible even when contact is indirect, but that proximity to other surfaces in the classroom does not influence community composition. PMID:24602274

  6. Function, expression, and characterization of the serotonin transporter in the native human intestine

    PubMed Central

    Gill, Ravinder K.; Pant, Nitika; Saksena, Seema; Singla, Amika; Nazir, Talat M.; Vohwinkel, Lisa; Turner, Jerrold R.; Goldstein, Jay; Alrefai, Waddah A.; Dudeja, Pradeep K.

    2016-01-01

    The enteric serotonin transporter (SERT) plays a critical role in modulating serotonin availability and thus has been implicated in the pathogenesis of various intestinal disorders. To date, SERT expression and function in the human intestine have not been investigated. Current studies were designed to characterize the function, expression, distribution, and membrane localization of SERT in the native human intestine. Real-time PCR studies showed relatively higher SERT mRNA expression in the human small intestine compared with colon (ileum ≫ duodenum ≫ jejunum). Northern blot analysis revealed three mRNA hybridizing species encoding SERT (3.0, 4.9, and 6.8 kb) in the human ileum. Consistent with SERT mRNA expression, SERT immunostaining was mainly detected in the epithelial cells of human duodenal and ileal resected tissues. Notably, SERT expression was localized predominantly to the apical and intracellular compartments and was distributed throughout the crypt-villus axis. Immunoblotting studies detected a prominent protein band (~70 kDa) in the ileal apical plasma membrane vesicles (AMVs) isolated from mucosa obtained from organ-donor intestine. Functional studies showed that uptake of [3H]serotonin (150 nM) in human ileal AMVs was 1) significantly increased in the presence of both Na+ and Cl−; 2) inhibited (~50%) by the neuronal SERT inhibitor, fluoxetine (10 μM) and by unlabeled 5-HT; and 3) exhibited saturation kinetics indicating the presence of a carrier-mediated process. Our studies demonstrated differential expression of SERT across various regions of the human intestine and provide evidence for the existence of a functional SERT capable of removing intraluminal serotonin in human ileal epithelial cells. PMID:17991706

  7. Effect of intestinal glucuronidation in limiting hepatic exposure and bioactivation of raloxifene in humans and rats.

    PubMed

    Dalvie, Deepak; Kang, Ping; Zientek, Michael; Xiang, Cathie; Zhou, Sue; Obach, R Scott

    2008-12-01

    Raloxifene (Evista) is a second generation selective estrogen receptor modulator used in the treatment of osteoporosis and for chemoprevention of breast cancer. It is bioactivated to reactive intermediates, which covalently bind to proteins and form GSH conjugates upon incubation with NADPH and GSH-supplemented human and rat liver microsomes. Despite these in vitro findings, no major raloxifene-related toxic events have been reported upon its oral administration to humans. This disconnect between safety of raloxifene and its in vitro bioactivation is attributed to its presystemic metabolism via glucuronidation. Current studies investigated the effect of hepatic and intestinal glucuronidation in modulating hepatic availability of raloxifene and its subsequent bioactivation, in vitro. The study design involved preincubation of raloxifene with intestinal microsomes followed by a sequential incubation with liver microsomes. The degree of bioactivation of raloxifene was assessed from the percentage of GSH conjugate formed in liver microsomal incubations or the amount of covalent binding of raloxifene-related material to liver microsomal proteins. The results indicated that human intestinal glucuronidation limited the hepatic exposure of raloxifene that underwent bioactivation in the liver. Similar experiments with rat microsomal preparations showed very little effect of intestinal glucuronidation. This effect of intestinal glucuronidation and the observed species difference were explained by comparing the efficiency (Cl(int)) of glucuronidation and oxidation in the two species. These findings suggested that even though the rate of bioactivation in the two species was similar, the Cl(int) of glucuronidation was 7.5-fold higher in the human intestine as compared to rats. These results support the hypothesis that intestinal glucuronidation modulates the amount of raloxifene undergoing bioactivation by liver and corroborate the importance of assessing other competitive metabolic pathways and species differences in metabolism prior to extrapolation of bioactivation results from rats to humans. PMID:19548350

  8. Fecal microbiota transplantation and bacterial consortium transplantation have comparable effects on the re-establishment of mucosal barrier function in mice with intestinal dysbiosis

    PubMed Central

    Li, Ming; Liang, Pin; Li, Zhenzhen; Wang, Ying; Zhang, Guobin; Gao, Hongwei; Wen, Shu; Tang, Li

    2015-01-01

    Fecal microbiota transplantation (FMT) is a promising therapy, despite some reports of adverse side effects. Bacterial consortia transplantation (BCT) for targeted restoration of the intestinal ecosystem is considered a relatively safe and simple procedure. However, no systematic research has assessed the effects of FMT and BCT on immune responses of intestinal mucosal barrier in patients. We conducted complementary studies in animal models on the effects of FMT and BCT, and provide recommendations for improving the clinical outcomes of these treatments. To establish the dysbiosis model, male BALB/c mice were treated with ceftriaxone intra-gastrically for 7 days. After that, FMT and BCT were performed on ceftriaxone-treated mice for 3 consecutive days to rebuild the intestinal ecosystem. Post-FMT and post-BCT changes of the intestinal microbial community and mucosal barrier functions were investigated and compared. Disruption of intestinal microbial homeostasis impacted the integrity of mucosal epithelial layer, resulting in increased intestinal permeability. These outcomes were accompanied by overexpression of Muc2, significant decrease of SIgA secretion, and overproduction of defensins and inflammatory cytokines. After FMT and BCT, the intestinal microbiota recovered quickly, this was associated with better reconstruction of mucosal barriers and re-establishment of immune networks compared with spontaneous recovery (SR). Although based on a short-term study, our results suggest that FMT and BCT promote the re-establishment of intestinal microbial communities in mice with antibiotic-induced dysbiosis, and contribute to the temporal and spatial interactions between microbiota and mucosal barriers. The effects of BCT are comparable to that of FMT, especially in normalizing the intestinal levels of Muc2, SIgA, and defensins. PMID:26217323

  9. Lactic acid bacteria protect human intestinal epithelial cells from Staphylococcus aureus and Pseudomonas aeruginosa infections.

    PubMed

    Affhan, S; Dachang, W; Xin, Y; Shang, D

    2015-01-01

    Staphylococcus aureus and Pseudomonas aeruginosa are opportunistic pathogens that cause nosocomial and food-borne infections. They promote intestinal diseases. Gastrointestinal colonization by S. aureus and P. aeruginosa has rarely been researched. These organisms spread to extra gastrointestinal niches, resulting in increasingly progressive infections. Lactic acid bacteria are Gram-positive bacteria that produce lactic acid as the major end-product of carbohydrate fermentation. These bacteria inhibit pathogen colonization and modulate the host immune response. This study aimed to investigate the effects of Lactobacillus acidophilus and Lactobacillus rhamnosus on enteric infections caused by the paradigmatic human pathogens S. aureus ATCC25923 and P. aeruginosa ATCC27853. The effect of whole cells and neutralized cell-free supernatant (CFS) of the lactobacilli on LoVo human carcinoma enterocyte (ATCC CCL-229) infection was analyzed by co-exposure, pre-exposure, and post-exposure studies. Simultaneous application of whole cells and CFS of the lactobacilli significantly eradicated enterocyte infection (P < 0.05); however, this effect was not seen when the whole cells and CFS were added after or prior to the infection (P > 0.05). This result could be attributed to interference by extracellular polymeric substances and cell surface hydrophobicity, which resulted in the development of a pathogen that did not form colonies. Furthermore, results of the plate count and LIVE/ DEAD BacLight bacterial viability staining attributed this inhibition to a non-bacteriocin-like substance, which acted independently of organic acid and H2O2 production. Based on these results, the cell-free supernatant derived from lactobacilli was concluded to restrain the development of S. aureus and P. aeruginosa enteric infections. PMID:26681052

  10. Study of the Biotransformation of Tongmai Formula by Human Intestinal Flora and Its Intestinal Permeability across the Caco-2 Cell Monolayer.

    PubMed

    Wu, Shuai; Xu, Wei; Wang, Fu-Rong; Yang, Xiu-Wei

    2015-01-01

    Tongmai formula (TMF) is a well-known Chinese medicinal preparation that contains isoflavones as its major bioactive constituents. As traditional Chinese medicines (TCMs) are usually used by oral administration, their fate inside the intestinal lumen, including their biotransformation by human intestinal flora (HIF) and intestinal absorption deserves study. In this work TMF extract was incubated with human intestinal bacteria under anaerobic conditions and the changes in the twelve main constituents of TMF were then investigated. Their intestinal permeabilities, i.e., the transport capability across the intestinal brush border were investigated with a human colon carcinoma cell line (Caco-2) cell monolayer model to predict the absorption mechanism. Meanwhile, rapid HPLC-DAD methods were established for the assay. According to the biotransformation curves of the twelve constituents and the permeability coefficients, the intestinal absorption capacity of the typical compounds was elevated from the levels of 10(-7) cm/s to 10(-5) cm/s from those of the original compounds in TMF. Among them the main isoflavone glycosides puerarin (4), mirificin (6) and daidzin (7) were transformed into the same aglycone, daidzein (10). Therefore it was predicted that the aglycone compounds might be the real active ingredients in TMF. The models used can represent a novel path for the TCM studies. PMID:26501241

  11. Characterization of monocarboxylate transporter 6: expression in human intestine and transport of the antidiabetic drug nateglinide.

    PubMed

    Kohyama, Noriko; Shiokawa, Hisae; Ohbayashi, Masayuki; Kobayashi, Yasuna; Yamamoto, Toshinori

    2013-11-01

    Monocarboxylate transporter (MCT) 6, encoded by SLC16A5, is a member of the monocarboxylate transporter family. Nateglinide, an oral hypoglycemic agent, quickly reaches the maximal serum concentration after its premeal administration. Although the functional existence of uptake systems for nateglinide in the intestine has been demonstrated, these transport systems have not yet been identified at the molecular level. The aim of this study was to demonstrate the localization of MCT6 in the human small intestine and characterize the transport properties of nateglinide via MCT6. Immunohistochemical analysis of the human small intestine revealed that anti-MCT6 antiserum stained the luminal side of the epithelial cells. When expressed in Xenopus laevis oocytes, MCT6-mediated uptake of [(14)C]nateglinide was sensitive to extracellular pH and membrane potential. Furthermore, the K(t) value of nateglinide (45.9 μM) for MCT6 was lower than those previously reported in Caco-2 cells and rat intestinal brush-border membrane vesicles. In addition, probenecid, fluorescein, valproic acid, and salicylic acid, which are inhibitors of nateglinide uptake in Caco-2 cells and rat intestine, did not inhibit the uptake of nateglinide via MCT6. These results suggest that MCT6 may play a role in the intestinal absorption of nateglinide, although other transporters are also likely involved. PMID:23935065

  12. The human milk oligosaccharide 2'-fucosyllactose augments the adaptive response to extensive intestinal.

    PubMed

    Mezoff, Ethan A; Hawkins, Jennifer A; Ollberding, Nicholas J; Karns, Rebekah; Morrow, Ardythe L; Helmrath, Michael A

    2016-03-15

    Intestinal resection resulting in short bowel syndrome (SBS) carries a heavy burden of long-term morbidity, mortality, and cost of care, which can be attenuated with strategies that improve intestinal adaptation. SBS infants fed human milk, compared with formula, have more rapid intestinal adaptation. We tested the hypothesis that the major noncaloric human milk oligosaccharide 2'-fucosyllactose (2'-FL) contributes to the adaptive response after intestinal resection. Using a previously described murine model of intestinal adaptation, we demonstrated increased weight gain from 21 to 56 days (P < 0.001) and crypt depth at 56 days (P < 0.0095) with 2'-FL supplementation after ileocecal resection. Furthermore, 2'-FL increased small bowel luminal content microbial alpha diversity following resection (P < 0.005) and stimulated a bloom in organisms of the genus Parabacteroides (log2-fold = 4.1, P = 0.035). Finally, transcriptional analysis of the intestine revealed enriched ontologies and pathways related to antimicrobial peptides, metabolism, and energy processing. We conclude that 2'-FL supplementation following ileocecal resection increases weight gain, energy availability through microbial community modulation, and histological changes consistent with improved adaptation. PMID:26702137

  13. Intestinal antigen handling at mucosal surfaces in health and disease: human and experimental studies.

    PubMed

    Reinhardt, M C; Paganelli, R; Levinsky, R J

    1983-08-01

    Intestinal uptake of antigenically intact food proteins was measured by a solid phase radioimmunoassay on serum samples after instillation of food proteins into a closed intestinal loop of adult Wistar rats. Compared to normal controls, rats fed protein deficient diets during five months had a higher macromolecular uptake. During the course of Nippostrongylus brasiliensis infection this uptake was decreased. In cholera toxin induced secretory states of the intestinal mucosa uptake of food proteins was increased. In human studies the uptake of Beta-Lactoglobulin after a milk meal was shown to be increased in premature compared to full-term neonates. In children suffering from intestinal helminth infection the macromolecular uptake was higher before treatment compared to that after treatment. These studies show that various pathological situations can alter the antigen handling at mucosal surfaces. PMID:6881621

  14. Diversity and Succession of the Intestinal Bacterial Community of the Maturing Broiler Chicken

    PubMed Central

    Lu, Jiangrang; Idris, Umelaalim; Harmon, Barry; Hofacre, Charles; Maurer, John J.; Lee, Margie D.

    2003-01-01

    The diversity of bacterial floras in the ilea and ceca of chickens that were fed a vegetarian corn-soy broiler diet devoid of feed additives was examined by analysis of 1,230 partial 16S rRNA gene sequences. Nearly 70% of sequences from the ileum were related to those of Lactobacillus, with the majority of the rest being related to Clostridiaceae (11%), Streptococcus (6.5%), and Enterococcus (6.5%). In contrast, Clostridiaceae-related sequences (65%) were the most abundant group detected in the cecum, with the other most abundant sequences being related to Fusobacterium (14%), Lactobacillus (8%), and Bacteroides (5%). Statistical analysis comparing the compositions of the different 16S rRNA libraries revealed that population succession occurred during some sampling periods. The significant differences among cecal libraries at 3 and 7 days of age, at 14 to 28 days of age, and at 49 days of age indicated that successions occurred from a transient community to one of increasing complexity as the birds aged. Similarly, the ileum had a stable bacterial community structure for birds at 7 to 21 days of age and between 21 to 28 days of age, but there was a very unique community structure at 3 and 49 days of age. It was also revealed that the composition of the ileal and cecal libraries did not significantly differ when the birds were 3 days old, and in fact during the first 14 days of age, the cecal microflora was a subset of the ileal microflora. After this time, the ileum and cecum had significantly different library compositions, suggesting that each region developed its own unique bacterial community as the bird matured. PMID:14602645

  15. Diversity and succession of the intestinal bacterial community of the maturing broiler chicken.

    PubMed

    Lu, Jiangrang; Idris, Umelaalim; Harmon, Barry; Hofacre, Charles; Maurer, John J; Lee, Margie D

    2003-11-01

    The diversity of bacterial floras in the ilea and ceca of chickens that were fed a vegetarian corn-soy broiler diet devoid of feed additives was examined by analysis of 1,230 partial 16S rRNA gene sequences. Nearly 70% of sequences from the ileum were related to those of Lactobacillus, with the majority of the rest being related to Clostridiaceae (11%), Streptococcus (6.5%), and Enterococcus (6.5%). In contrast, Clostridiaceae-related sequences (65%) were the most abundant group detected in the cecum, with the other most abundant sequences being related to Fusobacterium (14%), Lactobacillus (8%), and Bacteroides (5%). Statistical analysis comparing the compositions of the different 16S rRNA libraries revealed that population succession occurred during some sampling periods. The significant differences among cecal libraries at 3 and 7 days of age, at 14 to 28 days of age, and at 49 days of age indicated that successions occurred from a transient community to one of increasing complexity as the birds aged. Similarly, the ileum had a stable bacterial community structure for birds at 7 to 21 days of age and between 21 to 28 days of age, but there was a very unique community structure at 3 and 49 days of age. It was also revealed that the composition of the ileal and cecal libraries did not significantly differ when the birds were 3 days old, and in fact during the first 14 days of age, the cecal microflora was a subset of the ileal microflora. After this time, the ileum and cecum had significantly different library compositions, suggesting that each region developed its own unique bacterial community as the bird matured. PMID:14602645

  16. Bacterial Community Associated with the Intestinal Tract of Chinese Mitten Crab (Eriocheir sinensis) Farmed in Lake Tai, China

    PubMed Central

    Chen, Xiaobing; Di, Panpan; Wang, Hongming; Li, Bailin; Pan, Yingjie; Yan, Shuling; Wang, Yongjie

    2015-01-01

    Chinese mitten crab (CMC, Eriocheir sinensis) is an economically valuable species in South-East Asia that has been widely farmed in China. Characterization of the intestinal bacterial diversity of CMC will provide insights into the aquaculturing of CMCs. Based on the analysis of cloned 16S rRNA genes from culture-independent CMC gut bacteria, 124 out of 128 different clones reveal >95% nucleotide similarity to the species belonging to the four phyla of Tenericutes, Bacteroidetes, Firmicutes and Proteobacteria; one clone shows 91% sequence similarity to the member of TM7 (a candidate phylum without cultured representatives). Fluorescent in situ hybridization also reveals the abundance of Bacteroidetes in crab intestine. Electron micrographs show that spherical and filamentous bacteria are closely associated with the microvillus brush border of the midgut epithelium and are often inserted into the space between the microvilli using a stalk-like cell appendage. In contrast, the predominant rod-shaped bacteria in the hindgut are tightly attached to the epithelium surface by an unusual pili-like structure. Both 16S rRNA gene denaturing gel gradient electrophoresis and metagenome library indicate that the CMC Mollicutes group 2 appears to be present in both the midgut and hindgut with no significant difference in abundance. The CMC Mollicutes group 1, however, was found mostly in the midgut of CMCs. The CMC gut Mollicutes phylotypes appear to be most closely related to Mollicutes symbionts detected in the gut of isopods (Crustacea: Isopoda). Overall, the results suggest that CMCs harbor diverse, novel and specific gut bacteria, which are likely to live in close relationships with the CMC host. PMID:25875449

  17. Bacterial community associated with the intestinal tract of Chinese mitten crab (Eriocheir sinensis) farmed in Lake Tai, China.

    PubMed

    Chen, Xiaobing; Di, Panpan; Wang, Hongming; Li, Bailin; Pan, Yingjie; Yan, Shuling; Wang, Yongjie

    2015-01-01

    Chinese mitten crab (CMC, Eriocheir sinensis) is an economically valuable species in South-East Asia that has been widely farmed in China. Characterization of the intestinal bacterial diversity of CMC will provide insights into the aquaculturing of CMCs. Based on the analysis of cloned 16S rRNA genes from culture-independent CMC gut bacteria, 124 out of 128 different clones reveal >95% nucleotide similarity to the species belonging to the four phyla of Tenericutes, Bacteroidetes, Firmicutes and Proteobacteria; one clone shows 91% sequence similarity to the member of TM7 (a candidate phylum without cultured representatives). Fluorescent in situ hybridization also reveals the abundance of Bacteroidetes in crab intestine. Electron micrographs show that spherical and filamentous bacteria are closely associated with the microvillus brush border of the midgut epithelium and are often inserted into the space between the microvilli using a stalk-like cell appendage. In contrast, the predominant rod-shaped bacteria in the hindgut are tightly attached to the epithelium surface by an unusual pili-like structure. Both 16S rRNA gene denaturing gel gradient electrophoresis and metagenome library indicate that the CMC Mollicutes group 2 appears to be present in both the midgut and hindgut with no significant difference in abundance. The CMC Mollicutes group 1, however, was found mostly in the midgut of CMCs. The CMC gut Mollicutes phylotypes appear to be most closely related to Mollicutes symbionts detected in the gut of isopods (Crustacea: Isopoda). Overall, the results suggest that CMCs harbor diverse, novel and specific gut bacteria, which are likely to live in close relationships with the CMC host. PMID:25875449

  18. Paracellular porosity and pore size of the human intestinal epithelium in tissue and cell culture models.

    PubMed

    Linnankoski, Johanna; Mäkelä, Johanna; Palmgren, Joni; Mauriala, Timo; Vedin, Charlotta; Ungell, Anna-Lena; Lazorova, Lucia; Artursson, Per; Urtti, Arto; Yliperttula, Marjo

    2010-04-01

    The paracellular space defines the passive permeation of hydrophilic compounds in epithelia. The goal of this study was to characterise the paracellular permeation pathway in the human intestinal wall and differentiated epithelial cell models (MDCKII, Caco-2 and 2/4/A1). The permeabilities of hydrophilic polyethylene glycols (PEG) were investigated in diffusion chambers, and mass spectrometry was used to obtain accurate concentrations for each PEG molecule. The paracellular porosity and the size of the pores in the membranes were estimated from the PEG permeability data using an effusion-based approach. The porosities were found to be low (fraction 10(-7)-10(-5) of the epithelial surface) in all investigated membranes. Two different pore sizes (radii 5-6 and >10 A) were detected in the human intestinal epithelium and the Caco-2 and MDCKII cells, while only one (about 15 A) in the 2/4/A1 monolayer. The paracellular porosities of the human small intestine and 2/4/A1 monolayers were larger (>10(-7)) than that of the MDCKII and Caco-2 cells (<10(-7)). We report for the first time the quantitative values describing both porosity and pore size of the paracellular space in the human intestine. The cell models deviate from the small intestine either with respect to porosity (Caco-2, MDCKII) or pore size distribution (2/4/A1). PMID:19827099

  19. Localization of immunoglobulins in intestinal mucosa and the production of secretory antibodies in response to intraluminal administration of bacterial antigens in the preruminant calf.

    PubMed

    Allen, W D; Porter, P

    1975-09-01

    Immunofluorescent studies of intestinal tissues from young preruminant calves demonstrate the presence of two main populations of immunocytes synthesizing IgA and IgM. These cells had infiltrated the lamina propria of the intestine as early as 4 days of age. There was little evidence of any significant involvement of IgG1 in intestinal immune synthesis of calves at this age although activity was demonstrable in the ileum and colon of one calf. In general there were more IgG2-synthesizing cells than IgG1, but these were few compared with the main populations of IgA and IgM cells. Local antigenic stimulus to the intestinal mucosa of young fistulated calves using extracts of heat-killed Gram-negative bacteria produced antibody in the secretions over a period of approximately 3 weeks. A second administration of a similar antigenic dose produced a similar response indicating the requirement for continuous stimuli to maintain a measurable level of antibody secretion. Gel filtration and antiglobulin assays indicated that the antibacterial activity was predominantly associated with IgA and that IgM also played a significant role. Oral administration of bacterial antigens to colostrum-fed calves from 5 to 8 days of age produced a faecal antibody response, indicating that intestinal secretion could be successfully interrelated with the declining passive antibody to maintain an almost continuous level of intestinal antibody in early life. PMID:1106925

  20. Anti-Infective Activities of Lactobacillus Strains in the Human Intestinal Microbiota: from Probiotics to Gastrointestinal Anti-Infectious Biotherapeutic Agents

    PubMed Central

    Liévin-Le Moal, Vanessa

    2014-01-01

    SUMMARY A vast and diverse array of microbial species displaying great phylogenic, genomic, and metabolic diversity have colonized the gastrointestinal tract. Resident microbes play a beneficial role by regulating the intestinal immune system, stimulating the maturation of host tissues, and playing a variety of roles in nutrition and in host resistance to gastric and enteric bacterial pathogens. The mechanisms by which the resident microbial species combat gastrointestinal pathogens are complex and include competitive metabolic interactions and the production of antimicrobial molecules. The human intestinal microbiota is a source from which Lactobacillus probiotic strains have often been isolated. Only six probiotic Lactobacillus strains isolated from human intestinal microbiota, i.e., L. rhamnosus GG, L. casei Shirota YIT9029, L. casei DN-114 001, L. johnsonii NCC 533, L. acidophilus LB, and L. reuteri DSM 17938, have been well characterized with regard to their potential antimicrobial effects against the major gastric and enteric bacterial pathogens and rotavirus. In this review, we describe the current knowledge concerning the experimental antibacterial activities, including antibiotic-like and cell-regulating activities, and therapeutic effects demonstrated in well-conducted, placebo-controlled, randomized clinical trials of these probiotic Lactobacillus strains. What is known about the antimicrobial activities supported by the molecules secreted by such probiotic Lactobacillus strains suggests that they constitute a promising new source for the development of innovative anti-infectious agents that act luminally and intracellularly in the gastrointestinal tract. PMID:24696432

  1. Influence of Camembert consumption on the composition and metabolism of intestinal microbiota: a study in human microbiota-associated rats.

    PubMed

    Lay, Christophe; Sutren, Malène; Lepercq, Pascale; Juste, Catherine; Rigottier-Gois, Lionel; Lhoste, Evelyne; Lemée, Riwanon; Le Ruyet, Pascale; Doré, Joël; Andrieux, Claude

    2004-09-01

    The objective of the present study was to evaluate the consequence of Camembert consumption on the composition and metabolism of human intestinal microbiota. Camembert cheese was compared with milk fermented by yoghurt starters and Lactobacillus casei as a probiotic reference. The experimental model was the human microbiota-associated (HM) rat. HM rats were fed a basal diet (HMB group), a diet containing Camembert made from pasteurised milk (HMCp group) or a diet containing fermented milk (HMfm group). The level of micro-organisms from dairy products was measured in faeces using cultures on a specific medium and PCR-temporal temperature gradient gel electrophoresis. The metabolic characteristics of the caecal microbiota were also studied: SCFA, NH3, glycosidase and reductase activities, and bile acid degradations. The results showed that micro-organisms from cheese comprised 10(5)-10(8) bacteria/g faecal sample in the HMCp group. Lactobacillus species from fermented milk were detected in HMfm rats. Consumption of cheese and fermented milk led to similar changes in bacterial metabolism: a decrease in azoreductase activity and NH3 concentration and an increase in mucolytic activities. However, specific changes were observed: in HMCp rats, the proportion of ursodeoxycholic resulting from chenodeoxycholic epimerisation was higher; in HMfm rats, alpha and beta-galactosidases were higher than in other groups and both azoreductases and nitrate reductases were lower. The results show that, as for fermented milk, Camembert consumption did not greatly modify the microbiota profile or its major metabolic activities. Ingested micro-organisms were able to survive in part during intestinal transit. These dairy products exert a potentially beneficial influence on intestinal metabolism. PMID:15469646

  2. Infection of cultured human intestinal cells by monkey RRV and human Wa rotavirus as a function of intestinal epithelial cell differentiation.

    PubMed

    Jourdan, N; Cotte Laffitte, J; Forestier, F; Servin, A L; Quéro, A M

    1995-01-01

    Rotaviruses display in vivo a specific tropism for enterocytes of the small intestine. We examined here the infection of cultured human intestinal epithelial Caco-2 cells by rhesus monkey rotavirus (RRV) and human Wa rotavirus. The maximal infection of these cells was obtained when trypsin was present both in the viral inoculum before adsorption to the cells and in the culture medium during the course of cell infection. Since the differentiation process of Caco-2 cells in culture closely mimics in vivo differentiation of enterocytes along the crypt-villus axis, cell infection by RRV and Wa rotavirus was examined as a function of cell differentiation. We showed that RRV and Wa rotavirus can infect equally well both undifferentiated and differentiated Caco-2 cells. PMID:8578006

  3. Isolation and Identification of Intestinal CYP3A Inhibitors from Cranberry (Vaccinium macrocarpon) using Human Intestinal Microsomes

    PubMed Central

    Kim, Eunkyung; Sy-Cordero, Arlene; Graf, Tyler N.; Brantley, Scott J.; Paine, Mary F.; Oberlies, Nicholas H.

    2010-01-01

    Cranberry juice is used routinely, especially among women and the elderly, to prevent and treat urinary tract infections. These individuals are likely to be taking medications concomitantly with cranberry juice, leading to concern about potential drug-dietary substance interactions, particularly in the intestine, which, along with the liver, is rich in expression of the prominent drug metabolizing enzyme, cytochrome P450 3A (CYP3A). Using a systematic in vitro-in vivo approach, a cranberry juice product was identified recently that elicited a pharmacokinetic interaction with the CYP3A probe substrate midazolam in 16 healthy volunteers. Relative to water, a cranberry juice inhibited intestinal first-pass midazolam metabolism. In vitro studies were initiated to identify potential enteric CYP3A inhibitors from cranberry via a bioactivity-directed fractionation approach involving dried whole cranberry [Vaccinium macrocarpon Ait. (Ericaceae)], midazolam, and human intestinal microsomes (HIM). Three triterpenes (maslinic acid, corosolic acid, and ursolic acid) were isolated. The inhibitory potency (IC50) of maslinic acid, corosolic acid, and ursolic acid was 7.4, 8.8, and <10 μM, respectively, using HIM as the enzyme source and was 2.8, 4.3, and <10 μM, respectively, using recombinant CYP3A4 as the enzyme source. These in vitro inhibitory potencies, which are within the range of those reported for two CYP3A inhibitory components in grapefruit juice, suggest that these triterpenes may have contributed to the midazolam-cranberry juice interaction observed in the clinical study. PMID:20717876

  4. Association of germ-free mice with a simplified human intestinal microbiota results in a shortened intestine

    PubMed Central

    Slezak, Kathleen; Krupova, Zuzana; Rabot, Sylvie; Loh, Gunnar; Levenez, Florence; Descamps, Amandine; Lepage, Patricia; Doré, Joël; Bellier, Sylvain; Blaut, Michael

    2014-01-01

    Genetic, nutritional, and gut microbiota-derived factors have been proposed to play a role in the development of the whole intestine that is around 40% longer in PRM/Alf mice compared with other mouse strains. The PRM/Alf genotype explains 60% of this length difference. The remaining 40% are due to a maternal effect that could depend on the gut microbiota transmitted by the mother to their pups. Germ-free PRM/Alf mice and C3H/He mice were associated with a simplified human microbiota (SIHUMI) to study its impact on gut length. The small intestines of the SIHUMI-associated mice were 16.4% (PRM/Alf) and 9.7% (C3H/He) shorter than those of the corresponding germ-free counterparts. Temporal temperature gradient gel electrophoresis and quantitative real-time PCR revealed differences in microbiota composition between both SIHUMI-associated mouse strains. Anaerostipes caccae was one log lower in PRM/Alf mice than in C3H/He mice. Since polyamines and short-chain fatty acids (SCFAs) are important intestinal growth factors, their concentrations were explored. Cecal concentrations of putrescine, spermine, spermidine, and N-acetylspermine were 1.5-fold, 3.7-fold, 2.2-fold, and 1.4-fold higher, respectively, in the SIHUMI-C3H/He mice compared with the SIHUMI-PRM/Alf mice. In addition, cecal acetate, propionate, and butyrate concentrations in SIHUMI-C3H/He mice were 1.4-fold, 1.1-fold, and 2.1-fold higher, respectively, than in SIHUMI-PRM/Alf mice. These results indicate that polyamines and SCFAs did not promote gut lengthening in any of the two mouse strains. This suggests that as yet unknown factors provided by the SIHUMI prevented gut lengthening in the SIHUMI-associated mice compared with the germfree mice. PMID:24637599

  5. Identification of human cytochrome P450 enzymes involved in the hepatic and intestinal biotransformation of 20(S)-protopanaxadiol.

    PubMed

    Chiu, Nga Ting Colette; Tomlinson Guns, Emma S; Adomat, Hans; Jia, William; Deb, Subrata

    2014-03-01

    20(S)-Protopanaxadiol (aPPD), a ginseng sapogenin, has been shown to be a promising anti-cancer compound and anti-depressant agent. Although the bacterial biotransformation of ginsenosides has been studied thoroughly, few have reported on the cytochrome P450 (P450) mediated metabolism of aPPD. Taken orally, aPPD must first undergo absorption and metabolism in the intestine before further metabolism in the liver. The present study investigated the comparative biotransformation profile of aPPD in human intestinal microsomes (HIM) and human liver microsomes (HLM) and characterized the human P450 enzymes involved in aPPD metabolism. Three major monooxygenated metabolites and five minor dioxygenated metabolites were identified as the predominant products in aPPD incubations with HIM and HLM using liquid chromatography-mass spectrometry. Reaction phenotyping studies were performed with a panel of specific P450 chemical inhibitors, antibody inhibition and human recombinant P450 enzymes. Ketoconazole, a CYP3A inhibitor, blocked the formation of oxygenated metabolites of aPPD in both HIM and HLM in a concentration dependent manner. Among the human recombinant P450 enzymes assayed, CYP3A4 exhibited the highest activity towards aPPD oxidative metabolite formation, followed by CYP3A5. In summary, the results have shown that aPPD is extensively metabolized by HIM and the metabolite profile following in vitro incubations is similar in HIM and HLM. CYP3A4 and CYP3A5 isoforms are the predominant enzymes responsible for oxygenation of aPPD in HIM and HLM. The characterization of aPPD as a CYP3A substrate may facilitate better prediction of drug-herb interactions when aPPD is taken concomitantly with other therapeutic agents. PMID:24151189

  6. Generating human intestinal tissues from pluripotent stem cells to study development and disease

    PubMed Central

    Sinagoga, Katie L; Wells, James M

    2015-01-01

    As one of the largest and most functionally complex organs of the human body, the intestines are primarily responsible for the breakdown and uptake of macromolecules from the lumen and the subsequent excretion of waste from the body. However, the intestine is also an endocrine organ, regulating digestion, metabolism, and feeding behavior. Intricate neuronal, lymphatic, immune, and vascular systems are integrated into the intestine and are required for its digestive and endocrine functions. In addition, the gut houses an extensive population of microbes that play roles in digestion, global metabolism, barrier function, and host–parasite interactions. With such an extensive array of cell types working and performing in one essential organ, derivation of functional intestinal tissues from human pluripotent stem cells (PSCs) represents a significant challenge. Here we will discuss the intricate developmental processes and cell types that are required for assembly of this highly complex organ and how embryonic processes, particularly morphogenesis, have been harnessed to direct differentiation of PSCs into 3-dimensional human intestinal organoids (HIOs) in vitro. We will further describe current uses of HIOs in development and disease research and how additional tissue complexity might be engineered into HIOs for better functionality and disease modeling. PMID:25792515

  7. Human mesenchymal stem cells: New sojourn of bacterial pathogens.

    PubMed

    Kohli, Sakshi; Singh, Yadvir; Sowpati, Divya Tej; Ehtesham, Nasreen Z; Dobrindt, Ulrich; Hacker, Jörg; Hasnain, Seyed E

    2015-05-01

    Tuberculosis (TB), caused by Mycobacterium tuberculosis (M. tuberculosis), is the leading infectious disease which claims one human life every 15-20s globally. The persistence of this deadly disease in human population can be attributed to the ability of the bacterium to stay in latent form. M. tuberculosis possesses a plethora of mechanisms not only to survive latently under harsh conditions inside the host but also modulate the host immune cells in its favour. Various M. tuberculosis gene families have also been described to play a role in this process. Recently, human bone marrow derived mesenchymal stem cells (MSCs) have been reported as a niche for dormant M. tuberculosis. MSCs possess abilities to alter the host immune response. The bacterium finds this self-renewal and immune privileged nature of MSCs very favourable not only to modulate the host immune system, with some help from its own genes, but also to avoid the external drug pressure. We suggest that the MSCs not only provide a resting place for M. tuberculosis but could also, by virtue of their intrinsic ability to disseminate in the body, explain the genesis of extra-pulmonary TB. A similar exploitation of stem cells by other bacterial pathogens is a distinct possibility. It may be likely that other intracellular bacterial pathogens adopt this strategy to 'piggy-back' on to ovarian stem cells to ensure vertical transmission and successful propagation to the next generation. PMID:25648374

  8. From bacterial to human dihydrouridine synthase: automated structure determination

    SciTech Connect

    Whelan, Fiona Jenkins, Huw T.; Griffiths, Samuel C.; Byrne, Robert T.; Dodson, Eleanor J.; Antson, Alfred A.

    2015-06-30

    The crystal structure of a human dihydrouridine synthase, an enzyme associated with lung cancer, with 18% sequence identity to a T. maritima enzyme, has been determined at 1.9 Å resolution by molecular replacement after extensive molecular remodelling of the template. The reduction of uridine to dihydrouridine at specific positions in tRNA is catalysed by dihydrouridine synthase (Dus) enzymes. Increased expression of human dihydrouridine synthase 2 (hDus2) has been linked to pulmonary carcinogenesis, while its knockdown decreased cancer cell line viability, suggesting that it may serve as a valuable target for therapeutic intervention. Here, the X-ray crystal structure of a construct of hDus2 encompassing the catalytic and tRNA-recognition domains (residues 1–340) determined at 1.9 Å resolution is presented. It is shown that the structure can be determined automatically by phenix.mr-rosetta starting from a bacterial Dus enzyme with only 18% sequence identity and a significantly divergent structure. The overall fold of the human Dus2 is similar to that of bacterial enzymes, but has a larger recognition domain and a unique three-stranded antiparallel β-sheet insertion into the catalytic domain that packs next to the recognition domain, contributing to domain–domain interactions. The structure may inform the development of novel therapeutic approaches in the fight against lung cancer.

  9. ANGPTL4 expression induced by butyrate and rosiglitazone in human intestinal epithelial cells utilizes independent pathways.

    PubMed

    Korecka, Agata; de Wouters, Tomas; Cultrone, Antonietta; Lapaque, Nicolas; Pettersson, Sven; Doré, Joël; Blottière, Hervé M; Arulampalam, Velmurugesan

    2013-06-01

    Short-chain fatty acids (SCFAs), such as butyrate and propionate, are metabolic products of carbohydrate fermentation by the microbiota and constitute the main source of energy for host colonocytes. SCFAs are also important for gastrointestinal health, immunity, and host metabolism. Intestinally produced angiopoietin-like protein 4 (ANGPTL4) is a secreted protein with metabolism-altering properties and may offer a route by which microbiota can regulate host metabolism. Peroxisome proliferator-activated receptor (PPAR)-γ has previously been shown to be involved in microbiota-induced expression of intestinal ANGPTL4, but the role of bacterial metabolites in this process has remained elusive. Here, we show that the SCFA butyrate regulates intestinal ANGPTL4 expression in a PPAR-γ-independent manner. Although PPAR-γ is not required for butyrate-driven intestinal ANGPTL4 expression, costimulating with PPAR-γ ligands and SCFAs leads to additive increases in ANGPTL4 levels. We suggest that PPAR-γ and butyrate rely on two separate regulatory sites, a PPAR-responsive element downstream the transcription start site and a butyrate-responsive element(s) within the promoter region, 0.5 kb upstream of the transcription start site. Furthermore, butyrate gavage and colonization with Clostridium tyrobutyricum, a SCFA producer, can independently induce expression of intestinal ANGPTL4 in germ-free mice. Thus, oral administration of SCFA or use of SCFA-producing bacteria may be additional routes to maintain intestinal ANGPTL4 levels for preventive nutrition or therapeutic purposes. PMID:23518684

  10. Role of TLR4/NF-κB in Damage to Intestinal Mucosa Barrier Function and Bacterial Translocation in Rats Exposed to Hypoxia

    PubMed Central

    Luo, Han; Guo, Ping; Zhou, Qiquan

    2012-01-01

    The role of Toll-like receptor 4 (TLR4)/nuclear factor-kappa-B (NF-κB) in intestinal mucosal barrier damage and bacterial translocation under hypoxic exposure is unclear. Here, we investigated their role using an acute hypobaric hypoxia model. Adult Sprague-Dawley rats were divided into control (C), hypoxia (H), hypoxia+NF-κB inhibitor pyrrolidinedithiocarbamic acid (PDTC) (100 mg. kg) (HP), hypoxia+0.5 mg/kg lipopolysaccharide (HPL), and hypoxia+PDTC+LPS (HPL) group. Except control group, other four groups were placed in a hypobaric chamber set at 7000 m. Samples were collected at 72 h after pressure reduction. Damage in ultrastructure of the intestinal tract was examined by transmission electron microscopy and bacterial translocation was detected by cultivation. Kinetic turbidimetric assay was used to measure the serum LPS. ELISA was performed to detect TNF-α and IL-6 serum concentrations. Fluorescent quantitative RT-PCR was used to measure TLR4 mRNA levels was measured using quantitative RT-PCR and protein of NF-κB p65 was measured by western blotting. Different degrees of intestinal mucosa damage were observed in groups H and HL. The damage was significantly alleviated after blockage of the TLR4/NF-κB signaling pathway. PDTC- treatment also reversed hyoxia- and LPS-induced bacterial translocation rate and increased serum levels of LPS, TNF-α, and IL-6. TLR4 mRNA levels and NF-κB p65 expression were consistent with the serum factor results. This study suggested that TLR4 and NF-κB expression increased in rat intestinal tissues after acute hypoxia exposure. PDTC-treatment reversed TLR4 and NF-κB upregulation and alleviated damage to the intestinal tract and bacterial translocation. Thus, the TLR4/NF-κB signaling pathway may be critical to the mechanism underlying hypoxia-induced damage to intestinal barrier function and bacterial translocation. PMID:23082119

  11. Similarity of hydrolyzing activity of human and rat small intestinal disaccharidases

    PubMed Central

    Oku, Tsuneyuki; Tanabe, Kenichi; Ogawa, Shigeharu; Sadamori, Naoki; Nakamura, Sadako

    2011-01-01

    Background: The purpose of this study was to clarify whether it is possible to extrapolate results from studies of the hydrolyzing activity of disaccharidases from rats to humans. Materials and methods: We measured disaccharidase activity in humans and rats using identical preparation and assay methods, and investigated the similarity in hydrolyzing activity. Small intestinal samples without malignancy were donated by five patients who had undergone bladder tumor surgery, and homogenates were prepared to measure disaccharidase activity. Adult rat homogenates were prepared using small intestine. Results: Maltase activity was the highest among the five disaccharidases, followed by sucrase and then palatinase in humans and rats. Trehalase activity was slightly lower than that of palatinase in humans and was similar to that of sucrase in rats. Lactase activity was the lowest in humans, but was similar to that of palatinase in rats. Thus, the hydrolyzing activity of five disaccharidases was generally similar in humans and rats. The relative activity of sucrose and palatinase versus maltase was generally similar between humans and rats. The ratio of rat to human hydrolyzing activity of maltase, sucrase, and palatinase was 1.9–3.1, but this was not a significant difference. Leaf extract from Morus alba strongly inhibited the activity of maltase, sucrase, and palatinase, but not trehalase and lactase, and the degree of inhibition was similar in humans and rats. L-arabinose mildly inhibited sucrase activity, but hardly inhibited the activity of maltase, palatinase, trehalase and lactase in humans and rats. The digestibility of 1-kestose, galactosylsucrose, and panose by small intestinal enzymes was very similar between humans and rats. Conclusion: These results demonstrate that the digestibility of newly developed saccharide materials evaluated by rat small intestinal enzymes can substitute for evaluation using human enzymes. PMID:21904461

  12. Heparan sulfate and syndecan-1 are essential in maintaining murine and human intestinal epithelial barrier function

    PubMed Central

    Bode, Lars; Salvestrini, Camilla; Park, Pyong Woo; Li, Jin-Ping; Esko, Jeffrey D.; Yamaguchi, Yu; Murch, Simon; Freeze, Hudson H.

    2007-01-01

    Patients with protein-losing enteropathy (PLE) fail to maintain intestinal epithelial barrier function and develop an excessive and potentially fatal efflux of plasma proteins. PLE occurs in ostensibly unrelated diseases, but emerging commonalities in clinical observations recently led us to identify key players in PLE pathogenesis. These include elevated IFN-γ, TNF-α, venous hypertension, and the specific loss of heparan sulfate proteoglycans from the basolateral surface of intestinal epithelial cells during PLE episodes. Here we show that heparan sulfate and syndecan-1, the predominant intestinal epithelial heparan sulfate proteoglycan, are essential in maintaining intestinal epithelial barrier function. Heparan sulfate– or syndecan-1–deficient mice and mice with intestinal-specific loss of heparan sulfate had increased basal protein leakage and were far more susceptible to protein loss induced by combinations of IFN-γ, TNF-α, and increased venous pressure. Similarly, knockdown of syndecan-1 in human epithelial cells resulted in increased basal and cytokine-induced protein leakage. Clinical application of heparin has been known to alleviate PLE in some patients but its unknown mechanism and severe side effects due to its anticoagulant activity limit its usefulness. We demonstrate here that non-anticoagulant 2,3-de-O-sulfated heparin could prevent intestinal protein leakage in syndecan-deficient mice, suggesting that this may be a safe and effective therapy for PLE patients. PMID:18064305

  13. Acute induction of human IL-8 production by intestinal epithelium triggers neutrophil infiltration without mucosal injury

    PubMed Central

    Kucharzik, T; Hudson, J T; Lügering, A; Abbas, J A; Bettini, M; Lake, J G; Evans, M E; Ziegler, T R; Merlin, D; Madara, J L; Williams, I R

    2005-01-01

    Aim: Neutrophil migration in the intestine depends on chemotaxis of neutrophils to CXC chemokines produced by epithelial cells. The goal of this project was to determine if acute induction of a CXC chemokine gradient originating from intestinal epithelial cells is sufficient to induce neutrophil influx into intact intestinal tissue. Methods and results: The authors developed a double transgenic mouse model with doxycycline induced human IL-8 expression restricted to intestinal epithelial cells. Doxycycline treatment of double transgenic mice for three days resulted in a 50-fold increase in the caecal IL-8 concentration and influx of neutrophils into the lamina propria. Although neutrophils entered the paracellular space between epithelial cells, complete transepithelial migration was not observed. Doxycycline treatment also increased the water content of the caecal and colonic stool, indicating dysfunctional water transport. However, the transmural electrical resistance was not decreased. Neutrophils recruited to the intestinal epithelium did not show evidence of degranulation and the epithelium remained intact as judged by histology. Conclusions: This conditional transgenic model of chemokine expression provides evidence that acute induction of IL-8 in the intestinal epithelium is sufficient to trigger neutrophil recruitment to the lamina propria, but additional activation signals are needed for full activation and degranulation of neutrophils, mucosal injury, and complete transepithelial migration. PMID:15987794

  14. Slipping through the Cracks: Linking Low Immune Function and Intestinal Bacterial Imbalance to the Etiology of Rheumatoid Arthritis

    PubMed Central

    Terato, Kuniaki

    2015-01-01

    Autoimmune diseases (ADs) are considered to be caused by the host immune system which attacks and destroys its own tissue by mistake. A widely accepted hypothesis to explain the pathogenic mechanism of ADs is “molecular mimicry,” which states that antibodies against an infectious agent cross-react with a self-antigen sharing an identical or similar antigenic epitope. However, this hypothesis was most likely established based on misleading antibody assay data largely influenced by intense false positive reactions involved in immunoassay systems. Thus reinvestigation of this hypothesis using an appropriate blocking agent capable of eliminating all types of nonspecific reactions and proper assay design is strongly encouraged. In this review, we discuss the possibility that low immune function may be the fundamental, common defect in ADs, which increases the susceptibility to potential disease causative pathogens located in the gastrointestinal tract (GI), such as bacteria and their components or dietary components. In addition to these exogenous agents, aberrations in the host's physical condition may disrupt the host defense system, which is tightly orchestrated by “immune function,” “mucosal barrier function,” and “intestinal bacterial balance.” These disturbances may initiate a downward spiral, which can lead to chronic health problems that will evolve to an autoimmune disorder. PMID:25861466

  15. Duodenal Aspirates for Small Intestine Bacterial Overgrowth: Yield, PPIs, and Outcomes after Treatment at a Tertiary Academic Medical Center.

    PubMed

    Franco, Diana L; Disbrow, Molly B; Kahn, Allon; Koepke, Laura M; Harris, Lucinda A; Harrison, M Edwyn; Crowell, Michael D; Ramirez, Francisco C

    2015-01-01

    Duodenal aspirates are not commonly collected, but they can be easily used in detection of small intestinal bacterial overgrowth (SIBO). Proton pump inhibitor (PPI) use has been proposed to contribute to the development of SIBO. We aimed to determine the yield of SIBO-positive cultures detected in duodenal aspirates, the relationship between SIBO and PPI use, and the clinical outcomes of patients identified by this method. In a retrospective study, we analyzed electronic medical records from 1263 consecutive patients undergoing upper endoscopy at a tertiary medical center. Aspirates were collected thought out the third and fourth portions of the duodenum, and cultures were considered to be positive for SIBO if they produced more than 100,000 cfu/mL. Culture analysis of duodenal aspirates identified SIBO in one-third of patients. A significantly higher percentage of patients with SIBO use PPIs than patients without SIBO, indicating a possible association. Similar proportions of patients with SIBO improved whether or not they received antibiotic treatment, calling into question the use of this expensive therapy for this disorder. PMID:25694782

  16. Duodenal Aspirates for Small Intestine Bacterial Overgrowth: Yield, PPIs, and Outcomes after Treatment at a Tertiary Academic Medical Center

    PubMed Central

    Franco, Diana L.; Disbrow, Molly B.; Kahn, Allon; Koepke, Laura M.; Harris, Lucinda A.; Ramirez, Francisco C.

    2015-01-01

    Duodenal aspirates are not commonly collected, but they can be easily used in detection of small intestinal bacterial overgrowth (SIBO). Proton pump inhibitor (PPI) use has been proposed to contribute to the development of SIBO. We aimed to determine the yield of SIBO-positive cultures detected in duodenal aspirates, the relationship between SIBO and PPI use, and the clinical outcomes of patients identified by this method. In a retrospective study, we analyzed electronic medical records from 1263 consecutive patients undergoing upper endoscopy at a tertiary medical center. Aspirates were collected thought out the third and fourth portions of the duodenum, and cultures were considered to be positive for SIBO if they produced more than 100,000 cfu/mL. Culture analysis of duodenal aspirates identified SIBO in one-third of patients. A significantly higher percentage of patients with SIBO use PPIs than patients without SIBO, indicating a possible association. Similar proportions of patients with SIBO improved whether or not they received antibiotic treatment, calling into question the use of this expensive therapy for this disorder. PMID:25694782

  17. Intestinal Microbiota Distinguish Gout Patients from Healthy Humans.

    PubMed

    Guo, Zhuang; Zhang, Jiachao; Wang, Zhanli; Ang, Kay Ying; Huang, Shi; Hou, Qiangchuan; Su, Xiaoquan; Qiao, Jianmin; Zheng, Yi; Wang, Lifeng; Koh, Eileen; Danliang, Ho; Xu, Jian; Lee, Yuan Kun; Zhang, Heping

    2016-01-01

    Current blood-based approach for gout diagnosis can be of low sensitivity and hysteretic. Here via a 68-member cohort of 33 healthy and 35 diseased individuals, we reported that the intestinal microbiota of gout patients are highly distinct from healthy individuals in both organismal and functional structures. In gout, Bacteroides caccae and Bacteroides xylanisolvens are enriched yet Faecalibacterium prausnitzii and Bifidobacterium pseudocatenulatum depleted. The established reference microbial gene catalogue for gout revealed disorder in purine degradation and butyric acid biosynthesis in gout patients. In an additional 15-member validation-group, a diagnosis model via 17 gout-associated bacteria reached 88.9% accuracy, higher than the blood-uric-acid based approach. Intestinal microbiota of gout are more similar to those of type-2 diabetes than to liver cirrhosis, whereas depletion of Faecalibacterium prausnitzii and reduced butyrate biosynthesis are shared in each of the metabolic syndromes. Thus the Microbial Index of Gout was proposed as a novel, sensitive and non-invasive strategy for diagnosing gout via fecal microbiota. PMID:26852926

  18. Insights from human congenital disorders of intestinal lipid metabolism

    PubMed Central

    Levy, Emile

    2015-01-01

    The intestine must challenge the profuse daily flux of dietary fat that serves as a vital source of energy and as an essential component of cell membranes. The fat absorption process takes place in a series of orderly and interrelated steps, including the uptake and translocation of lipolytic products from the brush border membrane to the endoplasmic reticulum, lipid esterification, Apo synthesis, and ultimately the packaging of lipid and Apo components into chylomicrons (CMs). Deciphering inherited disorders of intracellular CM elaboration afforded new insight into the key functions of crucial intracellular proteins, such as Apo B, microsomal TG transfer protein, and Sar1b GTPase, the defects of which lead to hypobetalipoproteinemia, abetalipoproteinemia, and CM retention disease, respectively. These “experiments of nature” are characterized by fat malabsorption, steatorrhea, failure to thrive, low plasma levels of TGs and cholesterol, and deficiency of liposoluble vitamins and essential FAs. After summarizing and discussing the functions and regulation of these proteins for reader’s comprehension, the current review focuses on their specific roles in malabsorptions and dyslipidemia-related intestinal fat hyperabsorption while dissecting the spectrum of clinical manifestations and managements. The influence of newly discovered proteins (proprotein convertase subtilisin/kexin type 9 and angiopoietin-like 3 protein) on fat absorption has also been provided. Finally, it is stressed how the overexpression or polymorphism status of the critical intracellular proteins promotes dyslipidemia and cardiometabolic disorders. PMID:25387865

  19. Alterations in human intestinal microflora during experimental diarrhoea

    PubMed Central

    Gorbach, S. L.; Neale, G.; Levitan, R.; Hepner, G. W.

    1970-01-01

    Large quantities of fluid administered through an intestinal tube caused alterations in small bowel bacteriology in four of seven subjects. In two normal individuals, colonic bacteria were found after fluid infusion in areas of the small bowel which previously had none. The faecal microflora was also altered by the fluid purge: anaerobes were reduced in some subjects and large numbers of Enterobacter species emerged in others. In a patient with pancreatic insufficiency and diarrhoea, the concentration of Enterobacter in the faeces was directly related to the number of bowel motions per day. Treatment with pancreatic enzymes curtailed the diarrhoea and markedly reduced these organisms. Intubation showed that Enterobacter were harboured in the small intestine and suppressed in the large bowel during periods of normal bowel action. Diarrhoea caused by pancreatic enzyme withdrawal or fluid purgation removed the colonic inhibition and allowed these organisms to appear in the faeces. Acidic diarrhoea induced by lactose feeding to three hypolactasic patients caused reductions in the numbers of E. coli in the stool but increases in Enterobacter species. Bacteroides also declined in one subject. Certain alterations in small and large bowel bacteriology observed in these forms of experimental diarrhoea have also been described in naturally occurring diarrhoea of diverse aetiologies. PMID:4907839

  20. Intestinal Microbiota Distinguish Gout Patients from Healthy Humans

    PubMed Central

    Guo, Zhuang; Zhang, Jiachao; Wang, Zhanli; Ang, Kay Ying; Huang, Shi; Hou, Qiangchuan; Su, Xiaoquan; Qiao, Jianmin; Zheng, Yi; Wang, Lifeng; Koh, Eileen; Danliang, Ho; Xu, Jian; Lee, Yuan Kun; Zhang, Heping

    2016-01-01

    Current blood-based approach for gout diagnosis can be of low sensitivity and hysteretic. Here via a 68-member cohort of 33 healthy and 35 diseased individuals, we reported that the intestinal microbiota of gout patients are highly distinct from healthy individuals in both organismal and functional structures. In gout, Bacteroides caccae and Bacteroides xylanisolvens are enriched yet Faecalibacterium prausnitzii and Bifidobacterium pseudocatenulatum depleted. The established reference microbial gene catalogue for gout revealed disorder in purine degradation and butyric acid biosynthesis in gout patients. In an additional 15-member validation-group, a diagnosis model via 17 gout-associated bacteria reached 88.9% accuracy, higher than the blood-uric-acid based approach. Intestinal microbiota of gout are more similar to those of type-2 diabetes than to liver cirrhosis, whereas depletion of Faecalibacterium prausnitzii and reduced butyrate biosynthesis are shared in each of the metabolic syndromes. Thus the Microbial Index of Gout was proposed as a novel, sensitive and non-invasive strategy for diagnosing gout via fecal microbiota. PMID:26852926

  1. Identification of intestinal bacterial flora in Rhipicephalus microplus ticks by conventional methods and PCR-DGGE analysis.

    PubMed

    Xu, Xing-Li; Cheng, Tian-Yin; Yang, Hu; Yan, Fen

    2015-06-01

    In this study, we have analyzed the intestinal microbial flora associated with Rhipicephalus microplus ticks using both culture-dependent and independent methods based on PCR and denaturing gradient gel electrophoresis (PCR-DGGE). The R. microplus ticks were collected from cattle and goats in Jiangxi, Hunan and Guizhou Provinces of China. Three distinct strains of bacteria were isolated using culture-dependent methods: Staphylococcus simulans, Bacillus subtilis and Bacillus flexus strain. Nineteen distinct DGGE bands were found using PCR-DGGE analysis, and their search for identity shows that they belonged to Rickettsiaceae, Xanthomonadaceae, Coxiella sp., Ehrlichia sp., Pseudomonas sp., Ehrlichia sp., Orphnebius sp., Rickettsia peacockii, Bacillus flexus. Rickettsia peacockii and Coxiella genus were the dominant strain of the R. microplus ticks from cattle, Pseudomonas sp. and B. flexus strain were the most common species in all tick samples from goats. Ehrlichia canis were detected only in R. microplus ticks from Yongshun area in Hunan Province. The results indicate that the intestinal microbial diversity of R. microplus ticks was influenced by tick hosts and local differences in the sampling location and these two aspects may affect transmission of pathogen to humans and animals. PMID:25784070

  2. Life and death at the mucosal-luminal interface: New perspectives on human intestinal ischemia-reperfusion

    PubMed Central

    Grootjans, Joep; Lenaerts, Kaatje; Buurman, Wim A; Dejong, Cornelis H C; Derikx, Joep P M

    2016-01-01

    Intestinal ischemia is a frequently observed phenomenon. Morbidity and mortality rates are extraordinarily high and did not improve over the past decades. This is in part attributable to limited knowledge on the pathophysiology of intestinal ischemia-reperfusion (IR) in man, the paucity in preventive and/or therapeutic options and the lack of early diagnostic markers for intestinal ischemia. To improve our knowledge and solve clinically important questions regarding intestinal IR, we developed a human experimental intestinal IR model. With this model, we were able to gain insight into the mechanisms that allow the human gut to withstand short periods of IR without the development of severe inflammatory responses. The purpose of this review is to overview the most relevant recent advances in our understanding of the pathophysiology of human intestinal IR, as well as the (potential) future clinical implications. PMID:26973414

  3. Life and death at the mucosal-luminal interface: New perspectives on human intestinal ischemia-reperfusion.

    PubMed

    Grootjans, Joep; Lenaerts, Kaatje; Buurman, Wim A; Dejong, Cornelis H C; Derikx, Joep P M

    2016-03-01

    Intestinal ischemia is a frequently observed phenomenon. Morbidity and mortality rates are extraordinarily high and did not improve over the past decades. This is in part attributable to limited knowledge on the pathophysiology of intestinal ischemia-reperfusion (IR) in man, the paucity in preventive and/or therapeutic options and the lack of early diagnostic markers for intestinal ischemia. To improve our knowledge and solve clinically important questions regarding intestinal IR, we developed a human experimental intestinal IR model. With this model, we were able to gain insight into the mechanisms that allow the human gut to withstand short periods of IR without the development of severe inflammatory responses. The purpose of this review is to overview the most relevant recent advances in our understanding of the pathophysiology of human intestinal IR, as well as the (potential) future clinical implications. PMID:26973414

  4. Chemical form of selenium affects its uptake, transport and glutathione peroxidase activity in the human intestinal Caco-2 cell model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Determining the effect of selenium (Se) chemical form on uptake and transport in human intestinal cells is critical to assess Se bioavailability. In the present study, we measured the uptake and transport of various Se compounds in the human intestinal Caco-2 cell model. We found that two sources...

  5. Effects of the Probiotic Enterococcus faecium and Pathogenic Escherichia coli Strains in a Pig and Human Epithelial Intestinal Cell Model

    PubMed Central

    Lodemann, Ulrike; Strahlendorf, Julia; Schierack, Peter; Klingspor, Shanti; Aschenbach, Jörg R.

    2015-01-01

    The aim of this study has been to elucidate the effect of the probiotic Enterococcus faecium NCIMB 10415 on epithelial integrity in intestinal epithelial cells and whether pre- and coincubation with this strain can reproducibly prevent damage induced by enterotoxigenic (ETEC) and enteropathogenic Escherichia coli (EPEC). Porcine (IPEC-J2) and human (Caco-2) intestinal epithelial cells were incubated with bacterial strains and epithelial integrity was assessed by measuring transepithelial electrical resistance (TEER) and mannitol flux rates. E. faecium alone increased TEER of Caco-2 cells without affecting mannitol fluxes whereas the E. coli strains decreased TEER and concomitantly increased mannitol flux rates in both cell lines. Preincubation with E. faecium had no effect on the TEER decrease induced by E. coli in preliminary experiments. However, in a second set of experiments using a slightly different protocol, E. faecium ameliorated the TEER decrease induced by ETEC at 4 h in IPEC-J2 and at 2, 4, and 6 h in Caco-2 cells. We conclude that E. faecium positively affected epithelial integrity in monoinfected Caco-2 cells and could ameliorate the damage on TEER induced by an ETEC strain. Reproducibility of the results is, however, limited when experiments are performed with living bacteria over longer periods. PMID:25883829

  6. Effects of the Probiotic Enterococcus faecium and Pathogenic Escherichia coli Strains in a Pig and Human Epithelial Intestinal Cell Model.

    PubMed

    Lodemann, Ulrike; Strahlendorf, Julia; Schierack, Peter; Klingspor, Shanti; Aschenbach, Jörg R; Martens, Holger

    2015-01-01

    The aim of this study has been to elucidate the effect of the probiotic Enterococcus faecium NCIMB 10415 on epithelial integrity in intestinal epithelial cells and whether pre- and coincubation with this strain can reproducibly prevent damage induced by enterotoxigenic (ETEC) and enteropathogenic Escherichia coli (EPEC). Porcine (IPEC-J2) and human (Caco-2) intestinal epithelial cells were incubated with bacterial strains and epithelial integrity was assessed by measuring transepithelial electrical resistance (TEER) and mannitol flux rates. E. faecium alone increased TEER of Caco-2 cells without affecting mannitol fluxes whereas the E. coli strains decreased TEER and concomitantly increased mannitol flux rates in both cell lines. Preincubation with E. faecium had no effect on the TEER decrease induced by E. coli in preliminary experiments. However, in a second set of experiments using a slightly different protocol, E. faecium ameliorated the TEER decrease induced by ETEC at 4 h in IPEC-J2 and at 2, 4, and 6 h in Caco-2 cells. We conclude that E. faecium positively affected epithelial integrity in monoinfected Caco-2 cells and could ameliorate the damage on TEER induced by an ETEC strain. Reproducibility of the results is, however, limited when experiments are performed with living bacteria over longer periods. PMID:25883829

  7. Bacterial contamination of the small intestine as an important cause of chronic diarrhea and abdominal pain: diagnosis by breath hydrogen test.

    PubMed

    Davidson, G P; Robb, T A; Kirubakaran, C P

    1984-08-01

    Unsuspected bacterial contamination of the small intestine was indicated by breath hydrogen testing in nine patients aged 2 to 34 months during physical examinations for chronic diarrhea and abdominal pain. Elevated bacterial counts of questionable significance were found in duodenal aspirates before and after antibiotic treatment. There was no evidence of bile salt deconjugation or structural changes in the small intestine by light or electron microscopy. This may indicate that the site of colonization is distal to the biopsy site. Breath testing indicated lactose malabsorption in all patients, and four of five patients tested also malabsorbed sucrose. Duodenal disaccharidase levels in all patients were within the normal ranges, but in eight patients the lactase-sucrase ratio was greatly elevated (0.80 +/- 0.36; normal less than 0.45). Dietary restriction alone did not cause complete cessation of symptoms, whereas all patients responded dramatically to oral antibiotic therapy. When patients were well, the lactase-sucrase ratio had returned to normal in those tested, and all nine had normal lactose and lactulose breath hydrogen tests. Unsuspected bacterial contamination of the small intestine, which is easily detected using the breath hydrogen test, may be more commonly associated with chronic diarrhea in children than has been previously realized. In such cases, therapy should be directed at removing the contamination. PMID:6431389

  8. Identification of the transcriptional response of human intestinal mucosa to Lactobacillus plantarum WCFS1 in vivo

    PubMed Central

    Troost, Freddy J; van Baarlen, Peter; Lindsey, Patrick; Kodde, Andrea; de Vos, Willem M; Kleerebezem, Michiel; Brummer, Robert-Jan M

    2008-01-01

    Background There is limited knowledge on the extent and dynamics of the mucosal response to commensal and probiotic species in the human intestinal lumen. This study aimed to identify the acute, time-dependent responses of intestinal mucosa to commensal Lactobacillus plantarum WCFS1 in vivo in two placebo-controlled human intervention studies in healthy volunteers. Transcriptional changes in duodenal mucosa upon continuous intraduodenal infusion of L. plantarum WCFS1 for one- and six h, respectively, were studied using oro- and nasogastric intubations with dedicated orogastric catheters and tissue sampling by standard flexible gastroduodenoscopy. Results One- and six-h exposure of small intestinal mucosa to L. plantarum WCFS1 induced differential expression of 669 and 424 gene reporters, respectively. While short-term exposure to L. plantarum WCFS1 inhibited fatty acid metabolism and cell cycle progression, cells switched to a more proliferative phase after prolonged exposure with an overall expression profile characterized by upregulation of genes involved in lipid metabolism, cellular growth and development. Cell death and immune responses were triggered, but cell death-executing genes or inflammatory signals were not expressed. Proteome analysis showed differential expression of several proteins. Only the microsomal protein 'microsomal triglyceride transfer protein' was regulated on both the transcriptional and the protein level in all subjects. Conclusion Overall, this study showed that intestinal exposure to L. plantarum WCFS1 induced consistent, time-dependent transcriptional responses in healthy intestinal mucosa. This extensive exploration of the human response to L. plantarum WCFS1 could eventually provide molecular support for specific or probiotic activity of this strain or species, and exemplifies the strength of the applied technology to identify the potential bio-activity of microbes in the human intestine. PMID:18681965

  9. Human Oral Isolate Lactobacillus fermentum AGR1487 Reduces Intestinal Barrier Integrity by Increasing the Turnover of Microtubules in Caco-2 Cells

    PubMed Central

    Anderson, Rachel C.; Young, Wayne; Clerens, Stefan; Cookson, Adrian L.; McCann, Mark J.; Armstrong, Kelly M.; Roy, Nicole C.

    2013-01-01

    Lactobacillus fermentum is found in fermented foods and thought to be harmless. In vivo and clinical studies indicate that some L. fermentum strains have beneficial properties, particularly for gastrointestinal health. However, L. fermentum AGR1487 decreases trans-epithelial electrical resistance (TEER), a measure of intestinal barrier integrity. The hypothesis was that L. fermentum AGR1487 decreases the expression of intestinal cell tight junction genes and proteins, thereby reducing barrier integrity. Transcriptomic and proteomic analyses of Caco-2 cells (model of human intestinal epithelial cells) treated with L. fermentum AGR1487 were used to obtain a global view of the effect of the bacterium on intestinal epithelial cells. Specific functional characteristics by which L. fermentum AGR1487 reduces intestinal barrier integrity were examined using confocal microscopy, cell cycle progression and adherence bioassays. The effects of TEER-enhancing L. fermentum AGR1485 were investigated for comparison. L. fermentum AGR1487 did not alter the expression of Caco-2 cell tight junction genes (compared to L. fermentum AGR1485) and tight junction proteins were not able to be detected. However, L. fermentum AGR1487 increased the expression levels of seven tubulin genes and the abundance of three microtubule-associated proteins, which have been linked to tight junction disassembly. Additionally, Caco-2 cells treated with L. fermentum AGR1487 did not have defined and uniform borders of zona occludens 2 around each cell, unlike control or AGR1485 treated cells. L. fermentum AGR1487 cells were required for the negative effect on barrier integrity (bacterial supernatant did not cause a decrease in TEER), suggesting that a physical interaction may be necessary. Increased adherence of L. fermentum AGR1487 to Caco-2 cells (compared to L. fermentum AGR1485) was likely to facilitate this cell-to-cell interaction. These findings illustrate that bacterial strains of the same species can cause contrasting host responses and suggest that food-safe status should be given to individual strains not species. PMID:24244356

  10. Glucose induces intestinal human UDP-glucuronosyltransferase (UGT) 1A1 to prevent neonatal hyperbilirubinemia

    PubMed Central

    Aoshima, Naoya; Fujie, Yoshiko; Itoh, Tomoo; Tukey, Robert H.; Fujiwara, Ryoichi

    2014-01-01

    Inadequate calorie intake or starvation has been suggested as a cause of neonatal jaundice, which can further cause permanent brain damage, kernicterus. This study experimentally investigated whether additional glucose treatments induce the bilirubin-metabolizing enzyme – UDP-glucuronosyltransferase (UGT) 1A1 – to prevent the onset of neonatal hyperbilirubinemia. Neonatal humanized UGT1 (hUGT1) mice physiologically develop jaundice. In this study, UGT1A1 expression levels were determined in the liver and small intestine of neonatal hUGT1 mice that were orally treated with glucose. In the hUGT1 mice, glucose induced UGT1A1 in the small intestine, while it did not affect the expression of UGT1A1 in the liver. UGT1A1 was also induced in the human intestinal Caco-2 cells when the cells were cultured in the presence of glucose. Luciferase assays demonstrated that not only the proximal region (-1300/-7) of the UGT1A1 promoter, but also distal region (-6500/-4050) were responsible for the induction of UGT1A1 in the intestinal cells. Adequate calorie intake would lead to the sufficient expression of UGT1A1 in the small intestine to reduce serum bilirubin levels. Supplemental treatment of newborns with glucose solution can be a convenient and efficient method to treat neonatal jaundice while allowing continuous breastfeeding. PMID:25209391

  11. Improvement of the human intestinal flora by ingestion of the probiotic strain Lactobacillus johnsonii La1.

    PubMed

    Yamano, Toshihiko; Iino, Hisakazu; Takada, Mamiko; Blum, Stephanie; Rochat, Florence; Fukushima, Yoichi

    2006-02-01

    To exert beneficial effects for the host, for example, improving the intestinal microflora, a probiotic must reach the intestine as a viable strain. These properties must be demonstrated by in vitro as well as in vivo methods. However, only a few well-designed human clinical studies have shown these properties. Lactobacillus johnsonii La1 has been shown to give many beneficial effects for the host, but it is unclear whether a viable strain of L. johnsonii La1 has the effect of improving host intestinal microflora. In the present study, a randomised double-blind placebo-controlled cross-over trial was conducted to elucidate the effect of L. johnsonii La1 on human intestinal microflora. Twenty-two young healthy Japanese women were randomly divided into two groups, and either received fermented milk with L. johnsonii La1 or a fermented milk without L. johnsonii La1 (placebo) daily for 21 d. Consumption of the fermented milk: (a) increased total Bifidobacterium and Lactobacillus, and decreased lecithinase-positive Clostridium in the faeces; (b) increased the faecal lactic acid concentrations; (c) decreased the faecal pH; (d) increased the defecation frequency. These changes were stronger than those observed with the placebo. L. johnsonii La1 was identified in all subjects only after the consumption of the fermented milk. These results suggest that L. johnsonii La1 can contribute to improve intestinal microflora with probiotic properties. PMID:16469146

  12. Glucose induces intestinal human UDP-glucuronosyltransferase (UGT) 1A1 to prevent neonatal hyperbilirubinemia.

    PubMed

    Aoshima, Naoya; Fujie, Yoshiko; Itoh, Tomoo; Tukey, Robert H; Fujiwara, Ryoichi

    2014-01-01

    Inadequate calorie intake or starvation has been suggested as a cause of neonatal jaundice, which can further cause permanent brain damage, kernicterus. This study experimentally investigated whether additional glucose treatments induce the bilirubin-metabolizing enzyme--UDP-glucuronosyltransferase (UGT) 1A1--to prevent the onset of neonatal hyperbilirubinemia. Neonatal humanized UGT1 (hUGT1) mice physiologically develop jaundice. In this study, UGT1A1 expression levels were determined in the liver and small intestine of neonatal hUGT1 mice that were orally treated with glucose. In the hUGT1 mice, glucose induced UGT1A1 in the small intestine, while it did not affect the expression of UGT1A1 in the liver. UGT1A1 was also induced in the human intestinal Caco-2 cells when the cells were cultured in the presence of glucose. Luciferase assays demonstrated that not only the proximal region (-1300/-7) of the UGT1A1 promoter, but also distal region (-6500/-4050) were responsible for the induction of UGT1A1 in the intestinal cells. Adequate calorie intake would lead to the sufficient expression of UGT1A1 in the small intestine to reduce serum bilirubin levels. Supplemental treatment of newborns with glucose solution can be a convenient and efficient method to treat neonatal jaundice while allowing continuous breastfeeding. PMID:25209391

  13. From bacterial to human dihydrouridine synthase: automated structure determination

    PubMed Central

    Whelan, Fiona; Jenkins, Huw T.; Griffiths, Samuel C.; Byrne, Robert T.; Dodson, Eleanor J.; Antson, Alfred A.

    2015-01-01

    The reduction of uridine to dihydrouridine at specific positions in tRNA is catalysed by dihydrouridine synthase (Dus) enzymes. Increased expression of human dihydrouridine synthase 2 (hDus2) has been linked to pulmonary carcinogenesis, while its knockdown decreased cancer cell line viability, suggesting that it may serve as a valuable target for therapeutic intervention. Here, the X-ray crystal structure of a construct of hDus2 encompassing the catalytic and tRNA-recognition domains (residues 1–340) determined at 1.9 Å resolution is presented. It is shown that the structure can be determined automatically by phenix.mr_rosetta starting from a bacterial Dus enzyme with only 18% sequence identity and a significantly divergent structure. The overall fold of the human Dus2 is similar to that of bacterial enzymes, but has a larger recognition domain and a unique three-stranded antiparallel β-sheet insertion into the catalytic domain that packs next to the recognition domain, contributing to domain–domain interactions. The structure may inform the development of novel therapeutic approaches in the fight against lung cancer. PMID:26143927

  14. Human Intestinal Raf Kinase Inhibitor Protein (RKIP) Catalyzes Prasugrel as a Bioactivation Hydrolase.

    PubMed

    Kazui, Miho; Ogura, Yuji; Hagihara, Katsunobu; Kubota, Kazuishi; Kurihara, Atsushi

    2016-01-01

    Prasugrel is a thienopyridine antiplatelet prodrug that undergoes rapid hydrolysis in vivo to a thiolactone metabolite by human carboxylesterase-2 (hCE2) during gastrointestinal absorption. The thiolactone metabolite is further converted to a pharmacologically active metabolite by cytochrome P450 isoforms. The aim of the current study was to elucidate hydrolases other than hCE2 involved in the bioactivation step of prasugrel in human intestine. Using size-exclusion column chromatography of a human small intestinal S9 fraction, another peak besides the hCE2 peak was observed to have prasugrel hydrolyzing activity, and this protein was found to have a molecular weight of about 20 kDa. This prasugrel hydrolyzing protein was successfully purified from a monkey small intestinal cytosolic fraction by successive four-step column chromatography and identified as Raf-1 kinase inhibitor protein (RKIP) by liquid chromatography-tandem mass spectrometry. Second, we evaluated the enzymatic kinetic parameters for prasugrel hydrolysis using recombinant human RKIP and hCE2 and estimated the contributions of these two hydrolyzing enzymes to the prasugrel hydrolysis reaction in human intestine, which were approximately 40% for hRKIP and 60% for hCE2. Moreover, prasugrel hydrolysis was inhibited by anti-hRKIP antibody and carboxylesterase-specific chemical inhibitor (bis p-nitrophenyl phosphate) by 30% and 60%, respectively. In conclusion, another protein capable of hydrolyzing prasugrel to its thiolactone metabolite was identified as RKIP, and this protein may play a significant role with hCE2 in prasugrel bioactivation in human intestine. RKIP is known to have diverse functions in many intracellular signaling cascades, but this is the first report describing RKIP as a hydrolase involved in drug metabolism. PMID:26558823

  15. Modulation of Intestinal Barrier and Bacterial Endotoxin Production Contributes to the Beneficial Effect of Nicotinic Acid on Alcohol-Induced Endotoxemia and Hepatic Inflammation in Rats.

    PubMed

    Zhong, Wei; Li, Qiong; Zhang, Wenliang; Sun, Qian; Sun, Xinguo; Zhou, Zhanxiang

    2015-01-01

    Alcohol consumption causes nicotinic acid deficiency. The present study was undertaken to determine whether dietary nicotinic acid supplementation provides beneficial effects on alcohol-induced endotoxin signaling and the possible mechanisms at the gut-liver axis. Male Sprague-Dawley rats were pair-fed the Lieber-DeCarli liquid diets containing ethanol or isocaloric maltose dextrin for eight weeks, with or without dietary supplementation with 750 mg/liter nicotinic acid. Chronic alcohol feeding elevated the plasma endotoxin level and activated hepatic endotoxin signaling cascade, which were attenuated by nicotinic acid supplementation. Alcohol consumption remarkably decreased the mRNA levels of claudin-1, claudin-5, and ZO-1 in the distal intestine, whereas nicotinic acid significantly up-regulated these genes. The concentrations of endotoxin, ethanol, and acetaldehyde in the intestinal contents were increased by alcohol exposure, and niacin supplementation reduced the intestinal endotoxin and acetaldehyde levels. Nicotinic acid supplementation upregulated the intestinal genes involved in aldehyde detoxification via transcriptional regulation. These results demonstrate that modulation of the intestinal barrier function and bacterial endotoxin production accounts for the inhibitory effects of nicotinic acid on alcohol-induced endotoxemia and hepatic inflammation. PMID:26501337

  16. Modulation of Intestinal Barrier and Bacterial Endotoxin Production Contributes to the Beneficial Effect of Nicotinic Acid on Alcohol-Induced Endotoxemia and Hepatic Inflammation in Rats

    PubMed Central

    Zhong, Wei; Li, Qiong; Zhang, Wenliang; Sun, Qian; Sun, Xinguo; Zhou, Zhanxiang

    2015-01-01

    Alcohol consumption causes nicotinic acid deficiency. The present study was undertaken to determine whether dietary nicotinic acid supplementation provides beneficial effects on alcohol-induced endotoxin signaling and the possible mechanisms at the gut-liver axis. Male Sprague-Dawley rats were pair-fed the Lieber-DeCarli liquid diets containing ethanol or isocaloric maltose dextrin for eight weeks, with or without dietary supplementation with 750 mg/liter nicotinic acid. Chronic alcohol feeding elevated the plasma endotoxin level and activated hepatic endotoxin signaling cascade, which were attenuated by nicotinic acid supplementation. Alcohol consumption remarkably decreased the mRNA levels of claudin-1, claudin-5, and ZO-1 in the distal intestine, whereas nicotinic acid significantly up-regulated these genes. The concentrations of endotoxin, ethanol, and acetaldehyde in the intestinal contents were increased by alcohol exposure, and niacin supplementation reduced the intestinal endotoxin and acetaldehyde levels. Nicotinic acid supplementation upregulated the intestinal genes involved in aldehyde detoxification via transcriptional regulation. These results demonstrate that modulation of the intestinal barrier function and bacterial endotoxin production accounts for the inhibitory effects of nicotinic acid on alcohol-induced endotoxemia and hepatic inflammation. PMID:26501337

  17. Consensus hologram QSAR modeling for the prediction of human intestinal absorption.

    PubMed

    Moda, Tiago L; Andricopulo, Adriano D

    2012-04-15

    Consistent in silico models for ADME properties are useful tools in early drug discovery. Here, we report the hologram QSAR modeling of human intestinal absorption using a dataset of 638 compounds with experimental data associated. The final validated models are consistent and robust for the consensus prediction of this important pharmacokinetic property and are suitable for virtual screening applications. PMID:22425566

  18. Comparative transcriptional and functional profiling defines conserved programs of intestinal DC differentiation in humans and mice.

    PubMed

    Watchmaker, Payal B; Lahl, Katharina; Lee, Mike; Baumjohann, Dirk; Morton, John; Kim, Sun Jung; Zeng, Ruizhu; Dent, Alexander; Ansel, K Mark; Diamond, Betty; Hadeiba, Husein; Butcher, Eugene C

    2014-01-01

    Dendritic cells (DCs) that orchestrate mucosal immunity have been studied in mice. Here we characterized human gut DC populations and defined their relationship to previously studied human and mouse DCs. CD103(+)Sirpα(-) DCs were related to human blood CD141(+) DCs and to mouse intestinal CD103(+)CD11b(-) DCs and expressed markers of cross-presenting DCs. CD103(+)Sirpα(+) DCs aligned with human blood CD1c(+) DCs and mouse intestinal CD103(+)CD11b(+) DCs and supported the induction of regulatory T cells. Both CD103(+) DC subsets induced the TH17 subset of helper T cells, while CD103(-)Sirpα(+) DCs induced the TH1 subset of helper T cells. Comparative analysis of transcriptomes revealed conserved transcriptional programs among CD103(+) DC subsets and identified a selective role for the transcriptional repressors Bcl-6 and Blimp-1 in the specification of CD103(+)CD11b(-) DCs and intestinal CD103(+)CD11b(+) DCs, respectively. Our results highlight evolutionarily conserved and divergent programming of intestinal DCs. PMID:24292363

  19. Evidence of native starch degradation with human small intestinal maltase-glucoamylase (recombinant)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Action of human small intestinal brush border carbohydrate digesting enzymes is thought to involve only final hydrolysis reactions of oligosaccharides to monosaccharides. In vitro starch digestibility assays use fungal amyloglucosidase to provide this function. In this study, recombinant N-terminal ...

  20. IL-2 receptor γ-chain molecule is critical for intestinal T-cell reconstitution in humanized mice

    PubMed Central

    Denton, PW; Nochi, T; Lim, A; Krisko, JF; Martinez-Torres, F; Choudhary, SK; Wahl, A; Olesen, R; Zou, W; Di Santo, JP; Margolis, DM; Garcia, JV

    2013-01-01

    Intestinal immune cells are important in host defense, yet the determinants for human lymphoid homeostasis in the intestines are poorly understood. In contrast, lymphoid homeostasis has been studied extensively in mice, where the requirement for a functional common γ-chain molecule has been established. We hypothesized that humanized mice could offer insights into human intestinal lymphoid homeostasis if generated in a strain with an intact mouse common γ-chain molecule. To address this hypothesis, we used three mouse strains (non-obese diabetic (NOD)/severe-combined immunodeficient (SCID) (N/S); NOD/SCID γ-chain−/− (NSG); and Rag2−/− γ-chain−/− (DKO)) and two humanization techniques (bone marrow liver thymus (BLT) and human CD34+ cell bone marrow transplant of newborn mice (hu)) to generate four common types of humanized mice: N/S-BLT, NSG-BLT, NSG-hu, and DKO-hu mice. The highest levels of intestinal human T cells throughout the small and large intestines were observed in N/S-BLT mice, which have an intact common γ-chain molecule. Furthermore, the small intestine lamina propria T-cell populations of N/S-BLT mice exhibit a human intestine-specific surface phenotype. Thus, the extensive intestinal immune reconstitution of N/S-BLT mice was both quantitatively and qualitatively better when compared with the other models tested such that N/S-BLT mice are well suited for the analysis of human intestinal lymphocyte trafficking and human-specific diseases affecting the intestines. PMID:22569301

  1. Monitoring of Antibiotic-Induced Alterations in the Human Intestinal Microflora and Detection of Probiotic Strains by Use of Terminal Restriction Fragment Length Polymorphism

    PubMed Central

    Jernberg, Cecilia; Sullivan, Åsa; Edlund, Charlotta; Jansson, Janet K.

    2005-01-01

    Terminal restriction fragment length polymorphism (T-RFLP) was investigated as a tool for monitoring the human intestinal microflora during antibiotic treatment and during ingestion of a probiotic product. Fecal samples from eight healthy volunteers were taken before, during, and after administration of clindamycin. During treatment, four subjects were given a probiotic, and four subjects were given a placebo. Changes in the microbial intestinal community composition and relative abundance of specific microbial populations in each subject were monitored by using viable counts and T-RFLP fingerprints. T-RFLP was also used to monitor specific bacterial populations that were either positively or negatively affected by clindamycin. Some dominant bacterial groups, such as Eubacterium spp., were easily monitored by T-RFLP, while they were hard to recover by cultivation. Furthermore, the two probiotic Lactobacillus strains were easily tracked by T-RFLP and were shown to be the dominant Lactobacillus community members in the intestinal microflora of subjects who received the probiotic. PMID:15640226

  2. Dietary interactions with the bacterial sensing machinery in the intestine: the plant polyphenol case

    PubMed Central

    Ahmed Nasef, Noha; Mehta, Sunali; Ferguson, Lynnette R.

    2014-01-01

    There are millions of microbes that live in the human gut. These are important in digestion as well as defense. The host immune system needs to be able to distinguish between the harmless bacteria and pathogens. The initial interaction between bacteria and the host happen through the pattern recognition receptors (PRRs). As these receptors are in direct contact with the external environment, this makes them important candidates for regulation by dietary components and therefore potential targets for therapy. In this review, we introduce some of the main PRRs including a cellular process known as autophagy, and how they function. Additionally we review dietary phytochemicals from plants which are believed to be beneficial for humans. The purpose of this review was to give a better understanding of how these components work in order to create better awareness on how they could be explored in the future. PMID:24772116

  3. Intestinal transport of manganese from human milk, bovine milk and infant formula in rats

    SciTech Connect

    Chan, W.Y.; Bates, J.M. Jr.; Rennert, O.M.; Mahmood, A.; Torres-Pinedo, R.

    1984-12-10

    The transport of manganese from extrinsically labeled human milk, bovine milk and infant formula was studied by the everted intestinal sac method. Tissue/mucosal flux data indicated that transport of manganese into the intestinal tissue was significantly greater with bovine milk and formula than from human milk. Similarly, the total flux of manganese from the mucosal to serosal surface was less when human milk was used. Smaller molecular weight manganese binding ligands isolated from the milk samples enhanced the mucosal to tissue movement of manganese as contrasted to the higher molecular weight manganese binding ligands. Most significantly the data suggest that the transport and uptake of manganese is less in the presence of human milk and its isolated manganese fractions than it is in bovine milk or infant formula. 15 references, 3 tables.

  4. Human Intestinal Lumen and Mucosa-Associated Microbiota in Patients with Colorectal Cancer

    PubMed Central

    Ling, Zongxin; Tong, Xiaojuan; Xiang, Charlie

    2012-01-01

    Recent reports have suggested the involvement of gut microbiota in the progression of colorectal cancer (CRC). We utilized pyrosequencing based analysis of 16S rRNA genes to determine the overall structure of microbiota in patients with colorectal cancer and healthy controls; we investigated microbiota of the intestinal lumen, the cancerous tissue and matched noncancerous normal tissue. Moreover, we investigated the mucosa-adherent microbial composition using rectal swab samples because the structure of the tissue-adherent bacterial community is potentially altered following bowel cleansing. Our findings indicated that the microbial structure of the intestinal lumen and cancerous tissue differed significantly. Phylotypes that enhance energy harvest from diets or perform metabolic exchange with the host were more abundant in the lumen. There were more abundant Firmicutes and less abundant Bacteroidetes and Proteobacteria in lumen. The overall microbial structures of cancerous tissue and noncancerous tissue were similar; howerer the tumor microbiota exhibited lower diversity. The structures of the intestinal lumen microbiota and mucosa-adherent microbiota were different in CRC patients compared to matched microbiota in healthy individuals. Lactobacillales was enriched in cancerous tissue, whereas Faecalibacterium was reduced. In the mucosa-adherent microbiota, Bifidobacterium, Faecalibacterium, and Blautia were reduced in CRC patients, whereas Fusobacterium, Porphyromonas, Peptostreptococcus, and Mogibacterium were enriched. In the lumen, predominant phylotypes related to metabolic disorders or metabolic exchange with the host, Erysipelotrichaceae, Prevotellaceae, and Coriobacteriaceae were increased in cancer patients. Coupled with previous reports, these results suggest that the intestinal microbiota is associated with CRC risk and that intestinal lumen microflora potentially influence CRC risk via cometabolism or metabolic exchange with the host. However, mucosa-associated microbiota potentially affects CRC risk primarily through direct interaction with the host. PMID:22761885

  5. Secretor Genotype (FUT2 gene) Is Strongly Associated with the Composition of Bifidobacteria in the Human Intestine

    PubMed Central

    Wacklin, Pirjo; Mkivuokko, Harri; Alakulppi, Noora; Nikkil, Janne; Tenkanen, Heli; Rbin, Jarkko; Partanen, Jukka; Aranko, Kari; Mtt, Jaana

    2011-01-01

    Intestinal microbiota plays an important role in human health, and its composition is determined by several factors, such as diet and host genotype. However, thus far it has remained unknown which host genes are determinants for the microbiota composition. We studied the diversity and abundance of dominant bacteria and bifidobacteria from the faecal samples of 71 healthy individuals. In this cohort, 14 were non-secretor individuals and the remainders were secretors. The secretor status is defined by the expression of the ABH and Lewis histo-blood group antigens in the intestinal mucus and other secretions. It is determined by fucosyltransferase 2 enzyme, encoded by the FUT2 gene. Non-functional enzyme resulting from a nonsense mutation in the FUT2 gene leads to the non-secretor phenotype. PCR-DGGE and qPCR methods were applied for the intestinal microbiota analysis. Principal component analysis of bifidobacterial DGGE profiles showed that the samples of non-secretor individuals formed a separate cluster within the secretor samples. Moreover, bifidobacterial diversity (p<0.0001), richness (p<0.0003), and abundance (p<0.05) were significantly reduced in the samples from the non-secretor individuals as compared with those from the secretor individuals. The non-secretor individuals lacked, or were rarely colonized by, several genotypes related to B. bifidum, B. adolescentis and B. catenulatum/pseudocatenulatum. In contrast to bifidobacteria, several bacterial genotypes were more common and the richness (p<0.04) of dominant bacteria as detected by PCR-DGGE was higher in the non-secretor individuals than in the secretor individuals. We showed that the diversity and composition of the human bifidobacterial population is strongly associated with the histo-blood group ABH secretor/non-secretor status, which consequently appears to be one of the host genetic determinants for the composition of the intestinal microbiota. This association can be explained by the difference between the secretor and non-secretor individuals in their expression of ABH and Lewis glycan epitopes in the mucosa. PMID:21625510

  6. Identification of an intestine-specific promoter and inducible expression of bacterial α-galactosidase in mammalian cells by a lac operon system

    PubMed Central

    2012-01-01

    Background α-galactosidase has been widely used in animal husbandry to reduce anti-nutritional factors (such as α-galactoside) in feed. Intestine-specific and substrate inducible expression of α-galactosidase would be highly beneficial for transgenic animal production. Methods To achieve the intestine-specific and substrate inducible expression of α-galactosidase, we first identified intestine-specific promoters by comparing the transcriptional activity and tissue specificity of four intestine-specific promoters from human intestinal fatty acid binding protein, rat intestinal fatty acid binding protein, human mucin-2 and human lysozyme. We made two chimeric constructs combining the promoter and enhancer of human mucin-2, rat intestinal trefoil factor and human sucrase-isomaltase. Then a modified lac operon system was constructed to investigate the induction of α-galactosidase expression and enzyme activity by isopropyl β-D-1-thiogalactopyranoside (IPTG) and an α-galactosidase substrate, α-lactose. We declared that the research carried out on human (Zhai Yafeng) was in compliance with the Helsinki Declaration, and experimental research on animals also followed internationally recognized guidelines. Results The activity of the human mucin-2 promoter was about 2 to 3 times higher than that of other intestine-specific promoters. In the lac operon system, the repressor significantly decreased (P < 0.05) luciferase activity by approximately 6.5-fold and reduced the percentage of cells expressing green fluorescent protein (GFP) by approximately 2-fold. In addition, the expression level of α-galactosidase mRNA was decreased by 6-fold and α-galactosidase activity was reduced by 8-fold. In line with our expectations, IPTG and α-lactose supplementation reversed (P < 0.05) the inhibition and produced a 5-fold increase of luciferase activity, an 11-fold enhancement in the percentage of cells with GFP expression and an increase in α-galactosidase mRNA abundance (by about 5-fold) and α-galactosidase activity (by about 7-fold). Conclusions We have successfully constructed a high specificity inducible lac operon system in an intestine-derived cell line, which could be of great value for gene therapy applications and transgenic animal production. PMID:23111091

  7. Transcriptional Modulation of Intestinal Innate Defense/Inflammation Genes by Preterm Infant Microbiota in a Humanized Gnotobiotic Mouse Model

    PubMed Central

    Lu, Lei; Yu, Yueyue; Guo, Yuee; Wang, Yunwei; Chang, Eugene B.; Claud, Erika C.

    2015-01-01

    Background and Aims It is known that postnatal functional maturation of the small intestine is facilitated by microbial colonization of the gut. Preterm infants exhibit defects in gut maturation, weak innate immunity against intestinal infection and increased susceptibility to inflammatory disorders, all of which may be related to the inappropriate microbial colonization of their immature intestines. The earliest microbes to colonize the preterm infant gut encounter a naïve, immature intestine. Thus this earliest microbiota potentially has the greatest opportunity to fundamentally influence intestinal development and immune function. The aim of this study was to characterize the effect of early microbial colonization on global gene expression in the distal small intestine during postnatal gut development. Methods Gnotobiotic mouse models with experimental colonization by early (prior to two weeks of life) intestinal microbiota from preterm human infants were utilized. Microarray analysis was used to assess global gene expression in the intestinal epithelium. Results and Conclusion Multiple intestinal genes involved in metabolism, cell cycle regulation, cell-cell or cell-extracellular matrix communication, and immune function are developmental- and intestinal microbiota- regulated. Using a humanized gnotobiotic mouse model, we demonstrate that certain early preterm infant microbiota from prior to 2 weeks of life specifically induce increased NF-κB activation and a phenotype of increased inflammation whereas other preterm microbiota specifically induce decreased NF-κB activation. These fundamental differences correlate with altered clinical outcomes and suggest the existence of optimal early microbial communities to improve health outcomes. PMID:25928420

  8. Recombinant Human Epidermal Growth Factor Accelerates Recovery of Mouse Small Intestinal Mucosa After Radiation Damage

    SciTech Connect

    Lee, Kang Kyoo; Jo, Hyang Jeong; Hong, Joon Pio; Lee, Sang-wook Sohn, Jung Sook; Moon, Soo Young; Yang, Sei Hoon; Shim, Hyeok; Lee, Sang Ho; Ryu, Seung-Hee; Moon, Sun Rock

    2008-07-15

    Purpose: To determine whether systemically administered recombinant human epidermal growth factor (rhEGF) accelerates the recovery of mouse small intestinal mucosa after irradiation. Methods and Materials: A mouse mucosal damage model was established by administering radiation to male BALB/c mice with a single dose of 15 Gy applied to the abdomen. After irradiation, rhEGF was administered subcutaneously at various doses (0.04, 0.2, 1.0, and 5.0 mg/kg/day) eight times at 2- to 3-day intervals. The evaluation methods included histologic changes of small intestinal mucosa, change in body weight, frequency of diarrhea, and survival rate. Results: The recovery of small intestinal mucosa after irradiation was significantly improved in the mice treated with a high dose of rhEGF. In the mice that underwent irradiation without rhEGF treatment, intestinal mucosal ulceration, mucosal layer damage, and severe inflammation occurred. The regeneration of villi was noticeable in mice treated with more than 0.2 mg/kg rhEGF, and the villi recovered fully in mice given more than 1 mg/kg rhEGF. The frequency of diarrhea persisting for more than 3 days was significantly greater in the radiation control group than in the rhEGF-treated groups. Conclusions: Systemic administration of rhEGF accelerates recovery from mucosal damage induced by irradiation. We suggest that rhEGF treatment shows promise for the reduction of small intestinal damage after irradiation.

  9. The bioavailability of apigenin-7-glucoside is influenced by human intestinal microbiota in rats.

    PubMed

    Hanske, Laura; Loh, Gunnar; Sczesny, Silke; Blaut, Michael; Braune, Annett

    2009-06-01

    We investigated the impact of human intestinal microbiota on bioavailability of the flavone apigenin-7-glucoside (A7G) by comparing germ-free and human microbiota-associated (HMA) rats. First, the ability of the human intestinal microbiota to convert A7G was proven in vitro by incubating A7G with fecal suspensions. Apigenin, naringenin, and 3-(4-hydroxyphenyl)propionic acid were formed as main metabolites. After application of A7G to germ-free rats, apigenin, luteolin, and their conjugates were detected in urine and feces. In HMA rats, naringenin, eriodictyol, phloretin, 3-(3,4-dihydroxyphenyl)propionic acid, 3-(4-hydroxyphenyl)propionic acid, 3-(3-hydroxyphenyl)propionic acid, and 4-hydroxycinnamic acid in their free and conjugated forms were additionally formed. In whole-blood samples from germ-free and HMA rats, only apigenin conjugates and phloretin, respectively, were detected. The total excretion of A7G and its metabolites within 48 h was similarly low in both germ-free and HMA rats, with 11 and 13% of the A7G dose, respectively. In germ-free rats, A7G metabolites dominated by apigenin and its conjugates were mainly excreted with feces. In contrast, the compounds in HMA rats were predominantly recovered from urine, 3-(4-hydroxyphenyl)propionic acid being the main metabolite. The ability of selected gut bacteria and the host intestinal mucosa to deglycosylate A7G was tested using cell extracts. Apigenin was formed by cytosolic extracts of Eubacterium ramulus and Bacteroides distasonis and by the microsomal fraction of the small intestinal mucosa of rats. Overall, human intestinal microbiota largely contributed to A7G metabolism, indicating its influence on the bioactivity of flavones. PMID:19403720

  10. The role of intestinal barrier failure and bacterial translocation in the development of systemic infection and multiple organ failure.

    PubMed

    Deitch, E A

    1990-03-01

    Traditionally, evaluation of intestinal function has been limited largely to monitoring gastric pH and intestinal motility. This clinical approach has led clinicians to equate normal intestinal motility with normal intestinal function and to assume that if stress-induced gastric bleeding can be prevented, all will be well. However, it is becoming increasingly clear that the gastrointestinal tract is not a passive organ and that intestinal dysfunction is not limited to ileus and upper gastrointestinal bleeding. Instead, the gastrointestinal tract is recognized as having important endocrine, metabolic, immunologic, and barrier functions, as well as its traditional role in nutrient absorption. Over the last 5 years, there has been a resurgence of interest in the role of intestinal barrier failure in the development of systemic infection and multiple organ failure in the critically ill or injured patient. PMID:2407230

  11. Isolation from human serum of an inactivator of bacterial lipopolysaccharide.

    PubMed Central

    Johnson, K. J.; Ward, P. A.; Goralnick, S.; Osborn, M. J.

    1977-01-01

    By a series of chromatographic procedures involving precipitation by salt, gel filtration, anionic exchange, and hydroxyapatite elution, a protein--termed the lipopolysaccharide inactivator (LPS-I)--has been isolated from normal human serum. As a result of treatment of bacterial lipopolysaccharide (LPS) by LPS-I, the treated LPS loses its toxicity for mice and reactivity in the Limulus assay and appears to be irreversibly disaggregated. The inactivation of the LPS by the purified LPS-I is temperature and time dependent and is not blocked by the addition of irreversible inhibitors of serine esterases. The LPS inactivator migrates as an alpha-globulin in whole serum and has a sedimentation velocity of approximately 4.5S. Characteristics of the inactivated LPS are briefly described using internally labeled LPS. Images Figure 6 Figure 8 PMID:70173

  12. Functional heterogeneity of intestinal Escherichia coli strains expressing type 1 somatic pili (fimbriae): assessment of bacterial adherence to intestinal membranes and surface hydrophobicity.

    PubMed Central

    Sherman, P M; Houston, W L; Boedeker, E C

    1985-01-01

    Although the role of host-specific, nonmannose-sensitive pilus adhesins in the intestinal adherence of pathogenic Escherichia coli is well established, a similar role for mannose-sensitive type 1 or common pili is less clear, since these structures can be expressed by most E. coli, even nonpathogens. We first examined whether type 1 pili, expressed by the rabbit-effacing, adherent, enteropathogenic E. coli strain RDEC-1, mediated interactions with intestinal membranes of several species and compared these interactions with those mediated by the nonmannose-sensitive adhesin of RDEC-1. We next grew a series of E. coli intestinal strains in static broth to promote type 1 pilus expression and determined whether E. coli expressing type 1 pili differed in their affinity for intestinal membranes (as measured by phase-contrast microscopy and aggregometry), hydrophobic surface properties, net negative surface charge (as measured by hydrophobic interaction chromatography and salt aggregation), and hemagglutination patterns. In contrast to the species-specific attachment to rabbit brush borders of RDEC-1 expressing its nonmannose-sensitive adhesin, type 1 pili on RDEC-1 mediated mannose-sensitive attachment to intestinal membranes of all four species tested. Expression of type 1 pili on other E. coli strains resulted in varying degrees of nonspecies-specific, mannose-sensitive attachment to intestinal membranes. This attachment correlated with increasing surface hydrophobicity rather than with hemagglutination patterns. These results indicate that various E. coli strains expressing type 1 pili are functionally heterogeneous and suggest that some type 1 pili might contribute to in vivo enteroadherence. PMID:2863216

  13. Environmental contaminants and intestinal function

    PubMed Central

    Banwell, John G.

    1979-01-01

    The environmental contaminants which have their major effects on the small intestine may be classified into five major categories: (1) bacterial, viral, and parasitic agents, (2) food and plant substances, (3) environmental and industrial products, (4) pharmaceutical agents, and (5) toxic agents whose metabolic effects are dependent on interreaction with intestinal bacterial flora, other physical agents (detergents), human intestinal enzyme deficiency states, and the nutritional state of the host. Bacterial, viral, and parasitic agents are the most important of all such agents, being responsible for significant mortality and morbidity in association with diarrheal diseases of adults and children. Several plant substances ingested as foods have unique effects on the small bowel as well as from contaminants such as fungi on poorly preserved grains and cereals. Environmental and industrial products, in spite of their widespread prevalence in industrial societies as contaminants, are less important unless unexpectedly intense exposure occurs to the intestinal tract. Pharmaceutical agents of several types interreact with the small bowel mucosa causing impairment of transport processes for fluid and electrolytes, amino acid, lipid and sugars as well as vitamins. These interreactions may be dependent on bacterial metabolic activity, association with detergents, mucosal enzyme deficiency state (disaccharidases), and the state of nutrition of the subject. PMID:540611

  14. Lactobacillus reuteri Inhibition of Enteropathogenic Escherichia coli Adherence to Human Intestinal Epithelium

    PubMed Central

    Walsham, Alistair D. S.; MacKenzie, Donald A.; Cook, Vivienne; Wemyss-Holden, Simon; Hews, Claire L.; Juge, Nathalie; Schüller, Stephanie

    2016-01-01

    Enteropathogenic Escherichia coli (EPEC) is a major cause of diarrheal infant death in developing countries, and probiotic bacteria have been shown to provide health benefits in gastrointestinal infections. In this study, we have investigated the influence of the gut symbiont Lactobacillus reuteri on EPEC adherence to the human intestinal epithelium. Different host cell model systems including non-mucus-producing HT-29 and mucus-producing LS174T intestinal epithelial cell lines as well as human small intestinal biopsies were used. Adherence of L. reuteri to HT-29 cells was strain-specific, and the mucus-binding proteins CmbA and MUB increased binding to both HT-29 and LS174T cells. L. reuteri ATCC PTA 6475 and ATCC 53608 significantly inhibited EPEC binding to HT-29 but not LS174T cells. While pre-incubation of LS174T cells with ATCC PTA 6475 did not affect EPEC attaching/effacing (A/E) lesion formation, it increased the size of EPEC microcolonies. ATCC PTA 6475 and ATCC 53608 binding to the mucus layer resulted in decreased EPEC adherence to small intestinal biopsy epithelium. Our findings show that L. reuteri reduction of EPEC adhesion is strain-specific and has the potential to target either the epithelium or the mucus layer, providing further rationale for the selection of probiotic strains. PMID:26973622

  15. Lactobacillus reuteri Inhibition of Enteropathogenic Escherichia coli Adherence to Human Intestinal Epithelium.

    PubMed

    Walsham, Alistair D S; MacKenzie, Donald A; Cook, Vivienne; Wemyss-Holden, Simon; Hews, Claire L; Juge, Nathalie; Schüller, Stephanie

    2016-01-01

    Enteropathogenic Escherichia coli (EPEC) is a major cause of diarrheal infant death in developing countries, and probiotic bacteria have been shown to provide health benefits in gastrointestinal infections. In this study, we have investigated the influence of the gut symbiont Lactobacillus reuteri on EPEC adherence to the human intestinal epithelium. Different host cell model systems including non-mucus-producing HT-29 and mucus-producing LS174T intestinal epithelial cell lines as well as human small intestinal biopsies were used. Adherence of L. reuteri to HT-29 cells was strain-specific, and the mucus-binding proteins CmbA and MUB increased binding to both HT-29 and LS174T cells. L. reuteri ATCC PTA 6475 and ATCC 53608 significantly inhibited EPEC binding to HT-29 but not LS174T cells. While pre-incubation of LS174T cells with ATCC PTA 6475 did not affect EPEC attaching/effacing (A/E) lesion formation, it increased the size of EPEC microcolonies. ATCC PTA 6475 and ATCC 53608 binding to the mucus layer resulted in decreased EPEC adherence to small intestinal biopsy epithelium. Our findings show that L. reuteri reduction of EPEC adhesion is strain-specific and has the potential to target either the epithelium or the mucus layer, providing further rationale for the selection of probiotic strains. PMID:26973622

  16. Intestinal absorption of epoxy-beta-carotenes by humans.

    PubMed Central

    Barua, A B

    1999-01-01

    An increased intake of fruits and vegetables has been shown to be associated with reduced risk of cancer. In epidemiological studies, supplements of beta-carotene, which is abundant in fruits and vegetables, were not found to be beneficial in reducing the incidence of lung cancer in high-risk groups. Epoxycarotenoids are abundant in nature. 5,6-Epoxy-beta-carotene was much more active than beta-carotene in the induction of differentiation of NB4 cells [Duitsman, Becker, Barua and Olson (1996) FASEB J. 10, A732]. Epoxycarotenes may, therefore, have protective effects against cancer. In order to do this, however, epoxycarotenoids must be absorbed by the human body. There is no evidence that epoxycarotenoids, despite their abundance in dietary fruits and vegetables, are absorbed by humans. In this paper, it is demonstrated that orally administered dietary or synthetic epoxy-beta-carotenes are absorbed by humans, as indicated by their appearance in the circulating blood. PMID:10191267

  17. The colonization of a simulator of the human intestinal microbial ecosystem by a probiotic strain fed on a fermented oat bran product: effects on the gastrointestinal microbiota.

    PubMed

    Kontula, P; Jaskari, J; Nollet, L; De Smet, I; von Wright, A; Poutanen, K; Mattila-Sandholm, T

    1998-08-01

    The effects of Lactobacillus-GG-fermented oat bran product on the microbiota and its metabolic activity in the human gut were investigated, using a simulator of the human intestinal microbial ecosystem (SHIME), by analysing the bacterial population, shortchain fatty acids and gas production. In addition, the effects of fermented oat bran supernatant and supernatant samples from reactors 4, 5 and 6 (large intestine) on the growth of Escherichia coli IHE 13047, Enterococcus faecalis VTT E-93203, Lactobacillus rhamnosus VTT E-94522 (Lactobacillus GG) and Lactococcus lactis subsp. lactis VTT E-90414 were monitored to ascertain possible stimulatory/inhibitory effects by an in vitro turbidometric method. Our experiments showed that Lactobacillus GG colonized the SHIME reactor and this colonization could be maintained for several weeks without extra supplementation. Oat bran feeding also favoured the growth of bifidobacteria and caused an increase in the production of acetic, propionic and butyric acid as well as CH4 and CO2. However, the effects of oat bran, either on bacterial populations or on their metabolic activity, were not directly dose-dependent. In turbidometric measurements, the supernatant of fermented oat bran exerted an inhibitory effect of Lactobacillus GG, but stimulated the growth of enterococci. PMID:9763692

  18. Hydrolysis of Pyrethroids by Human and Rat Tissues: Examination of Intestinal, Liver and Serum Carboxylesterases

    PubMed Central

    Crow, J. Allen; Borazjani, Abdolsamad; Potter, Philip M.; Ross, Matthew K.

    2009-01-01

    Hydrolytic metabolism of pyrethroid insecticides in humans is one of the major catabolic pathways that clear these compounds from the body. Rodent models are often used to determine the disposition and clearance rates of these esterified compounds. In this study the distribution and activities of esterases that catalyze pyrethroid metabolism have been investigated in vitro using several human and rat tissues, including small intestine, liver, and serum. The major esterase in human intestine is carboxylesterase 2 (hCE2). We found that the pyrethroid trans-permethrin is effectively hydrolyzed by a sample of pooled human intestinal microsomes (5 individuals), while deltamethrin and bioresmethrin are not. This result correlates well with the substrate specificity of recombinant hCE2 enzyme. In contrast, a sample of pooled rat intestinal microsomes (5 animals) hydrolyze trans-permethrin 4.5-fold slower than the sample of human intestinal microsomes. Furthermore, it is demonstrated that pooled samples of cytosol from human or rat liver are ~2-fold less hydrolytically active (normalized per mg protein) than the corresponding microsomal fraction toward pyrethroid substrates; however, the cytosolic fractions do have significant amounts (~40%) of the total esteratic activity. Moreover, a 6-fold interindividual variation in carboxylesterase 1 protein expression in human hepatic cytosols was observed. Human serum was shown to lack pyrethroid hydrolytic activity, but rat serum has hydrolytic activity that is attributed to a single CE isozyme. We purified the serum CE enzyme to homogeneity to determine its contribution to pyrethroid metabolism in the rat. Both trans-permethrin and bioresmethrin were effectively cleaved by this serum CE, but deltamethrin, esfenvalerate, alpha-cypermethrin, and cis-permethrin were slowly hydrolyzed. Lastly, two model lipase enzymes were examined for their ability to hydrolyze pyrethroids. However, no hydrolysis products could be detected. Together, these results demonstrate that extrahepatic esterolytic metabolism of specific pyrethroids may be significant. Moreover, hepatic cytosolic and microsomal hydrolytic metabolism should each be considered during the development of pharmacokinetic models that predict the disposition of pyrethroids and other esterified compounds. PMID:17442360

  19. Hydrolysis of pyrethroids by human and rat tissues: Examination of intestinal, liver and serum carboxylesterases

    SciTech Connect

    Crow, J. Allen; Borazjani, Abdolsamad; Potter, Philip M.; Ross, Matthew K. . E-mail: mross@cvm.msstate.edu

    2007-05-15

    Hydrolytic metabolism of pyrethroid insecticides in humans is one of the major catabolic pathways that clear these compounds from the body. Rodent models are often used to determine the disposition and clearance rates of these esterified compounds. In this study the distribution and activities of esterases that catalyze pyrethroid metabolism have been investigated in vitro using several human and rat tissues, including small intestine, liver and serum. The major esterase in human intestine is carboxylesterase 2 (hCE2). We found that the pyrethroid trans-permethrin is effectively hydrolyzed by a sample of pooled human intestinal microsomes (5 individuals), while deltamethrin and bioresmethrin are not. This result correlates well with the substrate specificity of recombinant hCE2 enzyme. In contrast, a sample of pooled rat intestinal microsomes (5 animals) hydrolyze trans-permethrin 4.5-fold slower than the sample of human intestinal microsomes. Furthermore, it is demonstrated that pooled samples of cytosol from human or rat liver are {approx} 2-fold less hydrolytically active (normalized per mg protein) than the corresponding microsomal fraction toward pyrethroid substrates; however, the cytosolic fractions do have significant amounts ({approx} 40%) of the total esteratic activity. Moreover, a 6-fold interindividual variation in carboxylesterase 1 protein expression in human hepatic cytosols was observed. Human serum was shown to lack pyrethroid hydrolytic activity, but rat serum has hydrolytic activity that is attributed to a single CE isozyme. We purified the serum CE enzyme to homogeneity to determine its contribution to pyrethroid metabolism in the rat. Both trans-permethrin and bioresmethrin were effectively cleaved by this serum CE, but deltamethrin, esfenvalerate, alpha-cypermethrin and cis-permethrin were slowly hydrolyzed. Lastly, two model lipase enzymes were examined for their ability to hydrolyze pyrethroids. However, no hydrolysis products could be detected. Together, these results demonstrate that extrahepatic esterolytic metabolism of specific pyrethroids may be significant. Moreover, hepatic cytosolic and microsomal hydrolytic metabolism should each be considered during the development of pharmacokinetic models that predict the disposition of pyrethroids and other esterified compounds.

  20. Hydrolysis of pyrethroids by human and rat tissues: examination of intestinal, liver and serum carboxylesterases.

    PubMed

    Crow, J Allen; Borazjani, Abdolsamad; Potter, Philip M; Ross, Matthew K

    2007-05-15

    Hydrolytic metabolism of pyrethroid insecticides in humans is one of the major catabolic pathways that clear these compounds from the body. Rodent models are often used to determine the disposition and clearance rates of these esterified compounds. In this study the distribution and activities of esterases that catalyze pyrethroid metabolism have been investigated in vitro using several human and rat tissues, including small intestine, liver and serum. The major esterase in human intestine is carboxylesterase 2 (hCE2). We found that the pyrethroid trans-permethrin is effectively hydrolyzed by a sample of pooled human intestinal microsomes (5 individuals), while deltamethrin and bioresmethrin are not. This result correlates well with the substrate specificity of recombinant hCE2 enzyme. In contrast, a sample of pooled rat intestinal microsomes (5 animals) hydrolyze trans-permethrin 4.5-fold slower than the sample of human intestinal microsomes. Furthermore, it is demonstrated that pooled samples of cytosol from human or rat liver are approximately 2-fold less hydrolytically active (normalized per mg protein) than the corresponding microsomal fraction toward pyrethroid substrates; however, the cytosolic fractions do have significant amounts (approximately 40%) of the total esteratic activity. Moreover, a 6-fold interindividual variation in carboxylesterase 1 protein expression in human hepatic cytosols was observed. Human serum was shown to lack pyrethroid hydrolytic activity, but rat serum has hydrolytic activity that is attributed to a single CE isozyme. We purified the serum CE enzyme to homogeneity to determine its contribution to pyrethroid metabolism in the rat. Both trans-permethrin and bioresmethrin were effectively cleaved by this serum CE, but deltamethrin, esfenvalerate, alpha-cypermethrin and cis-permethrin were slowly hydrolyzed. Lastly, two model lipase enzymes were examined for their ability to hydrolyze pyrethroids. However, no hydrolysis products could be detected. Together, these results demonstrate that extrahepatic esterolytic metabolism of specific pyrethroids may be significant. Moreover, hepatic cytosolic and microsomal hydrolytic metabolism should each be considered during the development of pharmacokinetic models that predict the disposition of pyrethroids and other esterified compounds. PMID:17442360

  1. Comparative Genomics Analysis of Streptococcus Isolates from the Human Small Intestine Reveals their Adaptation to a Highly Dynamic Ecosystem

    PubMed Central

    Van den Bogert, Bartholomeus; Boekhorst, Jos; Herrmann, Ruth; Smid, Eddy J.; Zoetendal, Erwin G.; Kleerebezem, Michiel

    2013-01-01

    The human small-intestinal microbiota is characterised by relatively large and dynamic Streptococcus populations. In this study, genome sequences of small-intestinal streptococci from S. mitis, S. bovis, and S. salivarius species-groups were determined and compared with those from 58 Streptococcus strains in public databases. The Streptococcus pangenome consists of 12,403 orthologous groups of which 574 are shared among all sequenced streptococci and are defined as the Streptococcus core genome. Genome mining of the small-intestinal streptococci focused on functions playing an important role in the interaction of these streptococci in the small-intestinal ecosystem, including natural competence and nutrient-transport and metabolism. Analysis of the small-intestinal Streptococcus genomes predicts a high capacity to synthesize amino acids and various vitamins as well as substantial divergence in their carbohydrate transport and metabolic capacities, which is in agreement with observed physiological differences between these Streptococcus strains. Gene-specific PCR-strategies enabled evaluation of conservation of Streptococcus populations in intestinal samples from different human individuals, revealing that the S. salivarius strains were frequently detected in the small-intestine microbiota, supporting the representative value of the genomes provided in this study. Finally, the Streptococcus genomes allow prediction of the effect of dietary substances on Streptococcus population dynamics in the human small-intestine. PMID:24386196

  2. Type I Collagen as an Extracellular Matrix for the In Vitro Growth of Human Small Intestinal Epithelium

    PubMed Central

    Jabaji, Ziyad; Brinkley, Garrett J.; Khalil, Hassan A.; Sears, Connie M.; Lei, Nan Ye; Lewis, Michael; Stelzner, Matthias; Martn, Martn G.; Dunn, James C. Y.

    2014-01-01

    Background We previously reported in vitro maintenance and proliferation of human small intestinal epithelium using Matrigel, a proprietary basement membrane product. There are concerns over the applicability of Matrigel-based methods for future human therapies. We investigated type I collagen as an alternative for the culture of human intestinal epithelial cells. Methods Human small intestine was procured from fresh surgical pathology specimens. Small intestinal crypts were isolated using EDTA chelation. Intestinal subepithelial myofibroblasts were isolated from a pediatric sample and expanded in vitro. After suspension in Matrigel or type I collagen gel, crypts were co-cultured above a confluent layer of myofibroblasts. Crypts were also grown in monoculture with exposure to myofibroblast conditioned media; these were subsequently sub-cultured in vitro and expanded with a 1?2 split ratio. Cultures were assessed with light microscopy, RT-PCR, histology, and immunohistochemistry. Results Collagen supported viable human epithelium in vitro for at least one month in primary culture. Sub-cultured epithelium expanded through 12 passages over 60 days. Histologic sections revealed polarized columnar cells, with apical brush borders and basolaterally located nuclei. Collagen-based cultures gave rise to monolayer epithelial sheets at the gel-liquid interface, which were not observed with Matrigel. Immunohistochemical staining identified markers of differentiated intestinal epithelium and myofibroblasts. RT-PCR demonstrated expression of ?-smooth muscle actin and vimentin in myofibroblasts and E-Cadherin, CDX2, villin 1, intestinal alkaline phosphatase, chromogranin A, lysozyme, and Lgr5 in epithelial cells. These markers were maintained through several passages. Conclusion Type I collagen gel supports long-term in vitro maintenance and expansion of fully elaborated human intestinal epithelium. Collagen-based methods yield familiar enteroid structures as well as a new pattern of sheet-like growth, and they eliminate the need for Matrigel for in vitro human intestinal epithelial growth. Future research is required to further develop this cell culture system for tissue engineering applications. PMID:25222024

  3. Involvement of CYP2J2 and CYP4F12 in the metabolism of ebastine in human intestinal microsomes.

    PubMed

    Hashizume, Takanori; Imaoka, Susumu; Mise, Masashi; Terauchi, Yoshiaki; Fujii, Toshihiko; Miyazaki, Hisashi; Kamataki, Tetsuya; Funae, Yoshihiko

    2002-01-01

    The purpose of the study was to elucidate human intestinal cytochrome P450 isoform(s) involved in the metabolism of an antihistamine, ebastine, having two major pathways of hydroxylation and N-dealkylation. The ebastine dealkylase in human intestinal microsomes was CYP3A4, based on the inhibition studies with antibodies against CYP1A, CYP2A, CYP2C, CYP2D, CYP2E, and CYP3A isoforms and their selective inhibitors. However, ebastine hydroxylase could not be identified. We then examined the inhibitory effects of anti-CYP4F antibody and 17-octadecynoic acid, an inhibitor of the CYP4 family, on ebastine hydroxylation in intestinal microsomes, since CYP4F was recently found to be the predominant ebastine hydroxylase in monkey intestine; and a novel CYP4F isoform (CYP4F12), also capable of hydroxylating ebastine, was found to exist in human intestine. However, the inhibitory effects were only partial (about 20%) and thus it was thought that, although human CYP4F was involved in ebastine hydroxylation, another predominant enzyme exists. Further screening showed that the hydroxylation was inhibited by arachidonic acid. CYP2J2 was selected as a candidate expressed in the intestine and closely related to arachidonic acid metabolism. The catalytic activity of recombinant CYP2J2 was much higher than that of CYP4F12. Anti-CYP2J antibody inhibited the hydroxylation to about 70% in human intestinal microsomes. These results demonstrate that CYP2J2 is the predominant ebastine hydroxylase in human intestinal microsomes. Thus, the present paper for the first time indicates that, in human intestinal microsomes, both CYP2J and CYP4F subfamilies not only metabolize endogenous substrates but also are involved in the drug metabolism. PMID:11752129

  4. Epidermal growth factor upregulates serotonin transporter in human intestinal epithelial cells via transcriptional mechanisms

    PubMed Central

    Anbazhagan, Arivarasu Natarajan; Esmaili, Ali; Kumar, Anoop; Nazir, Saad; Malakooti, Jaleh; Alrefai, Waddah A.; Saksena, Seema

    2011-01-01

    Serotonin transporter (SERT) regulates extracellular availability of serotonin and is a potential pharmacological target for gastrointestinal disorders. A decrease in SERT has been implicated in intestinal inflammatory and diarrheal disorders. However, little is known regarding regulation of SERT in the intestine. Epidermal growth factor (EGF) is known to influence intestinal electrolyte and nutrient transport processes and has protective effects on intestinal mucosa. Whether EGF regulates SERT in the human intestine is not known. The present studies examined the regulation of SERT by EGF, utilizing Caco-2 cells grown on Transwell inserts as an in vitro model. Treatment with EGF from the basolateral side (10 ng/ml, 24 h) significantly stimulated SERT activity (?2-fold, P < 0.01) and mRNA levels compared with control. EGF increased the activities of the two alternate promoter constructs for human SERT gene: SERT promoter 1 (hSERTp1, upstream of exon 1a) and SERT promoter 2 (hSERTp2, upstream of exon 2). Inhibition of EGF receptor (EGFR) tyrosine kinase activity by PD168393 (1 nM) blocked the stimulatory effects of EGF on SERT promoters. Progressive deletions of the SERT promoter indicated that the putative EGF-responsive elements are present in the ?672/?472 region of the hSERTp1 and regions spanning ?1195/?738 and ?152/+123 of hSERTp2. EGF markedly increased the binding of Caco-2 nuclear proteins to the potential AP-1 cis-elements present in EGF-responsive regions of hSERTp1 and p2. Overexpression of c-jun but not c-fos specifically transactivated hSERTp2, with no effects on hSERTp1. Our findings define novel mechanisms of transcriptional regulation of SERT by EGF via EGFR at the promoter level that may contribute to the beneficial effects of EGF in gut disorders. PMID:21273531

  5. Human intestinal gas measurement systems: in vitro fermentation and gas capsules.

    PubMed

    Ou, Jian Zhen; Yao, C K; Rotbart, Asaf; Muir, Jane G; Gibson, Peter R; Kalantar-zadeh, Kourosh

    2015-04-01

    The biological and clinical significance of the human gut microbiome is currently attracting worldwide attention. While rRNA and DNA technologies led to a quantum leap in our understanding of the numbers and types of gut microorganisms, much less is known about these microorganisms' activity in situ and in real time. Accurately measuring their byproducts, including intestinal gases, may offer unique biomarkers for specific gut microbiota, accelerating our understanding of the relationships among intestinal gases, the metabolic activity of the gut microbiome, and human health states. Here we present two novel techniques, namely in vitro fermentation and gas capsule systems, for measuring and assessing selected gas species. We discuss new developments with these technologies and the methods of their implementation and provide an overall review of their operation. PMID:25772639

  6. Diagnosis of edema and inflammation in human intestines using ultrawideband radar

    NASA Astrophysics Data System (ADS)

    Smith, Sonny; Narayanan, Ram M.; Messaris, Evangelos

    2015-05-01

    Human intestines are vital organs, which are often subjected to chronic issues. In particular, Crohn's disease is a bowel aliment resulting in inflammation along the lining of one's digestive tract. Moreover, such an inflammatory condition causes changes in the thickness of the intestines; and we posit induce changes in the dielectric properties detectable by radar. This detection hinges on the increase in fluid content in the afflicted area, which is described by effective medium approximations (EMA). In this paper, we consider one of the constitutive parameters (i.e. relative permittivity) of different human tissues and introduce a simple numerical, electromagnetic multilayer model. We observe how the increase in water content in one layer can be approximated to predict the effective permittivity of that layer. Moreover, we note trends in how such an accumulation can influence the total effective reflection coefficient of the multiple layers.

  7. Generation of L-cells in mouse and human small intestine organoids

    PubMed Central

    Petersen, Natalia; Reimann, Frank; Bartfeld, Sina; Farin, Henner F.; Ringnalda, Femke C.; Vries, Robert G. J.; van den Brink, Stieneke; Clevers, Hans; Gribble, Fiona M.; de Koning, Eelco J. P.

    2015-01-01

    Upon a nutrient challenge, L-cells produce glucagon-like peptide 1 (GLP-1), a powerful stimulant of insulin release. Strategies to augment endogenous GLP-1 production include promoting L-cell differentiation and increasing L-cell number. Here we present a novel in vitro platform to generate functional L-cells from 3D cultures of mouse and human intestinal crypts. We show that short-chain fatty acids (SCFAs) selectively increase the number of L-cells resulting in an elevation of GLP-1 release. This is accompanied by up-regulation of transcription factors, associated with the endocrine lineage of intestinal stem cell development. Thus, our platform allows us to study and modulate the development of L-cells in mouse and human crypts as a potential basis for novel therapeutic strategies in type 2 diabetes. PMID:24130334

  8. Deglycosylation of flavonoid and isoflavonoid glycosides by human small intestine and liver beta-glucosidase activity.

    PubMed

    Day, A J; DuPont, M S; Ridley, S; Rhodes, M; Rhodes, M J; Morgan, M R; Williamson, G

    1998-09-25

    Flavonoid and isoflavonoid glycosides are common dietary phenolics which may be absorbed from the small intestine of humans. The ability of cell-free extracts from human small intestine and liver to deglycosylate various (iso)flavonoid glycosides was investigated. Quercetin 4'-glucoside, naringenin 7-glucoside, apigenin 7-glucoside, genistein 7-glucoside and daidzein 7-glucoside were rapidly deglycosylated by both tissue extracts, whereas quercetin 3,4'-diglucoside, quercetin 3-glucoside, kaempferol 3-glucoside, quercetin 3-rhamnoglucoside and naringenin 7-rhamnoglucoside remained unchanged. The Km for hydrolysis of quercetin 4'-glucoside and genistein 7-glucoside was approximately 32+/-12 and approximately 14+/-3 microM in both tissues respectively. The enzymatic activity of the cell-free extracts exhibits similar properties to the cytosolic broad-specificity -glucosidase previously described in mammals. PMID:9771896

  9. Listeria monocytogenes σB Contributes to Invasion of Human Intestinal Epithelial Cells

    PubMed Central

    Kim, Heesun; Boor, Kathryn J.; Marquis, Hélène

    2004-01-01

    The role of σB in Listeria monocytogenes infection of human intestinal epithelial cells was investigated. Invasion defects associated with loss of σB paralleled those of a ΔinlA strain independently of the σB-dependent P2prfA promoter. Concomitantly, amounts of inlA transcript and InlA protein were significantly decreased in the ΔsigB strain. PMID:15557671

  10. Development and Characterization of a Novel Mouse Line Humanized for the Intestinal Peptide Transporter PEPT1

    PubMed Central

    2015-01-01

    The proton-coupled oligopeptide transporter PEPT1 (SLC15A1) is abundantly expressed in the small intestine, but not colon, of mammals and found to mediate the uptake of di/tripeptides and peptide-like drugs from the intestinal lumen. However, species differences have been observed in both the expression (and localization) of PEPT1 and its substrate affinity. With this in mind, the objectives of this study were to develop a humanized PEPT1 mouse model (huPEPT1) and to characterize hPEPT1 expression and functional activity in the intestines. Thus, after generating huPEPT1 mice in animals previously nulled for mouse Pept1, phenotypic, PCR, and immunoblot analyses were performed, along with in situ single-pass intestinal perfusion and in vivo oral pharmacokinetic studies with a model dipeptide, glycylsarcosine (GlySar). Overall, the huPEPT1 mice had normal survival rates, fertility, litter size, gender distribution, and body weight. There was no obvious behavioral or pathological phenotype. The mRNA and protein profiles indicated that huPEPT1 mice had substantial PEPT1 expression in all regions of the small intestine (i.e., duodenum, jejunum, and ileum) along with low but measurable expression in both proximal and distal segments of the colon. In agreement with PEPT1 expression, the in situ permeability of GlySar in huPEPT1 mice was similar to but lower than wildtype animals in small intestine, and greater than wildtype mice in colon. However, a species difference existed in the in situ transport kinetics of jejunal PEPT1, in which the maximal flux and Michaelis constant of GlySar were reduced 7-fold and 2- to 4-fold, respectively, in huPEPT1 compared to wildtype mice. Still, the in vivo function of intestinal PEPT1 appeared fully restored (compared to Pept1 knockout mice) as indicated by the nearly identical pharmacokinetics and plasma concentration–time profiles following a 5.0 nmol/g oral dose of GlySar to huPEPT1 and wildtype mice. This study reports, for the first time, the development and characterization of mice humanized for PEPT1. This novel transgenic huPEPT1 mouse model should prove useful in examining the role, relevance, and regulation of PEPT1 in diet and disease, and in the drug discovery process. PMID:25148225

  11. Development and characterization of a novel mouse line humanized for the intestinal peptide transporter PEPT1.

    PubMed

    Hu, Yongjun; Xie, Yehua; Wang, Yuqing; Chen, Xiaomei; Smith, David E

    2014-10-01

    The proton-coupled oligopeptide transporter PEPT1 (SLC15A1) is abundantly expressed in the small intestine, but not colon, of mammals and found to mediate the uptake of di/tripeptides and peptide-like drugs from the intestinal lumen. However, species differences have been observed in both the expression (and localization) of PEPT1 and its substrate affinity. With this in mind, the objectives of this study were to develop a humanized PEPT1 mouse model (huPEPT1) and to characterize hPEPT1 expression and functional activity in the intestines. Thus, after generating huPEPT1 mice in animals previously nulled for mouse Pept1, phenotypic, PCR, and immunoblot analyses were performed, along with in situ single-pass intestinal perfusion and in vivo oral pharmacokinetic studies with a model dipeptide, glycylsarcosine (GlySar). Overall, the huPEPT1 mice had normal survival rates, fertility, litter size, gender distribution, and body weight. There was no obvious behavioral or pathological phenotype. The mRNA and protein profiles indicated that huPEPT1 mice had substantial PEPT1 expression in all regions of the small intestine (i.e., duodenum, jejunum, and ileum) along with low but measurable expression in both proximal and distal segments of the colon. In agreement with PEPT1 expression, the in situ permeability of GlySar in huPEPT1 mice was similar to but lower than wildtype animals in small intestine, and greater than wildtype mice in colon. However, a species difference existed in the in situ transport kinetics of jejunal PEPT1, in which the maximal flux and Michaelis constant of GlySar were reduced 7-fold and 2- to 4-fold, respectively, in huPEPT1 compared to wildtype mice. Still, the in vivo function of intestinal PEPT1 appeared fully restored (compared to Pept1 knockout mice) as indicated by the nearly identical pharmacokinetics and plasma concentration-time profiles following a 5.0 nmol/g oral dose of GlySar to huPEPT1 and wildtype mice. This study reports, for the first time, the development and characterization of mice humanized for PEPT1. This novel transgenic huPEPT1 mouse model should prove useful in examining the role, relevance, and regulation of PEPT1 in diet and disease, and in the drug discovery process. PMID:25148225

  12. Determining the Long-term Effect of Antibiotic Administration on the Human Normal Intestinal Microbiota Using Culture and Pyrosequencing Methods.

    PubMed

    Rashid, Mamun-Ur; Zaura, Egijia; Buijs, Mark J; Keijser, Bart J F; Crielaard, Wim; Nord, Carl Erik; Weintraub, Andrej

    2015-05-15

    The purpose of the study was to assess the effect of ciprofloxacin (500 mg twice daily for 10 days) or clindamycin (150 mg 4 times daily for 10 days) on the fecal microbiota of healthy humans for a period of 1 year as compared to placebo. Two different methods, culture and microbiome analysis, were used. Fecal samples were collected for analyses at 6 time-points. The interval needed for the normal microbiota to be normalized after ciprofloxacin or clindamycin treatment differed for various bacterial species. It took 1-12 months to normalize the human microbiota after antibiotic administration, with the most pronounced effect on day 11. Exposure to ciprofloxacin or clindamycin had a strong effect on the diversity of the microbiome, and changes in microbial composition were observed until the 12th month, with the most pronounced microbial shift at month 1. No Clostridium difficile colonization or C. difficile infections were reported. Based on the pyrosequencing results, it appears that clindamycin has more impact than ciprofloxacin on the intestinal microbiota. PMID:25922405

  13. Characterization of bacterial community shift in human Ulcerative Colitis patients revealed by Illumina based 16S rRNA gene amplicon sequencing

    PubMed Central

    2014-01-01

    Background The healthy human intestine is represented by the presence of bacterial communities predominantly belonging to obligate anaerobes; however disparity and dysanaerobiosis in intestinal microflora may lead to the progression of ulcerative colitis (UC). The foremost aim of this study is to consider and compare the gut microbiota composition in patients suffering from different stages of UC. Methods This study represents data from the biopsy samples of six individuals suffering from UC. The samples were collected by colonoscopy and were processed immediately for isolation of DNA. Mucosal microbiota was analyzed by means of 16S rRNA gene-based Illumina high throughput sequencing. Quantitative real-time PCR (qPCR) was performed to determine total bacterial abundances. Results Analysis of 23,927 OTUs demonstrated a significant reduction of bacterial diversity consistently from phylum to species level (p < 0.05) for individuals suffering from severe stage of UC. Significant increase in abundance of unusual aerobes and facultative anaerobes, including members from the phylum Proteobacteria (p- = 0.031) was also observed. A 10 fold increase in the total bacterial count was detected in patients suffering from severe inflammatory stage (2.98 +/-0.49 E + 09/ml) when compared with patients with moderate (1.03+/-0.29 E + 08/ml) and mild (1.76 +/-0.34 E + 08/ml) stages of inflammation. Conclusion The reduction of bacterial diversity with an increase in the total bacterial count indicates a shift of bacterial communities which signifies dysbiosis and dysanaerobiosis at the mucosal level for patients suffering from UC. PMID:25018784

  14. Rapid and accurate diagnosis of human intestinal spirochetosis by fluorescence in situ hybridization.

    PubMed

    Schmiedel, Dinah; Epple, Hans-Jörg; Loddenkemper, Christoph; Ignatius, Ralf; Wagner, Jutta; Hammer, Bettina; Petrich, Annett; Stein, Harald; Göbel, Ulf B; Schneider, Thomas; Moter, Annette

    2009-05-01

    Human intestinal spirochetosis (HIS) is associated with overgrowth of the large intestine by spirochetes of the genus Brachyspira. The microbiological diagnosis of HIS is hampered by the fastidious nature and slow growth of Brachyspira spp. In clinical practice, HIS is diagnosed histopathologically, and a significant portion of cases may be missed. Fluorescence in situ hybridization (FISH) is a molecular method that allows the visualization and identification of single bacteria within tissue sections. In this study, we analyzed intestinal biopsy samples from five patients with possible HIS. All specimens yielded positive results by histopathological techniques. PCR amplification and sequencing of the 16S rRNA gene were performed. Sequences of two isolates clustered in the group of Brachyspira aalborgi, whereas in three cases, the sequences were highly similar to that of Brachyspira pilosicoli. Three phylotypes showed mismatches at distinct nucleotide positions with Brachyspira sp. sequences published previously. In addition, culture for Brachyspira was successful in three cases. On the basis of these data, we designed and evaluated a Brachyspira genus-specific 16S rRNA-directed FISH probe that detects all of the Brachyspira spp. published to date. FISH of biopsy samples resulted in strong, unequivocal signals of brush-like formations at the crypt surfaces. This technique allowed simultaneous visualization of single spirochetes and their identification as Brachyspira spp. In conclusion, FISH provides a fast and accurate technique for the visualization and identification of intestinal spirochetes in tissue sections. It therefore represents a valuable tool for routine diagnosis of HIS. PMID:19279178

  15. Rapid and Accurate Diagnosis of Human Intestinal Spirochetosis by Fluorescence In Situ Hybridization▿

    PubMed Central

    Schmiedel, Dinah; Epple, Hans-Jörg; Loddenkemper, Christoph; Ignatius, Ralf; Wagner, Jutta; Hammer, Bettina; Petrich, Annett; Stein, Harald; Göbel, Ulf B.; Schneider, Thomas; Moter, Annette

    2009-01-01

    Human intestinal spirochetosis (HIS) is associated with overgrowth of the large intestine by spirochetes of the genus Brachyspira. The microbiological diagnosis of HIS is hampered by the fastidious nature and slow growth of Brachyspira spp. In clinical practice, HIS is diagnosed histopathologically, and a significant portion of cases may be missed. Fluorescence in situ hybridization (FISH) is a molecular method that allows the visualization and identification of single bacteria within tissue sections. In this study, we analyzed intestinal biopsy samples from five patients with possible HIS. All specimens yielded positive results by histopathological techniques. PCR amplification and sequencing of the 16S rRNA gene were performed. Sequences of two isolates clustered in the group of Brachyspira aalborgi, whereas in three cases, the sequences were highly similar to that of Brachyspira pilosicoli. Three phylotypes showed mismatches at distinct nucleotide positions with Brachyspira sp. sequences published previously. In addition, culture for Brachyspira was successful in three cases. On the basis of these data, we designed and evaluated a Brachyspira genus-specific 16S rRNA-directed FISH probe that detects all of the Brachyspira spp. published to date. FISH of biopsy samples resulted in strong, unequivocal signals of brush-like formations at the crypt surfaces. This technique allowed simultaneous visualization of single spirochetes and their identification as Brachyspira spp. In conclusion, FISH provides a fast and accurate technique for the visualization and identification of intestinal spirochetes in tissue sections. It therefore represents a valuable tool for routine diagnosis of HIS. PMID:19279178

  16. Refining small intestinal bacterial overgrowth diagnosis by means of carbohydrate specificity: a proof-of-concept study

    PubMed Central

    Enko, Dietmar; Halwachs-Baumann, Gabriele; Stolba, Robert; Mangge, Harald; Kriegshäuser, Gernot

    2015-01-01

    Background: Diagnosis of small intestinal bacterial overgrowth (SIBO) remains challenging. This study aimed at proving the diagnostic concept of carbohydrate-specific SIBO (cs-SIBO) using glucose, fructose and sorbitol hydrogen (H2)/methane (CH4) breath testing (HMBT). Methods: In this study 125 patients referred to our outpatient clinic for SIBO testing were included. All individuals underwent glucose (50 g), fructose (25 g) and sorbitol (12.5 g) HMBT at 3 consecutive days. Patients with cs-SIBO (i.e. early H2/CH4 peak) were given rifaximin (600 mg/day) in a 10-day treatment. HMBT results were reassessed in a subset of patients 3–6 months after antibiotic therapy. In view of cs-SIBO diagnosis, agreements between HMBT results obtained for different sugars were calculated using Cohen’s kappa (κ) with 95% confidence intervals (CIs). Results: A total of 59 (47.2%) patients presented an early H2/CH4 peak with one or more sugars. Among these, 21 (16.8%), 10 (8.0%) and 7 (5.6%) individuals had a positive HMBT result with either glucose, fructose or sorbitol, respectively. Another 21 (16.8%) patients with a positive glucose HMBT result were also found positive with an early H2/CH4 peak obtained after ingestion of fructose and/or sorbitol. Fair agreement was observed between glucose and fructose (κ = 0.26, p = 0.0018) and between glucose and sorbitol (κ = 0.18, p = 0.0178) HMBT results. Slight agreement was observed between fructose and sorbitol (κ = 0.03, p = 0.6955) HMBT results only. Successful antibiotic therapy with rifaximin could be demonstrated in 26/30 (86.7%) of patients as indicated by normal HMBT results and symptom remission. Conclusions: Combined glucose, fructose and sorbitol HMBT has the potential to optimize cs-SIBO diagnosis. Furthermore, the majority of patients with cs-SIBO seem to benefit from rifaximin therapy regardless of its carbohydrate specificity.

  17. Human amniotic membrane as an intestinal patch for neomucosal growth in the rabbit model.

    PubMed

    Barlas, M; Gökçora, H; Erekul, S; Dindar, H; Yücesan, S

    1992-05-01

    This experiment was carried out as a preliminary study, an attempt to grow new intestinal mucosa on human amniotic membrane in the terminal ileum in 37 rabbits. After ketamin sulfate anesthesia at laparatomy, 5-cm ileal defects were patched with human amniotic membrane (5 x 2 cm). These patched intestines were investigated on the first postoperative day and the 2nd, 5th, 10th, and 20th weeks corresponding to 4, 5, 5, 10, and 10 rabbits, respectively. Only three rabbits died in the early postoperative period. There was no evidence of intestinal obstruction or dilatation with barium meal. Microscopically, the neomucosa consisted of a thin layer of columnar epithelial cells at 2 weeks with more maturity of the villi and less irregularity and branching by 20 weeks. All patches were covered with neomucosa commencing at 2 weeks and covering the whole patch area by 20 weeks. This technique's advantages are the large size and the ease of the availability of the human amniotic membrane for neonates at risk without jeopardizing the neonates tissues. It is hoped that this method might be considered when neonatal material is scarce. PMID:1625130

  18. Paneth cell granule depletion in the human small intestine under infective and nutritional stress.

    PubMed

    Kelly, P; Feakins, R; Domizio, P; Murphy, J; Bevins, C; Wilson, J; McPhail, G; Poulsom, R; Dhaliwal, W

    2004-02-01

    Paneth cells are important contributors to the intestinal antimicrobial barrier through synthesis and release of antimicrobial peptides and proteins. Animal studies indicate that Paneth cell numbers, location and granule morphology are altered by infection and zinc status. We examined human tissue to determine whether Paneth cell numbers, distribution or granule morphology are altered in infective, inflammatory and nutritional disorders. Archival sections from infective disorders (giardiasis, cryptosporidiosis, HIV, helminth infection) were compared with active inflammatory conditions (coeliac, Crohn's and graft-versus-host diseases) and histologically normal tissues. A subset of tissues was studied by electron microscopy and TUNEL staining for apoptosis. Human defensin-5 (HD5) peptide and mRNA was analysed by immunohistochemistry, in situ hybridization and quantitative reverse transcription polymerase chain reaction. Sections from a tropical population cohort study were then analysed to determine the relationship of granule depletion to infection, nutritional status and plasma zinc concentration. In HIV-related cryptosporidiosis, but not other disorders, Paneth cells were reduced in number and markedly depleted of granules. Paneth cell granule depletion was associated with reduced HD5 immunoreactivity, but this was not due to apoptosis and there was no reduction in mRNA transcripts. In the tropical population studied, depletion of granules was associated with reduced body mass index, reduced plasma zinc levels and HIV infection. Paneth cell granules in human small intestine may be depleted in response to infective and nutritional stress. We postulate that this is one mechanism through which zinc status influences host susceptibility to intestinal infection. PMID:14738460

  19. Safety assessment of genetically modified rice expressing human serum albumin from urine metabonomics and fecal bacterial profile.

    PubMed

    Qi, Xiaozhe; Chen, Siyuan; Sheng, Yao; Guo, Mingzhang; Liu, Yifei; He, Xiaoyun; Huang, Kunlun; Xu, Wentao

    2015-02-01

    The genetically modified (GM) rice expressing human serum albumin (HSA) is used for non-food purposes; however, its food safety assessment should be conducted due to the probability of accidental mixture with conventional food. In this research, Sprague Dawley rats were fed diets containing 50% (wt/wt) GM rice expressing HSA or non-GM rice for 90 days. Urine metabolites were detected by (1)H NMR to examine the changes of the metabolites in the dynamic process of metabolism. Fecal bacterial profiles were detected by denaturing gradient gel electrophoresis to reflect intestinal health. Additionally, short chain fatty acids and fecal enzymes were investigated. The results showed that compared with rats fed the non-GM rice, some significant differences were observed in rats fed with the GM rice; however, these changes were not significantly different from the control diet group. Additionally, the gut microbiota was associated with blood indexes and urine metabolites. In conclusion, the GM rice diet is as safe as the traditional daily diet. Furthermore, urine metabonomics and fecal bacterial profiles provide a non-invasive food safety assessment rat model for genetically modified crops that are used for non-food/feed purposes. Fecal bacterial profiles have the potential for predicting the change of blood indexes in future. PMID:25478734

  20. Safety assessment of genetically modified rice expressing human serum albumin from urine metabonomics and fecal bacterial profile.

    TOXLINE Toxicology Bibliographic Information

    Qi X; Chen S; Sheng Y; Guo M; Liu Y; He X; Huang K; Xu W

    2015-02-01

    The genetically modified (GM) rice expressing human serum albumin (HSA) is used for non-food purposes; however, its food safety assessment should be conducted due to the probability of accidental mixture with conventional food. In this research, Sprague Dawley rats were fed diets containing 50% (wt/wt) GM rice expressing HSA or non-GM rice for 90 days. Urine metabolites were detected by (1)H NMR to examine the changes of the metabolites in the dynamic process of metabolism. Fecal bacterial profiles were detected by denaturing gradient gel electrophoresis to reflect intestinal health. Additionally, short chain fatty acids and fecal enzymes were investigated. The results showed that compared with rats fed the non-GM rice, some significant differences were observed in rats fed with the GM rice; however, these changes were not significantly different from the control diet group. Additionally, the gut microbiota was associated with blood indexes and urine metabolites. In conclusion, the GM rice diet is as safe as the traditional daily diet. Furthermore, urine metabonomics and fecal bacterial profiles provide a non-invasive food safety assessment rat model for genetically modified crops that are used for non-food/feed purposes. Fecal bacterial profiles have the potential for predicting the change of blood indexes in future.

  1. Changes in bacterial glycolipids as an index of intestinal lactobacilli and epithelial glycolipids in the digestive tracts of mice after administration of penicillin and streptomycin.

    PubMed

    Iwamori, Masao; Iwamori, Yuriko; Adachi, Shigeki; Nomura, Taisei

    2013-12-01

    The major lipid constituent of symbiotic gram-positive bacteria in animals are phosphatidylglycerol, cardiolipin and dihexaosyl diglycerides (DH-DG), whose hydrophobic structures are characteristic of the environments, and the carbohydrate structures of DH-DGs are bacterial species-characteristic. Immunization of rabbits with intestinal lactobacilli generated antibodies against DH-DGs and their modified structures, among which Galα1-6-substituted DH-DG, i.e., Lactobacillus tetrahexaosyl diglyceride (LacTetH-DG), reacted with antibodies more intensely than DH-DG. Whereas, from the 16S-rRNA sequence, the intestinal lactobacilli in murine digestive tracts were revealed to be L. johnsonii, in which LacTetH-DG is present at the concentration of 2.2 ng per 1 × 10(6) cells. To obtain more accurate estimates of intestinal lactobacilli in several regions of the digestive tract of mice, LacTetH-DG was detected by TLC-immunostaining with anti-Lactobacillus antisera, being found in the stomach, cecum and colon of normal breeding mice, 1.0 × 10(9), 3.5 × 10(9) and 7.4 × 10(9) cells, respectively. Administration of penicillin and streptomycin for 6 days resulted in a reduction in the number of intestinal lactobacilli, the levels being 0 %, 30 % and 4 % of the control ones in the stomach, cecum and colon, respectively, which was associated with the accumulation of the contents in the tracts from the stomach to the cecum and with diarrhea. In addition, a reduced amount of fucosyl GA1 (FGA1) and a compensatory increase in GA1 due to the reduced activity of α1,2-fucosyltransferase in the small intestine and the enhanced discharge of FGA1 into the contents occurred in mice, probably due to the altered population of bacteria caused by administration of penicillin and streptomycin. PMID:23996013

  2. Anaerobic Metabolism of 1-Amino-2-Naphthol-Based Azo Dyes (Sudan Dyes) by Human Intestinal Microflora▿

    PubMed Central

    Xu, Haiyan; Heinze, Thomas M.; Chen, Siwei; Cerniglia, Carl E.; Chen, Huizhong

    2007-01-01

    The rates of metabolism of Sudan I and II and Para Red by human intestinal microflora were high compared to those of Sudan III and IV under anaerobic conditions. Metabolites of the dyes were identified as aniline, 2,4-dimethylaniline, o-toluidine, and 4-nitroaniline through high-performance liquid chromatography and liquid chromatography electrospray ionization tandem mass spectrometry analyses. These data indicate that human intestinal bacteria are able to reduce Sudan dyes to form potentially carcinogenic aromatic amines. PMID:17933925

  3. Loss of TMF/ARA160 Protein Renders Colonic Mucus Refractory to Bacterial Colonization and Diminishes Intestinal Susceptibility to Acute Colitis*

    PubMed Central

    Bel, Shai; Elkis, Yoav; Lerer-Goldstein, Tali; Nyska, Abraham; Shpungin, Sally; Nir, Uri

    2012-01-01

    TMF/ARA160 is a Golgi-associated protein with several cellular functions, among them direction of the NF-?B subunit, p65 RelA, to ubiquitination and proteasomal degradation in stressed cells. We sought to investigate the role of TMF/ARA160 under imposed stress conditions in vivo. TMF?/? and wild-type (WT) mice were treated with the ulcerative agent dextran sulfate sodium (DSS), and the severity of the inflicted acute colitis was determined. TMF?/? mice were found to be significantly less susceptible to DSS-induced colitis, with profoundly less bacterial penetration into the colonic epithelia. Surprisingly, unlike in WT mice, no bacterial colonies were visualized in colons of healthy untreated TMF?/? mice, indicating the constitutive resistance of TMF?/? colonic mucus to bacterial retention and penetration. Gene expression analysis of colon tissues from unchallenged TMF?/? mice revealed 5-fold elevated transcription of the muc2 gene, which encodes the major component of the colonic mucus gel, the MUC2 mucin. Accordingly, the morphology of the colonic mucus in TMF?/? mice was found to differ from the mucus structure in WT colons. The NF-?B subunit, p65, a well known transcription inducer of muc2, was up-regulated significantly in TMF?/? intestinal epithelial cells. However, this did not cause spontaneous inflammation or increased colonic crypt cell proliferation. Collectively, our findings demonstrate that absence of TMF/ARA160 renders the colonic mucus refractory to bacterial colonization and the large intestine less susceptible to the onset of colitis. PMID:22553199

  4. Bacterial protein AvrA stabilizes intestinal epithelial tight junctions via blockage of the C-Jun N-terminal kinase pathway.

    PubMed

    Zhang, Yongguo; Wu, Shaoping; Ma, Jun; Xia, Yinglin; Ai, Xun; Sun, Jun

    2015-01-01

    The Salmonella type III secretory system secretes virulence proteins, called effectors. Effectors are responsible for the alteration of tight junctions (TJ) and epithelial functions in intestinal infection and inflammation. In a previous study, we have demonstrated that a bacterial effector AvrA plays a role in stabilizing TJs and balancing the opposing action of other bacterial effectors. However, the molecular mechanisms by which AvrA-modulates TJ protein expression remain unknown. AvrA possesses acetyltransferase activity toward specific mitogen-activated protein kinase kinases (MAPKKs) and potently inhibits the c-Jun N-terminal kinase (JNK) pathway in inflammation. Inhibition of the JNK pathway is known to inhibit the TJ protein disassemble. Therefore, we hypothesize that AvrA stabilizes intestinal epithelial TJs via c-Jun and JNK pathway blockage. Using both in vitro and in vivo models, we showed that AvrA targets the c-Jun and JNK pathway that in turn stabilizes TJ protein ZO-1. Inhibition of JNK abolished the effect of AvrA on ZO-1. We further determined that AvrA suppressed the transcription factor activator protein-1, which was regulated by activated JNK. Moreover, we identified the functional domain of AvrA that directly regulated TJs using a series of AvrA mutants. The role of AvrA represents a highly refined bacterial strategy that helps the bacteria survive in the host and dampens the inflammatory response of the host. Our findings have uncovered a novel role of the bacterial protein AvrA in suppressing the inflammatory response of the host through JNK-regulated blockage of epithelial cell barrier function. PMID:25838979

  5. Activation of RegIII?/? and interferon ? expression in the intestinal tract of SCID mice: an innate response to bacterial colonisation of the gut

    PubMed Central

    Keilbaugh, S A; Shin, M E; Banchereau, R F; McVay, L D; Boyko, N; Artis, D; Cebra, J J; Wu, G D

    2005-01-01

    Background and aims: The mechanisms by which commensal bacteria provoke intestinal inflammation in animal models of inflammatory bowel disease (IBD) remain incompletely defined, leading to increasing interest in the innate immune response of the colonic mucosa to bacterial colonisation. Methods: Using gene expression profiling of colonic RNA from C.B17.SCID germ free mice and those colonised with altered Schaedlers flora, we investigated the innate immune response to bacterial colonisation in vivo. The two most consistently induced gene groups were RegIII? and ? as well as interferon ? (IFN-?) response genes. Results: Using quantitative reverse transcription-polymerase chain reaction, we showed that RegIII?, RegIII?, and IFN-? were constitutively expressed in the colon of conventionally housed SCID mice compared with either germ free SCID or conventionally housed BALB/c mice. Induction of these genes was reproduced by chronic monoassociation of germ free SCID mice with either of two separate gut commensal bacterial speciessegmented filamentous bacteria and Schaedlers Escherichia coli. The cellular source for IFN-? on monoassociation of SCID mice with Schaedlers E coli was localised to a subset of intraepithelial natural killer (IENK) cells that express asialo-GM1. In vivo IFN-? immunoneutralisation studies failed to demonstrate any alteration in RegIII? or ? expression. Conclusions: Thus bacterial colonisation of the colon independently activates two distinct innate immune cell types at the mucosal interface with the colonic lumen, intestinal epithelial cells, and IENK cells, a response that may be regulated by the adaptive immune system. These innate immune responses may play a role in the pathogenesis of colitis in SCID adoptive transfer models in mice and possibly in patients with IBD. PMID:15831905

  6. Bacterial protein AvrA stabilizes intestinal epithelial tight junctions via blockage of the C-Jun N-terminal kinase pathway

    PubMed Central

    Zhang, Yongguo; Wu, Shaoping; Ma, Jun; Xia, Yinglin; Ai, Xun; Sun, Jun

    2014-01-01

    The Salmonella type III secretory system secretes virulence proteins, called effectors. Effectors are responsible for the alteration of tight junctions (TJ) and epithelial functions in intestinal infection and inflammation. In a previous study, we have demonstrated that a bacterial effector AvrA plays a role in stabilizing TJs and balancing the opposing action of other bacterial effectors. However, the molecular mechanisms by which AvrA-modulates TJ protein expression remain unknown. AvrA possesses acetyltransferase activity toward specific mitogen-activated protein kinase kinases (MAPKKs) and potently inhibits the c-Jun N-terminal kinase (JNK) pathway in inflammation. Inhibition of the JNK pathway is known to inhibit the TJ protein disassemble. Therefore, we hypothesize that AvrA stabilizes intestinal epithelial TJs via c-Jun and JNK pathway blockage. Using both in vitro and in vivo models, we showed that AvrA targets the c-Jun and JNK pathway that in turn stabilizes TJ protein ZO-1. Inhibition of JNK abolished the effect of AvrA on ZO-1. We further determined that AvrA suppressed the transcription factor activator protein-1, which was regulated by activated JNK. Moreover, we identified the functional domain of AvrA that directly regulated TJs using a series of AvrA mutants. The role of AvrA represents a highly refined bacterial strategy that helps the bacteria survive in the host and dampens the inflammatory response of the host. Our findings have uncovered a novel role of the bacterial protein AvrA in suppressing the inflammatory response of the host through JNK-regulated blockage of epithelial cell barrier function. PMID:25838979

  7. Ricin Crosses Polarized Human Intestinal Cells and Intestines of Ricin-Gavaged Mice without Evident Damage and Then Disseminates to Mouse Kidneys

    PubMed Central

    Flora, Alyssa D.; Teel, Louise D.; Smith, Mark A.; Sinclair, James F.; Melton-Celsa, Angela R.; O’Brien, Alison D.

    2013-01-01

    Ricin is a potent toxin found in the beans of Ricinus communis and is often lethal for animals and humans when aerosolized or injected and causes significant morbidity and occasional death when ingested. Ricin has been proposed as a bioweapon because of its lethal properties, environmental stability, and accessibility. In oral intoxication, the process by which the toxin transits across intestinal mucosa is not completely understood. To address this question, we assessed the impact of ricin on the gastrointestinal tract and organs of mice after dissemination of toxin from the gut. We first showed that ricin adhered in a specific pattern to human small bowel intestinal sections, the site within the mouse gut in which a variable degree of damage has been reported by others. We then monitored the movement of ricin across polarized human HCT-8 intestinal monolayers grown in transwell inserts and in HCT-8 cell organoids. We observed that, in both systems, ricin trafficked through the cells without apparent damage until 24 hours post intoxication. We delivered a lethal dose of purified fluorescently-labeled ricin to mice by oral gavage and followed transit of the toxin from the gastrointestinal tracts to the internal organs by in vivo imaging of whole animals over time and ex vivo imaging of organs at various time points. In addition, we harvested organs from unlabeled ricin-gavaged mice and assessed them for the presence of ricin and for histological damage. Finally, we compared serum chemistry values from buffer-treated versus ricin-intoxicated animals. We conclude that ricin transverses human intestinal cells and mouse intestinal cells in situ prior to any indication of enterocyte damage and that ricin rapidly reaches the kidneys of intoxicated mice. We also propose that mice intoxicated orally with ricin likely die from distributive shock. PMID:23874986

  8. Azoreductase activity of anaerobic bacteria isolated from human intestinal microflora.

    PubMed Central

    Rafii, F; Franklin, W; Cerniglia, C E

    1990-01-01

    A plate assay was developed for the detection of anaerobic bacteria that produce azoreductases. With this plate assay, 10 strains of anaerobic bacteria capable of reducing azo dyes were isolated from human feces and identified as Eubacterium hadrum (2 strains), Eubacterium spp. (2 species), Clostridium clostridiiforme, a Butyrivibrio sp., a Bacteroides sp., Clostridium paraputrificum, Clostridium nexile, and a Clostridium sp. The average rate of reduction of Direct Blue 15 dye (a dimethoxybenzidine-based dye) in these strains ranged from 16 to 135 nmol of dye per min per mg of protein. The enzymes were inactivated by oxygen. In seven isolates, a flavin compound (riboflavin, flavin adenine dinucleotide, or flavin mononucleotide) was required for azoreductase activity. In the other three isolates and in Clostridium perfringens, no added flavin was required for activity. Nondenaturing polyacrylamide gel electrophoresis showed that each bacterium expressed only one azoreductase isozyme. At least three types of azoreductase enzyme were produced by the different isolates. All of the azoreductases were produced constitutively and released extracellularly. Images PMID:2202258

  9. Permeability of plumbagin across human intestinal cell in vitro.

    PubMed

    Sumsakul, Wiriyaporn; Na-Bangchang, Kesara

    2016-03-01

    Plumbagin is the active compound isolated from plants used in traditional medicine for treatment of various diseases such as activities malaria, leishmaniasis, viral infections and cancers. The aim of the study was to investigate the permeability of plumbagin across Caco-2 (human epithelial colorectal adenocarcinoma) cell monolayer and its effects on the expression and function of P-glycoprotein. The integrity of Caco-2 cell monolayer was evaluated by measuring trans-epithelial electrical resistance and permeation (Papp) of Lucifer yellow across the cell monolayer. The effect of plumbagin on P-glycoprotein was detected by measuring its interference with the transport of the P-glycoprotein substrate (R123) and the effect on MDR-1 mRNA expression was detected by RT-PCR. The Papp of plumbagin (2-8 µM) for the apical to basolateral and basolateral to apical directions were 10.29-15.96 × 10(-6) and 7.40-9.02 × 10(-6) cm/s, respectively, with the efflux ratios of 0.57-0.73. Plumbagin is not either a substrate or inhibitor of P-glycoprotein. It did not interfere with the P-glycoprotein-mediated R123 transport across Caco-2 cell monolayer, as well as the function of P-glycoprotein and the expression of MDR-1 mRNA. Results suggest moderate permeability of plumbagin across the Caco-2 cell monolayer in both directions. The transport mechanism is likely to be a passive transport. PMID:26620575

  10. Anthocyanin Absorption and Metabolism by Human Intestinal Caco-2 Cells—A Review

    PubMed Central

    Kamiloglu, Senem; Capanoglu, Esra; Grootaert, Charlotte; Van Camp, John

    2015-01-01

    Anthocyanins from different plant sources have been shown to possess health beneficial effects against a number of chronic diseases. To obtain any influence in a specific tissue or organ, these bioactive compounds must be bioavailable, i.e., effectively absorbed from the gut into the circulation and transferred to the appropriate location within the body while still maintaining their bioactivity. One of the key factors affecting the bioavailability of anthocyanins is their transport through the gut epithelium. The Caco-2 cell line, a human intestinal epithelial cell model derived from a colon carcinoma, has been proven to be a good alternative to animal studies for predicting intestinal absorption of anthocyanins. Studies investigating anthocyanin absorption by Caco-2 cells report very low absorption of these compounds. However, the bioavailability of anthocyanins may be underestimated since the metabolites formed in the course of digestion could be responsible for the health benefits associated with anthocyanins. In this review, we critically discuss recent findings reported on the anthocyanin absorption and metabolism by human intestinal Caco-2 cells. PMID:26370977

  11. Anthocyanin Absorption and Metabolism by Human Intestinal Caco-2 Cells--A Review.

    PubMed

    Kamiloglu, Senem; Capanoglu, Esra; Grootaert, Charlotte; Van Camp, John

    2015-01-01

    Anthocyanins from different plant sources have been shown to possess health beneficial effects against a number of chronic diseases. To obtain any influence in a specific tissue or organ, these bioactive compounds must be bioavailable, i.e., effectively absorbed from the gut into the circulation and transferred to the appropriate location within the body while still maintaining their bioactivity. One of the key factors affecting the bioavailability of anthocyanins is their transport through the gut epithelium. The Caco-2 cell line, a human intestinal epithelial cell model derived from a colon carcinoma, has been proven to be a good alternative to animal studies for predicting intestinal absorption of anthocyanins. Studies investigating anthocyanin absorption by Caco-2 cells report very low absorption of these compounds. However, the bioavailability of anthocyanins may be underestimated since the metabolites formed in the course of digestion could be responsible for the health benefits associated with anthocyanins. In this review, we critically discuss recent findings reported on the anthocyanin absorption and metabolism by human intestinal Caco-2 cells. PMID:26370977

  12. The IL-33/ST2 pathway contributes to intestinal tumorigenesis in humans and mice

    PubMed Central

    Mertz, Kirsten D.; Mager, Lukas F.; Wasmer, Marie-Hlne; Thiesler, Thore; Koelzer, Viktor H.; Ruzzante, Giulia; Joller, Stefanie; Murdoch, Jenna R.; Brmmendorf, Thomas; Genitsch, Vera; Lugli, Alessandro; Cathomas, Gieri; Moch, Holger; Weber, Achim; Zlobec, Inti; Junt, Tobias; Krebs, Philippe

    2016-01-01

    ABSTRACT Colorectal cancer (CRC) develops through a multistep process and is modulated by inflammation. However, the inflammatory pathways that support intestinal tumors at different stages remain incompletely understood. Interleukin (IL)-33 signaling plays a role in intestinal inflammation, yet its contribution to the pathogenesis of CRC is unknown. Using immunohistochemistry on 713 resected human CRC specimens, we show here that IL-33 and its receptor ST2 are expressed in low-grade and early-stage human CRCs, and to a lesser extent in higher-grade and more advanced-stage tumors. In a mouse model of CRC, ST2-deficiency protects from tumor development. Moreover, bone marrow (BM) chimera studies indicate that engagement of the IL-33/ST2 pathway on both the radio-resistant and radio-sensitive compartment is essential for CRC development. Mechanistically, activation of IL-33/ST2 signaling compromises the integrity of the intestinal barrier and triggers the production of pro-tumorigenic IL-6 by immune cells. Together, this data reveals a tumor-promoting role of IL-33/ST2 signaling in CRC.

  13. Subversion of human intestinal mucosa innate immunity by a Crohn's disease-associated E. coli.

    PubMed

    Jarry, A; Crémet, L; Caroff, N; Bou-Hanna, C; Mussini, J M; Reynaud, A; Servin, A L; Mosnier, J F; Liévin-Le Moal, V; Laboisse, C L

    2015-05-01

    Adherent-invasive Escherichia coli (AIEC), associated with Crohn's disease, are likely candidate contributory factors in the disease. However, signaling pathways involved in human intestinal mucosa innate host response to AIEC remain unknown. Here we use a 3D model of human intestinal mucosa explant culture to explore the effects of the AIEC strain LF82 on two innate immunity platforms, i.e., the inflammasome through evaluation of caspase-1 status, and NFκB signaling. We showed that LF82 bacteria enter and survive within a few intestinal epithelial cells and macrophages, without altering the mucosa overall architecture. Although 4-h infection with a Salmonella strain caused crypt disorganization, caspase-1 activation, and mature IL-18 production, LF82 bacteria were unable to activate caspase-1 and induce IL-18 production. In parallel, LF82 bacteria activated NFκB signaling in epithelial cells through IκBα phosphorylation, NFκBp65 nuclear translocation, and TNFα secretion. In addition, NFκB activation was crucial for the maintenance of epithelial homeostasis upon LF82 infection. In conclusion, here we decipher at the whole-mucosa level the mechanisms of the LF82-induced subversion of innate immunity that, by maintaining host cell integrity, ensure intracellular bacteria survival. PMID:25269707

  14. Structural features of resistant starch at the end of the human small intestine.

    PubMed

    Faisant, N; Champ, M; Colonna, P; Buleon, A; Molis, C; Langkilde, A M; Schweizer, T; Flourie, B; Galmiche, J P

    1993-04-01

    Structural features of in vivo resistant starch were assessed using the ileal contents of four humans. Two of the latter were collected by ileostomy after ingestion of bean flakes or potato flakes and the other two were collected by an intubation technique after ingestion of retrograded high-amylose maize starch or complexed high-amylose maize starch. The degree of polymerizations (DP), solubility and crystallinity were assessed. For all samples, starch fractions which escaped digestion in the small intestine were composed of three populations of alpha-glucans with proportions differing according to the substrate. Small quantities of oligosaccharides made up the first population, illustrating a limitation of absorption in the small intestine. The second population, the main resistant fraction, was comprised of retrograded amylose of mean DPn of about 35 glucose units with a melting temperature at 150 degrees C and exhibiting a B-type pattern. Finally high molecular weight semi-crystalline alpha-glucans were attributed to fragments of starch. This study showed that some potentially digestible starch could reach the colon and crystalline fractions constituted only part of the starch that escaped digestion in the human small intestine. PMID:8491166

  15. Insulin Acutely Inhibits Intestinal Lipoprotein Secretion in Humans in Part by Suppressing Plasma Free Fatty Acids

    PubMed Central

    Pavlic, Mirjana; Xiao, Changting; Szeto, Linda; Patterson, Bruce W.; Lewis, Gary F.

    2010-01-01

    OBJECTIVE Intestinal lipoprotein production has recently been shown to be increased in insulin resistance, but it is not known whether it is regulated by insulin in humans. Here, we investigated the effect of acute hyperinsulinemia on intestinal (and hepatic) lipoprotein production in six healthy men in the presence and absence of concomitant suppression of plasma free fatty acids (FFAs). RESEARCH DESIGN AND METHODS Each subject underwent the following three lipoprotein turnover studies, in random order, 46 weeks apart: 1) insulin and glucose infusion (euglycemic-hyperinsulinemic clamp) to induce hyperinsulinemia, 2) insulin and glucose infusion plus Intralipid and heparin infusion to prevent the insulin-induced suppression of plasma FFAs, and 3) saline control. RESULTS VLDL1 and VLDL2-apoB48 and -apoB100 production rates were suppressed by 4762% by insulin, with no change in clearance. When the decline in FFAs was prevented by concomitant infusion of Intralipid and heparin, the production rates of VLDL1 and VLDL2-apoB48 and -apoB100 were intermediate between insulin and glucose infusion and saline control. CONCLUSIONS This is the first demonstration in humans that intestinal apoB48-containing lipoprotein production is acutely suppressed by insulin, which may involve insulin's direct effects and insulin-mediated suppression of circulating FFAs. PMID:20028946

  16. Interleukin 10 receptor signaling: master regulator of intestinal mucosal homeostasis in mice and humans.

    PubMed

    Shouval, Dror S; Ouahed, Jodie; Biswas, Amlan; Goettel, Jeremy A; Horwitz, Bruce H; Klein, Christoph; Muise, Aleixo M; Snapper, Scott B

    2014-01-01

    Interleukin 10 (IL10) is a key anti-inflammatory cytokine that can inhibit proinflammatory responses of both innate and adaptive immune cells. An association between IL10 and intestinal mucosal homeostasis became clear with the discovery that IL10 and IL10 receptor (IL10R)-deficient mice develop spontaneous intestinal inflammation. Similarly, patients with deleterious mutations in IL10, IL10RA, or IL10RB present with severe enterocolitis within the first months of life. Here, we review recent findings on how IL10- and IL10R-dependent signaling modulates innate and adaptive immune responses in the murine gastrointestinal tract, with implications of their role in the prevention of inflammatory bowel disease (IBD). In addition, we discuss the impact of IL10 and IL10R signaling defects in humans and their relationship to very early-onset IBD (VEO-IBD). PMID:24507158

  17. Interleukin 10 Receptor Signaling: Master Regulator of Intestinal Mucosal Homeostasis in Mice and Humans

    PubMed Central

    Shouval, Dror S.; Ouahed, Jodie; Biswas, Amlan; Goettel, Jeremy A.; Horwitz, Bruce H.; Klein, Christoph; Muise, Aleixo M.; Snapper, Scott B.

    2016-01-01

    Interleukin 10 (IL10) is a key anti-inflammatory cytokine that can inhibit proinflammatory responses of both innate and adaptive immune cells. An association between IL10 and intestinal mucosal homeostasis became clear with the discovery that IL10 and IL10 receptor (IL10R)-deficient mice develop spontaneous intestinal inflammation. Similarly, patients with deleterious mutations in IL10, IL10RA, or IL10RB present with severe enterocolitis within the first months of life. Here, we review recent findings on how IL10- and IL10R-dependent signaling modulates innate and adaptive immune responses in the murine gastrointestinal tract, with implications of their role in the prevention of inflammatory bowel disease (IBD). In addition, we discuss the impact of IL10 and IL10R signaling defects in humans and their relationship to very early-onset IBD (VEO-IBD). PMID:24507158

  18. Vasoactive Intestinal Peptide Inhibits Human Small-Cell Lung Cancer Proliferation in vitro and in vivo

    NASA Astrophysics Data System (ADS)

    Maruno, Kaname; Absood, Afaf; Said, Sami I.

    1998-11-01

    Small-cell lung carcinoma (SCLC) is an aggressive, rapidly growing and metastasizing, and highly fatal neoplasm. We report that vasoactive intestinal peptide inhibits the proliferation of SCLC cells in culture and dramatically suppresses the growth of SCLC tumor-cell implants in athymic nude mice. In both cases, the inhibition was mediated apparently by a cAMP-dependent mechanism, because the inhibition was enhanced by the adenylate cyclase activator forskolin and the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine in proportion to increases in intracellular cAMP levels, and the inhibition was abolished by selective inhibition of cAMP-dependent protein kinase. If confirmed in clinical trials, this antiproliferative action of vasoactive intestinal peptide may offer a new and promising means of suppressing SCLC in human subjects, without the toxic side effects of chemotherapeutic agents.

  19. Interaction of Macrolide Antibiotics with Intestinally Expressed Human and Rat Organic Anion-Transporting Polypeptides

    PubMed Central

    Lan, Tian; Rao, Anuradha; Haywood, Jamie; Davis, Charles B.; Han, Chao; Garver, Eric

    2009-01-01

    The macrolide antibiotics azithromycin and clarithromycin are large molecular weight compounds that exhibit moderate to excellent oral bioavailability in preclinical species and humans. Previous concomitant dosing studies in rats using rifamycin SV, a general organic anion-transporting polypeptide (OATP) inhibitor, suggested that the high oral absorption of azithromycin and clarithromycin may be caused by facilitative uptake by intestinal Oatps. In this study, we used OATP/Oatp-expressing cells to investigate the interaction of macrolides with rat Oatp1a5, human OATP1A2, and human/rat OATP2B1/Oatp2b1. These experiments showed that azithromycin and clarithromycin were potent inhibitors of rat Oatp1a5-mediated taurocholate uptake with apparent inhibitor constant (Ki) values of 3.3 and 2.4 μM, respectively. The macrolides functioned as noncompetitive inhibitors but were not transport substrates for rat Oatp1a5, as assessed by direct uptake measurements of radiolabeled azithromycin and clarithromycin. cis-Inhibition and direct uptake studies further showed that azithromycin and clarithromycin were only very weak inhibitors and not substrates for human OATP1A2 and human/rat OATP2B1/Oatp2b1. In summary, these results indicate that the macrolides azithromycin and clarithromycin potently inhibit rat Oatp1a5 but do not significantly interact with OATP1A2 and OATP2B1/Oatp2b1. These intestinally expressed OATP/Oatp(s) are not responsible for the postulated facilitative uptake of azithromycin and clarithromycin, and alternative facilitative pathways must exist for their intestinal absorption. PMID:19741038

  20. Autochthonous Intestinal Bacterial Flora and Cholesterol Levels in Specific Pathogen-free Swine Fed High-Lipid and High-Sucrose Diets

    PubMed Central

    Graber, C. D.; Moore, R. W.; Suzuki, M.; Redmond, W. E.; O'Neal, R. M.; Lockhart, B. M.

    1966-01-01

    Graber, C. D. (Baylor University College of Medicine, Houston, Tex.). R. W. Moore, M. Suzuki, W. E. Redmond, R. M. O'Neal, and B. M. Lockhart. Autochthonous intestinal bacterial flora and cholesterol levels in specific pathogen-free swine fed high-lipid and high-sucrose diets. J. Bacteriol. 92:1290–1297. 1966.—Thirty-two specific pathogen-free (SPF) and conventional swine fed high fat, high sugar, and a standard ration were cultured for intestinal flora, and their blood cholesterol levels were measured. The diets, whether sterilized or not sterilized, fed ad libitum or restricted, did not alter bacterial flora greatly or influence blood cholesterol levels. Anaerobes outnumbered aerobes by several logs. Four autochthonous bacteria, lactobacilli, Escherichia coli, enterococci, and gram-variable, nonspore-forming anaerobes (GVNSA; a type of bacteroides), were shown to be constantly present in all animals regardless of dietary conditions. From the duodenum and jejunum of 14 pigs, GVNSA and Bacteroides nigrescens were cultured in rather large numbers, a finding not previously reported in swine or in most other mammals. This finding may have special significance in reference to bile acid and cholesterol metabolism. PMID:5332699

  1. Bidirectional FcRn-dependent IgG transport in a polarized human intestinal epithelial cell line

    PubMed Central

    Dickinson, Bonny L.; Badizadegan, Kamran; Wu, Zhen; Ahouse, Jeremy C.; Zhu, Xiaoping; Simister, Neil E.; Blumberg, Richard S.; Lencer, Wayne I.

    1999-01-01

    The MHC class I–related Fc receptor, FcRn, mediates the intestinal absorption of maternal IgG in neonatal rodents and the transplacental transport of maternal IgG in humans by receptor-mediated transcytosis. In mice and rats, expression of FcRn in intestinal epithelial cells is limited to the suckling period. We have recently observed, however, clear expression of FcRn in the adult human intestine, suggesting a function for FcRn in intestinal IgG transport beyond neonatal life in humans. We tested this hypothesis using the polarized human intestinal T84 cell line as a model epithelium. Immunocytochemical data show that FcRn is present in T84 cells in a punctate apical pattern similar to that found in human small intestinal enterocytes. Solute flux studies show that FcRn transports IgG across T84 monolayers by receptor-mediated transcytosis. Transport is bidirectional, specific for FcRn, and dependent upon endosomal acidification. These data define a novel bidirectional mechanism of IgG transport across epithelial barriers that predicts an important effect of FcRn on IgG function in immune surveillance and host defense at mucosal surfaces. PMID:10510331

  2. Immunomodulatory Properties of Streptococcus and Veillonella Isolates from the Human Small Intestine Microbiota

    PubMed Central

    Zoetendal, Erwin G.; Wells, Jerry M.; Kleerebezem, Michiel

    2014-01-01

    The human small intestine is a key site for interactions between the intestinal microbiota and the mucosal immune system. Here we investigated the immunomodulatory properties of representative species of commonly dominant small-intestinal microbial communities, including six streptococcal strains (four Streptococcus salivarius, one S. equinus, one S. parasanguinis) one Veillonella parvula strain, one Enterococcus gallinarum strain, and Lactobacillus plantarum WCFS1 as a bench mark strain on human monocyte-derived dendritic cells. The different streptococci induced varying levels of the cytokines IL-8, TNF-α, and IL-12p70, while the V. parvula strain showed a strong capacity to induce IL-6. E. gallinarum strain was a potent inducer of cytokines and TLR2/6 signalling. As Streptococcus and Veillonella can potentially interact metabolically and frequently co-occur in ecosystems, immunomodulation by pair-wise combinations of strains were also tested for their combined immunomodulatory properties. Strain combinations induced cytokine responses in dendritic cells that differed from what might be expected on the basis of the results obtained with the individual strains. A combination of (some) streptococci with Veillonella appeared to negate IL-12p70 production, while augmenting IL-8, IL-6, IL-10, and TNF-α responses. This suggests that immunomodulation data obtained in vitro with individual strains are unlikely to adequately represent immune responses to mixtures of gut microbiota communities in vivo. Nevertheless, analysing the immune responses of strains representing the dominant species in the intestine may help to identify immunomodulatory mechanisms that influence immune homeostasis. PMID:25479553

  3. Ganglioside composition of differentiated Caco-2 cells resembles human colostrum and neonatal rat intestine.

    PubMed

    Schnabl, Kareena L; Field, Catherine; Clandinin, M T

    2009-03-01

    Gangliosides are glycosphingolipids found in cell membranes and human milk with important roles in cell proliferation, differentiation, growth, adhesion, migration, signalling and apoptosis. Similar changes in ganglioside composition occur during embryonic development, lactation and cancer cell differentiation. It is not known, however, whether ganglioside compositional changes that occur in differentiating colon cancer cells reflect changes that occur during intestinal development. The Caco-2 cell line is commonly used to study physiological and pathophysiological processes in the small intestine and colon. Therefore, to examine this question, undifferentiated and differentiated Caco-2 cells were grown and total lipid was extracted from cell supernatant fractions using the Folch method. The upper aqueous phase containing gangliosides was collected and purified. Total gangliosides were measured as ganglioside-bound N-acetyl neuraminic acid, while individual ganglioside content was quantified via a colorimetric assay for sialic acid and scanning densitometry. The total ganglioside content of differentiated Caco-2 cells was 2.5 times higher compared with undifferentiated cells. Differentiated Caco-2 cells had significantly more (N-acetylneuraminyl) 2-galactosylglucosyl ceramide (GD3) and polar gangliosides, and a lower N-acetylneuraminylgalactosylglucosylceramide (GM3):GD3 ratio than undifferentiated cells. The present study demonstrates that the total ganglioside content and individual ganglioside composition of differentiated Caco-2 cells are similar to those of human colostrum and neonatal rat intestine. Differentiated Caco-2 cells may therefore be an alternative model for studying physiological and pathological processes in the small intestine and colon, and may help to elucidate possible functions for specific gangliosides in development and differentiation. Further research using more sensitive techniques of ganglioside analysis is needed to confirm these findings. PMID:18713482

  4. Resident bacterial flora and immune system.

    PubMed

    Biancone, L; Monteleone, I; Del Vecchio Blanco, G; Vavassori, P; Pallone, F

    2002-09-01

    The "controlled inflammation" of the normal human gut is a closely controlled phenomenon and any change in the cell type number and/or functions, including the release of soluble mediators can lead to an "uncontrolled" inflammation. The physiological inflammation in the human gut plays a crucial role in maintaining a local immune response that is appropriate, efficiently protective and which respects the gut structure and function. The intestinal mucosa represents a considerable proportion of the human immune system. Disregulation of the mucosal immune response can switch a "controlled" toward an "uncontrolled" intestinal inflammation. A key role in the maintenance of an adequate balance between antigenic stimulation and host immune response is played by the immunoregulatory molecules released by activated immunocytes in the human gut. The role of the host immune system in the maintenance of an adequate balance between luminal antigens, including the resident bacterial flora and host immune response, is strongly supported by animal models of uncontrolled intestinal inflammation. Besides the aetiology of inflammatory bowel disease, luminal antigens (including food, viral and bacterial antigens) contribute to the maintenance of the inflammatory process in inflammatory bowel disease, by stimulating the immunocompetent cells in the intestinal mucosa. Of the luminal antigens, the resident bacterial flora seems to play a major role in the development of animal models of "uncontrolled" intestinal inflammation. Recent evidence also suggest that bacterial flora can modulate the function of the intestinal mucosal cells. These observations support the role of the intestinal bacterial flora in the induction of an uncontrolled inflammation in the human gut, leading to tissue damage. Probiotics, defined as living micro-organisms which, when taken in appropriate amounts, improve the health status, have been proposed in the treatment of inflammatory bowel disease, but their mechanisms of action still remain to be fully elucidated. PMID:12408438

  5. Intestinal Commitment and Maturation of Human Pluripotent Stem Cells Is Independent of Exogenous FGF4 and R-spondin1.

    PubMed

    Tamminen, Kaisa; Balboa, Diego; Toivonen, Sanna; Pakarinen, Mikko P; Wiener, Zoltan; Alitalo, Kari; Otonkoski, Timo

    2015-01-01

    Wnt/beta-catenin signaling plays a central role in guiding the differentiation of the posterior parts of the primitive gut tube into intestinal structures in vivo and some studies suggest that FGF4 is another crucial factor for intestinal development. The aim of this study was to define the effects of Wnt and FGF4 on intestinal commitment in vitro by establishing conditions for differentiation of human pluripotent stem cells (hPSC) into posterior endoderm (hindgut) and further to self-renewing intestinal-like organoids. The most prominent induction of the well-established intestinal marker gene CDX2 was achieved when hPSC-derived definitive endoderm cells were treated with Wnt agonist molecule CHIR99021 during differentiation to hindgut. FGF4 was found to be dispensable during intestinal commitment, but it had an early role in repressing development towards the hepatic lineage. When hindgut stage cells were further cultured in 3D, they formed self-renewing organoid structures containing all major intestinal cell types even without exogenous R-spondin1 (RSPO1), a crucial factor for the culture of epithelial organoids derived from adult intestine. This may be explained by the presence of a mesenchymal compartment in the hPSC-derived organoids. Addition of WNT3A increased the expression of the Paneth cell marker Lysozyme in hPSC-derived organoid cultures, whereas FGF4 inhibited both the formation and maturation of intestinal-like organoids. Similar hindgut and organoid cultures were established from human induced pluripotent stem cells, implying that this approach can be used to create patient-specific intestinal tissue models for disease modeling in vitro. PMID:26230325

  6. Intestinal Commitment and Maturation of Human Pluripotent Stem Cells Is Independent of Exogenous FGF4 and R-spondin1

    PubMed Central

    Tamminen, Kaisa; Balboa, Diego; Toivonen, Sanna; Pakarinen, Mikko P.; Wiener, Zoltan; Alitalo, Kari; Otonkoski, Timo

    2015-01-01

    Wnt/beta-catenin signaling plays a central role in guiding the differentiation of the posterior parts of the primitive gut tube into intestinal structures in vivo and some studies suggest that FGF4 is another crucial factor for intestinal development. The aim of this study was to define the effects of Wnt and FGF4 on intestinal commitment in vitro by establishing conditions for differentiation of human pluripotent stem cells (hPSC) into posterior endoderm (hindgut) and further to self-renewing intestinal-like organoids. The most prominent induction of the well-established intestinal marker gene CDX2 was achieved when hPSC-derived definitive endoderm cells were treated with Wnt agonist molecule CHIR99021 during differentiation to hindgut. FGF4 was found to be dispensable during intestinal commitment, but it had an early role in repressing development towards the hepatic lineage. When hindgut stage cells were further cultured in 3D, they formed self-renewing organoid structures containing all major intestinal cell types even without exogenous R-spondin1 (RSPO1), a crucial factor for the culture of epithelial organoids derived from adult intestine. This may be explained by the presence of a mesenchymal compartment in the hPSC-derived organoids. Addition of WNT3A increased the expression of the Paneth cell marker Lysozyme in hPSC-derived organoid cultures, whereas FGF4 inhibited both the formation and maturation of intestinal-like organoids. Similar hindgut and organoid cultures were established from human induced pluripotent stem cells, implying that this approach can be used to create patient-specific intestinal tissue models for disease modeling in vitro. PMID:26230325

  7. Intestinal concentrations of free and encapsulated dietary medium-chain fatty acids and effects on gastric microbial ecology and bacterial metabolic products in the digestive tract of piglets.

    PubMed

    Zentek, Jürgen; Buchheit-Renko, Susanne; Männer, Klaus; Pieper, Robert; Vahjen, Wilfried

    2012-02-01

    The influence of low dietary levels of free and encapsulated medium-chain fatty acids on their concentrations in the digesta, the gastric microbial ecology and bacterial metabolic products in the gastrointestinal tract (GIT) in weaned piglets was studied. Starting after weaning, 36 piglets were fed a diet without (Control) or with medium-chain fatty acids uncoated (MCFA) or coated with vegetable fat and lecithin (MCFAc). After 4 weeks, the animals were killed, and digesta from the stomach and different sections of the GIT were collected. The concentrations of caprylic (p < 0.001) and capric (p = 0.001) acids were higher in the stomachs of piglets fed diets MCFA and MCFAc compared to the Control group. The concentrations dropped rapidly along the GIT, regardless of encapsulation, and tended to be higher in groups MCFA and MCFAc compared to the Control. Compared to the Control group, ingestion of diet MCFAc led to an increase in the number of eubacteria (p = 0.001), enterobacteriaceae (p < 0.001), clostridial clusters I (p = 0.001) and IV (p = 0.019), Lactobacillus johnsonii (p < 0.001) and Lactobacillus amylovorus (p = 0.001) in gastric contents. A similar trend was seen with diet MCFA. Relative concentrations of short-chain fatty acids were characterised by lower propionic acid levels (p = 0.045), numerically (p < 0.1) higher acetic, lower n-butyric and i-valeric acid concentrations in the small intestine. Lactic acid concentrations were not significantly changed in the GIT, but ammonia concentrations increased (p < 0.001) in the distal small intestine in the MCFA and MCFAc groups. In conclusion, medium-chain fatty acids affected microbial ecology parameters in the gastric contents and bacterial metabolites in the small intestine. At low dietary levels, medium-chain fatty acids may be regarded as modulators of the gastric microbiota in weaned piglets. PMID:22397093

  8. Natural Pig Plasma Immunoglobulins Have Anti-Bacterial Effects: Potential for Use as Feed Supplement for Treatment of Intestinal Infections in Pigs.

    PubMed

    Hedegaard, Chris J; Strube, Mikael L; Hansen, Marie B; Lindved, Bodil K; Lihme, Allan; Boye, Mette; Heegaard, Peter M H

    2016-01-01

    There is an increasing demand for non-antibiotics solutions to control infectious disease in intensive pig production. Here, one such alternative, namely pig antibodies purified from slaughterhouse blood was investigated in order to elucidate its potential usability to control post-weaning diarrhoea (PWD), which is one of the top indications for antibiotics usage in the pig production. A very cost-efficient and rapid one-step expanded bed adsorption (EBA) chromatography procedure was used to purify pig immunoglobulin G from slaughterhouse pig plasma (more than 100 litres), resulting in >85% pure pig IgG (ppIgG). The ppIgG thus comprised natural pig immunoglobulins and was subsequently shown to contain activity towards four pig-relevant bacterial strains (three different types of Escherichia coli and one type of Salmonella enterica) but not towards a fish pathogen (Yersinia ruckeri), and was demonstrated to inhibit the binding of the four pig relevant bacteria to a pig intestinal cell line (IPEC-J2). Finally it was demonstrated in an in vivo weaning piglet model for intestinal colonization with an E. coli F4+ challenge strain that ppIgG given in the feed significantly reduced shedding of the challenge strain, reduced the proportion of the bacterial family Enterobacteriaceae, increased the proportion of families Enterococcoceae and Streptococcaceae and generally increased ileal microbiota diversity. Conclusively, our data support the idea that natural IgG directly purified from pig plasma and given as a feed supplement can be used in modern swine production as an efficient and cost-effective means for reducing both occurrence of PWD and antibiotics usage and with a potential for the prevention and treatment of other intestinal infectious diseases even if the causative agent might not be known. PMID:26824607

  9. Natural Pig Plasma Immunoglobulins Have Anti-Bacterial Effects: Potential for Use as Feed Supplement for Treatment of Intestinal Infections in Pigs

    PubMed Central

    Hedegaard, Chris J.; Strube, Mikael L.; Hansen, Marie B.; Lindved, Bodil K.; Lihme, Allan; Boye, Mette; Heegaard, Peter M. H.

    2016-01-01

    There is an increasing demand for non-antibiotics solutions to control infectious disease in intensive pig production. Here, one such alternative, namely pig antibodies purified from slaughterhouse blood was investigated in order to elucidate its potential usability to control post-weaning diarrhoea (PWD), which is one of the top indications for antibiotics usage in the pig production. A very cost-efficient and rapid one-step expanded bed adsorption (EBA) chromatography procedure was used to purify pig immunoglobulin G from slaughterhouse pig plasma (more than 100 litres), resulting in >85% pure pig IgG (ppIgG). The ppIgG thus comprised natural pig immunoglobulins and was subsequently shown to contain activity towards four pig-relevant bacterial strains (three different types of Escherichia coli and one type of Salmonella enterica) but not towards a fish pathogen (Yersinia ruckeri), and was demonstrated to inhibit the binding of the four pig relevant bacteria to a pig intestinal cell line (IPEC-J2). Finally it was demonstrated in an in vivo weaning piglet model for intestinal colonization with an E. coli F4+ challenge strain that ppIgG given in the feed significantly reduced shedding of the challenge strain, reduced the proportion of the bacterial family Enterobacteriaceae, increased the proportion of families Enterococcoceae and Streptococcaceae and generally increased ileal microbiota diversity. Conclusively, our data support the idea that natural IgG directly purified from pig plasma and given as a feed supplement can be used in modern swine production as an efficient and cost-effective means for reducing both occurrence of PWD and antibiotics usage and with a potential for the prevention and treatment of other intestinal infectious diseases even if the causative agent might not be known. PMID:26824607

  10. Alpinia katsumadai Extracts Inhibit Adhesion and Invasion of Campylobacter jejuni in Animal and Human Foetal Small Intestine Cell Lines.

    PubMed

    Pogačar, Maja Šikić; Klančnik, Anja; Bucar, Franz; Langerholc, Tomaž; Možina, Sonja Smole

    2015-10-01

    Alpinia katsumadai is used in traditional Chinese medicine for abdominal distention, pain, and diarrhoea. Campylobacter jejuni is the most common cause of bacterial food-borne diarrhoeal illnesses worldwide. Adhesion to gut epithelium is a prerequisite in its pathogenesis. The antimicrobial, cytotoxic, and anti-adhesive activities of a chemically characterised extract (SEE) and its residual material of hydrodistillation (hdSEE-R) from A. katsumadai seeds were evaluated against C. jejuni. Minimal inhibitory concentrations for SEE and hdSEE-R were 0.5 mg/mL and 0.25 mg/mL, respectively, and there was no cytotoxic influence in the anti-adhesion tests, as these were performed at much lower concentrations of these tested plant extracts. Adhesion of C. jejuni to pig (PSI) and human foetal (H4) small-intestine cell lines was significantly decreased at lower concentrations (0.2 to 50 µg/mL). In the same concentration range, the invasiveness of C. jejuni in PSI cells was reduced by 45% to 65% when they were treated with SEE or hdSEE-R. The hdSEE-R represents a bioactive waste with a high phenolic content and an anti-adhesive activity against C. jejuni and thus has the potential for use in pharmaceutical and food products. PMID:26058384

  11. Fluorescent bacterial rosetting of lymphocyte subpopulations. II. Identification of human lymphocyte subpopulations.

    PubMed

    Niemetz, A H; Mayr, W R

    1981-01-01

    In a previous study, fluorochrome-labelled bacteria were found to be a very objective tool to investigate human lymphocyte heterogeneity with regard to bacterial rosette formation. The application of these assay systems (mono-, double- and anti-Ig/bacterial rosetting test) to identify lymphocyte subpopulations is given. PMID:7034372

  12. Human intestinal parasites in non-biting synanthropic flies in Ogun State, Nigeria.

    PubMed

    Adenusi, Adedotun Adesegun; Adewoga, Thomas O Sunday

    2013-01-01

    Filth-feeding and breeding, non-biting synanthropic flies have been incriminated in the dissemination of human enteropathogens in the environment. This study determined the species of non-biting synanthropic flies associated with four filthy sites in Ilishan, Ogun State, southwest Nigeria, and assessed their potentials for mechanical transmission of human intestinal parasites. 7190 flies identified as Musca domestica (33.94%), Chrysomya megacephala (26.01%), Musca sorbens (23.23%), Lucilia cuprina (8.76%), Calliphora vicina (4.59%), Sarcophaga sp. (2.78%) and Fannia scalaris (0.70%) were examined for human intestinal parasites by the formol-ether concentration and modified Ziehl-Neelsen techniques. Eggs of the following parasites: Ascaris lumbricoides (34.08%), Trichuris trichiura (25.87%), hookworms (20.45%), Taenia sp. (2.36%), Hymenolepis nana (1.11%), Enterobius vermicularis (0.56%), Strongyloides stercoralis (larvae; 3.89%) and cysts of Entamoeba histolytica/dispar (27.26%), Entamoeba coli (22.67%), Giardia lamblia (3.34%) and Cryptosporidium sp. (1.81%) were isolated from the body surfaces and or gut contents of 75.24% of 719 pooled fly batches. The helminths A. lumbricoides and T. trichiura and the protozoans, E. histolytica/dispar and E. coli were the dominant parasites detected, both on body surfaces and in the gut contents of flies. C. megacephala was the highest carrier of parasites (diversity and number). More parasites were isolated from the gut than from body surfaces (P < 0.05). Flies from soiled ground often carried more parasites than those from abattoir, garbage or open-air market. Synanthropic fly species identified in this study can be of potential epidemiological importance as mechanical transmitters of human intestinal parasites acquired naturally from filth and carried on their body surfaces and or in the gut, because of their vagility and feeding mechanisms. PMID:23290716

  13. PXR/CYP3A4-humanized mice for studying drug-drug interactions involving intestinal P-glycoprotein

    PubMed Central

    Holmstock, Nico; Gonzalez, Frank J.; Baes, Myriam; Annaert, Pieter; Augustijns, Patrick

    2013-01-01

    Rodent models are less suitable for predicting drug-drug interactions at the level of the human intestinal mucosa, especially when nuclear receptors like pregnane X receptor (PXR) are involved. Recently, a transgenic mouse model, expressing both human PXR and CYP3A4, was developed and shown to be a better predictor of CYP3A4 induction by xenobiotics in humans as compared to wild-type mice. In the present study, we tested the hypothesis that this mouse model can also predict PXR-mediated induction of intestinal P-gp in humans. By use of the in situ intestinal perfusion technique with mesenteric blood sampling, the effect of oral rifampicin treatment on intestinal permeability for the HIV protease inhibitor darunavir, a dual CYP3A4/P-gp substrate, was investigated. Rifampicin treatment lowered the intestinal permeability for darunavir by 50 % compared to non-treated mice. The P-gp inhibitor GF120918 increased the permeability for darunavir by 400 % in rifampicin-treated mice, while this was only 56 % in mice that were not treated, thus indicating P-gp induction by rifampicin. The non-specific P450 inhibitor aminobenzotriazole (100 μM) did not affect the permeability for darunavir. Quantitative Western blot analysis of the intestinal tissue showed that rifampicin treatment induced intestinal P-gp levels four-fold, while CYP3A4 levels remained unchanged. Oral co-administration of rifampicin with the phytochemical sulforaphane for three days increased the permeability for darunavir by 50 % compared to rifampicin treatment alone. These data show that PXR/CYP3A4-humanized mice can be used to study the inducing effects of xenobiotics on intestinal P-gp. PMID:23360470

  14. Small-intestinal dysfunction accompanies the complex endocrinopathy of human proprotein convertase 1 deficiency

    PubMed Central

    Jackson, Robert S.; Creemers, John W.M.; Farooqi, I. Sadaf; Raffin-Sanson, Marie-Laure; Varro, Andrea; Dockray, Graham J.; Holst, Jens J.; Brubaker, Patricia L.; Corvol, Pierre; Polonsky, Kenneth S.; Ostrega, Diane; Becker, Kenneth L.; Bertagna, Xavier; Hutton, John C.; White, Anne; Dattani, Mehul T.; Hussain, Khalid; Middleton, Stephen J.; Nicole, Thomasina M.; Milla, Peter J.; Lindley, Keith J.; O’Rahilly, Stephen

    2003-01-01

    We have previously described the only reported case of human proprotein convertase 1 (PC1) deficiency, in a female (Subject A) with obesity, hypogonadism, hypoadrenalism, and reactive hypoglycemia. We now report the second case of human PC1 deficiency (Subject B), also due to compound heterozygosity for novel missense and nonsense mutations. While both subjects shared the phenotypes of obesity, hypoadrenalism, reactive hypoglycemia, and elevated circulating levels of certain prohormones, the clinical presentation of Subject B was dominated by severe refractory neonatal diarrhea, malabsorptive in type. Subsequent investigation of Subject A revealed marked small-intestinal absorptive dysfunction, which was not previously clinically suspected. We postulate that PC1, presumably in the enteroendocrine cells, is essential for the normal absorptive function of the human small intestine. The differences in the nature and severity of presentation between the two cases cannot readily be explained on the basis of allelic heterogeneity, as the nonsense and missense mutations from both subjects had comparably severe effects on the catalytic activity of PC1. Despite Subject A’s negligible PC1 activity, some mature ACTH and glucagon-like peptide 17-36amide were detectable in her plasma, suggesting that the production of these hormones, at least in humans, does not have an absolute dependence on PC1. The presence of severe obesity and the absence of growth retardation in both subjects contrast markedly with the phenotype of mice lacking PC1 and suggest that the precise physiological repertoire of this enzyme may vary between mammalian species. PMID:14617756

  15. Human Milk Oligosaccharides in Premature Infants: Absorption, Excretion and Influence on the Intestinal Microbiota

    PubMed Central

    Underwood, Mark A.; Gaerlan, Stephanie; De Leoz, M. Lorna A.; Dimapasoc, Lauren; Kalanetra, Karen M.; Lemay, Danielle G.; German, J. Bruce; Mills, David A.; Lebrilla, Carlito B.

    2015-01-01

    Background Human milk oligosaccharides (HMOs) shape the intestinal microbiota in term infants. In premature infants, alterations in the intestinal microbiota (dysbiosis) are associated with risk of necrotizing enterocolitis and sepsis and the influence of HMOs on the microbiota is unclear. Methods Milk, urine, and stool specimens from 14 mother-premature infant dyads were investigated by mass spectrometry for HMO composition. The stools were analyzed by next-generation sequencing (NGS) to complement a previous analysis. Results Percentages of fucosylated and sialylated HMOs were highly variable between individuals but similar in urine, feces and milk within dyads. Differences in urine and fecal HMO composition suggest variability in absorption. Secretor status of the mother correlated with the urine and fecal content of specific HMO structures. Trends toward higher levels of Proteobacteria and lower levels of Firmicutes, were noted in premature infants of non-secretor mothers. Specific HMO structures in the milk, urine and feces were associated with alterations in fecal Proteobacteria and Firmicutes. Conclusion HMOs may influence the intestinal microbiota in premature infants. Specific HMOs, for example those associated with secretor mothers, may have a protective effect by decreasing pathogens associated with sepsis and necrotizing enterocolitis while other HMOs may increase dysbiosis in this population. PMID:26322410

  16. Bovine and soybean milk bioactive compounds: Effects on inflammatory response of human intestinal Caco-2 cells.

    PubMed

    Calvello, Rosa; Aresta, Antonella; Trapani, Adriana; Zambonin, Carlo; Cianciulli, Antonia; Salvatore, Rosaria; Clodoveo, Maria Lisa; Corbo, Filomena; Franchini, Carlo; Panaro, Maria Antonietta

    2016-11-01

    In this study the effects of commercial bovine and soybean milks and their bioactive compounds, namely genistein, daidzein and equol, on the inflammatory responses induced by lipopolysaccharide (LPS) treatment of human intestinal Caco-2 cells were examined, in terms of nitric oxide (NO) release and inducible nitric oxide synthetase (iNOS) expression. Both milks and their bioactive compounds significantly inhibited, dose-dependently, the expression of iNOS mRNA and protein, resulting in a decreased NO production. The NF-κB activation in LPS-stimulated intestinal cells was also examined. In all cases we observed that cell pre-treatment before LPS activation inhibited the IkB phosphorylation. Accordingly, quantification of bioactive compounds by solid phase microextraction coupled with liquid chromatography has shown that they were absorbed, metabolized and released by Caco-2 cells in culture media. In conclusion, we demonstrated that milks and compounds tested are able to reduce LPS-induced inflammatory responses from intestinal cells, interfering with NF-kB dependent molecular mechanisms. PMID:27211648

  17. Proteomic analysis of nuclear proteins from proliferative and differentiated human colonic intestinal epithelial cells.

    PubMed

    Turck, Natacha; Richert, Sophie; Gendry, Patrick; Stutzmann, Jeanne; Kedinger, Michèle; Leize, Emmanuelle; Simon-Assmann, Patricia; Van Dorsselaer, Alain; Launay, Jean-François

    2004-01-01

    Self-renewing tissues such as the intestine contain progenitor proliferating cells which subsequently differentiate. Cell proliferation and differentiation involve gene regulation processes which take place in the nucleus. A human intestinal epithelial cell line model (Caco2/TC7) which reproduces these dynamic processes has been used to perform proteomic studies on nuclear proteins. Nuclei from Caco2/TC7 cells at proliferative and differentiated stages were purified by subcellular fractionation. After two-dimensional gel electrophoresis separation and ruthenium staining, 400 protein spots were detected by image analysis. Eighty-five spots corresponding to 60 different proteins were identified by matrix-assisted laser desorption/ionization mass spectrometry in nuclei from proliferative cells. Comparison of nuclear proteomes from proliferative or differentiated cells by differential display resulted in the identification of differentially expressed proteins such as nucleolin, hnRNP A2/B1 and hnRNP A1. By using Western blot analysis, we found that the expression and number of specific isoforms of these nuclear proteins decreased in differentiated cells. Immunocytochemistry experiments also showed that in proliferative cells nucleolin was distributed in nucleoli-like bodies. In contrast, hnRNPs A2/B1 and A1 were dispersed throughout the nucleus. This study of the nuclear proteome from intestinal epithelial cells represents the first step towards the establishment of a protein database which will be a valuable resource in future studies on the differential expression of nuclear proteins in response to physiological, pharmacological and pathological modulations. PMID:14730675

  18. Effects of oat β-glucan and barley β-glucan on fecal characteristics, intestinal microflora, and intestinal bacterial metabolites in rats.

    PubMed

    Shen, Rui-Ling; Dang, Xue-Ya; Dong, Ji-Lin; Hu, Xin-Zhong

    2012-11-14

    The primary objective was to determine the beneficial effects of oat β-glucan (OG) and barley β-glucan (BG) on gut health. A total of 200 male Sprague-Dawley rats were divided into 5 groups of 40 rats each, control group (CON), low-dose OG-administered group (OGL), high-dose OG-administered group (OGH), low-dose BG-administered group (BGL), and high-dose BG-administered group (BGH). OGL and OGH were administered oat β-glucan by intragastric gavage at a dose of 0.35 g/kg of body weight (BW) and 0.70 g/kg of BW daily for 6 weeks, and BGL and BGH were administered barley β-glucan. The CON received normal saline. Intestinal-health-related indexes were analyzed at baseline, week 3, week 6, and week 7. Cereal β-glucan significantly influenced the fecal water content, pH value, ammonia levels, β-glucuronidase activity, azoreductase activity, and colonic short-chain fatty acid (SCFA) concentrations (p < 0.05). Moreover, the population of Lactobacillus and Bifidobacterium increased (p < 0.05), whereas the number of Enterobacteriaceae decreased (p < 0.05) in a dose-dependent manner during the period of cereal β-glucan administration. These results suggested that cereal β-glucan might exert favorable effects on improving intestinal functions and health but the gut-health-promoting effects of oat β-glucan were better than those of barley β-glucan. PMID:23113683

  19. Hypermutation, diversity and dissemination of human intestinal lamina propria plasma cells.

    PubMed

    Dunn-Walters, D K; Boursier, L; Spencer, J

    1997-11-01

    In this work we have microdissected lamina propria plasma cells and used polymerase chain reaction and sequencing to investigate immunoglobulin (Ig) gene rearrangements and mutations in human intestine. In addition, specific primers were designed for individual Ig gene rearrangements to analyze the distribution of related B cell and plasma cell clones at different sites along the bowel. Confirming our earlier work, intestinal IgVH genes were highly mutated in plasma cells from older individuals (> 30 years). IgVH genes were significantly less mutated in samples taken from patients aged 11-30 years, and there were fewer mutations again in samples from young children (< 11 years). In age-matched specimens the number of mutations was equivalent in the duodenum and colon. Using complementarity-determining region 3 primers to amplify specific Ig gene rearrangements, evidence was also found for the existence of related lamina propria plasma cells along the small bowel and colon, although these were quite scarce. In addition, analysis of the numbers of related clones in a random sampling from discrete areas of lamina propria indicates that the local population is diverse. These results suggest that the highly mutated IgVH genes in adult intestinal plasma cells are a consequence of chronic antigen exposure with age. Duodenal plasma cells are as highly mutated as colonic plasma cells, despite the fact that the upper bowel has no indigenous microbial flora (the stimulus for intestinal plasma cells). They also show that the plasma cell population is diverse and can be widely disseminated along the bowel. PMID:9394824

  20. Functional modulation of human intestinal epithelial cell responses by Bifidobacterium infantis and Lactobacillus salivarius

    PubMed Central

    O'Hara, Ann M; O'Regan, Padraig; Fanning, Áine; O'Mahony, Caitlin; MacSharry, John; Lyons, Anne; Bienenstock, John; O'Mahony, Liam; Shanahan, Fergus

    2006-01-01

    Intestinal epithelial cells (IECs) and dendritic cells (DCs) play a pivotal role in antigen sampling and the maintenance of gut homeostasis. However, the interaction of commensal bacteria with the intestinal surface remains incompletely understood. Here we investigated immune cell responses to commensal and pathogenic bacteria. HT-29 human IECs were incubated with Bifidobacterium infantis 35624, Lactobacillus salivarius UCC118 or Salmonella typhimurium UK1 for varying times, or were pretreated with a probiotic for 2 hr prior to stimulation with S. typhimurium or flagellin. Gene arrays were used to examine inflammatory gene expression. Nuclear factor (NF)-κB activation, interleukin (IL)-8 secretion, pathogen adherence to IECs, and mucin-3 (MUC3) and E-cadherin gene expression were assayed by TransAM assay, enzyme-linked immunosorbent assay (ELISA), fluorescence, and real-time reverse transcriptase–polymerase chain reaction (RT-PCR), respectively. IL-10 and tumour necrosis factor (TNF)-α secretion by bacteria-treated peripheral blood-derived DCs were measured using ELISA. S. typhimurium increased expression of 36 of the 847 immune-related genes assayed, including NF-κB and IL-8. The commensal bacteria did not alter expression levels of any of the 847 genes. However, B. infantis and L. salivarius attenuated both IL-8 secretion at baseline and S. typhimurium-induced pro-inflammatory responses. B. infantis also limited flagellin-induced IL-8 protein secretion. The commensal bacteria did not increase MUC3 or E-cadherin expression, or interfere with pathogen binding to HT-29 cells, but they did stimulate IL-10 and TNF-α secretion by DCs. The data demonstrate that, although the intestinal epithelium is immunologically quiescent when it encounters B. infantis or L. salivarius, these commensal bacteria exert immunomodulatory effects on intestinal immune cells that mediate host responses to flagellin and enteric pathogens. PMID:16771855

  1. Effects of Antibiotics on Bacterial Species Composition and Metabolic Activities in Chemostats Containing Defined Populations of Human Gut Microorganisms

    PubMed Central

    Newton, Dorothy F.; Macfarlane, George T.

    2013-01-01

    The composition and metabolic activities of the human colonic microbiota are modulated by a number of external factors, including diet and antibiotic therapy. Changes in the structure and metabolism of the gut microbiota may have long-term consequences for host health. The large intestine harbors a complex microbial ecosystem comprising several hundreds of different bacterial species, which complicates investigations on intestinal physiology and ecology. To facilitate such studies, a highly simplified microbiota consisting of 14 anaerobic and facultatively anaerobic organisms (Bacteroides thetaiotaomicron, Bacteroides vulgatus, Bifidobacterium longum, Bifidobacterium infantis, Bifidobacterium pseudolongum, Bifidobacterium adolescentis, Clostridium butyricum, C. perfringens, C. bifermentans, C. innocuum, Escherichia coli, Enterococcus faecalis, Enterococcus faecium, Lactobacillus acidophilus) was used in this investigation. Ampicillin [9.2 μg (ml culture)−1] was added to two chemostats operated at different dilution rates (D; 0.10 h−1 and 0.21 h−1), and metronidazole [76.9 μg (ml culture)−1] was added to a third vessel (D = 0.21 h−1). Perturbations in bacterial physiology and metabolism were sampled over a 48-h period. Lactobacillus acidophilus and C. bifermentans populations did not establish in the fermentors under the imposed growth conditions. Ampicillin resulted in substantial reductions in bacteroides and C. perfringens populations at both dilution rates. Metronidazole strongly affected bacteroides communities but had no effect on bifidobacterial communities. The bacteriostatic effect of ampicillin on bifidobacterial species was growth rate dependent. Several metabolic activities were affected by antibiotic addition, including fermentation product formation and enzyme synthesis. The growth of antibiotic-resistant bifidobacteria in the large bowel may enable them to occupy ecological niches left vacant after antibiotic administration, preventing colonization by pathogenic species. PMID:23403424

  2. Transepithelial transport of ambroxol hydrochloride across human intestinal Caco-2 cell monolayers.

    PubMed

    Stetinová, Vera; Smetanová, Libuse; Kholová, Dagmar; Svoboda, Zbynek; Kvetina, Jaroslav

    2009-09-01

    This study aimed i) to characterize the transepithelial transport of the mucolytic agent ambroxol hydrochloride across the intestinal barrier, ii) to classify the ambroxol according to Biopharmaceutics Classification System (BCS) and iii) to predict ambroxol absorption in humans. Transport of ambroxol (100, 300 and 1000 micromol/l) was studied in a human colon carcinoma cell line Caco-2 in apical to basolateral and basolateral to apical direction, under iso-pH 7.4 and pH-gradient (6 vs. 7.4) conditions. The relative contribution of the paracellular route was estimated using Ca2+-free transport medium. Ambroxol samples from receiver compartments were analysed by HPLC with UV detection (242 nm). Results showed that ambroxol transport is linear with time, pH-dependent and direction-independent, displays non-saturable (first-order) kinetics. Thus, the transport seems to be transcellular mediated by passive diffusion. Estimated high solubility and high permeability (P(app) = 45 x 10(-6) cm/s) of ambroxol rank it among well absorbed compounds and class I of BCS. It can be expected that the oral dose fraction of ambroxol absorbed in human intestine is high. PMID:20037197

  3. Combined Effects of Lipophilic Phycotoxins (Okadaic Acid, Azapsiracid-1 and Yessotoxin) on Human Intestinal Cells Models

    PubMed Central

    Ferron, Pierre-Jean; Dumazeau, Kevin; Beaulieu, Jean-François; Le Hégarat, Ludovic; Fessard, Valérie

    2016-01-01

    Phycotoxins are monitored in seafood because they can cause food poisonings in humans. Phycotoxins do not only occur singly but also as mixtures in shellfish. The aim of this study was to evaluate the in vitro toxic interactions of binary combinations of three lipophilic phycotoxins commonly found in Europe (okadaic acid (OA), yessotoxin (YTX) and azaspiracid-1 (AZA-1)) using the neutral red uptake assay on two human intestinal cell models, Caco-2 and the human intestinal epithelial crypt-like cells (HIEC). Based on the cytotoxicity of individual toxins, we studied the interactions between toxins in binary mixtures using the combination index-isobologram equation, a method widely used in pharmacology to study drug interactions. This method quantitatively classifies interactions between toxins in mixtures as synergistic, additive or antagonistic. AZA-1/OA, and YTX/OA mixtures showed increasing antagonism with increasing toxin concentrations. In contrast, the AZA-1/YTX mixture showed increasing synergism with increasing concentrations, especially for mixtures with high YTX concentrations. These results highlight the hazard potency of AZA-1/YTX mixtures with regard to seafood intoxication. PMID:26907345

  4. Initiation of an Inflammatory Response in Resident Intestinal Lamina Propria Cells -Use of a Human Organ Culture Model

    PubMed Central

    Schröder-Braunstein, Jutta; Gras, Judith; Brors, Benedikt; Schwarz, Sonja; Szikszai, Timea; Lasitschka, Felix; Wabnitz, Guido; Heidtmann, Antje; Lee, Young-Seon; Schiessling, Serin; Leowardi, Christine; Al-Saeedi, Mohammed; Ulrich, Alexis; Engelke, Antonia; Winter, Johannes; Samstag, Yvonne; Giese, Thomas; Meuer, Stefan

    2014-01-01

    Resident human lamina propria immune cells serve as powerful effectors in host defense. Molecular events associated with the initiation of an intestinal inflammatory response in these cells are largely unknown. Here, we aimed to characterize phenotypic and functional changes induced in these cells at the onset of intestinal inflammation using a human intestinal organ culture model. In this model, healthy human colonic mucosa was depleted of epithelial cells by EDTA treatment. Following loss of the epithelial layer, expression of the inflammatory mediators IL1B, IL6, IL8, IL23A, TNFA, CXCL2, and the surface receptors CD14, TLR2, CD86, CD54 was rapidly induced in resident lamina propria cells in situ as determined by qRT-PCR and immunohistology. Gene microarray analysis of lamina propria cells obtained by laser-capture microdissection provided an overview of global changes in gene expression occurring during the initiation of an intestinal inflammatory response in these cells. Bioinformatic analysis gave insight into signalling pathways mediating this inflammatory response. Furthermore, comparison with published microarray datasets of inflamed mucosa in vivo (ulcerative colitis) revealed a significant overlap of differentially regulated genes underlining the in vivo relevance of the organ culture model. Furthermore, genes never been previously associated with intestinal inflammation were identified using this model. The organ culture model characterized may be useful to study molecular mechanisms underlying the initiation of an intestinal inflammatory response in normal mucosa as well as potential alterations of this response in inflammatory bowel disease. PMID:24841635

  5. Intestinal parasite co-infection among pulmonary tuberculosis cases without human immunodeficiency virus infection in a rural county in China.

    PubMed

    Li, Xin-Xu; Chen, Jia-Xu; Wang, Li-Xia; Tian, Li-Guang; Zhang, Yu-Ping; Dong, Shuang-Pin; Hu, Xue-Guang; Liu, Jian; Wang, Feng-Feng; Wang, Yue; Yin, Xiao-Mei; He, Li-Jun; Yan, Qiu-Ye; Zhang, Hong-Wei; Xu, Bian-Li; Zhou, Xiao-Nong

    2014-01-01

    Epidemiologic studies of co-infection with tuberculosis (TB) and intestinal parasites in humans have not been extensively investigated in China. A cross-section study was conducted in a rural county of Henan Province, China. Pulmonary TB (PTB) case-patients receiving treatment for infection with Mycobacterium tuberculosis and healthy controls matched for geographic area, age, and sex were surveyed by using questionnaires. Fecal and blood specimens were collected for detection of intestinal parasites, routine blood examination, and infection with human immunodeficiency virus. The chi-square test was used for univariate analysis and multivariate logistic regression models were used to adjust for potential confounding factors. A total of 369 persons with PTB and 366 healthy controls were included; all participants were negative for human immunodeficiency virus. The overall prevalence of intestinal parasites in persons with PTB was 14.9%, including intestinal protozoa (7.9%) and helminthes (7.6%). The infection spectrum of intestinal parasites was Entamoeba spp. (1.4%), Blastocystis hominis (6.2%), Trichomonas hominis (0.3%), Clonorchis sinensis (0.3%), Ascaris lumbricoides (0.5%), Trichuris trichiura (2.2%), and hookworm (4.6%). The prevalence of intestinal parasites showed no significant difference between persons with PTB and healthy controls after adjusting for potential confounding factors. There was no factor that affected infection rates for intestinal parasites between the two groups. Infection with intestinal parasites of persons with PTB was associated with female sex (adjusted odds ratio [AOR] = 2.05, 95% confidence interval [CI] = 1.01-4.17), body mass index ≤ 19 (AOR = 3.02, 95% CI = 1.47-6.20), and anemia (AOR = 2.43, 95% CI = 1.17-5.03). Infection of healthy controls was only associated with an annual labor time in farmlands > 2 months (AOR = 4.50, 95% CI = 2.03-10.00). In addition, there was no significant trend between rates of infection with intestinal parasites and duration of receiving treatment for infection with M. tuberculosis in persons with PTB. The prevalence of intestinal parasites was not higher in persons with PTB, and there was no evidence that PTB increased susceptibility to intestinal parasites in this study. However, for patients with PTB, women and patients with comorbidities were more likely to be infected with intestinal parasites. PMID:24166044

  6. Card9 Mediates Intestinal Epithelial Cell Restitution, T-Helper 17 Responses, and Control of Bacterial Infection in Mice

    PubMed Central

    SOKOL, HARRY; CONWAY, KARA L.; ZHANG, MEI; CHOI, MYUNGHWAN; MORIN, BRET; CAO, ZHIFANG; VILLABLANCA, EDUARDO J.; LI, CHUN; WIJMENGA, CISCA; YUN, SEOK HYUN; SHI, HAI NING; XAVIER, RAMNIK J.

    2013-01-01

    BACKGROUND & AIMS Caspase recruitment domain 9 (CARD9) is an adaptor protein that integrates signals downstream of pattern recognition receptors. CARD9 has been associated with autoinflammatory disorders, and loss-of-function mutations have been associated with chronic mucocutaneous candidiasis, but the role of CARD9 in intestinal inflammation is unknown. We characterized the role of Card9 in mucosal immune responses to intestinal epithelial injury and infection. METHODS We induced intestinal inflammation in Card9-null mice by administration of dextran sulfate sodium (DSS) or Citrobacter rodentium. We analyzed body weight, assessed inflammation by histology, and measured levels of cytokines and chemokines using quantitative reverse-transcription polymerase chain reaction and enzyme-linked immunosorbent assay. Cell populations were compared between wild-type and Card9-null mice by flow cytometry analysis. RESULTS Colon tissues and mesenteric lymph nodes of Card9-null mice had reduced levels of interleukin (IL)-6, interferon-γ, and T-helper (Th)17 cytokines after administration of DSS, compared with wild-type mice. IL-17A and IL-22 expression were reduced in the recovery phase after DSS administration, coincident with decreased expression of antimicrobial peptides and the chemokine (C-C motif) ligand 20 (Ccl20). Although Card9-null mice had more intestinal fungi based on 18S analysis, their Th17 responses remained defective even when an antifungal agent was administered throughout DSS exposure. Moreover, Card9-null mice had impaired immune responses to C rodentium, characterized by decreased levels of colonic IL-6, IL-17A, IL-22, and regenerating islet-derived 3 gamma (RegIIIγ), as well as fewer IL-22—producing innate lymphoid cells (ILCs) in colon lamina propria. CONCLUSIONS The adaptor protein CARD9 coordinates Th17- and innate lymphoid cell-mediated intestinal immune responses after epithelial injury in mice. PMID:23732773

  7. Bacterial pathogens: from natural ecosystems to human hosts.

    PubMed

    Martínez, José L

    2013-02-01

    The analysis of the genomes of bacterial pathogens indicates that they have acquired their pathogenic capability by incorporating different genetic elements through horizontal gene transfer. The ancestors of virulent bacteria, as well as the origin of virulence determinants, lay most likely in the environmental microbiota. Studying the role that these determinants may have in non-clinical ecosystems is thus of value for understanding in detail the evolution and the ecology of bacterial pathogens. In this article, I propose that classical virulence determinants might be relevant for basic metabolic processes (for instance iron-uptake systems) or in modulating prey/predator relationships (toxins) in natural, non-infective ecosystems. The different role that horizontal gene transfer and mutation may have in the evolution of bacterial pathogens either for their speciation or in short-sighted evolution processes is also discussed. PMID:22857004

  8. Failure of d-psicose absorbed in the small intestine to metabolize into energy and its low large intestinal fermentability in humans.

    PubMed

    Iida, Tetsuo; Hayashi, Noriko; Yamada, Takako; Yoshikawa, Yuko; Miyazato, Shoko; Kishimoto, Yuka; Okuma, Kazuhiro; Tokuda, Masaaki; Izumori, Ken

    2010-02-01

    Experiments with rats have produced data on the metabolism and energy value of d-psicose; however, no such data have been obtained in humans. The authors assessed the availability of d-psicose absorbed in the small intestine by measuring carbohydrate energy expenditure (CEE) by indirect calorimetry. They measured the urinary excretion rate by quantifying d-psicose in urine for 48 hours. To examine d-psicose fermentation in the large intestine, the authors measured breath hydrogen gas and fermentability using 35 strains of intestinal bacteria. Six healthy subjects participated in the CEE test, and 14 participated in breath hydrogen gas and urine tests. d-Psicose fermentation subsequent to an 8-week adaptation period was also assessed by measuring hydrogen gas in 8 subjects. d-Psicose absorbed in the small intestine was not metabolized into energy, unlike glucose, because CEE did not increase within 3 hours of d-psicose ingestion (0.35 g/kg body weight [BW]). The accumulated d-psicose urinary excretion rates were around 70% for 0.34, 0.17, and 0.08 g/kg BW of ingested d-psicose. Low d-psicose fermentability was observed in intestinal bacteria and breath hydrogen gas tests, in which fructooligosaccharide (0.34, 0.17, and 0.08 g/kg BW) was used as a positive control because its available energy is known to be 8.4 kJ/g. Based on the results of the plot of breath hydrogen concentration vs calories ingested, the energy value of d-psicose was expected to be less than 1.6 kJ/g. Incremental d-psicose fermentability subsequent to an adaptation period was not observed. PMID:19765780

  9. Characterization and distribution of alpha 2-adrenergic receptors in the human intestinal mucosa.

    PubMed Central

    Valet, P; Senard, J M; Devedjian, J C; Planat, V; Salomon, R; Voisin, T; Drean, G; Couvineau, A; Daviaud, D; Denis, C

    1993-01-01

    The subtype and the expression of the alpha 2-adrenergic receptor were investigated in the normal mucosa from human intestine by means of radioligand binding, RNase mapping, and measurement of adenylate cyclase activity. The study of the binding of the alpha 2-adrenergic antagonist, [3H]RX821002, to epithelial cell membranes indicated the existence of a single class of noninteracting sites displaying a high affinity for the radioligand (Kd = 1.1 +/- 0.5 nM). The rank order of potency of antagonists to inhibit [3H]RX821002 binding (RX821002 > yohimbine = rauwolscine > phentolamine approximately idazoxan >> chlorpromazine > prazosin) suggested that the receptor is of the alpha 2A subtype. A conclusion which is confirmed by the fact that only alpha 2C10 transcripts were found in the human intestine mucosa. Competition curves with (-)-norepinephrine demonstrated that 60% of the receptor population exhibited high affinity for agonists. This high-affinity state was abolished by the addition of GTP plus Na+ or by prior treatment of the membranes with pertussis toxin indicating it corresponded to G protein-coupled receptors. [32P]ADP-ribosylation and immunoblotting experiments identified two pertussis toxin-sensitive G proteins corresponding to Gi2 and Gi3. The study of the distribution of the receptor indicated that (a) the proximal colon is the intestine segment exhibiting the highest receptor density and (b) the receptor is predominantly expressed in crypts and is preferentially located in the basolateral membrane of the polarized cell. The distribution of the receptor along the crypt-surface axis of the colon mucosa can be correlated with a higher level of alpha 2C10-specific mRNA and a higher efficiency of UK14304 to inhibit adenylate cyclase in crypt cells. Images PMID:8098045

  10. Biotransformation and metabolic profile of catalpol with human intestinal microflora by ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry.

    PubMed

    Tao, Jin-Hua; Zhao, Min; Wang, Dong-Geng; Yang, Chi; Du, Le-Yue; Qiu, Wen-Qian; Jiang, Shu

    2016-01-15

    Traditional Chinese medicine (TCM) has been used in clinical practice for thousands of years. Catalpol, an iridoid glucoside, abundantly found in the root of the common used herb medicine Rehmannia glutinosa Libosch, has been reported to show various biological effects and pharmacological activities. After oral administration, the active ingredient might have interactions with the intestinal bacteria, which could help unravel how the medicine was processed in vivo. In this work, different pure bacteria from healthy human feces were isolated and used to bioconvert catalpol. Ultra performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF/MS) technique combined with Metabolynx(™) software was applied to analyze catalpol metabolites. Compared with blank samples, parent compound (M0) and four metabolites (M1-M4) were detected and tentatively identified based on the characteristics of their protonated ions. The metabolites were likely to be: catalpol aglycone (M1), acetylated catalpol (M2), dimethylated and hydroxylated catalpol aglycone (M3), nitrogen-containing catalpol aglycone (M4). M1 and M4 were generated in the majority of the samples like Bacteroides sp. 45. M3 was obtained in several bacterial samples like Enterococcus sp. 8-2 and M2 was detected only in the sample of Enterococcus sp. 43-1. To our knowledge, the metabolic routes and metabolites of catalpol produced by human intestinal bacteria were all firstly reported. PMID:26741989

  11. Modulation of pathogen-induced CCL20 secretion from HT-29 human intestinal epithelial cells by commensal bacteria

    PubMed Central

    Sibartie, Shomik; O'Hara, Ann M; Ryan, Jude; Fanning, Áine; O'Mahony, Jim; O'Neill, Shaun; Sheil, Barbara; O'Mahony, Liam; Shanahan, Fergus

    2009-01-01

    Background Human intestinal epithelial cells (IECs) secrete the chemokine CCL20 in response to infection by various enteropathogenic bacteria or exposure to bacterial flagellin. CCL20 recruits immature dendritic cells and lymphocytes to target sites. Here we investigated IEC responses to various pathogenic and commensal bacteria as well as the modulatory effects of commensal bacteria on pathogen-induced CCL20 secretion. HT-29 human IECs were incubated with commensal bacteria (Bifidobacterium infantis or Lactobacillus salivarius), or with Salmonella typhimurium, its flagellin, Clostridium difficile, Mycobacterium paratuberculosis, or Mycobacterium smegmatis for varying times. In some studies, HT-29 cells were pre-treated with a commensal strain for 2 hr prior to infection or flagellin stimulation. CCL20 and interleukin (IL)-8 secretion and nuclear factor (NF)-κB activation were measured using enzyme-linked immunosorbent assays. Results Compared to untreated cells, S. typhimurium, C. difficile, M. paratuberculosis, and flagellin activated NF-κB and stimulated significant secretion of CCL20 and IL-8 by HT-29 cells. Conversely, B. infantis, L. salivarius or M. smegmatis did not activate NF-κB or augment CCL20 or IL-8 production. Treatment with B. infantis, but not L. salivarius, dose-dependently inhibited the baseline secretion of CCL20. In cells pre-treated with B. infantis, C. difficile-, S. typhimurium-, and flagellin-induced CCL20 were significantly attenuated. B. infantis did not limit M. Paratuberculosis-induced CCL20 secretion. Conclusion This study is the first to demonstrate that a commensal strain can attenuate CCL20 secretion in HT-29 IECs. Collectively, the data indicate that M. paratuberculosis may mediate mucosal damage and that B. infantis can exert immunomodulatory effects on IECs that mediate host responses to flagellin and flagellated enteric pathogens. PMID:19814810

  12. Sugars Increase Non-Heme Iron Bioavailability in Human Epithelial Intestinal and Liver Cells

    PubMed Central

    Christides, Tatiana; Sharp, Paul

    2013-01-01

    Previous studies have suggested that sugars enhance iron bioavailability, possibly through either chelation or altering the oxidation state of the metal, however, results have been inconclusive. Sugar intake in the last 20 years has increased dramatically, and iron status disorders are significant public health problems worldwide; therefore understanding the nutritional implications of iron-sugar interactions is particularly relevant. In this study we measured the effects of sugars on non-heme iron bioavailability in human intestinal Caco-2 cells and HepG2 hepatoma cells using ferritin formation as a surrogate marker for iron uptake. The effect of sugars on iron oxidation state was examined by measuring ferrous iron formation in different sugar-iron solutions with a ferrozine-based assay. Fructose significantly increased iron-induced ferritin formation in both Caco-2 and HepG2 cells. In addition, high-fructose corn syrup (HFCS-55) increased Caco-2 cell iron-induced ferritin; these effects were negated by the addition of either tannic acid or phytic acid. Fructose combined with FeCl3 increased ferrozine-chelatable ferrous iron levels by approximately 300%. In conclusion, fructose increases iron bioavailability in human intestinal Caco-2 and HepG2 cells. Given the large amount of simple and rapidly digestible sugars in the modern diet their effects on iron bioavailability may have important patho-physiological consequences. Further studies are warranted to characterize these interactions. PMID:24340076

  13. A cost-effective system for differentiation of intestinal epithelium from human induced pluripotent stem cells.

    PubMed

    Ogaki, Soichiro; Morooka, Mayu; Otera, Kaito; Kume, Shoen

    2015-01-01

    The human intestinal epithelium is a useful model for pharmacological studies of absorption, metabolism, drug interactions, and toxicology, as well as for studies of developmental biology. We established a rapid and cost effective system for differentiation of human induced pluripotent stem (iPS) cells into definitive endoderm (DE) cells. In the presence of dimethyl sulfoxide (DMSO), a low concentration of Activin at 6.25 ng/ml is sufficient to give a similar differentiation efficiency with that using Activin at 100 ng/ml at the presence of Wnt activator. In the presence of DMSO, Activin at low concentration triggered hiPS cells to undergo differentiation through G1 arrest, reduce apoptosis, and potentiate activation of downstream targets, such as SMAD2 phosphorylation and SOX17 expression. This increased differentiation into CDX2 + SOX17 + DE cells. The present differentiation procedure therefore permits rapid and efficient derivation of DE cells, capable of differentiating into intestinal epithelium upon BIO and DAPT treatment and of giving rise to functional cells, such as enterocytes. PMID:26616277

  14. Antigenic and structural features of goblet-cell mucin of human small intestine.

    PubMed Central

    Mantle, M; Forstner, G G; Forstner, J F

    1984-01-01

    With the use of a newly developed solid-phase radioimmunoassay method, the major antigenic determinants of human small-intestinal goblet-cell mucin were investigated and related to the overall tertiary structure of the mucin. Preliminary hapten inhibition studies with various oligosaccharides of known sequence and structure suggested that the determinants did not reside in carbohydrate. Exhaustive thiol reduction, however, almost abolished antigenicity, caused breakdown of the mucin into small heterogeneous glycopeptides, and liberated a 'link' peptide of Mr 118000. Western 'blots' of reduced mucin from polyacrylamide gels on to nitrocellulose sheets showed that a small amount of residual antigenicity remained in large-Mr glycopeptides (Mr greater than 200000). The 'link' peptide was not antigenic. Timed Pronase digestion of native mucin resulted in a progressive loss of antigenic determinants. Gel electrophoresis revealed that after 8h of digestion the 118000-Mr peptide had disappeared, whereas antigenicity, which was confined to large-Mr glycopeptides, was destroyed much more slowly with time (70% by 24h, 100% by 72h). Despite the loss of antigenicity, 72h-Pronase-digested glycopeptides retained all of the carbohydrate of the native mucin. Therefore the antibody to human small-intestinal mucin appears to recognize a 'naked' (non-glycosylated and Pronase-susceptible) peptide region(s) of mucin glycopeptides. For full antigenicity, however, disulphide bonds are required to stabilize a specific three-dimensional configuration of the 'naked' region. Images Fig. 4. Fig. 6. PMID:6199017