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Small intestinal bacterial overgrowth syndrome.  


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

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



Small intestinal bacterial overgrowth in human cirrhosis is associated with systemic endotoxemia  

Microsoft Academic Search

OBJECTIVES:Systemic endotoxemia has been implicated in various pathophysiological sequelae of chronic liver disease. One of its potential causes is increased intestinal absorption of endotoxin. We therefore examined the association of small intestinal bacterial overgrowth with systemic endotoxemia in patients with cirrhosis.METHODS:Fifty-three consecutive patients with cirrhosis (Child-Pugh group A, 23; group B, 18; group C, 12) were included. Jejunal secretions were

Tilman M. Bauer; Henning Schwacha; Bernhard Steinbrückner; Folke E. Brinkmann; Anette K. Ditzen; John J. Aponte; Klaus Pelz; Dieter Berger; Manfred Kist; Hubert E. Blum



Intestinal epithelial defense systems protect against bacterial threats  

Microsoft Academic Search

Numerous bacterial species inhabit the lumen of the human intestine. The epithelial cells that line the intestinal barrier\\u000a are in direct contact with many of these species and have developed sophisticated strategies to prevent bacterial invasion\\u000a of host tissue beyond simply providing a physical blockade. Intestinal epithelial cells (IECs) possess receptors that are\\u000a capable of recognizing bacterial products, and engagement

Bryan P. Hurley; Beth A. McCormick



Cytokine responses in primary chicken embryo intestinal cells infected with Campylobacter jejuni strains of human and chicken origin and the expression of bacterial virulence-associated genes  

Microsoft Academic Search

BACKGROUND: Campylobacter jejuni is a major cause of inflammatory diarrhoea in humans and is considered a commensal of the gastroenteric tract of the avian host. However, little is known about the interaction between C. jejuni and the avian host including the cytokine responses and the expression of the bacterial genes. We have investigated the invasiveness of primary chicken embryo intestinal

Yi-Ping Li; Hanne Ingmer; Mogens Madsen; Dang D Bang



[Transplantation of the intestines and bacterial translocation].  


Infections, sepsis and multiple organ failure syndrome are associated with high morbidity and mortality in human and experimental small bowel transplantation (SBTx). These complications are attributed to bacterial translocation demonstrated in animal and human studies. Bacterial translocation (BT) is defined as the passage of viable bacteria from the intestinal lumen to other tissues or organs. BT has been associated with different clinical and experimental situations, hemorrhagic shock, trauma, bowel obstruction, immunodepression, total parenteral nutrition, antibiotics. Although BT has been investigated in several small and large animal models of SBTx, precise information on the mechanisms involved are not available. It is possible that the operative procedure by itself may promote BT for the interaction of a number of factors such as preservation, ischemia/reperfusion, abnormal motility, lymphatic disruption and aberrant systemic venous drainage, acute or chronic rejection and antibiotic therapy. Furthermore, the potent immunosuppressive therapy used in these patients may augment the deleterious effects caused by BT. In this review we examined the existing literature concerning BT with particular regard to intestinal transplantation, to better understand the alterations in the symbiotic relationship between immunocompromised host and his gut microflora after SBTx. PMID:10812777

Sileri, P; Rastellini, C; Dicuonzo, G; Gaspari, A; Benedetti, E; Cicalese, L



Association between Hypothyroidism and Small Intestinal Bacterial Overgrowth  

Microsoft Academic Search

Objectives: Small intestinal bacterial overgrowth is defined as an abnormally high bacterial population level in the small intestine. Intestinal motor dysfunction associated with hypothyroidism could predispose to bacterial overgrowth. Luminal bacteria could modulate gastrointestinal symptoms and interfere with levothyroxine absorp- tion. The aims of the present study were to assess the prevalence and clinical pattern of bacterial overgrowth in patients

Ernesto Cristiano Lauritano; Anna Lisa Bilotta; Maurizio Gabrielli; Emidio Scarpellini; Andrea Lupascu; Antonio Laginestra; Marialuisa Novi; Sandra Sottili; Michele Serricchio; Giovanni Cammarota; Giovanni Gasbarrini; Alfredo Pontecorvi; Antonio Gasbarrini


[Chronic bacterial overgrowth in the small intestine].  


The small intestinal bacterial overgrowth (SIBO) is defined by the presence in the proximal part of the intestine of a bacterial population and qualitatively abnormal. It is necessary to distinguish the "non-symptomatic" SIBO and the "symptomatic" SIBO responsible for a chronic diarrhoea and/or of a malabsorption syndrome. The main factor encouraging the intervening of a SIBO is the stasis of the intestinal juice. The gold standard test to confirm the diagnosis of SIBO is the jejunal bacteriological intubation, but it is about a trying and expensive method. It is currently supplanted by the respiratory test to hydrogen after ingestion of glucose that is simple, no invasive and little expensive. The treatment usually consists on the repeated administration of antibiotics and nutritional support. PMID:11458610

Bouhnik, Y



Shiga Toxin Interaction with Human Intestinal Epithelium  

PubMed Central

After ingestion via contaminated food or water, enterohaemorrhagic E. coli colonises the intestinal mucosa and produces Shiga toxins (Stx). No Stx-specific secretion system has been described so far, and it is assumed that Stx are released into the gut lumen after bacterial lysis. Human intestinal epithelium does not express the Stx receptor Gb3 or other Stx binding sites, and it remains unknown how Stx cross the intestinal epithelial barrier and gain access to the systemic circulation. This review summarises current knowledge about the influence of the intestinal environment on Stx production and release, Stx interaction with intestinal epithelial cells and intracellular uptake, and toxin translocation into underlying tissues. Furthermore, it highlights gaps in understanding that need to be addressed by future research.

Schuller, Stephanie



A Model of Bacterial Intestinal Infections in Drosophila melanogaster  

PubMed Central

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.

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



The role of small intestinal bacterial overgrowth in Parkinson's disease.  


Parkinson's disease is associated with gastrointestinal motility abnormalities favoring the occurrence of local infections. The aim of this study was to investigate whether small intestinal bacterial overgrowth contributes to the pathophysiology of motor fluctuations. Thirty-three patients and 30 controls underwent glucose, lactulose, and urea breath tests to detect small intestinal bacterial overgrowth and Helicobacter pylori infection. Patients also underwent ultrasonography to evaluate gastric emptying. The clinical status and plasma concentration of levodopa were assessed after an acute drug challenge with a standard dose of levodopa, and motor complications were assessed by Unified Parkinson's Disease Rating Scale-IV and by 1-week diaries of motor conditions. Patients with small intestinal bacterial overgrowth were treated with rifaximin and were clinically and instrumentally reevaluated 1 and 6 months later. The prevalence of small intestinal bacterial overgrowth was significantly higher in patients than in controls (54.5% vs. 20.0%; P?=?.01), whereas the prevalence of Helicobacter pylori infection was not (33.3% vs. 26.7%). Compared with patients without any infection, the prevalence of unpredictable fluctuations was significantly higher in patients with both infections (8.3% vs. 87.5%; P?=?.008). Gastric half-emptying time was significantly longer in patients than in healthy controls but did not differ in patients based on their infective status. Compared with patients without isolated small intestinal bacterial overgrowth, patients with isolated small intestinal bacterial overgrowth had longer off time daily and more episodes of delayed-on and no-on. The eradication of small intestinal bacterial overgrowth resulted in improvement in motor fluctuations without affecting the pharmacokinetics of levodopa. The relapse rate of small intestinal bacterial overgrowth at 6 months was 43%. © 2013 Movement Disorder Society. PMID:23712625

Fasano, Alfonso; Bove, Francesco; Gabrielli, Maurizio; Petracca, Martina; Zocco, Maria Assunta; Ragazzoni, Enzo; Barbaro, Federico; Piano, Carla; Fortuna, Serena; Tortora, Annalisa; Di Giacopo, Raffaella; Campanale, Mariachiara; Gigante, Giovanni; Lauritano, Ernesto Cristiano; Navarra, Pierluigi; Marconi, Stefano; Gasbarrini, Antonio; Bentivoglio, Anna Rita



Diagnosis of small intestinal bacterial overgrowth: the challenges persist!  


Small intestinal bacterial overgrowth was originally defined in the context of an overt malabsorption syndrome and diagnostic tests were developed and validated accordingly. More recently, the concept of intestinal contamination with excessive numbers of bacteria, especially those of colonic type, has been extended beyond the bounds of frank maldigestion and malabsorption to explain symptomatology in disorders as diverse as irritable bowel syndrome, celiac sprue and nonalcoholic fatty liver disease. Owing to a lack of consensus with regard to the optimal diagnostic criteria (the 'gold standard') for the diagnosis of bacterial overgrowth, the status of these new concepts is unclear. This review sets out to critically appraise the various diagnostic approaches that have been taken and are currently employed to diagnose small intestinal bacterial overgrowth. PMID:19210115

Abu-Shanab, Ahmed; Quigley, Eamonn Mm



Early bacterial colonisation of the intestine: why it matters La colonizzazione batterica intestinale precoce: perché è importante  

Microsoft Academic Search

Summary The birth process allows the progressive formation of complex intestinal microflora com- posed of myriad bacteria, leading to this recently identified host-bacterial mutualism in the human intestine. This kind of cross-talk originating from birth is opportunistically used by the young host to initiate its own immune system. Recent epidemiological data support the hypothesis that some increasing immune deviances observed



Immunization Against Bacterial Diseases of the Intestine  

Microsoft Academic Search

More than two thirds of the world's infants and chil- dren live in less developed countries, often in conditions in which the unavailability of potable water and sanita- tion and of refrigeration for foods fosters the transmis- sion of enteric pathogens. In such areas, bacterial enteric pathogens are common causes of infant diarrhea, dysen- tery in toddlers, and enteric (typhoid

Myron M. Levine



Small intestinal bacterial overgrowth in patients with rheumatoid arthritis.  

PubMed Central

OBJECTIVES--To examine the microflora of the upper small intestine in patients with seropositive rheumatoid arthritis (RA) using a combination of microbial cultivation and tests for microbial metabolic activity. METHODS--Twenty five patients with seropositive RA, 12 achlorhydric control subjects, and 11 control subjects with normal gastric acid secretion were investigated. Disease activity was evaluated in the patients with RA by three different indices. Eight (32%) of the patients with RA had hypochlorhydria or achlorhydria. The acid secretory capacity was determined with pentagastrin stimulation. A modified Crosby capsule was used to obtain biopsy specimens and samples of intestinal fluid from the proximal jejunum; aerobic and anaerobic microbial cultivation of mucosal specimens/intestinal fluid was carried out, and gas production and microflora associated characteristics in jejunal fluid were determined. Additionally, a bile acid deconjugation breath test was performed. RESULTS--Subjects with at least one of the following findings were considered to have bacterial overgrowth: positive bile acid deconjugation test; growth of Enterobacteriaceae; positive gas production; or low tryptic activity. By these criteria half of the patients with RA with hypochlorhydria or achlorhydria and half of the achlorhydric controls had bacterial overgrowth. Thirty five per cent of the patients with RA with normal gastric acid secretion had bacterial overgrowth compared with none of the normal controls. Disease activity indices and rheumatoid factor titres were significantly higher in patients with RA with bacterial overgrowth than in those without. CONCLUSIONS--A high frequency of small intestinal bacterial overgrowth was found in patients with RA; it was associated with a high disease activity and observed in patients with hypochlorhydria or achlorhydria and in those with normal acid secretion.

Henriksson, A E; Blomquist, L; Nord, C E; Midtvedt, T; Uribe, A



Small Intestinal Bacterial Overgrowth Recurrence After Antibiotic Therapy  

Microsoft Academic Search

OBJECTIVES:Current treatment for small intestinal bacterial overgrowth (SIBO) is based on courses of broad-spectrum antibiotics. No data concerning SIBO recurrence are available. The aims of the present study were to investigate SIBO recurrence as assessed by glucose breath test (GBT) after antibiotic treatment and conditions associated to SIBO recurrence.METHODS:Eighty consecutive patients affected by SIBO and decontaminated by rifaximin (1,200 mg

Ernesto C. Lauritano; Maurizio Gabrielli; Emidio Scarpellini; Andrea Lupascu; Marialuisa Novi; Sandra Sottili; Giovanna Vitale; Valentina Cesario; Michele Serricchio; Giovanni Cammarota; Giovanni Gasbarrini; Antonio Gasbarrini



Small intestinal bacterial overgrowth in patients with irritable bowel syndrome  

Microsoft Academic Search

Background: Small intestinal bacterial overgrowth (SIBO) has been proposed to be common in irritable bowel syndrome (IBS), with altered small-bowel motility as a possible predisposing factor.Aim: To assess the prevalence of SIBO, by culture of small-bowel aspirate, and its correlation to symptoms and motility in IBS.Methods: 162 patients with IBS who underwent small-bowel manometry and culture of jejunal aspirate were

Iris Posserud; Per-Ove Stotzer; Einar S Bjo?rnsson; Hasse Abrahamsson; Magnus Simre?n



A model for Vibrio cholerae colonization of the human intestine  

PubMed Central

Vibrio cholerae is a strict human pathogen that causes the disease cholera. It is an old-world pathogen that has re-emerged as a new threat since the early 1990s. V. cholerae colonizes the upper, small intestine where it produces a toxin that leads to watery diarrhea, characterizing the disease [36]. The dynamics of colonization by the bacteria of the intestines are largely unknown. Although a large initial infectious dose is required for infection, data suggests that only a smaller sub-population colonizes a portion of the small bowel leading to disease. There are many barriers to colonization in the intestines including peristalsis, fluid wash-out, viscosity of the mucus layer, and pH. We are interested in identifying the mechanisms that allow this sub-population of bacteria to survive and colonize the intestines when faced with these barriers. To elaborate the dynamics of V. cholerae infection, we have developed a mathematical model based on a convection-diffusion-reaction-swimming equation capturing bacterial dynamics coupled with Stokes equations governing fluid velocity where we developed a novel non-local boundary condition. Our results indicate that both host and bacterial factors contribute to bacterial density in the gut. Host factors include intestinal diffusion and convection rates while bacterial factors include adherence, motility and growth rates. This model can ultimately be used to test therapeutic strategies against V. cholerae.

Spagnuolo, Anna Maria; DiRita, Victor; Kirschner, Denise



Effect of fermented soy milk on the intestinal bacterial ecosystem  

Microsoft Academic Search

Abstract Abstract Abstract Abstract AIM: To investigate the effect of fermented soy milk on human ecosystem in the intestinal tract by way of examining the population of different microorganisms isolated from fecal samples. METHODS: A crossover experimental design was applied. Twenty-eight healthy adults completed this experiment. Each subject consumed 250 mL, twice a day between meals, of either fermented soy

I-Chi Cheng; Huey-Fang Shang; Tzann-Feng Lin; Tseng-Hsing Wang; Hao-Sheng Lin; Shyh-Hsiang Lin



Patients with Chronic Renal Failure Have Abnormal Small Intestinal Motility and a High Prevalence of Small Intestinal Bacterial Overgrowth  

Microsoft Academic Search

Background\\/Aims: Gastrointestinal (GI) symptoms are common among patients with chronic renal failure (CRF). The pathogenesis of these symptoms is probably multifactorial. Our aims were to assess gastric and small intestinal motility and the prevalence of small intestinal bacterial overgrowth (SIBO) in order to clarify possible pathophysiological mechanisms behind these symptoms in CRF patients. Methods: Twenty-two patients with CRF, 12 with

Hans Strid; Magnus Simrén; Per-Ove Stotzer; Gisela Ringström; Hasse Abrahamsson; Einar S. Björnsson



High-Throughput Quantitative Analysis of the Human Intestinal Microbiota with a Phylogenetic Microarray  

Microsoft Academic Search

Gut microbiota carry out key functions in health and participate in the pathogenesis of a growing number of diseases. The aim of this study was to develop a custom microarray that is able to identify hundreds of intestinal bacterial species. We used the Entrez nucleotide database to compile a data set of bacterial 16S rRNA gene sequences isolated from human

Oleg Paliy; Harshavardhan Kenche; Frank Abernathy; Sonia Michail



The Mucin degrader Akkermansia muciniphila is an abundant resident of the human intestinal tract.  


A 16S rRNA-targeted probe, MUC-1437, was designed and validated in order to determine the presence and numbers of cells of Akkermansia muciniphila, a mucin degrader, in the human intestinal tract. As determined by fluorescent in situ hybridization, A. muciniphila accounted more than 1% of the total fecal cells and was shown to be a common bacterial component of the human intestinal tract. PMID:18083887

Derrien, Muriel; Collado, M Carmen; Ben-Amor, Kaouther; Salminen, Seppo; de Vos, Willem M



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

NASA Astrophysics Data System (ADS)

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.

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



Bacterial translocation and changes in the intestinal microbiome in mouse models of liver disease  

PubMed Central

Background & Aims Intestinal dysbiosis and bacterial translocation is common in patients with advanced liver disease, and there is strong evidence that the translocation of bacteria and their products across the epithelial barrier drives experimental liver disease progression. The aims of our study were to investigate dynamics of bacterial translocation and changes in the enteric microbiome in early stages of liver disease. Methods Cholestatic liver injury was induced by ligation of the common bile duct (BDL) and toxic liver injury by injection of carbon tetrachloride (CCl4) in mice. Results Increased intestinal permeability and bacterial translocation occurred one day following liver injury in both disease models. This was accompanied by decreased intestinal expression of the tight junction protein occludin. Although BDL resulted in a rapid onset of intestinal bacterial overgrowth, bacterial overgrowth was observed in mice injected with CCl4 only in advanced stages of liver fibrosis. To further assess the qualitative changes in the intestinal microbiome, massively parallel pyrosequencing of 16S rRNA genes revealed minor microbial changes following BDL, while CCl4 administration resulted in a relative abundance of Firmicutes and Actinobacteria compared with oil injected mice. Four different liver disease models (cholestasis, toxic, alcohol, obesity) show few similarities in their intestinal microbiome. Conclusions Acute liver injury is associated with an early onset of increased intestinal permeability and bacterial translocation that precede changes in the microbiome. The enteric microbiome differs with respect to the etiology of liver disease.

Fouts, Derrick E.; Torralba, Manolito; Nelson, Karen E.; Brenner, David A.; Schnabl, Bernd



Bacterial translocation and changes in the intestinal microbiome associated with alcoholic liver disease  

PubMed Central

Alcoholic liver disease progresses through several stages of tissue damage, from simple steatosis to alcoholic hepatitis, fibrosis, or cirrhosis. Alcohol also affects the intestine, increases intestinal permeability and changes the bacterial microflora. Liver disease severity correlates with levels of systemic bacterial products in patients, and experimental alcoholic liver disease is dependent on gut derived bacterial products in mice. Supporting evidence for the importance of bacterial translocation comes from animal studies demonstrating that intestinal decontamination is associated with decreased liver fibrogenesis. In addition, mice with a gene mutation or deletion encoding receptors for either bacterial products or signaling molecules downstream from these receptors, are resistant to alcohol-induced liver disease. Despite this strong association, the exact molecular mechanism of bacterial translocation and of how changes in the intestinal microbiome contribute to liver disease progression remains largely unknown. In this review we will summarize evidence for bacterial translocation and enteric microbial changes in response to alcoholic liver injury and chronic alcoholic liver disease. We will further describe consequences of intestinal dysbiosis on host biology. We finally discuss how therapeutic interventions may modify the gastrointestinal microflora and prevent or reduce alcoholic liver disease progression.

Yan, Arthur W; Schnabl, Bernd



Bovine colostrum prevents bacterial translocation in an intestinal ischemia/reperfusion-injured rat model.  


This study evaluated whether or not bovine colostrum (BC) is able to treat or prevent intestinal barrier damage, bacterial translocation, and the related systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction syndrome (MODS) in an intestinal ischemia/reperfusion (I/R)-injured rat model. Fifty Sprague-Dawley rats were used. The rats' intestinal I/R injuries were induced by clamping the superior mesenteric artery for 30 minutes. After 3 hours of reperfusion and then twice daily reclamping during the experiment, the experimental group was given BC (4 mL/kg/day) perorally, and the other groups received 0.9% saline and low fat milk (LFM) after intestinal I/R injury. Seventy-two hours later we assessed (1) intestinal damage and intestinal permeability, (2) enteric bacterial count and bacterial translocation, (3) serum albumin, protein, and hepatic enzyme levels, (4) pathologic findings of ileum and lung, (5) activity of oxygen-free radical species, and (6) pro-inflammatory cytokines (tumor necrosis factor-alpha and interleukin-1beta). Intestinal damage, intestinal permeability, and bacterial translocation to other organs were significantly reduced in rats fed with BC after I/R when compared to rats fed LFM/saline after I/R (P < .05). In the evaluation of acute lung injury, neutrophils were found only in the lungs of the saline-fed group after I/R, and the wet/dry ratio of the lung tissue was significantly reduced in the BC-fed group after I/R compared to other I/R groups. A marked difference was found between LFM/saline-fed groups and BC-fed groups regarding malondialdehyde (P < .05) and pro-inflammatory cytokines (P < .01). In conclusion, BC may have beneficial effects in treating and preventing intestinal barrier damage, bacterial translocation and the related SIRS and MODS in the intestinal I/R-injured rat model. PMID:19298194

Choi, Han Sung; Jung, Kyung Hee; Lee, Seung Chul; Yim, Sung Vin; Chung, Joo-Ho; Kim, Youn Wha; Jeon, Woo Kyu; Hong, Hoon Pyo; Ko, Young Gwan; Kim, Chul-Ho; Jang, Ki-Hyo; Kang, Soon Ah



[The intestinal microbiota and human disease].  


Advances in sequencing technology and the development of metagenomics have opened up new ways to investigate the microorganisms inhabiting the human gut. The intestinal microbiota confer protection against pathogens, contribute to the maturation of the immune system, and regulate host metabolism. The composition of gut microbiota in early life is influenced by mode of birth, diet, and antibiotics. Decreased biodiversity and alterations in the composition of the intestinal microbiota have been observed in many diseases including obesity, neonatal necrotizing enterocolitis, inflammatory bowel disease, and recurrent Clostridium difficile infection. Therapeutic options for the diseases linked to imbalance in the microbiota include modifying the gut microbiota through diet, probiotics, and fecal transplants. PMID:23981941

Ko, Jae Sung



Etiologic structure of bacterial intestinal infections in monkeys of Adler breeding center.  


We studied etiologic structure of bacterial intestinal infections in monkeys of Adler nursery. A total of 533 monkeys with diarrhea syndrome and monkeys dead from intestinal infections, as well as clinically healthy monkeys and animals dead from other pathologies were examined by bacteriological and molecular-genetic methods. Pathogenic enterobacteria Shigella and Salmonella and microaerophile Campylobacter were found in 5 and 19%, respectively. A high percentage (49%) of intestinal diseases of unknown etiology was revealed in monkeys. The fact that the number of detected opportunistic enterobacteria did not differ in healthy and diseased monkeys suggests that they are not involved into the etiology of intestinal disease. PMID:22485220

Ardasheliya, S N; Kalashnikova, V A; Dzhikidze, E K



Composition, Diversity, and Origin of the Bacterial Community in Grass Carp Intestine  

PubMed Central

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.

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



Bacterial population in intestines of the black tiger shrimp (Penaeus monodon) under different growth stages.  


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

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



Secretory immunoglobulin A, intestinal mucin, and mucosal permeability in nutritionally induced bacterial translocation in rats.  

PubMed Central

OBJECTIVE. The authors investigated the role of mucin and secretory immunoglobulin A (slgA) in a model of nutritionally induced bacterial translocation. BACKGROUND. Parenteral and certain elemental diets have been shown to impair intestinal barrier function, whereas fiber has been shown to protect against nutritionally induced bacterial translocation. However, the factors responsible for these phenomenon have not been fully determined. METHODS. Intestinal mucin levels, mucosal protein content, slgA, intestinal morphology, and permeability to horseradish peroxidase, bacterial translocation, and intestinal bacterial population levels were measured in rats 7 days after receiving total parenteral nutrition (TPN) solution (28% glucose, 4.25% amino acids; 307 kcal/kg/day) enterally (ORAL-TPN) or parenterally (IV-TPN) with or without enteral bulk fiber supplementation. Chow-fed rats served as control subjects. RESULTS. The incidence of bacterial translocation in the ORAL-TPN and IV-TPN groups was reduced significantly by the provision of fiber (p < 0.05). Mucosal protein, slgA, and insoluble mucin levels were decreased in the jejunum of the ORAL-TPN and IV-TPN groups, with mucosal protein levels being decreased to a greater extent than slgA or mucin. Although similar decreases in these parameters were observed in the fiber-fed groups, fiber appeared to improve intestinal barrier function as measured by horseradish peroxidase permeability. CONCLUSIONS. The provision of bulk-forming fiber improves intestinal barrier function as measured by peroxidase permeability and bacterial translocation, but does not restore mucosal protein content, intestinal mucin, or slgA levels to normal. Images Figure 2. Figure 3. Figure 4. Figure 5.

Spaeth, G; Gottwald, T; Specian, R D; Mainous, M R; Berg, R D; Deitch, E A



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

SciTech Connect

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.

Grant, D.; Hurlbut, D.; Zhong, R.; Wang, P.Z.; Chen, H.F.; Garcia, B.; Behme, R.; Stiller, C.; Duff, J. (University of Western Ontario (Canada))



The Human Intestinal Microbiome: A New Frontier of Human Biology  

PubMed Central

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.

Hattori, Masahira; Taylor, Todd D.



Interaction of bacteria and bacterial toxins with intestinal epithelial cells  

Microsoft Academic Search

The epithelium of the intestinal tract is a key barrier between the external environment and the internal body environment.\\u000a Intestinal epithelial cells are targets for luminal bacteria and viruses and must discriminate between pathogenic and nonpathogenic\\u000a commensal organisms. Pathogenic bacteria and their secreted products influence epithelial cell function and induce diarrhea\\u000a by numerous mechanisms that range from an effect on

Asma Nusrat; Shanthi V. Sitaraman; Andrew Neish



Bacterial Diversity within the Human Subgingival Crevice  

Microsoft Academic Search

Molecular, sequence-based environmental surveys of microorganisms have revealed a large degree of previously uncharacterized diversity. However, nearly all studies of the human endogenous bacterial flora have relied on cultivation and biochemical characterization of the resident organisms. We used molecular methods to characterize the breadth of bacterial diversity within the human subgingival crevice by comparing 264 small subunit rDNA sequences from

Ian Kroes; Paul W. Lepp; David A. Relman



Eradication of small intestinal bacterial overgrowth reduces symptoms of irritable bowel syndrome  

Microsoft Academic Search

OBJECTIVES:Irritable bowel syndrome is the most common gastrointestinal diagnosis. The symptoms of irritable bowel syndrome are similar to those of small intestinal bacterial overgrowth. The purpose of this study was to test whether overgrowth is associated with irritable bowel syndrome and whether treatment of overgrowth reduces their intestinal complaints.METHODS:Two hundred two subjects in a prospective database of subjects referred from

Mark Pimentel; Evelyn J. Chow; Henry C. Lin



Quantification of Intestinal Bacterial Populations by Real-Time PCR with a Universal Primer Set and Minor Groove Binder Probes: a Global Approach to the Enteric Flora  

Microsoft Academic Search

The composition of the human intestinal flora is important for the health status of the host. The global composition and the presence of specific pathogens are relevant to the effects of the flora. Therefore, accurate quantification of all major bacterial populations of the enteric flora is needed. A TaqMan real-time PCR-based method for the quantification of 20 dominant bacterial species

Stephan J. Ott; Meike Musfeldt; Uwe Ullmann; Jochen Hampe; Stefan Schreiber



Vitamin D Receptor Negatively Regulates Bacterial-Stimulated NF-?B Activity in Intestine  

PubMed Central

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)-?B pathway in intestinal epithelial cells remain unexplored. This study investigated the effects of VDR ablation on NF-?B 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-?B 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-?B 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-?B activation and attenuates response to infection. Therefore, VDR is an important contributor to intestinal homeostasis and host protection from bacterial invasion and infection.

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



The Role of Milk Sialyllactose in Intestinal Bacterial Colonization123  

PubMed Central

Milk oligosaccharides influence the composition of intestinal microbiota and thereby mucosal inflammation. Some of the major milk oligosaccharides are ?2,3-sialyllactose (3SL) and ?2,6-sialyllactose, which are mainly produced by the sialyltransferases ST3GAL4 and ST6GAL1, respectively. Recently, we showed that mice fed milk deficient in 3SL were more resistant to dextran sulfate sodium-induced colitis. By contrast, the exposure to milk containing or deficient in 3SL had no impact on the development of mucosal leukocyte populations. Milk 3SL mainly affected the colonization of the intestine by clostridial cluster IV bacteria.

Weiss, G. Adrienne; Hennet, Thierry



Bacterial diversity in the intestinal tract of the fungus- cultivating termite Macrotermes michaelseni (Sjöstedt)  

Microsoft Academic Search

Microorganisms in the intestinal tracts of termites play a crucial role in the nutritional physiology of termites. The bacterial diversity in the fungus-cultivating Macrotermes michaelseni was examined using both molecular and culture dependent methods. Total DNA was extracted from the gut of the termite and 16S rRNA genes were amplified using bacterial specific primers. Representatives from forty-one (41) RFLP patterns

Lucy Mwende Mackenzie; Anne Thairu Muigai; Ellie Onyango Osir; Wilber Lwande; Martin Keller; Gerardo Toledo; Hamadi Iddi Boga



Expression of intestinal alkaline phosphatase in human organs  

Microsoft Academic Search

Human intestinal alkaline phosphatase was immunohistochemically identified and localized in the pancreas, liver and kidney by use of a monoclonal antibody specific for intestinal alkaline phosphatase isozyme and by amplified biotin-streptavidin staining. In all the examined organs, the intestinal isozyme was found to be localized in the epithelial cells of ducts: bile ducts in the liver, distal convoluted tubules and

Ulla Domar; Berith Nilsson; Vladimir Baranov; Ulf Gerdes; Torgny Stigbrand



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


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

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



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


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 - ?)) ]. 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

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



Small intestinal bacterial overgrowth is diagnosed in some cases of irritable bowel syndrome  

Microsoft Academic Search

Introduction: Irritable bowel syndrome (IBS) is a chronic gastrointestinal tract disfunction characterized by abdominal pain (or discomfort) and alteration in bowel movements. The etiology of presented symptoms despite numerous studies is unclear. Small intestinal bacterial overgrowth (SIBO) is one of potential factors causing symptoms of some gastrointe- stinal functional disorders. The aim of the study was to check whether SIBO

Agnieszka Meder


Modulation of Intestinal Goblet Cell Function during Infection by an Attaching and Effacing Bacterial Pathogen  

Microsoft Academic Search

The attaching and effacing (A\\/E) bacterial pathogens enteropathogenic Escherichia coli and enterohemor- rhagic E. coli and the related mouse pathogen Citrobacter rodentium colonize their hosts' intestines by infecting the apical surfaces of enterocytes, subverting their function, and they ultimately cause diarrhea. Surprisingly, little is known about the interactions of these organisms with goblet cells, which are specialized epithelial cells that

Kirk S. B. Bergstrom; Julian A. Guttman; Mohammad Rumi; Caixia Ma; Saied Bouzari; Mohammed A. Khan; Deanna L. Gibson; A. Wayne Vogl; Bruce A. Vallance



[Bacterial overgrowth syndrome in the small intestine: pathogenesis, clinical significance and therapy tactics].  


The redundant bacterial growth syndrome in the small intestine is associated with the increased total semination of over 10(5) CFU/ml presented by enterobacteria, bacteroids, clostridia, fusobacteria, etc. It is developed at the dysfunction of the gastrointestinal tract, insufficient bacteria inhibition at the time when they come from the large intestine (atony, stasis, bypasses) and is accompanied by the enhanced intestinal barrier permeability along with chronic diarrhea and intoxication. Intestinal absorption disorders cause B12-deficiency anemia, hypovitaminosis and protein deficiency. The redundant growth is diagnosed based on the hydrogen concentration in the expired air or bacterial inoculation of the small intestine aspirate. Tetracycline, Vancomycin, Metronidazole and aminoglycoside are used for the therapy; Amoxicillin/clavunate and cephalosporins of the second generation are also applied with success. Decontamination of the small intestine is more successful when probiotics are prescribed (both after antibiotics and independently), which suppress the opportunistic flora, protect the mucous coat, improve digestion and arrest diarrhea. Probifor or Bifidumbacterin forte in the complex with probiotics comprising lactobacteria can also have a therapeutic effect. PMID:17378388

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



The treatment of small intestinal bacterial overgrowth with enteric-coated peppermint oil: a case report.  


Recent investigations have shown that bacterial overgrowth of the small intestine is associated with a number of functional somatic disorders, including irritable bowel syndrome (IBS), fibromyalgia, and chronic fatigue syndrome. A number of controlled studies have shown that enteric-coated peppermint oil (ECPO) is of benefit in the treatment of IBS. However, despite evidence of strong antimicrobial activity, ECPO has not been specifically investigated for an effect on small intestinal bacterial overgrowth (SIBO). A case report of a patient with SIBO who showed marked subjective improvement in IBS-like symptoms and significant reductions in hydrogen production after treatment with ECPO is presented. While further investigation is necessary, the results in this case suggest one of the mechanisms by which ECPO improves IBS symptoms is antimicrobial activity in the small intestine. PMID:12410625

Logan, Alan C; Beaulne, Tracey M



Human intestinal fatty acid binding protein: Report of an assay with studies in normal volunteers and intestinal ischemia  

Microsoft Academic Search

Background. Human intestinal fatty acid binding protein (hIFABP) is a cytoplasmic protein of mature small intestinal epithelium. Work with the rat demonstrated that serum levels of IFABP correlated with early phases of intestinal mucosal injury. The aim of this study was to develop an assay for hIFABP and assess its usefulness as a marker for intestinal mucosal injury in human

Joshua M Lieberman; James Sacchettini; Christine Marks; William H Marks



Liquid enteral diets induce bacterial translocation by increasing cecal flora without changing intestinal motility.  


The aim of this study was to determine the contribution of intestinal motility and cecal bacterial overgrowth to liquid diet-induced bacterial translocation (BT). Three different commercially available liquid diets were offered to mice for 1 week. BT to the mesenteric lymph nodes (MLN), spleen, and liver were examined as well as cecal bacterial counts and populations, small bowel length and weight, and histopathologic changes in the ileal and jejunal mucosa. In addition, the effect of the various diets on intestinal motility was measured by the transit index of a charcoal mixture introduced into the stomach. The incidence of BT to the mesenteric lymph nodes was significantly and similarly increased (p < .05) in mice fed Vivonex (30%), Ensure (30%), and Osmolite (33%) compared with chow-fed controls (0%). Compared with chow-fed controls, all three liquid diets were associated with the development of cecal bacterial overgrowth (p < .01). There were no significant changes in the transit index for the three liquid diet groups compared with the chow-fed controls. BT to the MLN was induced by all three liquid diets tested, casting some doubts as to their role in preventing BT in clinical use. BT was associated with a statistically significant increase in cecal bacterial count but was not associated with gut motility changes in this model. In fact, no significant changes in intestinal motility were noted in all groups tested. PMID:11284471

Haskel, Y; Udassin, R; Freund, H R; Zhang, J M; Hanani, M


Surface Expression of Toll-Like Receptor 9 Is Upregulated on Intestinal Epithelial Cells in Response to Pathogenic Bacterial DNA  

Microsoft Academic Search

Colonic epithelial cells are constantly exposed to high levels of bacterial DNA in the intestinal lumen and must recognize and respond appropriately to pathogens, while they maintain a tolerance to non- pathogenic commensal bacterial strains. Bacterial DNA is recognized by Toll-like receptor 9 (TLR9). The aim of this study was to investigate TLR9 expression and localization in colonic epithelial cells

Julia B. Ewaschuk; Jody L. Backer; Thomas A. Churchill; Florian Obermeier; Denis O. Krause; Karen L. Madsen



Intestinal bacterial community and growth performance of chickens fed diets containing antibiotics.  


This study was conducted to relate the performance of broiler chickens fed diets containing growth-promoting antibiotics to changes in the intestinal microbiota. The technique of denaturing gradient gel electrophoresis (DGGE) of amplicons of the region V3 of 16S rDNA was used to characterize the microbiota. Two experiments were conducted, one with broilers raised in battery cages and the other with broilers raised in floor pens. Antibiotics improved the performance of the chickens raised in floor pens only. Avilamycin, bacitracin methylene disalicylate, and enramycin induced changes in the composition of the intestinal bacterial community of the birds in both experiments. The number of bacterial genotypes found in the intestinal tract of chickens was not reduced by the antibiotics supplemented in either environment. However, the changes in the composition of the intestinal bacterial community induced by antibiotics may be related to improvement in growth performance. This was indicated by the suppression of 6 amplicons and the presence of 4 amplicons exclusive to the treatment that had the best performance in the floor pen experiment. PMID:16615359

Pedroso, A A; Menten, J F M; Lambais, M R; Racanicci, A M C; Longo, F A; Sorbara, J O B



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

PubMed Central

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 ?-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.

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




PubMed Central

Cytochromes P450 (P450s) 3A, 2C, and 1A2 constitute the major “pieces” of the human liver P450 “pie” and account, on average, for 40, 25, and 18%, respectively, of total immunoquantified P450s (J Pharmacol Exp Ther 270:414–423, 1994). The P450 profile in the human small intestine has not been fully characterized. Therefore, microsomes prepared from mucosal scrapings from the duodenal/jejunal portion of 31 human donor small intestines were analyzed by Western blot using selective P450 antibodies. P450s 3A4, 2C9, 2C19, and 2J2 were detected in all individuals and ranged from 8.8 to 150, 2.9 to 27, <0.6 to 3.9, and <0.2 to 3.1 pmol/mg, respectively. CYP2D6 was detected in 29 individuals and ranged from <0.2 to 1.4 pmol/mg. CYP3A5 was detected readily in 11 individuals, with a range (average) of 4.9 to 25 (16) pmol/mg that represented from 3 to 50% of total CYP3A (CYP3A4 + CYP3A5) content. CYP1A1 was detected readily in three individuals, with a range (average) of 3.6 to 7.7 (5.6) pmol/mg. P450s 1A2, 2A6, 2B6, 2C8, and 2E1 were not or only faintly detected. As anticipated, average CYP3A content (50 pmol/mg) was the highest. Excluding CYP1A1, the remaining enzymes had the following rank order: 2C9 > 2C19 > 2J2 > 2D6 (8.4, 1.1, 0.9, and 0.5 pmol/mg, respectively). Analysis of a pooled preparation of the 31 donor specimens substantiated these results. In summary, as in the liver, large interindividual variation exists in the expression levels of individual P450s. On average, CYP3A and CYP2C9 represents the major pieces of the intestinal P450 pie, accounting for 80 and 15%, respectively, of total immunoquantified P450s.

Paine, Mary F.; Hart, Heather L.; Ludington, Shana S.; Haining, Robert L.; Rettie, Allan E.; Zeldin, Darryl C.



Inhibition of human intestinal ?-glucosidases by calystegines.  


Calystegines are polyhydroxylated nortropane alkaloids found in Convolvulaceae, Solanaceae, and other plant families. These plants produce common fruits and vegetables. The calystegine structures resemble sugars and suggest interaction with enzymes of carbohydrate metabolism. Maltase and sucrase are ?-glucosidases contributing to human carbohydrate degradation in the small intestine. Inhibition of these enzymes by orally administered drugs is one option for treatment of diabetes mellitus type 2. In this study, inhibition of maltase and sucrase by calystegines A3 and B2 purified from potatoes was investigated. In silico docking studies confirmed binding of both calystegines to the active sites of the enzymes. Calystegine A3 showed low in vitro enzyme inhibition; calystegine B2 inhibited mainly sucrose activity. Both compounds were not transported by Caco-2 cells indicating low systemic availability. Vegetables rich in calystegine B2 should be further investigated as possible components of a diet preventing a steep increase in blood glucose after a carbohydrate-rich meal. PMID:23697377

Jockovi?, Nebojša; Fischer, Wiebke; Brandsch, Matthias; Brandt, Wolfgang; Dräger, Birgit



Campylobacter-induced interleukin-8 responses in human intestinal epithelial cells and primary intestinal chick cells  

Microsoft Academic Search

Campylobacter (C.) jejuni and C. coli can cause gastrointestinal disorders in humans characterized by acute inflammation. Inflammatory signals are initiated during interaction between these pathogens and human intestinal cells, but nothing is known about the stimulation of avian intestinal cells by Campylobacter. Interleukin-8 (IL-8) as a proinflammatory chemokine plays an important role in mobilizing cellular defence mechanism. IL-8 mRNA expression

Erika Borrmann; Angela Berndt; Ingrid Hänel; Heike Köhler



Bacterial contamination of enteral nutrient solutions: intestinal colonization and sepsis in mice after ingestion.  


Contaminated enteral nutrient solution (ENS) was used to assess the risks of intestinal colonization and invasive sepsis using normal mice. Dilute Osmolite containing 10(6) Group B Streptococci/ml given for 2 to 10 consecutive days resulted in the detection of organisms by rectal washing sampling and in the recovery of 10(3) to 10(4) organisms from the cecum, large intestine, and rectum. Only 10(1) organisms survived in the small intestine. Colonization, or the persistence of organisms for 10 days after exposure, was produced after 2 days of ingestion in 44% of animals and in 100% after exposure for 5 days. There were 39 septic deaths. During the 7-day ingestion interval 15 died and 24 died within 10 days after exposure. The risk of sepsis was highest for young mice. Ways to minimize bacterial contamination of ENS intended for administration to patients are discussed. PMID:3093708

Van Enk, R A; Furtado, D


Small Intestinal Bacterial Overgrowth in Patients with Interstitial Cystitis and Gastrointestinal Symptoms  

Microsoft Academic Search

Purpose Interstitial cystitis (IC) often coexists with irritable bowel syndrome (IBS). IBS may be explained by small-intestinal bacterial\\u000a overgrowth (SIBO), which increases immune activation and visceral hypersensitivity. This prospective pilot study tested hypotheses\\u000a that IC patients with gastrointestinal (GI) symptoms have SIBO, that nonabsorbable antibiotic use improves symptoms, and that\\u000a improvement is sustained by prokinetic therapy. Methods Consecutive IC patients

Leonard B. Weinstock; Carl G. Klutke; Henry C. Lin



Molecular analysis of intestinal bacterial microbiota of broiler chickens fed diets containing fermented cottonseed meal.  


The study was conducted to investigate the effects of dietary inclusion of fermented cottonseed meal (FCM) on the ileal and cecal bacterial microbiota of broiler chickens. A total of 300 newborn yellow-feathered broiler chickens were randomly divided into 2 treatments with 3 replicates each (50 birds per replicate): control and 80 g/kg of FCM group. The feeding trial lasted for 42 d. Ileal and cecal digesta samples were collected from 8 chicks per replicate at 21 and 42 d of age to determine the composition of bacterial microbiota using denaturing gradient gel electrophoresis, cloning, sequencing, and real-time quantitative PCR analysis. The results demonstrated that the microbial composition in the ileum and cecum were considerably affected by the diet. The similarity dendrogram of banding profiles showed a more rapid stabilization of intestinal bacterial microbiota in broilers fed diets supplemented with FCM, compared with that of the birds fed the control diet. No significant difference was observed in total number of bands and Shannon-Weaver index, indicating that FCM had no effects on bacterial diversity. However, enumeration of bacteria in the ileal and cecal contents by quantitative PCR showed an increased (P < 0.05) population of lactobacilli, as well as a decreased (P < 0.05) Escherichia coli number by the dietary inclusion of FCM. In summary, dietary inclusion of FCM did not affect the intestinal microbial diversity but shifted intestinal microbiota, with a more homogenous population and an increased colonization of lactobacilli. The results also support the concept that dietary FCM inclusion could promote the beneficial bacteria in the intestinal tract. PMID:23300306

Sun, H; Tang, J W; Fang, C L; Yao, X H; Wu, Y F; Wang, X; Feng, J



Small Intestinal Motility Disturbances and Bacterial Overgrowth in Patients With Liver Cirrhosis and Portal Hypertension  

Microsoft Academic Search

OBJECTIVES:Altered small bowel motility and a high prevalence of small intestinal bacterial overgrowth (SIBO) has been observed in patients with liver cirrhosis. Our aim was to explore the relationship between motility abnormalities, portal hypertension, and SIBO.METHODS:Twenty-four patients with liver cirrhosis were included. Twelve had portal hypertension (PH) and 12 had liver cirrhosis (LC) alone. Child-Pugh score was the same in

Steingerdur Anna Gunnarsdottir; Riadh Sadik; Steven Shev; Magnus Simrén; Henrik Sjövall; Per-Ove Stotzer; Hasse Abrahamsson; Rolf Olsson; Einar S. Bjornsson; Anna Gunnarsdottir



The Intestinal Bacterial Community in the Food Waste-Reducing Larvae of Hermetia illucens  

Microsoft Academic Search

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\\u000a the ability of catabolic degradation by BSF larvae might be due to intestinal microorganisms. Herein, we analysed the bacterial\\u000a communities in the gut of BSF larvae

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



Antimicrobial peptides in innate immunity of the human intestine  

Microsoft Academic Search

The intestinal mucosa has to withstand exposure to a variety of substances, challenges in pH, temperature, and osmolarity; and, finally, bacterial products which might induce local and systemic inflammatory responses. The mucosal integrity is conserved by a defense system which consisting of constitutive and inducible mechanisms. These include the physical barrier function; the secretion of factors into the lumen, such

Jan-Michel Otte; Karlheinz Kiehne; Karl-Heinz Herzig



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

Microsoft Academic Search

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

Erik RM Eckhardt; Jassir Witta; Jian Zhong; Razvan Arsenescu; Violeta Arsenescu; Yu Wang; Sarbani Ghoshal; Marcielle C de Beer; Frederick C de Beer; Willem JS de Villiers



Intestinal bacterial overgrowth includes potential pathogens in the carbohydrate overload models of equine acute laminitis.  


Carbohydrate overload models of equine acute laminitis are used to study the development of lameness. It is hypothesized that a diet-induced shift in cecal bacterial communities contributes to the development of the pro-inflammatory state that progresses to laminar failure. It is proposed that vasoactive amines, protease activators and endotoxin, all bacterial derived bioactive metabolites, play a role in disease development. Questions regarding the oral bioavailability of many of the bacterial derived bioactive metabolites remain. This study evaluates the possibility that a carbohydrate-induced overgrowth of potentially pathogenic cecal bacteria occurs and that bacterial translocation contributes toward the development of the pro-inflammatory state. Two groups of mixed-breed horses were used, those with laminitis induced by cornstarch (n=6) or oligofructan (n=6) and non-laminitic controls (n=8). Cecal fluid and tissue homogenates of extra-intestinal sites including the laminae were used to enumerate Gram-negative and -positive bacteria. Horses that developed Obel grade2 lameness, revealed a significant overgrowth of potentially pathogenic Gram-positive and Gram-negative intestinal bacteria within the cecal fluid. Although colonization of extra-intestinal sites with potentially pathogenic bacteria was not detected, results of this study indicate that cecal/colonic lymphadenopathy and eosinophilia develop in horses progressing to lameness. It is hypothesized that the pro-inflammatory state in carbohydrate overload models of equine acute laminitis is driven by an immune response to the rapid overgrowth of Gram-positive and Gram-negative cecal bacterial communities in the gut. Further equine research is indicated to study the immunological response, involving the lymphatic system that develops in the model. PMID:22633481

Onishi, Janet C; Park, Joong-Wook; Prado, Julio; Eades, Susan C; Mirza, Mustajab H; Fugaro, Michael N; Häggblom, Max M; Reinemeyer, Craig R



Wnt2 inhibits enteric bacterial-induced inflammation in intestinal epithelial cells  

PubMed Central

Background Wnt signaling plays an essential role in gastrointestinal epithelial proliferation. Most investigations have focused on developmental and immune responses. Bacterial infection can be chronic and increases the risk of inflammatory bowel disease and colitis-associated cancer. However, we lack studies on how bacteria regulate Wnt proteins and how Wnts modulate the host responses to enteric bacteria. This study investigated the effects of Salmonella and E. coli on Wnt2, one of the Wnt family members, in intestinal epithelia cells. Methodology/Findings Using cultured epithelial cells, a Salmonella-colitis mouse model, and a gnotobiotic mouse model, we found that Wnt2 mRNA and protein expression levels were elevated after bacterial infection. Enteric bacteria regulate Wnt2 location in the intestine. Furthermore, we found that elevation of Wnt2 was a strategy for host defense by inhibiting cell apoptosis and inflammatory responses to infection. Using Wnt2 siRNA analysis, we show enhanced inflammatory cytokine IL-8 in epithelial cells. Cells over-expressed Wnt2 had less bacterial-induced IL-8 secretion. AvrA is a bacterial protein that inhibits inflammation by stabilizing beta-catenin, the down-stream target of Wnt. We found that the stabilization of Wnt2 was regulated through ubiquitination. Moreover, the bacterial protein AvrA from Salmonella and E. coli stabilized Wnt2 protein expression in vivo. In an ex-germ-free system, E. coli F18 expressing AvrA increased Wnt2 expression and changed Wnt2 distribution in intestine. Conclusion Wnt2 contributes to host protection in response to enteric bacteria. Our findings thus reveal a previously undefined role of Wnt for host-pathogen interaction and inflammation.

Liu, Xingyin; Lu, Rong; Wu, Shaoping; Zhang, Yong-guo; Xia, Yinglin; Sartor, R. Balfour; Sun, Jun



Milk sialyllactose influences colitis in mice through selective intestinal bacterial colonization.  


Milk oligosaccharides contribute to the development of the intestinal environment by acting as decoy receptors for pathogens and as prebiotics, which promote the colonization of commensal bacteria. Here, using ?2,3- and ?2,6-sialyltransferase-deficient mice, we investigated the role of the sialylated milk oligosaccharides sialyl(?2,3)lactose and sialyl(?2,6)lactose on mucosal immunity. The exposure of newborn mice to milk containing or deficient in sialyllactose had no impact on the development of mucosal leukocyte populations. However, when challenged by dextran sulfate sodium (DSS) in drinking water, adult mice that had been fostered on sialyl(?2,3)lactose-deficient milk were more resistant to colitis compared with mice fostered on normal milk or sialyl(?2,6)lactose-deficient milk. Analysis of intestinal microbiota showed different colonization patterns depending on the presence or absence of sialyl(?2,3)lactose in the milk. Germ-free mice reconstituted with intestinal microbiota isolated from mice fed on sialyl(?2,3)lactose-deficient milk were more resistant to DSS-induced colitis than germ-free mice reconstituted with standard intestinal microbiota. Thus, exposure to sialyllactose during infancy affects bacterial colonization of the intestine, which influences the susceptibility to DSS-induced colitis in adult mice. PMID:21098096

Fuhrer, Andrea; Sprenger, Norbert; Kurakevich, Ekaterina; Borsig, Lubor; Chassard, Christophe; Hennet, Thierry



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

PubMed Central

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.

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



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

SciTech Connect

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.

Scheepers, P.T.J.; Straetemans, M.M.E.; Koopman, J.P.; Bos, R.P. [Univ. of Nijmegen (Netherlands)



Colonization of Mucin by Human Intestinal Bacteria and Establishment of Biofilm Communities in a Two-Stage Continuous Culture System  

Microsoft Academic Search

The human large intestine is covered with a protective mucus coating, which is heavily colonized by complex bacterial populations that are distinct from those in the gut lumen. Little is known of the composition and metabolic activities of these biofilms, although they are likely to play an important role in mucus breakdown. The aims of this study were to determine

Sandra Macfarlane; Emma J. Woodmansey; George T. Macfarlane



Bacterial diversity within the human subgingival crevice  

PubMed Central

Molecular, sequence-based environmental surveys of microorganisms have revealed a large degree of previously uncharacterized diversity. However, nearly all studies of the human endogenous bacterial flora have relied on cultivation and biochemical characterization of the resident organisms. We used molecular methods to characterize the breadth of bacterial diversity within the human subgingival crevice by comparing 264 small subunit rDNA sequences from 21 clone libraries created with products amplified directly from subgingival plaque, with sequences obtained from bacteria that were cultivated from the same specimen, as well as with sequences available in public databases. The majority (52.5%) of the directly amplified 16S rRNA sequences were <99% identical to sequences within public databases. In contrast, only 21.4% of the sequences recovered from cultivated bacteria showed this degree of variability. The 16S rDNA sequences recovered by direct amplification were also more deeply divergent; 13.5% of the amplified sequences were more than 5% nonidentical to any known sequence, a level of dissimilarity that is often found between members of different genera. None of the cultivated sequences exhibited this degree of sequence dissimilarity. Finally, direct amplification of 16S rDNA yielded a more diverse view of the subgingival bacterial flora than did cultivation. Our data suggest that a significant proportion of the resident human bacterial flora remain poorly characterized, even within this well studied and familiar microbial environment.

Kroes, Ian; Lepp, Paul W.; Relman, David A.



High-throughput quantitative analysis of the human intestinal microbiota with a phylogenetic microarray.  


Gut microbiota carry out key functions in health and participate in the pathogenesis of a growing number of diseases. The aim of this study was to develop a custom microarray that is able to identify hundreds of intestinal bacterial species. We used the Entrez nucleotide database to compile a data set of bacterial 16S rRNA gene sequences isolated from human intestinal and fecal samples. Identified sequences were clustered into separate phylospecies groups. Representative sequences from each phylospecies were used to develop a microbiota microarray based on the Affymetrix GeneChip platform. The designed microbiota array contains probes to 775 different bacterial phylospecies. In our validation experiments, the array correctly identified genomic DNA from all 15 bacterial species used. Microbiota array has a detection sensitivity of at least 1 pg of genomic DNA and can detect bacteria present at a 0.00025% level of overall sample. Using the developed microarray, fecal samples from two healthy children and two healthy adults were analyzed for bacterial presence. Between 227 and 232 species were detected in fecal samples from children, whereas 191 to 208 species were found in adult stools. The majority of identified phylospecies belonged to the classes Clostridia and Bacteroidetes. The microarray revealed putative differences between the gut microbiota of healthy children and adults: fecal samples from adults had more Clostridia and less Bacteroidetes and Proteobacteria than those from children. A number of other putative differences were found at the genus level. PMID:19363078

Paliy, Oleg; Kenche, Harshavardhan; Abernathy, Frank; Michail, Sonia



Phytase activity in the human and rat small intestine.  

PubMed Central

Phytate is the major storage form of phosphorus in seeds and so is a common dietary constituent. Excessive ingestion of undegraded phytates can cause mineral deficiencies in humans. In addition, phytic acid is antineoplastic in animal models of both colon and breast carcinoma. There have been no previous studies quantifying phytase activity in the human small intestine although it is present in animals. Small intestinal phytase and alkaline phosphatase activity and distribution was measured in vitro in mucosal homogenates from two human small intestinal specimens obtained from transplant donors. Rat intestine was also studied for comparison. Phytase activity was found in human small intestine at low values (30 times less than that in rat tissue and 1000-fold lower than alkaline phosphatase in the same tissue). The activity was greatest in the duodenum and lowest in the ileum. In conclusion, the normal human small intestine has very limited ability to digest undegraded phytates. Although this may have adverse nutritional consequences with respect to metabolic cation imbalances, the presence of undigested phytate in the colon may protect against the development of colonic carcinoma.

Iqbal, T H; Lewis, K O; Cooper, B T



Fusion between Hematopoietic and Epithelial Cells in Adult Human Intestine  

PubMed Central

Following transplantation of hematopoietic lineage cells, genetic markers unique to the transplanted cells have been detected in non-hematopoietic recipient cells of human liver, vascular endothelium, intestinal epithelium and brain. The underlying mechanisms by which this occurs are unclear. Evidence from mice suggests it is due in part to fusion between cells of hematopoietic and non-hematopoietic origins; however, direct evidence for this in humans is scant. Here, by quantitative and statistical analysis of X- and Y-chromosome numbers in epithelial and non-epithelial intestinal cells from gender-mismatched hematopoietic cell transplant patients, we provide evidence that transplanted cells of the hematopoietic lineage incorporate into human intestinal epithelium through cell fusion. This is the first definitive identification of cell fusion between hematopoietic cells and any epithelial cell type in humans, and provides the basis for further understanding the physiological and potential pathological consequences of cell fusion in humans.

Silk, Alain D.; Gast, Charles E.; Davies, Paige S.; Fakhari, Farnaz D.; Vanderbeek, Gretchen E.; Mori, Motomi; Wong, Melissa H.



Distribution of vasoactive intestinal polypeptide and substance P receptors in human colon and small intestine  

SciTech Connect

Vasoactive intestinal polypeptide (VIP) and substance P are found in neurons in the lamina propria and submucosa and muscularis propria of human small intestine and colon. VIP receptors coupled to adenylate cyclase are present on epithelial, smooth muscle, and mononuclear cells. This study analyzes the distribution of (/sup 125/I)VIP binding and (/sup 125/I)substance P in human colon and small intestine using autoradiographic techniques. (/sup 125/I)VIP binding was present in high density in the mucosal layer of colon and small intestine. (/sup 125/I)VIP binding was not significantly greater than nonspecific binding in smooth muscle layers or the lymphoid follicles. In contrast, (/sup 125/I)substance P binding was present in high density over the colonic muscle but was not present over the mucosal layer. In human colon cancer, (/sup 125/I)VIP grain density over the malignant tissue was only slightly higher than background. These autoradiographic studies of (/sup 125/I)VIP binding indicate that the highest density of VIP receptors was found in the small intestine and superficial colonic mucosa, whereas the density of substance P receptors was highest over the smooth muscle layers. These findings suggest a mismatch between immunochemical content of the peptide and autoradiographic density of the receptor.

Korman, L.Y.; Sayadi, H.; Bass, B.; Moody, T.W.; Harmon, J.W.



Intestinal Epithelial Cells Modulate Antigen-Presenting Cell Responses to Bacterial DNA  

PubMed Central

Intestinal epithelial cells and antigen-presenting cells orchestrate mucosal innate immunity. This study investigated the role of bacterial DNA in modulating epithelial and bone marrow-derived antigen-presenting cells (BM-APCs) and subsequent T-lymphocyte responses. Murine MODE-K epithelial cells and BM-APCs were treated with DNA from either Bifidobacterium breve or Salmonella enterica serovar Dublin directly and under coculture conditions with CD4+ T cells. Apical stimulation of MODE-K cells with S. Dublin DNA enhanced secretion of cytokines from underlying BM-APCs and induced interleukin-17 (IL-17) and gamma interferon (IFN-?) secretion from CD4+ T cells. Bacterial DNA isolated from either strain induced maturation and increased cytokine secretion from BM-APCs. Conditioned medium from S. Dublin-treated MODE-K cells elicited an increase in cytokine secretion similar to that seen for S. Dublin DNA. Treatment of conditioned medium from MODE-K cells with RNase and protease prevented the S. Dublin-induced increased cytokine secretion. Oral feeding of mice with B. breve DNA resulted in enhanced levels of colonic IL-10 and transforming growth factor ? (TGF?) compared with what was seen for mice treated with S. Dublin DNA. In contrast, feeding mice with S. Dublin DNA increased levels of colonic IL-17 and IL-12p70. T cells from S. Dublin DNA-treated mice secreted high levels of IL-12 and IFN-? compared to controls and B. breve DNA-treated mice. These results demonstrate that intestinal epithelial cells are able to modulate subsequent antigen-presenting and T-cell responses to bacterial DNA with pathogenic but not commensal bacterial DNA inducing effector CD4+ T lymphocytes.

Campeau, J. L.; Salim, S. Y.; Albert, E. J.; Hotte, N.



Generating human intestinal tissue from pluripotent stem cells in vitro.  


Here we describe a protocol for generating 3D human intestinal tissues (called organoids) in vitro from human pluripotent stem cells (hPSCs). To generate intestinal organoids, pluripotent stem cells are first differentiated into FOXA2(+)SOX17(+) endoderm by treating the cells with activin A for 3 d. After endoderm induction, the pluripotent stem cells are patterned into CDX2(+) mid- and hindgut tissue using FGF4 and WNT3a. During this patterning step, 3D mid- or hindgut spheroids bud from the monolayer epithelium attached to the tissue culture dish. The 3D spheroids are further cultured in Matrigel along with prointestinal growth factors, and they proliferate and expand over 1-3 months to give rise to intestinal tissue, complete with intestinal mesenchyme and epithelium comprising all of the major intestinal cell types. To date, this is the only method for efficiently directing the differentiation of hPSCs into 3D human intestinal tissue in vitro. PMID:22082986

McCracken, Kyle W; Howell, Jonathan C; Wells, James M; Spence, Jason R



The Small Intestine in Human Schistosomiasis.  

National Technical Information Service (NTIS)

The 13 patients with intestinal schistosomiasis, aged 18 to 41 years, presented the primary complaints of diarrhea and weakness. The 24-hr excretion of the ova of S. mansoni in the stool ranged from 10,725 to 696,475 (mean 241,441 plus or minus SEM 53,475...

C. H. Halsted S. Sheir F. O. Raasch



Bile salt biotransformations by human intestinal bacteria  

Microsoft Academic Search

Secondary bile acids, produced solely by intesti- nal bacteria, can accumulate to high levels in the enter- ohepatic circulation of some individuals and may contribute to the pathogenesis of colon cancer, gallstones, and other gastrointestinal (GI) diseases. Bile salt hydrolysis and hy- droxy group dehydrogenation reactions are carried out by a broad spectrum of intestinal anaerobic bacteria, whereas bile acid

Jason M. Ridlon; Dae-Joong Kang; Phillip B. Hylemon



Characterization of intracellular pteroylpolyglutamate hydrolase (PPH) from human intestinal mucosa  

Microsoft Academic Search

There are two forms of pteroylpolyglutamate hydrolase (PPH) in the human intestinal mucosa, one in the brush border membrane and the other intracellular; brush border PPH is an exopeptidase with optimal activity at pH 6.5 and a requirement for zinc. The presence study characterized human intracellular PPH and compared its properties to those of brush border PPH. Intracellular PPH was

T. T. Y. Wang; C. J. Chandler; C. H. Halsted



Methane production and small intestinal bacterial overgrowth in children living in a slum  

PubMed Central

AIM: To analyze small intestinal bacterial overgrowth in school-aged children and the relationship between hydrogen and methane production in breath tests. METHODS: This transversal study included 85 children residing in a slum and 43 children from a private school, all aged between 6 and 10 years, in Osasco, Brazil. For characterization of the groups, data regarding the socioeconomic status and basic housing sanitary conditions were collected. Anthropometric data was obtained in children from both groups. All children completed the hydrogen (H2) and methane (CH4) breath test in order to assess small intestinal bacterial overgrowth (SIBO). SIBO was diagnosed when there was an increase in H2 ? 20 ppm or CH4 ? 10 ppm with regard to the fasting value until 60 min after lactulose ingestion. RESULTS: Children from the slum group had worse living conditions and lower nutritional indices than children from the private school. SIBO was found in 30.9% (26/84) of the children from the slum group and in 2.4% (1/41) from the private school group (P = 0.0007). Greater hydrogen production in the small intestine was observed in children from the slum group when compared to children from the private school (P = 0.007). A higher concentration of hydrogen in the small intestine (P < 0.001) and in the colon (P < 0.001) was observed among the children from the slum group with SIBO when compared to children from the slum group without SIBO. Methane production was observed in 63.1% (53/84) of the children from the slum group and in 19.5% (8/41) of the children from the private school group (P < 0.0001). Methane production was observed in 38/58 (65.5%) of the children without SIBO and in 15/26 (57.7%) of the children with SIBO from the slum. Colonic production of hydrogen was lower in methane-producing children (P = 0.017). CONCLUSION: Children who live in inadequate environmental conditions are at risk of bacterial overgrowth and methane production. Hydrogen is a substrate for methane production in the colon.

Mello, Carolina Santos; Tahan, Soraia; Melli, Ligia Cristina FL; Rodrigues, Mirian Silva do Carmo; de Mello, Ricardo Martin Pereira; Scaletsky, Isabel Cristina Affonso; de Morais, Mauro Batista



Probiotic yogurt in the elderly with intestinal bacterial overgrowth: endotoxaemia and innate immune functions.  


A study was conducted in healthy elderly living independently in senior housing to assess the impact of a probiotic yoghurt supplement on small intestinal bacterial overgrowth. Twenty-three participants with positive and thirteen participants with negative hydrogen breath test were studied before and after a period of 4 weeks of probiotic yoghurt administration. Intestinal permeability, plasma endotoxin levels, phagocytic activity of leucocytes, cytokine production by monocytes and free radical response of neutrophils were determined. Intestinal permeability was similar for the two groups and was unaffected by probiotic treatment. Both plasma endotoxin levels and the basal phagocytic activity of leucocytes decreased after yoghurt intake in the two groups. Exposure of monocytes and neutrophils ex vivo led to an increased cytokine response and free radical response, respectively. The normalisation of the various cytokine responses was more apparent in the group with positive breath test. In addition, the plasma levels of lipoplysaccharide binding protein and soluble CD14, lipoplysaccharide pattern recognition receptors and surrogate markers of lipoplysaccharide permeability were diminished by the end of the study. In conclusion, probiotic administration in the elderly normalises the response to endotoxin, and modulates activation markers in blood phagocytes, and therefore may help reduce low-grade chronic inflammation. PMID:19353762

Schiffrin, Eduardo J; Parlesak, Alexandr; Bode, Christiane; Bode, J Christian; van't Hof, Martin A; Grathwohl, Dominik; Guigoz, Yves



Safety and risk assessment of the genetically modified Lactococci on rats intestinal bacterial flora.  


The interaction between Lactococcus lactis NZ9000/pNZPNK and intestinal microflora was evaluated as a method to assess safety of genetically modified microorganisms (GMMs). L. lactis NZ9000/pNZPNK is one kind of GMM and able to produce the intracellular subtilisin NAT (nattokinase) under induction with nisin. The host strain L. lactis NZ9000 was a generally recognized as safe (GRAS) microorganism. Six groups of Wistar rats were orally administered with L. lactis NZ9000/pNZPNK and L. lactis NZ9000 for 6 weeks. Fecal and cecal contents were collected to determine the number of L. lactis NZ9000, L. lactis NZ9000/pNZPNK, Lactobacillus, coliform bacteria, beneficial bacteria Bifidobacterium and harmful bacteria Clostridium perfringens. The liver, spleen, kidney and blood were evaluated for the bacterial translocation. After 6 weeks consumption with GM and non-GM Lactococcus, no adverse effects were observed on the rat's body weight, hematological or serum biochemical parameters, or intestinal microflora. The bacterial translocation test showed that L. lactis NZ9000/pNZPNK did not translocate to any organ or blood. Bifidobacterium was significantly increased in feces after administration of both Lactococcus strains (L. lactis NZ9000 and L. lactis NZ9000/pNZPNK), while C. perfringens remained undetectable during the experiment. These results suggested that L. lactis NZ9000/pNZPNK could be safe in animal experiments and monitoring of the interaction between test strains and intestinal microflora might be applied as a method for other GMM safety assessments. PMID:20619909

Lee, Kai-Chien; Liu, Chin-Feng; Lin, Tzu-Hsing; Pan, Tzu-Ming



Modulation of pathogen-induced CCL20 secretion from HT29 human intestinal epithelial cells by commensal bacteria  

Microsoft Academic Search

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

Shomik Sibartie; Ann M O'Hara; Jude Ryan; Áine Fanning; Jim O'Mahony; Shaun O'Neill; Barbara Sheil; Liam O'Mahony; Fergus Shanahan



Molecular Characterisation of Bacterial Community Structure along the Intestinal Tract of Zebrafish (Danio rerio): A Pilot Study  

PubMed Central

The bacterial composition along the intestinal tract of Danio rerio was investigated by cultivation-independent analysis of the 16S rRNA gene. Clone libraries were constructed for three compartments of the intestinal tract of individual fish. 566 individual clones were differentiated by amplified 16S rRNA gene restriction analysis (ARDRA), and clone representatives from each operational taxonomic unit (OTU) were sequenced. As reported in other studies, we found that Proteobacteria was the most prominent phylum among clone libraries from different fish. Data generated from this pilot study indicated some compositional differences in bacterial communities. Two dominant classes, Gammaproteobacteria and Bacilli, displayed different levels of abundance in different compartments; Gammaproteobacteria increased along the intestinal tract, while Bacilli decreased its abundance along the proximal-distal axis. Less obvious spatial patterns were observed for other classes. In general, bacterial diversity in the intestinal bulb was greater than that in the posterior intestine. Interindividual differences in bacterial diversity and composition were also noted in this study.

Lan, Chuan-Ching; Love, Donald R.



Sensitivity of bile acid breath test in the diagnosis of bacterial overgrowth in the small intestine with and without the stagnant (blind) loop syndrome  

Microsoft Academic Search

The bile acid breath test was studied to examine its sensitivity for establishing the diagnosis of bacterial overgrowth in comparison to that of the Schilling test and small-intestinal cultures in 12 patients with a stagnant (blind) loop syndrome, as well as in 38 patients who had other conditions with suspected bacterial contamination of the small intestine. The presence of bile

Sirus Farivar; Hans Fromm; Detlef Schindler; Friedrich W. Schmidt



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

SciTech Connect

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.

Montoudis, Alain [Department of Nutrition, Universite de Montreal and Research Center, CHU Sainte Justine, 3175 Cote Ste-Catherine, Montreal, Que., H3T 1C5 (Canada); Delvin, Edgard [Department of Biochemistry, Universite de Montreal and Research Center, CHU Sainte Justine, 3175 Cote Ste-Catherine, Montreal, Que., H3T 1C5 (Canada); Canadian Institute of Health Research, Group of the Functional Development and Physiopathology of the Digestive Tract, and Department of Anatomy and Cellular Biology, Faculty of Medicine and Health Sciences, Universite de Sherbrooke, Sherbrooke, Que., Canada J1H 5N4 (Canada); Menard, Daniel [Department of Pathology and Cell Biology, Universite de Montreal and Research Center, CHU Sainte Justine, 3175 Cote Ste-Catherine, Montreal, Que., H3T 1C5 (Canada); Canadian Institute of Health Research, Group of the Functional Development and Physiopathology of the Digestive Tract, and Department of Anatomy and Cellular Biology, Faculty of Medicine and Health Sciences, Universite de Sherbrooke, Sherbrooke, Que., J1H 5N4 (Canada)] (and others)



HLA-DR expression in human fetal intestinal epithelium.  

PubMed Central

Villus epithelial cells in fetal human small intestine are HLA-DR- until 17 weeks gestation. At 18 weeks HLA-DR begins to be expressed in the epithelial cells, usually at the villus tips. Of 13 specimens examined between 18 and 22 weeks gestation, two were HLD-DR-, seven had HLA-DR expressed only at the villus tips and in four most of the villus epithelial cells were HLA-DR+. The epithelium overlying the Peyer's patches in fetal intestine was also HLA-DR+. T cells in explant cultures of fetal intestine were activated in situ using pokeweed mitogen. The local cell mediated immune reaction increased expression of HLA-DR on the villus and crypt epithelial cells. Organ culture supernatants from explants treated with pokeweed mitogen induced HLA-DR expression on the HT-29 epithelial cell line; an effect inhibited by antibody against human interferon gamma. Images Fig. 1 Fig. 2 Fig. 3

MacDonald, T T; Weinel, A; Spencer, J



Inflammation in the developing human intestine: A possible pathophysiologic contribution to necrotizing enterocolitis  

PubMed Central

Necrotizing enterocolitis (NEC), a major cause of morbidity and mortality in premature infants, occurs after the introduction of oral feedings in conjunction with initial bacterial colonization of the gut and is hypothesized to be due to an immature (inappropriate) enterocyte response to bacterial stimuli. To test this hypothesis, we compared the enterocyte IL-8 response to inflammatory stimuli [lipopolysaccharide (LPS) and IL-1?] in immature vs. mature human small intestine. Initial in vitro studies comparing confluent Caco-2 cells, a model for mature human enterocytes, with a primary human fetal intestinal cell line (H4 cells) demonstrated that after inflammatory stimulation fetal cells secreted more IL-8 (LPS, 8-fold; IL-1?, 20-fold) than Caco-2 cells. IL-8 mRNA activity in fetal compared to Caco-2 cells was proportionately increased by the same magnitude with both stimuli. To validate the in vitro observations, small intestinal organ cultures from fetuses vs. older children were exposed to LPS and IL-1?. Again in human organ cultures from fetuses compared to older children, IL-8 secretion was greater (LPS, 2.5-fold; IL-1?, 200-fold) and mRNA activity after stimulation was comparably higher, suggesting that increased transcription of the IL-8 gene may account for the excessive response. Using immunohistochemical staining to identify the cellular source of IL-8, activity was noted predominantly in villous and crypt epithelium but also in a few immunoresponsive lymphoid cells. The observation that immature human enterocytes react with excessive pro-inflammatory cytokine production after inflammatory stimulation may help in part explain why prematures exposed to initial colonizing bacteria develop necrotizing enterocolitis.

Nanthakumar, N. Nanda; Fusunyan, Robert D.; Sanderson, Ian; Walker, W. Allan



Quantitation of small intestinal permeability during normal human drug absorption  

PubMed Central

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 ( 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??m. 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.



Human intestinal diamine oxidase: Substrate specificity and comparative inhibitor study  

Microsoft Academic Search

For an 80-fold purified preparation of human intestinal diamine oxidase the optimum conditions of incubation, the substrate and the inhibitor specificity were tested. Putrescine was the most favoured substrate butN?-methylhistamine and 2-methylhistamine were metabolized at optimum conditions with nearly the same velocity. Histamine reached about 50% of the reaction velocity of putrescine.

T. Biega?ski; J. Kusche; K.-D. Feußner; R. Hesterberg; H. Richter; W. Lorenz



The Role of Methane in Intestinal Diseases  

Microsoft Academic Search

The volume of human intestinal gas is about 200 ml, and it is derived from complex physiological processes including swallowed air, diffusion from bloodstream into the lumen, and particularly intraluminal production by chemical reactions and bacterial fermentation. Gas is continuously removed by eructation, anal evacuation, absorption through the intestinal mucosa, and bacterial consumption. More than 99% of it is composed

Davide Roccarina; Ernesto Cristiano Lauritano; Maurizio Gabrielli; Francesco Franceschi; Veronica Ojetti; Antonio Gasbarrini



Studies on the preservation of the intestinal microbiota's DNA in human mummies from cold environments.  


Analysis of ancient microorganism DNA represents one of the newest and most promising branches of molecular archaeology. In particular, microbial DNA associated with human remains can provide direct evidence of the occurrence and frequency of infectious diseases in historic times. Human mummies represent very interesting subjects for palaeomicrobiological investigations as they retain soft tissues. Recently reports on the identification of ancient bacterial pathogens in human mummies by DNA analysis are steadily becoming more numerous. However, despite this favourable trend, the analysis of ancient microbial DNA is still a contentious issue. As a model system, we studied the preservation of the intestinal microbiota's DNA in two naturally freeze-dried human mummies found on the Alps. This kind of mummy is an ideal subject for ancient DNA investigations. The first is a male body historically dated 1918 A.D. while the second is the famous Tyrolean Iceman (3.350-3.100 BC). PMID:18175619

Rollo, Franco; Ermini, Luca; Luciani, Stefania; Marota, Isolina; Olivieri, Cristina



The ex vivo response of human intestinal mucosa to enteropathogenic Escherichia coli infection  

PubMed Central

Summary In vitro organ culture (IVOC) represents a gold standard model to study enteropathogenic E. coli (EPEC) infection of human intestinal mucosa. However, the optimal examination of the bacterial - host cell interaction requires a directional epithelial exposure, without serosal or cut surface stimulation. A polarised IVOC system (pIVOC) was developed in order to overcome such limitations: apical EPEC infection produced negligible bacterial leakage via biopsy edges, resulted in enhanced colonisation compared to standard IVOC, and showed evidence of bacterial detachment, as in natural rabbit EPEC infections. Examination of mucosal innate immune responses in pIVOC showed both interleukin (IL)-8 mRNA and protein levels were significantly increased after apical EPEC infection. Increased IL-8 levels mainly depended on flagellin expression as fliC-negative EPEC did not elicit a significant IL-8 response despite increased mucosal colonisation compared to wild type EPEC. In addition, apical application of purified flagella significantly increased IL-8 protein levels over non-infected controls. Immunofluorescence staining of EPEC-infected small intestinal biopsies revealed apical and basolateral distribution of Toll-like receptor (TLR) 5 on epithelium suggesting that EPEC can trigger mucosal IL-8 responses by apical flagellin/TLR5 interaction ex vivo and does not require access to the basolateral membrane as postulated in cell culture models.

Schuller, Stephanie; Lucas, Mark; Kaper, James B.; Giron, Jorge A.; Phillips, Alan D.



Glycan-modifying bacteria-derived soluble factors from Bacteroides thetaiotaomicron and Lactobacillus casei inhibit rotavirus infection in human intestinal cells  

Microsoft Academic Search

Rotaviruses attach to intestinal cells in a process that requires glycan recognition. Some bacteria from the gut microflora have been shown to modify cell-surface glycans. In this study, human intestinal cultured cells were incubated with bacteria-derived soluble factors and infected with rotavirus. Results show that only bacterial soluble factors that increase cell-surface galactose namely, those of Bacteroides thetaiotaomicron and Lactobacillus

Svetlana Varyukhina; Miguel Freitas; Sabine Bardin; Emilie Robillard; Emmanuelle Tavan; Catherine Sapin; Jean-Pierre Grill; Germain Trugnan


Small intestinal bacterial overgrowth in irritable bowel syndrome: are there any predictors?  

PubMed Central

Background Small intestinal bacterial overgrowth (SIBO) is a condition in which excessive levels of bacteria, mainly the colonic-type species are present in the small intestine. Recent data suggest that SIBO may contribute to the pathophysiology of Irritable bowel syndrome (IBS). The purpose of this study was to identify potential predictors of SIBO in patients with IBS. Methods Adults with IBS based on Rome II criteria who had predominance of bloating and flatulence underwent a glucose breath test (GBT) to determine the presence of SIBO. Breath samples were obtained at baseline and at 30, 45, 60, 75 and 90 minutes after ingestion of 50 g of glucose dissolved in 150 mL of water. Results of the glucose breath test, which measures hydrogen and methane levels in the breath, were considered positive for SIBO if 1) the hydrogen or methane peak was >20 ppm when the baseline was <10 ppm, or 2) the hydrogen or methane peak increased by 12 ppm when baseline was ?10 ppm. Results Ninety-eight patients were identified who underwent a GBT (mean age, 49 y; 78% female). Thirty-five patients (36%) had a positive GBT result suggestive of SIBO. A positive GBT result was more likely in patients >55 years of age (odds ratio [OR], 3.6; 95% confidence interval [CI], 1.4-9.0) and in females (OR, 4.0; 95% CI, 1.1-14.5). Hydrogen was detected more frequently in patients with diarrhea-predominant IBS (OR, 8; 95% CI, 1.4-45), and methane was the main gas detected in patients with constipation-predominant IBS (OR, 8; 95% CI, 1.3-44). There was no significant correlation between the presence of SIBO and the predominant bowel pattern or concurrent use of tegaserod, proton pump inhibitors, or opiate analgesics. Conclusions Small intestinal bacterial overgrowth was present in a sizeable percentage of patients with IBS with predominance of bloating and flatulence. Older age and female sex were predictors of SIBO in patients with IBS. Identification of possible predictors of SIBO in patients with IBS could aid in the development of successful treatment plans.



Campylobacter-Induced Interleukin8 Secretion in Polarized Human Intestinal Epithelial Cells Requires Campylobacter-Secreted Cytolethal Distending Toxin and Toll-Like Receptor-Mediated Activation of NF B  

Microsoft Academic Search

Campylobacter jejuni and Campylobacter coli colonize and infect the intestinal epithelium and cause acute inflammatory diarrhea. The intestinal epithelium serves as a physical barrier to, and a sensor of, bacterial infection by secreting proinflammatory cytokines. This study examined the mechanisms for Campylobacter- induced secretion of the proinflammatory chemokine interleukin-8 (IL-8) by using polarized T84 human colonic epithelial cells as a

Jie Zheng; Jianghong Meng; Shaohua Zhao; Ruby Singh; Wenxia Song



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


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-?-D-galactosamine increase, ?-L-fucose, and neuraminic-acid-?-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

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



Development of the Human Infant Intestinal Microbiota  

Microsoft Academic Search

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,

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



Localization of human intestinal defensin 5 in Paneth cell granules.  

PubMed Central

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.

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



Effect of graded levels of dietary betaine on ileal and total tract nutrient digestibilities and intestinal bacterial metabolites in piglets.  


The study was conducted to investigate the effects of graded dietary inclusion levels of betaine on ileal and total tract nutrient digestibilities and intestinal bacterial metabolites in piglets. A total of eight barrows with an average initial body weight of 7.9 kg were randomly allocated to one of the four assay diets with two pigs per treatment in four repeated measurement periods. The assay diets included a basal diet based on wheat, barley and soybean meal alone, or supplemented with a liquid betaine product at dietary levels of 1.5, 3.0, or 6.0 g betaine per kilogram diet (as-fed). Ileal digestibilities of dry matter and neutral detergent fibre increased both quadratically and linearly, and ileal digestibility of glycine increased linearly as dietary betaine level increased (p < 0.05). Furthermore, total tract digestibility of crude protein increased quadratically (p < 0.05) and total tract digestibilities of most amino acids tended to increase quadratically (p = 0.06 to p = 0.11) with increasing dietary betaine level. Moreover, there were linear increases in the concentrations of most bacterial metabolites which were significant p < 0.05 for ileal d-lactic acid and for faecal diaminopimelic acid. The results demonstrate that dietary betaine supplementation stimulates bacterial fermentation of fibre in the small intestine and bacterial degradation of crude protein in the large intestine. PMID:20455968

Ratriyanto, A; Mosenthin, R; Jezierny, D; Eklund, M



Distribution of membrane bound guanylyl cyclases in human intestine.  

PubMed Central

The quantification and distinction of particulate guanylyl cyclases in the human intestine were considered by an enzymatic approach, which comprised the signal transduction from receptor binding to cGMP formation, and, in addition, by showing the expression of an intracellular portion of these transmembrane proteins. Basal guanylyl cyclase (GC) activities were 50 to 80 pmol cGMP formation/min/mg protein and were stimulated up to twofold by heat stable enterotoxin, but were not significantly influenced by atrial natriuretic factor. Enzymatic analysis of colonoscopic specimens pointed to the prevalence of guanylyl cyclase C in the terminal ileum and in the large bowel including colon ascendens, colon descendens, sigmoid, and rectum. The availability of sequence information on human guanylyl cyclases permitted the development of a polymerase chain reaction approach for distinguishing the expression of GC-A and GC-C in human tissue samples. The expression levels of particulate guanylyl cyclases found by polymerase chain reaction in surgical biopsy specimens confirmed the enzymatic data, in that substantial expression of GC-C was found not only in the small intestine but also in the large bowel. According to the restriction mapping of amplificates, GC-C prevailed over GC-A throughout the human intestine, particularly in the mucosal layers. Images Figure 5 Figure 6

Krause, G; Bayerl, A; Heim, J M; Singh, S; Gerzer, R



Collagen production by human smooth muscle cells isolated during intestinal organogenesis  

Microsoft Academic Search

The extracellular matrix influences organogenesis by modulating cell behavior. In humans, collagen is the major matrix constituent of the adult intestinal wall and is synthesized by smooth muscle cells. The objective of the current study was to examine collagen production by fetal human intestinal smooth muscle cells isolated during intestinal morphogenesis. Techniques were developed for the isolation and culture of

Hilary A. Perr; John R. Grider; A. Scott Mills; Michael Kornstein; David A. Turner; Robert F. Diegelmann; Martin F. Graham



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

PubMed Central

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.

Ohkuma, M; Kudo, T



[Algorithm for the coproscopic diagnosis of human intestinal parasites].  


The purpose of the study was to elaborate a detection algorithm for human intestinal helminth eggs. There is a broad spectrum ofcoproscopic methods recommended for the detection of Opisthorchis eggs in man and animals; these include Fulleborn's method, formalin-ether method, Goryachev's, Katoh's, Kalantaryan's, Shcherbovich's, and Kotelnikov-Varenichev methods. Combined coproscopic methods are significantly more effective in detecting the causative agents of enteric parasitoses than is Katoh's method. Among the considered coproscopic techniques for the diagnosis of human ascariasis, it is most rational to use a combined method for fecal examination, the basis for which is a multicomponent flotation system (such as the author's one). The Kotelnikov-Varenichev method is optimal for diagnosing opisthorchiasis. It is optimal to use 2-3 methods of different groups simultaneously for the screening diagnosis of intestinal parasitoses. PMID:22774504

Dolbin, D A; Tiurin, Iu A; Kha?rullin, R M


The effect of rejection and graft-versus-host disease on small intestinal microflora and bacterial translocation after rat small bowel transplantation.  


Bacterial translocation and the development of sepsis after small bowel transplantation may be promoted by immunological damage to the intestinal mucosa or by quantitative and qualitative changes in intestinal microflora. This study assessed the effects of rejection, graft-versus-host disease (GVHD) and immunosuppression on intestinal microflora and bacterial translocation after heterotopic rat small bowel transplantation. Isografts, allografts with and without CsA immunosuppression, and the semi-allogeneic parent to the F1 hybrid GVHD model were studied. Intestinal microflora in graft and host loops and bacterial translocation to host organs and the graft mesenteric lymph node were determined. Bacterial colonies were counted and individual colonies identified using API 20E nutrient and fermentation indicator techniques. Colony counts in isografts and allografts were significantly higher than in the native intestine, whereas there was a massive overgrowth in the native intestine in the GVHD group. The species profile for the host and graft loops was similar in animals that had received isografts, allografted animals receiving CsA, and animals undergoing GVHD. However, there was a large increase in Staphylococcus epidermidis in animals with rejection. Bacterial translocation was not detected in isografted animals, but was observed in all other animal groups, with S. epidermidis being the most prevalent organism. These findings demonstrate that rejection and GVHD are associated with shifts in intestinal microflora toward potentially pathogenic organisms and that bacterial translocation into recipient tissues poses a major threat for the development of sepsis. PMID:8249102

Price, B A; Cumberland, N S; Clark, C L; Pockley, A G; Lear, P A; Wood, R F



Angiotensin I Converting Enzyme (Kininase II) of the Brush Border of Human and Swine Intestine.  

National Technical Information Service (NTIS)

Mucosal brush border of human and swine small intestine is rich in angiotensin I converting enzyme or kininase II (ACE). The brush border of the intestinal mucosa was purified by centrifugation over a discontinuous glycerol gradient. Transmission electron...

P. E. Ward M. A. Sheridan K. J. Hammon E. G. Erdoes



In Silico Modelling of the Human Intestinal Microflora  

Microsoft Academic Search

The ecology of the human intestinal microflora and its interaction with the host are poorly understood. Though more and more\\u000a data are being acquired, in part using modern molecular methods, development of a quantitative theory has not kept pace with\\u000a this development. This is in part due to the complexity of the system, and to the lack of simulation environments

Derk Jan Kamerman; Michael H. F. Wilkinson



Metabolism of saikosaponin c and naringin by human intestinal bacteria  

Microsoft Academic Search

By human intestinal bacteria, saikosaponin c was transformed to four metabolites, prosaikogenin E1 (E1) prosaikogenin E2 (E2),\\u000a prosaikogenin E3 (E3) and saikogenin E. Metabolic time course of saikosaponin c was as follows; in early time, saikosaponin\\u000a c was converted to E1 and E2, and then these were transformed to saikogenin E via E3. Also, this metabolic pathway was similar\\u000a to

Ki-Ung Yu; Il-Sung Jang; Keung-Hyung Kang; Chung-Ki Sung; Dong-Hyun Kim



Genome sequence of Victivallis vadensis ATCC BAA548, an anaerobic bacterium from the phylum Lentisphaerae, isolated from the human gastro-intestinal tract  

Microsoft Academic Search

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.

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



Nod1 and Nod2 signaling does not alter the composition of intestinal bacterial communities at homeostasis.  


Patients with inflammatory bowel diseases (IBD) harbour intestinal bacterial communities with altered composition compared with healthy counterparts; however, it is unknown whether changes in the microbiota are associated with genetic susceptibility of individuals for developing disease or instead reflect other changes in the intestinal environment related to the disease itself. Since deficiencies in the innate immune receptors Nod1 and Nod2 are linked to IBD, we tested the hypothesis that Nod-signaling alters intestinal immune profiles and subsequently alters bacterial community structure. We used qPCR to analyze expression patterns of selected immune mediators in the ileum and cecum of Nod-deficient mice compared with their Nod-sufficient littermates and assessed the relative abundance of major bacterial groups sampled from the ileum, cecum and colon. The Nod1-deficient ileum exhibited significantly lower expression of Nod2, Muc2, ?- and ?-defensins and keratinocyte-derived chemokine (KC), suggesting a weakened epithelial barrier compared with WT littermates; however, there were no significant differences in the relative abundance of targeted bacterial groups, indicating that Nod1-associated immune differences alone do not promote dysbiosis. Furthermore, Nod2-deficient mice did not display any changes in the expression of immune markers or bacterial communities. Shifts in bacterial communities that were observed in this study correlated with housing conditions and were independent of genotype. These findings emphasize the importance of using F2 littermate controls to minimize environmental sources of variation in microbial analyses, to establish baseline conditions for host-microbe homeostasis in Nod-deficient mice and to strengthen models for testing factors contributing to microbial dysbiosis associated with IBD. PMID:23549220

Robertson, Susan J; Zhou, Jun Yu; Geddes, Kaoru; Rubino, Stephen J; Cho, Joon Ho; Girardin, Stephen E; Philpott, Dana J



Development of the Human Infant Intestinal Microbiota  

PubMed Central

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.

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



Identification of Bacterial Isolates Obtained from Intestinal Contents Associated with 12,000-Year-Old Mastodon Remains  

PubMed Central

Mastodon (Mammut americanum) remains unearthed during excavation of ancient sediments usually consist only of skeletal material, due to postmortem decomposition of soft tissues by microorganisms. Two recent excavations of skeletal remains in anoxic sediments in Ohio and Michigan, however, have uncovered organic masses which appear to be remnants of the small and large intestines, respectively. Macrobotanical examinations of the composition of these masses revealed assemblages of plant material radiocarbon dated to approximately 11,500 years before the present and thought to be incompletely digested food remains from this extinct mammal. We attempted to cultivate and identify bacteria from the intestinal contents, bone-associated sediments, and sediments not in proximity to the remains using a variety of general and selective media. In all, 295 isolates were cultivated, and 38 individual taxa were identified by fatty acid-methyl ester (FAME) profiles and biochemical characteristics (API-20E). The taxonomic positions of selected enteric and obligately anaerobic bacteria were confirmed by 16S ribosomal DNA (rDNA) sequencing. Results indicate that the intestinal and bone-associated samples contained the greatest diversity of bacterial taxa and that members of the family Enterobacteriaceae represented 41% of all isolates and were predominant in the intestinal masses and sediments in proximity to the skeleton but were uncommon in the background sediments. Enterobacter cloacae was the most commonly identified isolate, and partial rDNA sequencing revealed that Rahnella aquatilis was the correct identity of strains suggested by FAME profiles to be Yersinia enterocolitica. No Bacteroides spp. or expected intestinal anaerobes were recovered. The only obligate anaerobes recovered were clostridia, and these were not recovered from the small intestinal masses. Microbiological evidence from this study supports other, macrobotanical data indicating the intestinal origin of these masses. Whether these organisms are direct descendants of the original intestinal microbiota, however, cannot be established.

Rhodes, A. N.; Urbance, J. W.; Youga, H.; Corlew-Newman, H.; Reddy, C. A.; Klug, M. J.; Tiedje, J. M.; Fisher, D. C.



Oral ornithine a-ketoglutarate accelerates healing of thesmall intestine and reduces bacterial translocation after abdominal radiation  

Microsoft Academic Search

The effect of dietary ornithine a-ketoglutarate (OKG) on intestinal mucosal integrity and bacterial translocation was studied in rats following administration of a single dose of abdominal radiation (1100 cGy). Following the radiation injury the rats were randomized to receive a nutritionally incomplete diet which contained only water and OKG or a control diet with water and the non-essential amino-acid glycine.

F. Kalfarentzos; J. Spiliotis; M. Melachrinou; C. H. Katsarou; I. Spiliopoulou; C. Panagopoulos; T. H. Alexandrides



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

PubMed Central

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

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



Rates of intestinal absorption of molybdenum in humans.  


The intestinal absorption of molybdenum in healthy human volunteers has been measured by simultaneous oral and intravenous administration of the stable isotopes 95Mo and 96Mo, and the results were analysed using the convolution integral technique. The results showed that molybdenum ingested in liquid form was rapidly and totally absorbed into the circulation under ordinary intake regimes. The rates and extent of absorption were lower for composite meals, and also for increasing levels of administration. This information can be helpful in the application of the new ICRP model of the human alimentary tract. PMID:16439140

Giussani, Augusto; Arogunjo, Adeseye M; Claire Cantone, Marie; Tavola, Federico; Veronese, Ivan



Influence of purified dietary fibre on bacterial protein synthesis in the large intestine of pigs, as measured by the gas production technique  

Microsoft Academic Search

Microbial fermentation of non-digestible carbohydrates in the pig's large intestine induces a shift of N excretion from urea in urine to bacterial protein in faeces. Experiments were carried out to measure the mineral N incorporation by the pig intestinal microflora using 5 purified carbohydrates in a gas-test: starch (S), cellulose (C), inulin (I), pectin (P) and xylan (X). Fermentation kinetics

J. Bindelle; A. Buldgen; D. Michaux; J. Wavreille; J. P. Destain; P. Leterme



Parenteral Antibiotics and Selective Intestinal Decontamination Do Not Prevent Enteric Bacterial Overgrowth or Translocation Observed in a Swine Model of Small Bowel Transplantation  

Microsoft Academic Search

Alterations in the luminal microflora and increased intestinal translocation have been reported to occur following experimental and clinical small bowel transplantation (SBT). Selective intestinal decontamination (SID) has been used to prevent luminal overgrowth and bacterial translocation. Despite the wide use of SID in clinical SBT, there are no data supporting its usefulness in this situation. Thus, the aim of this

Roberto Biffi; Gaetano Privitera; Caterina Matinato; Simonetta Pozzi; Lorenzo Marzona; Paolo De Rai; Bruno Andreoni; Giorgio Tiberio; Ermenegildo Frezza; David H. Van Thiel



Intestinal pathology in human metagonimiasis with ultrastructural observations of parasites.  

PubMed Central

A human case of intestinal metagonimiasis that was incidentally found during the histological examination of a resected segment of jejunum was described. The small adults trematode of Metagonimus yokogawai were found free in jejunal lumen as well as impacted in intervillous spaces. Histologically intestinal lesions were massive lymphoplasmacytic and eosinophilic infiltration in stroma, erosion of neanby enterocytes, goblet cell depletion and occasional villous edema. Scanning electron microscopy revealed the worm of spatulate appearance with rake-shaped tegumental spines. By transmission electron microscopy, the syncytial integument with dense discoidal bodies, basement membrane muscle cells and subtegumental cells were observed. Characteristic junctional complex was demonstrated between subtegumental and parenchymal cells as well as between parenchymal cells.

Chi, J. G.; Kim, C. W.; Kim, J. R.; Hong, S. T.; Lee, S. H.



Effects of Interleukin-1? Administration on Intestinal Ischemia and Reperfusion Injury, Mucosal Permeability, and Bacterial Translocation in Burn and Sepsis  

PubMed Central

Objective To evaluate the effect of interleukin-1? (IL-1?) on the mesenteric circulation, intestinal mucosal integrity, and bacterial translocation in a burn/endotoxemia chronic porcine model. Summary Background Data Major burn and sepsis are associated with a high mortality, ischemia/reperfusion injury to the intestine, and an increased rate of bacterial translocation. Pathologic alterations of IL-1 synthesis, degradation, and binding to receptors have been reported. Manipulation of IL-1-mediated effects might be of therapeutic utility. Methods Twenty-one female pigs were instrumented with an ultrasonic flow probe on the superior mesenteric artery and a catheter into the superior mesenteric vein. After 5 days, all animals were anesthetized, and 14 received 40% total body surface area third-degree burn. IL-1? was administered intravenously at 1,000 ng/kg to seven pigs immediately after burn. Eighteen hours after burn, 100 ?g/kg Escherichia coli lipopolysaccharide (LPS) was administered intravenously. Systemic and splanchnic hemodynamics were measured and blood samples were drawn for blood gas analysis. Intestinal permeability was assessed every 6 hours by measuring the lactulose/mannitol (L/M) excretion ratio. At the end of the study (42 hours), tissue samples were harvested for bacteriologic cultures. Results Mesenteric blood flow was significantly decreased after burn and endotoxin. Administration of IL-1? significantly improved mesenteric blood flow postburn and post-LPS. Mesenteric oxygen supply and consumption showed a significant reduction after burn. In contrast, animals treated with IL-1? showed an increase in postburn mesenteric oxygen supply and consumption. LPS-induced mesenteric hypoxia was also ameliorated by IL-1? treatment. Intestinal permeability, as assessed by the L/M ratio, showed a 7- and 10-fold elevation after thermal injury and LPS, respectively. In contrast, IL-1?-treated animals showed an increase of only three- and fourfold in the L/M ratio, respectively. Bacterial translocation was significantly increased in the burn/endotoxin group. IL-1? significantly reduced the rates of bacterial translocation. Conclusions IL-1? treatment attenuates mesenteric ischemia and reperfusion injury induced by thermal injury and endotoxemia by improving mesenteric blood flow and oxygenation. Subsequently, IL-1? reduces intestinal permeability and bacterial translocation after burn and sepsis.

Tadros, Tamer; Traber, Daniel L.; Heggers, John P.; Herndon, David N.



Functional Metagenomic Investigations of the Human Intestinal Microbiota  

PubMed Central

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.

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



Human milk hyaluronan enhances innate defense of the intestinal epithelium.  


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 ?-defensin 2 and is abrogated by digestion of milk HA with a specific hyaluronidase. Milk HA induction of human ?-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 H? 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

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



Nonsteroidal antiinflammatory drug-induced intestinal inflammation in humans  

SciTech Connect

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.

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



Diversity of human small intestinal Streptococcus and Veillonella populations.  


Molecular and cultivation approaches were employed to study the phylogenetic richness and temporal dynamics of Streptococcus and Veillonella populations in the small intestine. Microbial profiling of human small intestinal samples collected from four ileostomy subjects at four time points displayed abundant populations of Streptococcus spp. most affiliated with S. salivarius, S. thermophilus, and S. parasanguinis, as well as Veillonella spp. affiliated with V. atypica, V. parvula, V. dispar, and V. rogosae. Relative abundances varied per subject and time of sampling. Streptococcus and Veillonella isolates were cultured using selective media from ileostoma effluent samples collected at two time points from a single subject. The richness of the Streptococcus and Veillonella isolates was assessed at species and strain level by 16S rRNA gene sequencing and genetic fingerprinting, respectively. A total of 160 Streptococcus and 37 Veillonella isolates were obtained. Genetic fingerprinting differentiated seven Streptococcus lineages from ileostoma effluent, illustrating the strain richness within this ecosystem. The Veillonella isolates were represented by a single phylotype. Our study demonstrated that the small intestinal Streptococcus populations displayed considerable changes over time at the genetic lineage level because only representative strains of a single Streptococcus lineage could be cultivated from ileostoma effluent at both time points. PMID:23614882

van den Bogert, Bartholomeus; Erkus, Oylum; Boekhorst, Jos; de Goffau, Marcus; Smid, Eddy J; Zoetendal, Erwin G; Kleerebezem, Michiel



Small Intestinal Bacterial Overgrowth and Lactose Intolerance Contribute to Irritable Bowel Syndrome Symptomatology in Pakistan  

PubMed Central

Background /Aim: The symptoms of irritable bowel syndrome resemble those of small intestinal bacterial overgrowth (SIBO). The aim of this study was to determine the frequency of SIBO and lactose intolerance (LI) occurrence in patients with diarrhea-predominant irritable bowel syndrome (IBS-D) according to Rome III criteria. Patients and Methods: In this retrospective case-control study, patients over 18 years of age with altered bowel habit, bloating, and patients who had lactose Hydrogen breath test (H2BT) done were included. The “cases” were defined as patients who fulfill Rome III criteria for IBS-D, while “controls” were those having chronic nonspecific diarrhea (CNSD) who did not fulfill Rome III criteria for IBS-D. Demographic data, predominant bowel habit pattern, concurrent use of medications, etc., were noted. Results: Patients with IBS-D were 119 (51%) with a mean age of 35 ± 13 years, while those with CNSD were 115 (49%) with mean age 36 ± 15 years. Patients in both IBS-D and CNSD were comparable in gender, with male 87 (74%) and female 77 (64%). SIBO was documented by lactose H2BT in 32/234 (14%) cases. It was positive in 22/119 (19%) cases with IBS-D, while 10/115 (9%) cases had CNSD (P = 0.03). LI was positive in 43/234 (18%) cases. Of these, 25/119 (21%) cases had IBS-D and 18/115 (16%) cases had CNSD (P = 0.29). Conclusion: SIBO was seen in a significant number of our patients with IBS-D. There was no significant age or gender difference in patients with or without SIBO.

Yakoob, Javed; Abbas, Zaigham; Khan, Rustam; Hamid, Saeed; Awan, Safia; Jafri, Wasim



Mechanisms that control bacterial populations in continuous-flow culture models of mouse large intestinal flora.  


A previous study had established that anaerobic continuous-flow (CF) cultures of conventional mouse cecal flora were able to maintain the in vivo ecological balance among the indigenous bacterial species tested. This paper describes experiments designed to determine the mechanisms which control the population sizes of these species in such CF cultures. One strain each of Escherichia coli, Fusobacterium sp., and Eubacterium sp. were studied. Growth of these strains in filtrates of CF cultures was considerably more rapid than in the CF cultures themselves, indicating that the inhibitory activity had been lost in the process of filtration. Growth rates to match those in CF cultures could be obtained, however, by restoring the original levels of H(2)S in the culture filtrates. The inhibitory effect of H(2)S in filtrates and in dialysates of CF cultures could be abolished by adding glucose or pyruvate, but not formate or lactate. The fatty acids present in CF cultures matched those in the cecum of conventional mice in both quality and concentration. These acids could not account for the slow rates of growth of the tested strains in CF cultures, but they did cause a marked increase in the initial lag phase of E. coli growth. The results obtained are compatible with the hypothesis that the populations of most indigenous intestinal bacteria are controlled by one or a few nutritional substrates which a given strain can utilize most efficiently in the presence of H(2)S and at the prevailing conditions of pH and anaerobiosis. This hypothesis consequently implies that the populations of enterobacteria, such as the E. coli strain tested, and those of the predominant anaerobes are controlled by analogous mechanisms. PMID:6339388

Freter, R; Brickner, H; Botney, M; Cleven, D; Aranki, A



T cell receptor V beta expression in human intestine: regional variation in postnatal intestine and biased usage in fetal gut.  

PubMed Central

A panel of T cell receptor V beta specific monoclonal antibodies was used to analyse V beta gene usage at different sites in human postnatal and fetal intestine. In normal small intestine, at a single site, different patients showed expansion of T cells expressing individual V beta s. Lamina propria and epithelial T cells from the same patient showed overlapping but not identical V beta dominance. V beta dominance was also shown in the T cells of the colonic lamina propria. Analysis of two separate regions of intestine from the same patient (5-100 cm apart) showed that T cells expressing a dominant V beta region were often present at both sites. In most patients, however, major biases in T cell V beta usage (two to 12-fold variation) were also apparent between the two sites. Analysis of V beta expression in human fetal intestine also showed considerable skewing, although the most common dominant V beta in postnatal intestine (V beta 22) was never predominant in fetal intestine. Patchy local variation in the expression of individual V beta s therefore occurs against a background of V beta dominance over large regions of the human gut. Furthermore the results from fetal gut show that factors other than luminal antigen control V beta expression in the gut.

Thomas, R; Schurmann, G; Lionetti, P; Pender, S L; MacDonald, T T



Effect of Steroid on Mitochondrial Oxidative Stress Enzymes, Intestinal Microflora, and Bacterial Translocation in Rats Subjected to Temporary Liver Inflow Occlusion  

Microsoft Academic Search

Protective effects of steroids against ischemia-reperfusion (I\\/R) injury are well known, but there is little information about the influence of temporary inflow occlusion on intestinal barrier function or bacterial translocation. The aim of this experimental study was to investigate the effects on liver, kidney, spleen, ileal mitochondrial stress enzymes, and bacterial translocation of methylprednisolone (MP) in rats undergoing temporary liver

V. Kirimlioglu; H. Kirimlioglu; S. Yilmaz; T. Piskin; S. Tekerekoglu; Y. Bayindir



The Human Intestinal IgA Response; Burning Questions  

PubMed Central

The title of this special topic invites us to identify areas in the field of IgA biology that are uncertain or in need of clarification. The inductive phase of the human intestinal IgA response has been a controversial area for some years. Therefore, to structure this review, we have identified key questions that are debated in this field. We have provided explanations of the origins of the uncertainties and have provided our own reasoned answers to the questions we pose.

Spencer, Jo; Klavinskis, Linda S.; Fraser, Louise D.



[Progress in the knowledge of the intestinal human microbiota].  


New sequencing technologies together with the development of bio-informatics allow a description of the full spectrum of the microbial communities that inhabit the human intestinal tract, as well as their functional contributions to host health. Most community members belong to the domain Bacteria, but Archaea, Eukaryotes (yeasts and protists), and Viruses are also present. Only 7 to 9 of the 55 known divisions or phyla of the domain Bacteria are detected in faecal or mucosal samples from the human gut. Most taxa belong to just two divisions: Bacteroidetes and Firmicutes, and the other divisions that have been consistently found are Proteobacteria, Actinobacteria, Fusobacteria, and Verrucomicrobia. Bacteroides, Faecalibacterium and Bifidobacterium are the most abundant genera but their relative proportion is highly variable across individuals. Full metagenomic analysis has identified more than 5 million non-redundant microbial genes encoding up to 20,000 biological functions related with life in the intestinal habitat. The overall structure of predominant genera in the human gut can be assigned into three robust clusters, which are known as "enterotypes". Each of the three enterotypes is identifiable by the levels of one of three genera: Bacteroides (enterotype 1), Prevotella (enterotype 2) and Ruminococcus (enterotype 3). This suggests that microbiota variations across individuals are stratified, not continuous. Next steps include the identification of changes that may play a role in certain disease states. A better knowledge of the contributions of microbial symbionts to host health will help in the design of interventions to improve symbiosis and combat disease. PMID:23848071

Robles-Alonso, Virginia; Guarner, Francisco


Computational approaches for modeling human intestinal absorption and permeability  

PubMed Central

Human intestinal absorption (HIA) is an important roadblock in the formulation of new drug substances. Computational models are needed for the rapid estimation of this property. The measurements are determined via in vivo experiments or in vitro permeability studies. We present several computational models that are able to predict the absorption of drugs by the human intestine and the permeability through human Caco-2 cells. The training and prediction sets were derived from literature sources and carefully examined to eliminate compounds that are actively transported. We compare our results to models derived by other methods and find that the statistical quality is similar. We believe that models derived from both sources of experimental data would provide greater consistency in predictions. The performance of several QSPR models that we investigated to predict outside the training set for either experimental property clearly indicates that caution should be exercised while applying any of the models for quantitative predictions. However, we are able to show that the qualitative predictions can be obtained with close to a 70% success rate. Electronic Supplementary Material Supplementary material is available for this article at

Subramanian, Govindan



Vasoactive intestinal peptide signaling axis in human leukemia  

PubMed Central

The vasoactive intestinal peptide (VIP) signaling axis constitutes a master “communication coordinator” between cells of the nervous and immune systems. To date, VIP and its two main receptors expressed in T lymphocytes, vasoactive intestinal peptide receptor (VPAC)1 and VPAC2, mediate critical cellular functions regulating adaptive immunity, including arresting CD4 T cells in G1 of the cell cycle, protection from apoptosis and a potent chemotactic recruiter of T cells to the mucosa associated lymphoid compartment of the gastrointestinal tissues. Since the discovery of VIP in 1970, followed by the cloning of VPAC1 and VPAC2 in the early 1990s, this signaling axis has been associated with common human cancers, including leukemia. This review highlights the present day knowledge of the VIP ligand and its receptor expression profile in T cell leukemia and cell lines. Also, there will be a discussion describing how the anti-leukemic DNA binding transcription factor, Ikaros, regulates VIP receptor expression in primary human CD4 T lymphocytes and T cell lymphoblastic cell lines (e.g. Hut-78). Lastly, future goals will be mentioned that are expected to uncover the role of how the VIP signaling axis contributes to human leukemogenesis, and to establish whether the VIP receptor signature expressed by leukemic blasts can provide therapeutic and/or diagnostic information.

Dorsam, Glenn Paul; Benton, Keith; Failing, Jarrett; Batra, Sandeep



Human Intestinal M Cells Display the Sialyl Lewis A Antigen  

PubMed Central

The biochemical features that distinguish human M cells from other intestinal epithelial cell types are important for understanding microbial pathogenesis and for targeting vaccines to the mucosal immune system. We applied a large panel of carbohydrate-specific monoclonal antibodies and lectins to Peyer’s patch and cecum biopsy specimens from three normal individuals and a patient with inflammatory bowel disease. The results show that human M-cell glycosylation patterns are distinct from those of other species examined and that human M cells preferentially display the sialyl Lewis A antigen. This carbohydrate epitope is also present in a small subpopulation of enterocytes in the follicle-associated epithelium and in goblet cell mucins.

Giannasca, Paul J.; Giannasca, Karen T.; Leichtner, Alan M.; Neutra, Marian R.



Importance of intestinal mucosal immunity and luminal bacterial cell wall polymers in the aetiology of inflammatory joint diseases.  


The distal intestine contains bacterial cell wall polymers capable of inducing acute and chronic polyarthritis if systemically distributed. Parenteral injection of peptidoglycan-polysaccharide (PG-PS) polymers from certain bacterial species produces spontaneously relapsing erosive synovitis in susceptible rat strains, and normally subarthropathic amounts of PG-PS and lipopolysaccharide (endotoxin) can reactivate arthritis initially induced by PG-PS. These experimental results illustrate the inflammatory potential of luminal bacterial products and the importance of genetically determined host susceptibility factors in the pathogenesis of arthritis. Normally, luminal complexing by secretory IgA and an intact epithelial barrier limits uptake of luminal antigen; however, intestinal inflammation enhances mucosal uptake and systemic distribution of potentially injurious macromolecules, including PG-PS and lipopolysaccharide. Occult intestinal inflammation, which may be related to non-steroidal anti-inflammatory drugs or may be disease-associated, occurs in approximately two thirds of patients with rheumatoid arthritis, idiopathic reactive arthritis and ankylosing spondylitis. Enhanced mucosal permeability to macromolecules occurs in rheumatoid arthritis, enteric infections and idiopathic inflammatory bowel disease. Intestinal inflammation is associated with increased mucosal IgG production and circulating immune complexes. Hyperactive IgA synthesis occurs in many types of inflammatory joint disease. Polyclonal IgA is increased in rheumatoid arthritis, Sjögren's syndrome, ankylosing spondylitis, Reiter's syndrome, and reactive arthritis following Yersinia infection. Anti-Klebsiella IgA cross-reacts with HLA-B27 antigen, and antibodies to enteric bacteria are able to lyse lymphocytes from HLA-B27 patients with ankylosing spondylitis. Anti-Yersinia IgA is produced at the mucosa in increased quantities in patients who develop arthritis following Yersinia enteritis, possibly as a consequence of defective cellular immunity. Serum concentrations of IgA correlate with activity of rheumatoid arthritis and ankylosing spondylitis, and serum IgA immune complexes are associated with rheumatoid vasculitis, suggesting that IgA contributes to the pathogenesis of arthritis. We speculate that intestinal injury may also induce or perpetuate arthritis by systemic distribution of inflammatory mediators produced by intestinal immune effector cells. PMID:2670253

Sartor, R B



Alpha2 adrenoceptors regulate proliferation of human intestinal epithelial cells  

PubMed Central

BACKGROUND AND AIMS—Previous studies on rodents have suggested that catecholamines stimulate proliferation of the intestinal epithelium through activation of ?2 adrenoceptors located on crypt cells. The occurrence of this effect awaits demonstration in humans and the molecular mechanisms involved have not yet been elucidated. Here, we examined the effect of ?2 agonists on a clone of Caco2 cells expressing the human ?2A adrenoceptor.?METHODS—Cells were transfected with a bicistronic plasmid containing the ?2C10 and neomycin phosphotransferase genes. G418 resistant clones were assayed for receptor expression using radioligand binding. Receptor functionality was assessed by testing its ability to couple Gi proteins and to inhibit cAMP production. Mitogen activated protein kinase (MAPK) phosphorylation was followed by western blot, and cell proliferation was estimated by measuring protein and DNA content.?RESULTS—Permanent transfection of Caco2 cells allowed us to obtain a clone (Caco2-3B) expressing ?2A adrenoceptors at a density similar to that found in normal human intestinal epithelium. Caco2-3B retained morphological features and brush border enzyme expression characteristic of enterocytic differentiation. The receptor was coupled to Gi2/Gi3 proteins and its stimulation caused marked diminution of forskolin induced cAMP production. Treatment of Caco2-3B with UK14304 (?2 agonist) induced a rapid increase in the phosphorylation state of MAPK, extracellular regulated protein kinase 1 (Erk1), and 2 (Erk2). This event was totally abolished in pertussis toxin treated cells and in the presence of kinase inhibitors (genistein or PD98059). It was unaffected by protein kinase C downregulation but correlated with a transient increase in Shc tyrosine phosphorylation. Finally, sustained exposure of Caco2-3B to UK14304 resulted in modest but significant acceleration of cell proliferation. None of these effects was observed in the parental cell line Caco2.?CONCLUSION—The results obtained in the present study support a regulatory role for ?2 adrenoceptors in intestinal cell proliferation.???Keywords: ?2 adrenoceptor; Caco2; mitogen activated protein kinase; intestinal cell proliferation

Schaak, S; Cussac, D; Cayla, C; Devedjian, J; Guyot, R; Paris, H; Denis, C



Use of Stable Isotopes To Measure the Metabolic Activity of the Human Intestinal Microbiota?  

PubMed Central

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.

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



Mucosal Immune Regulation in Intestinal Disease. The role of bacterial products, food components and drugs  

Microsoft Academic Search

The challenge of the mucosal gut associated immune system is to remain unresponsive to food products and commensal microbiota, while mounting an appropriate immune response towards pathogens. This implicates the necessity of tight immune regulation within the gut associated lymphoid tissue (GALT). Imbalance between tolerance and immunity (e.g. intestinal homeostasis) contributes to the pathogenesis of intestinal diseases like inflammatory bowel

M. Bol-Schoenmakers



Antibiotic residues and drug resistance in human intestinal flora.  

PubMed Central

The effect of residual levels of ampicillin on the drug resistance of fecal flora was studied in human volunteers given 1.5 mg of ampicillin orally per day for 21 days. This treatment failed to have any significant reproducible effect on the number of resistant Escherichia coli in their feces. The effect of continuous administration of small doses of ampicillin, chlortetracycline, or streptomycin in the drinking water was studied in gnotobiotic mice inoculated with a human fecal flora. In this animal model, which is free of many interfering factors, an increase in the fecal concentration of resistant E. coli was observed when the mice were given 0.5 microgram of ampicillin or chlortetracycline per ml of water. This model is therefore a sensitive system for testing the effect of antimicrobial drugs on the resistance characteristics of the intestinal flora.

Corpet, D E



Human Oral Bacterial Biofilms: Composition, Dynamics, and Pathogenesis  

Microsoft Academic Search

\\u000a The oral cavity has a diverse and dynamic bacterial flora that is significantly more complex than other sites in and on the\\u000a human body, with the exception of the gut. Bacterial communities differ in composition depending on location in the mouth.\\u000a Spatial relationships within the communities seem to be important for their function. Composition of the communities varies\\u000a temporally and

Robert J. Palmer Jr; Richard Darveau; Richard J. Lamont; Bente Nyvad; Ricardo P. Teles


Production of enterodiol from defatted flaxseeds through biotransformation by human intestinal bacteria  

PubMed Central

Background The effects of enterolignans, e.g., enterodiol (END) and particularly its oxidation product, enterolactone (ENL), on prevention of hormone-dependent diseases, such as osteoporosis, cardiovascular diseases, hyperlipemia, breast cancer, colon cancer, prostate cancer and menopausal syndrome, have attracted much attention. To date, the main way to obtain END and ENL is chemical synthesis, which is expensive and inevitably leads to environmental pollution. To explore a more economic and eco-friendly production method, we explored biotransformation of enterolignans from precursors contained in defatted flaxseeds by human intestinal bacteria. Results We cultured fecal specimens from healthy young adults in media containing defatted flaxseeds and detected END from the culture supernatant. Following selection through successive subcultures of the fecal microbiota with defatted flaxseeds as the only carbon source, we obtained a bacterial consortium, designated as END-49, which contained the smallest number of bacterial types still capable of metabolizing defatted flaxseeds to produce END. Based on analysis with pulsed field gel electrophoresis, END-49 was found to consist of five genomically distinct bacterial lineages, designated Group I-V, with Group I strains dominating the culture. None of the individual Group I-V strains produced END, demonstrating that the biotransformation of substrates in defatted flaxseeds into END is a joint work by different members of the END-49 bacterial consortium. Interestingly, Group I strains produced secoisolariciresinol, an important intermediate of END production; 16S rRNA analysis of one Group I strain established its close relatedness with Klebsiella. Genomic analysis is under way to identify all members in END-49 involved in the biotransformation and the actual pathway leading to END-production. Conclusion Biotransformation is a very economic, efficient and environmentally friendly way of mass-producing enterodiol from defatted flaxseeds.



Mast cells are an important cellular source of tumour necrosis factor ? in human intestinal tissue  

Microsoft Academic Search

BACKGROUNDSeveral inflammatory disorders of the intestine are characterised by enhanced expression of tumour necrosis factor ? (TNF-?). Monocytes and macrophages have been suggested as a major cellular source of TNF-? in human gut, whereas mast cells, although known to be capable of producing TNF-?, have been poorly examined in this respect.AIMSTo investigate whether human intestinal mast cells can produce TNF-?,

S C Bischoff; A Lorentz; S Schwengberg; G Weier; R Raab; M P Manns



Small bowel bacterial overgrowth  


Overgrowth - intestinal bacteria; Bacterial overgrowth - intestine ... Normally, the small intestine contains a low number of bacteria. This is different from the large intestine, which contains large numbers of bacteria. ...


Effect of Administration of Milk Fermented with Lactobacillus acidophilus LA2 on Fecal Mutagenicity and Microflora in the Human Intestine  

Microsoft Academic Search

ABSTRACT To demonstrate,the antimutagenic,effect of fer- mented milk in the human intestine, fecal mutagenic- ity and bacterial composition,of six healthy,subjects consuming,their regular diet were investigated before and during the administration,of milk fermented,with Lactobacillus acidophilus LA-2. The administration,of the fermented,milk,caused,a remarkable,decrease (71.9% on the average; range,of 19.4 to 90.6%) in fecal mutagenicity,compared,with that before the ad- ministration; Lactobacillus spp. and Bifidobacterium

M. Hosoda; H. Hashimoto; F. He; H. Morita; A. Hosonof



Long-term monitoring of the human intestinal microbiota composition.  


The microbiota that colonizes the human intestinal tract is complex and its structure is specific for each of us. In this study we expand the knowledge about the stability of the subject-specific microbiota and show that this ecosystem is stable in short-term intervals (?10 years). The faecal microbiota composition of five unrelated and healthy subjects was analysed using a comprehensive and highly reproducible phylogenetic microarray, the HITChip. The results show that the use of antibiotics, application of specific dietary regimes and distant travelling have limited impact on the microbiota composition. Several anaerobic genera, including Bifidobacterium and a number of genera within the Bacteroidetes and the Firmicutes phylum, exhibit significantly higher similarity than the total microbiota. Although the gut microbiota contains subject-specific species, the presence of which is preserved throughout the years, their relative abundance changes considerably. Consequently, the recently proposed enterotype status appears to be a varying characteristic of the microbiota. Our data show that the intestinal microbiota contains a core community of permanent colonizers, and that environmentally introduced changes of the microbiota throughout adulthood are primarily affecting the abundance but not the presence of specific microbial species. PMID:23286720

Rajili?-Stojanovi?, Mirjana; Heilig, Hans G H J; Tims, Sebastian; Zoetendal, Erwin G; de Vos, Willem M



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

PubMed Central

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.



Luminal bacteria recruit CD103+ dendritic cells into the intestinal epithelium to sample bacterial antigens for presentation.  


CD103+ dendritic cells (DCs) carry bacteria from the small intestine and can present antigens to T cells. Yet they have not been recorded sampling luminal bacteria or presenting bacterial antigens in mesentery lymph nodes. We used 2-photon microscopy in live Cx3cr1(+/gfp) ×Cd11c-YFP mice to study these processes. At steady state, sparse CD103+ DCs occupied the epithelium. They patrolled among enterocytes while extending dendrites toward the lumen, likely using tight-junction proteins to penetrate the epithelium. Challenge with Salmonella triggered chemokine- and toll-like receptor (TLR)-dependent recruitment of additional DCs from the lamina propria (LP). The DCs efficiently phagocytosed the bacteria using intraepithelial dendrites. Noninvasive bacteria were similarly sampled. In contrast, CD103+ DCs sampled soluble luminal antigen inefficiently. In mice harboring CD103+ DCs, antigen-specific CD8 T cells were subsequently activated in MLNs. Intestinal CD103+ DCs are therefore equipped with unique mechanisms to independently complete the processes of uptake, transportation, and presentation of bacterial antigens. PMID:23395676

Farache, Julia; Koren, Idan; Milo, Idan; Gurevich, Irina; Kim, Ki-Wook; Zigmond, Ehud; Furtado, Glaucia C; Lira, Sergio A; Shakhar, Guy



Adherence to lipids and intestinal mucin by a recently recognized human pathogen, Campylobacter upsaliensis.  

PubMed Central

Campylobacter upsaliensis is a recently recognized human enteric pathogen associated with enteritis, colitis, bacteremia, and sepsis. Very little is known about the mechanisms of pathogenesis of this organism. The goals of this study were to determine whether C. upsaliensis binds to epithelial cells and whether there are specific lipid molecules that might serve as cell membrane receptors. In addition, we also explored C. upsaliensis binding to purified human small-intestinal mucin, since the mucus gel overlying the epithelium provides an initial contact surface for the bacteria and must be penetrated for the organisms to reach their cell receptors. Binding of C. upsaliensis to model epithelial cells was shown by microscopy adhesion assays, and binding to lipids was detected by thin-layer chromatography-overlay assays. Bacteria bound to phosphatidylethanolamine (PE), gangliotetraosylceramide (Gg4), and, more weakly, to phosphatidylserine (PS). There was no binding to ceramide, cholesterol, phosphatidylcholine, and globosides. Using receptor-based microtiter well immunoassays, we observed binding to be equal, specific, and saturable for PE and Gg 4 but low and nonspecific for PS. At least five bacterial surface proteins (50 to 90 kDa) capable of PE binding were identified by a lipid-silica affinity column technique. In slot blot overlay assays, biotin-labeled C. upsaliensis also bound in a concentration-dependent fashion to purified human small-intestinal mucin, implying that these microorganisms also express an adhesin(s) recognizing a specific mucin epitope(s). We speculate that binding to mucins may influence access of the bacteria to cell membrane receptors and thereby influence host resistance to infection.

Sylvester, F A; Philpott, D; Gold, B; Lastovica, A; Forstner, J F



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


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

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



Bacterial peptides are intensively present throughout the human proteome  

PubMed Central

Forty bacterial proteomes—20 pathogens and 20 non-pathogens—were examined for amino acid sequence similarity to the human proteome. All bacterial proteomes, independent of their pathogenicity, share hundreds of nonamer sequences with the human proteome. This overlap is very widespread, with one third of human proteins sharing at least one nonapeptide with one of these bacteria. On the whole, the bacteria-versus-human nonamer overlap is numerically defined by 47,610 total perfect matches disseminated through 10,701 human proteins. These findings open new perspectives on the immune relationship between bacteria and host, and might help our understanding of fundamental phenomena such as self-nonself discrimination and tolerance versus auto-reactivity.

Trost, Brett; Kusalik, Anthony; Lucchese, Guglielmo



Influence of a synbiotic mixture consisting of Lactobacillus acidophilus 74-2 and a fructooligosaccharide preparation on the microbial ecology sustained in a simulation of the human intestinal microbial ecosystem (SHIME reactor)  

Microsoft Academic Search

Lactobacillus acidophilus 74-2, which is used in probiotic products, was administered, with fructooligosaccharide in a milk-based product, to the second\\u000a vessel (duodenum\\/jejunum) of the SHIME reactor, an in vitro simulation of the human intestinal microbial ecology. The main\\u000a focus of this study was to monitor the changes of the population density of selected bacterial species in the intestine and\\u000a the

M. Gmeiner; W. Kneifel; K. D. Kulbe; R. Wouters; P. De Boever; L. Nollet; W. Verstraete



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

Microsoft Academic Search

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.

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



Ileocecal valve dysfunction in small intestinal bacterial overgrowth: A pilot study  

PubMed Central

AIM: To explore whether patients with a defective ileocecal valve (ICV)/cecal distension reflex have small intestinal bacterial overgrowth. METHODS: Using a colonoscope, under conscious sedation, the ICV was intubated and the colonoscope was placed within the terminal ileum (TI). A manometry catheter with 4 pressure channels, spaced 1 cm apart, was passed through the biopsy channel of the colonoscope into the TI. The colonoscope was slowly withdrawn from the TI while the manometry catheter was advanced. The catheter was placed across the ICV so that at least one pressure port was within the TI, ICV and the cecum respectively. Pressures were continuously measured during air insufflation into the cecum, under direct endoscopic visualization, in 19 volunteers. Air was insufflated to a maximum of 40 mmHg to prevent barotrauma. All subjects underwent lactulose breath testing one month after the colonoscopy. The results of the breath tests were compared with the results of the pressures within the ICV during air insufflation. RESULTS: Nineteen subjects underwent colonoscopy with measurements of the ICV pressures after intubation of the ICV with a colonoscope. Initial baseline readings showed no statistical difference in the pressures of the TI and ICV, between subjects with positive lactulose breath tests and normal lactulose breath tests. The average peak ICV pressure during air insufflation into the cecum in subjects with normal lactulose breath tests was significantly higher than cecal pressures during air insufflation (49.33 ± 7.99 mmHg vs 16.40 ± 2.14 mmHg, P = 0.0011). The average percentage difference of the area under the pressure curve of the ICV from the cecum during air insufflations in subjects with normal lactulose breath tests was significantly higher (280.72% ± 43.29% vs 100% ± 0%, P = 0.0006). The average peak ICV pressure during air insufflation into the cecum in subjects with positive lactulose breath tests was not significantly different than cecal pressures during air insufflation 21.23 ± 3.52 mmHg vs 16.10 ± 3.39 mmHg. The average percentage difference of the area under the pressure curve of the ICV from the cecum during air insufflation was not significantly different 101.08% ± 7.96% vs 100% ± 0%. The total symptom score for subjects with normal lactulose breath tests and subjects with positive lactulose breath tests was not statistically different (13.30 ± 4.09 vs 24.14 ± 6.58). The ICV peak pressures during air insufflations were significantly higher in subjects with normal lactulose breath tests than in subjects with positive lactulose breath tests (P = 0.005). The average percent difference of the area under the pressure curve in the ICV from cecum was significantly higher in subjects with normal lactulose breath tests than in subjects with positive lactulose breath tests (P = 0.0012). Individuals with positive lactulose breath tests demonstrated symptom scores which were significantly higher for the following symptoms: not able to finish normal sized meal, feeling excessively full after meals, loss of appetite and bloating. CONCLUSION: Compared to normal, subjects with a positive lactulose breath test have a defective ICV cecal distension reflex. These subjects also more commonly have higher symptom scores.

Miller, Larry S; Vegesna, Anil K; Sampath, Aiswerya Madanam; Prabhu, Shital; Kotapati, Sesha Krishna; Makipour, Kian



Directed differentiation of human pluripotent stem cells into intestinal tissue in vitro.  


Studies in embryonic development have guided successful efforts to direct the differentiation of human embryonic and induced pluripotent stem cells (PSCs) into specific organ cell types in vitro. For example, human PSCs have been differentiated into monolayer cultures of liver hepatocytes and pancreatic endocrine cells that have therapeutic efficacy in animal models of liver disease and diabetes, respectively. However, the generation of complex three-dimensional organ tissues in vitro remains a major challenge for translational studies. Here we establish a robust and efficient process to direct the differentiation of human PSCs into intestinal tissue in vitro using a temporal series of growth factor manipulations to mimic embryonic intestinal development. This involved activin-induced definitive endoderm formation, FGF/Wnt-induced posterior endoderm pattering, hindgut specification and morphogenesis, and a pro-intestinal culture system to promote intestinal growth, morphogenesis and cytodifferentiation. The resulting three-dimensional intestinal 'organoids' consisted of a polarized, columnar epithelium that was patterned into villus-like structures and crypt-like proliferative zones that expressed intestinal stem cell markers. The epithelium contained functional enterocytes, as well as goblet, Paneth and enteroendocrine cells. Using this culture system as a model to study human intestinal development, we identified that the combined activity of WNT3A and FGF4 is required for hindgut specification whereas FGF4 alone is sufficient to promote hindgut morphogenesis. Our data indicate that human intestinal stem cells form de novo during development. We also determined that NEUROG3, a pro-endocrine transcription factor that is mutated in enteric anendocrinosis, is both necessary and sufficient for human enteroendocrine cell development in vitro. PSC-derived human intestinal tissue should allow for unprecedented studies of human intestinal development and disease. PMID:21151107

Spence, Jason R; Mayhew, Christopher N; Rankin, Scott A; Kuhar, Matthew F; Vallance, Jefferson E; Tolle, Kathryn; Hoskins, Elizabeth E; Kalinichenko, Vladimir V; Wells, Susanne I; Zorn, Aaron M; Shroyer, Noah F; Wells, James M



Directed differentiation of human pluripotent stem cells into intestinal tissue in vitro  

PubMed Central

Studies in embryonic development have guided successful efforts to direct the differentiation of human embryonic and induced pluripotent stem cells (PSCs) into specific organ cell types in vitro 1,2. For example, human PSCs have been differentiated into monolayer cultures of liver hepatocytes and pancreatic endocrine cells3–6 that have therapeutic efficacy in animal models of liver disease 7,8 and diabetes 9 respectively. However the generation of complex three-dimensional organ tissues in vitro remains a major challenge for translational studies. We have established a robust and efficient process to direct the differentiation of human PSCs into intestinal tissue in vitro using a temporal series of growth factor manipulations to mimic embryonic intestinal development 10 (Summarized in supplementary Fig. 1). This involved activin-induced definitive endoderm (DE) formation 11, FGF/Wnt induced posterior endoderm pattering, hindgut specification and morphogenesis 12–14; and a pro-intestinal culture system 15,16 to promote intestinal growth, morphogenesis and cytodifferentiation. The resulting three-dimensional intestinal “organoids” consisted of a polarized, columnar epithelium that was patterned into villus-like structures and crypt-like proliferative zones that expressed intestinal stem cell markers17. The epithelium contained functional enterocytes, as well as goblet, Paneth, and enteroendocrine cells. Using this culture system as a model to study human intestinal development, we identified that the combined activity of Wnt3a and FGF4 is required for hindgut specification whereas FGF4 alone is sufficient to promote hindgut morphogenesis. Our data suggests that human intestinal stem cells form de novo during development. Lastly we determined that NEUROG3, a pro-endocrine transcription factor that is mutated in enteric anendocrinosis 18, is both necessary and sufficient for human enteroendocrine cell development in vitro. In conclusion, PSC-derived human intestinal tissue should allow for unprecedented studies of human intestinal development and disease.

Spence, Jason R.; Mayhew, Christopher N.; Rankin, Scott A.; Kuhar, Matthew; Vallance, Jefferson E.; Tolle, Kathryn; Hoskins, Elizabeth E.; Kalinichenko, Vladimir V.; Wells, Susanne I.; Zorn, Aaron M.; Shroyer, Noah F.; Wells, James M.



Small Intestinal Bacterial Overgrowth in Nonalcoholic Steatohepatitis: Association with Toll-Like Receptor 4 Expression and Plasma Levels of Interleukin 8  

Microsoft Academic Search

Background  Experimental and clinical studies suggest an association between small intestinal bacterial overgrowth (SIBO) and nonalcoholic\\u000a steatohepatitis (NASH). Liver injury and fibrosis could be related to exposure to bacterial products of intestinal origin\\u000a and, most notably, endotoxin, including lipopolysaccharide (LPS).\\u000a \\u000a \\u000a \\u000a \\u000a Aim  To compare the prevalence of SIBO and its relationships to LPS receptor levels and systemic cytokines in NASH patients and\\u000a healthy

Ahmed Abu Shanab; Paul Scully; Orla Crosbie; Martin Buckley; Liam O’Mahony; Fergus Shanahan; Sanaa Gazareen; Eileen Murphy; Eamonn M. M. Quigley



Ontogeny of FOXP3+ Regulatory T Cells in the Postnatal Human Small Intestinal and Large Intestinal Lamina Propria  

PubMed Central

Background FOXP3+ regulatory T cells (Treg) suppress innate and adaptive immune responses and are critical for intestinal immune homeostasis. Our objective was to define the postnatal developmental regulation of Treg in relationship to other T cells in the human intestinal tract. Methods We analyzed 41 small and 18 large intestinal paraffin-embedded tissue samples from preterm and term infants with and without necrotizing enterocolitis (NEC) for presence of CD3+, CD4+, CD8+, and FOXP3+ cells by immunohistochemistry. We compared labeled cells against age, gestational age (GA), or (corrected) postmenstrual age (PMA). Results The GA ranged from 23 to 40 weeks, with a mean of 32 (SD 4.7) weeks. Independent of age, GA, or PMA, the numbers of CD4+ cells were higher in the small compared to the large intestine (p=0.046), except in patients with NEC. FOXP3+ cells could be detected as early as 23 weeks GA in both large and small bowel, and similar quantities were detected at the highest GA examined (40 weeks). We saw no statistically significant effect of GA, age, or PMA on total number of FOXP3+ cells, or by comparing FOXP3+ to CD4+ or FOXP3+to CD8+ ratios, suggesting intact ontogeny of Treg in intestinal tissue early in gestation. Conclusion Human infants exhibit presence of mucosal FOXP3+ cells in the small and large intestinal mucosa at birth and as early as 23 weeks GA. The frequency of FOXP3+ cells and the ratios of FOXP3+ to CD4+ or CD8+ cells do not change with increasing intrauterine development or postnatal age.

Weitkamp, Jorn-Hendrik; Rudzinski, Erin; Koyama, Tatsuki; Correa, Hernan; Matta, Pranathi; Alberty, Brannon; Polk, D-Brent



A metagenomic ?-glucuronidase uncovers a core adaptive function of the human intestinal microbiome.  


In the human gastrointestinal tract, bacterial ?-D-glucuronidases (BG; E.C. are involved both in xenobiotic metabolism and in some of the beneficial effects of dietary compounds. Despite their biological significance, investigations are hampered by the fact that only a few BGs have so far been studied. A functional metagenomic approach was therefore performed on intestinal metagenomic libraries using chromogenic glucuronides as probes. Using this strategy, 19 positive metagenomic clones were identified but only one exhibited strong ?-D-glucuronidase activity when subcloned into an expression vector. The cloned gene encoded a ?-D-glucuronidase (called H11G11-BG) that had distant amino acid sequence homologies and an additional C terminus domain compared with known ?-D-glucuronidases. Fifteen homologs were identified in public bacterial genome databases (38-57% identity with H11G11-BG) in the Firmicutes phylum. The genomes identified derived from strains from Ruminococcaceae, Lachnospiraceae, and Clostridiaceae. The genetic context diversity, with closely related symporters and gene duplication, argued for functional diversity and contribution to adaptive mechanisms. In contrast to the previously known ?-D-glucuronidases, this previously undescribed type was present in the published microbiome of each healthy adult/child investigated (n = 11) and was specific to the human gut ecosystem. In conclusion, our functional metagenomic approach revealed a class of BGs that may be part of a functional core specifically evolved to adapt to the human gut environment with major health implications. We propose consensus motifs for this unique Firmicutes ?-D-glucuronidase subfamily and for the glycosyl hydrolase family 2. PMID:20615998

Gloux, Karine; Berteau, Olivier; El Oumami, Hanane; Béguet, Fabienne; Leclerc, Marion; Doré, Joël



Interleukin6 Production in Human Intestinal Epithelial Cells Increases in Association with the Heat Shock Response  

Microsoft Academic Search

Background.In recent studies, IL-1? stimulated the production of IL-6 in human enterocytes. The heat shock response influences the production of inflammatory mediators in certain cell types. We tested the hypothesis that heat shock regulates IL-1?-induced IL-6 production in human intestinal epithelial cells.Materials and methods.Cultured Caco-2 cells, a human intestinal epithelial cell line, were exposed to thermal heat shock at 43°C

Alexander A. Parikh; M. Ryan Moon; Christine D. Kane; Andrew L. Salzman; Josef E. Fischer; Per-Olof Hasselgren



Movement and Fixation of Intestinal Microbiota after Administration of Human Feces to Germfree Mice  

Microsoft Academic Search

Human flora-associated (HFA) mice have been considered a tool for studying the ecology and metabolism of intestinal bacteria in humans, although they have some limitations as a model. Shifts in dominant species of microbiota in HFA mice after the administration of human intestinal microbiota was revealed by 16S rRNA gene sequence and terminal restriction fragment length polymorphism (T-RFLP) analyses. Characteristic

Ryoko Kibe; Mitsuo Sakamoto; Hiroshi Yokota; Hiroki Ishikawa; Yuji Aiba; Yasuhiro Koga; Yoshimi Benno



Increased accuracy of the carbon-14d-xylose breath test in detecting small-intestinal bacterial overgrowth by correction with the gastric emptying rate  

Microsoft Academic Search

To date, there is no general agreement as to which test is to be preferred for the diagnosis of small-intestinal bacterial overgrowth. The 1-g carbon-14d-xylose breath test has been proposed as a very sensitive and specific test for the diagnosis of bacterial overgrowth. However, in patients with severe gastrointestinal motor dysfunction, the lack of consistent delivery of14C-d-xylose to the region

Chi-Sen Chang; Gran-Hum Chen; Chia-Hung Kao; Shyh-Jen Wang; Shih-Nen Peng; Chih-Kuen Huang; Sek-Kwong Poon



The Nucleotide Synthesis Enzyme CAD Inhibits NOD2 Antibacterial Function in Human Intestinal Epithelial Cells  

PubMed Central

BACKGROUND & AIMS Polymorphisms that reduce the function of nucleotide-binding oligomerization domain (NOD)2, a bacterial sensor, have been associated with Crohn’s disease (CD). No proteins that regulate NOD2 activity have been identified as selective pharmacologic targets. We sought to discover regulators of NOD2 that might be pharmacologic targets for CD therapies. METHODS Carbamoyl phosphate synthetase/ aspartate transcarbamylase/dihydroorotase (CAD) is an enzyme required for de novo pyrimidine nucleotide synthesis; it was identified as a NOD2-interacting protein by immunoprecipitation-coupled mass spectrometry. CAD expression was assessed in colon tissues from individuals with and without inflammatory bowel disease by immunohistochemistry. The interaction between CAD and NOD2 was assessed in human HCT116 intestinal epithelial cells by immunoprecipitation, immunoblot, reporter gene, and gentamicin protection assays. We also analyzed human cell lines that express variants of NOD2 and the effects of RNA interference, overexpression and CAD inhibitors. RESULTS CAD was identified as a NOD2-interacting protein expressed at increased levels in the intestinal epithelium of patients with CD compared with controls. Overexpression of CAD inhibited NOD2-dependent activation of nuclear factor ?B and p38 mitogen-activated protein kinase, as well as intracellular killing of Salmonella. Reduction of CAD expression or administration of CAD inhibitors increased NOD2-dependent signaling and antibacterial functions of NOD2 variants that are and are not associated with CD. CONCLUSIONS The nucleotide synthesis enzyme CAD is a negative regulator of NOD2. The antibacterial function of NOD2 variants that have been associated with CD increased in response to pharmacologic inhibition of CAD. CAD is a potential therapeutic target for CD.

Richmond, Amy L.; Kabi, Amrita; Homer, Craig R.; Garcia, Noemi Marina; Nickerson, Kourtney P.; NesvizhskiI, Alexey I.; Sreekumar, Arun; Chinnaiyan, Arul M.; Nunez, Gabriel; McDonald, Christine



Degradation of neohesperidin dihydrochalcone by human intestinal bacteria.  


The degradation of neohesperidin dihydrochalcone by human intestinal microbiota was studied in vitro. Human fecal slurries converted neohesperidin dihydrochalcone anoxically to 3-(3-hydroxy-4-methoxyphenyl)propionic acid or 3-(3,4-dihydroxyphenyl)propionic acid. Two transient intermediates were identified as hesperetin dihydrochalcone 4'-beta-d-glucoside and hesperetin dihydrochalcone. These metabolites suggest that neohesperidin dihydrochalcone is first deglycosylated to hesperetin dihydrochalcone 4'-beta-d-glucoside and subsequently to the aglycon hesperetin dihydrochalcone. The latter is hydrolyzed to the corresponding 3-(3-hydroxy-4-methoxyphenyl)propionic acid and probably phloroglucinol. Eubacterium ramulus and Clostridium orbiscindens were not capable of converting neohesperidin dihydrochalcone. However, hesperetin dihydrochalcone 4'-beta-d-glucoside was converted by E. ramulus to hesperetin dihydrochalcone and further to 3-(3-hydroxy-4-methoxyphenyl)propionic acid, but not by C. orbiscindens. In contrast, hesperetin dihydrochalcone was cleaved to 3-(3-hydroxy-4-methoxyphenyl)propionic acid by both species. The latter reaction was shown to be catalyzed by the phloretin hydrolase from E. ramulus. PMID:15740074

Braune, Annett; Engst, Wolfram; Blaut, Michael



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


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

Seifert, P; Spitznas, M



Molecular analysis of the bacterial microbiota in the human stomach  

PubMed Central

The microbiota of the human stomach and the influence of Helicobacter pylori colonization on its composition remain largely unknown. We characterized bacterial diversity within the human gastric mucosa by using a small subunit 16S rDNA clone library approach and analyzed 1,833 sequences generated by broad-range bacterial PCR from 23 gastric endoscopic biopsy samples. A diverse community of 128 phylotypes was identified, featuring diversity at this site greater than previously described. The majority of sequences were assigned to the Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes, and Fusobacteria phyla. Ten percent of the phylotypes were previously uncharacterized, including a Deinococcus-related organism, relatives of which have been found in extreme environments but not reported before in humans. The gastric clone libraries from 19 subjects contained H. pylori rDNA; however, only 12 of these subjects tested positive for H. pylori by conventional laboratory methods. Statistical analysis revealed a large degree of intersubject variability of the gastric ecosystem. The presence of H. pylori did not affect the composition of the gastric community. This gastric bacterial rDNA data set was significantly different from sequence collections of the human mouth and esophagus described in other studies, indicating that the human stomach may be home to a distinct microbial eco-system. The gastric microbiota may play important, as-yet-undiscovered roles in human health and disease.

Bik, Elisabeth M.; Eckburg, Paul B.; Gill, Steven R.; Nelson, Karen E.; Purdom, Elizabeth A.; Francois, Fritz; Perez-Perez, Guillermo; Blaser, Martin J.; Relman, David A.



Role of TLR4/NF-?B in Damage to Intestinal Mucosa Barrier Function and Bacterial Translocation in Rats Exposed to Hypoxia  

PubMed Central

The role of Toll-like receptor 4 (TLR4)/nuclear factor-kappa-B (NF-?B) 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-?B 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-? 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-?B 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-?B signaling pathway. PDTC- treatment also reversed hyoxia- and LPS-induced bacterial translocation rate and increased serum levels of LPS, TNF-?, and IL-6. TLR4 mRNA levels and NF-?B p65 expression were consistent with the serum factor results. This study suggested that TLR4 and NF-?B expression increased in rat intestinal tissues after acute hypoxia exposure. PDTC-treatment reversed TLR4 and NF-?B upregulation and alleviated damage to the intestinal tract and bacterial translocation. Thus, the TLR4/NF-?B signaling pathway may be critical to the mechanism underlying hypoxia-induced damage to intestinal barrier function and bacterial translocation.

Luo, Han; Guo, Ping; Zhou, Qiquan



Microbial EcoPhysiology of the human intestinal tract: a flow cytometric approach  

Microsoft Academic Search

This thesis describes a multifaceted approach to further enhance our view of the complex human intestinal microbial ecosystem. This approach combines me advantages of flow cyrometry (FCM), a single cell and high-throughput technology, and molecular techniques that have proven themselves to be invaluabIe tools in studying the microbial diversity and structure of the intestinal microbiota. The ultimate aim was to

K. Ben Amor



Rotavirus induces apoptosis in fully differentiated human intestinal Caco-2 cells  

Microsoft Academic Search

Rotaviruses, which are the main cause of viral gastroenteritis in young children, induce structural and functional damages in infected mature enterocytes of the small intestine. To investigate a relationship between rotavirus infection and cell death by apoptosis, we used the human intestinal Caco-2 cell line. We demonstrated by several methods including TUNEL and ELISA detection of cytoplasmic histone-associated DNA fragments

Charlotte Chaïbi; Jacqueline Cotte-Laffitte; Catherine Sandré; Audrey Esclatine; Alain L. Servin; Anne-Marie Quéro; Monique Géniteau-Legendre



Some bacterial pathogens in the intestine of cultivated silver carp and common carp  

Microsoft Academic Search

There is an increasing demand for cultivated fish in all over the world. Unfortunately all of these fish are sold in whole states with viscera in the fish markets in Iran. The flora of water influences intestinal flora of the live fish. Fish captured in lakes, rivers and fish farms often carry a wide range of pathogenic microorganisms in their

Afshin Akhondzadeh Basti; Taghi Zahrae Salehi; Saied Bokaie



Adult Human Milk Intolerance and Intestinal Lactase Deficiency: A Review.  

National Technical Information Service (NTIS)

In man, the dietary milk sugar, lactose, is hydrolyzed to glucose and galactose by the small intestinal enzyme, lactase. This enzyme is located in the brush border of the small intestinal epithelial cell. Recent studies have called attention to the associ...

N. S. Rosenweig



Beta adrenergic modulation of human upper intestinal propulsive forces  

Microsoft Academic Search

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

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



Oral glutamine does not prevent bacterial translocation in rats subjected to intestinal obstruction and Escherichia coli challenge but reduces systemic bacteria spread  

Microsoft Academic Search

Objective: We investigated whether oral glutamine prevents bacterial translocation.Methods: Male Wistar rats were fed with isocaloric and isoproteic standard rat chow and randomly assigned to receive glutamine (GLN) or glycine administered through an orogastric tube at 1.5 g · kg?1 · d?1 for 7 d. On day 8 of the study, the animals were anesthetized and intestinal obstruction was produced

Paolo R. O Salvalaggio; Clementino Zeni Neto; André R. D Tolazzi; Emerson L Gasparetto; Júlio C. U Coelho; Antonio C. L Campos



Pseudomonas reactans, a bacterial strain isolated from the intestinal flora of Blattella germanica with anti-Beauveria bassiana activity.  


Anti-Beauveria bassiana activity of aqueous fecal extracts from conventional German cockroaches [Blattella germanica (L.)] was detected, but was not detected in samples from germ-free German cockroaches. Subsequently, bacterial strain BGI-14 was isolated from the gut of conventional German cockroaches and was identified as Pseudomonas reactans based on 16S rDNA sequence. The strain BGI-14 not only inhibited the germination of conidia, but also inhibited the growth of B. bassiana hyphae. Further studies demonstrated that B. bassiana infections in German cockroaches orally treated with the extracts of BGI-14 fermentation were significantly weakened. Compared with the control group, the cumulative mortality rate of treatment group was reduced by 10.3% at 20 d postinoculation. These studies imply that intestinal flora with anti-B. bassiana activity might contribute to resistance of infection by entomopathogenic fungi. PMID:23726054

Zhang, Fan; Huang, Yan Hong; Liu, Shu Zhen; Zhang, Lei; Li, Bo Tai; Zhao, Xiao Xu; Fu, Ying; Liu, Jian Jun; Zhang, Xue Xia



Bacterial peptidoglycan breaks down intestinal tolerance via mast cell activation: The role of TLR2 and NOD2  

Microsoft Academic Search

Intestinal microbes are believed to be involved in the pathogenesis of inflammatory bowel disease. Microbes and their products are generally well tolerated by intestinal epithelial cells in the intestinal tract of healthy individuals. It is of significance to understand what breaks down the established tolerance leading to intestinal barrier dysfunction and intestinal inflammation. T84 monolayer transported peptidoglycan (PGN) was determined

Linda Wu; Bai-Sui Feng; Shao-Heng He; Peng-Yuan Zheng; Kenneth Croitoru; Ping-Chang Yang



Role of bacterial microflora in development of intestinal lesions from graft-versus-host reaction.  


Acute secondary disease was induced in (C57BL X CBA)F1 mice by transplanting CBA bone marrow and spleen cells following lethal whole-body irradiation. The lesions of graft-versus-host (GvH) disease were scored quantitatively by counting of degenerated crypts in subcutaneous fetal gut implants that were free of bacteria. In conventional F1 mice the damage in F1 fetal gut was twice as great as in F1 fetal gut implants carried by decontaminated chimeras. CBA fetal gut implants developed substantial damage when present in conventional chimeras, but not when present in decontaminated chimeras. These results could be explained by assuming the presence of cross-reacting antigens on intestinal bacteria and in the gut epithelial tissue. They also explained the profound protection against delayed GvH mortality provided by removal of the intestinal microflora. PMID:14265

van Bekkum, D W; Knaan, S



Safety and risk assessment of the genetically modified Lactococci on rats intestinal bacterial flora  

Microsoft Academic Search

The interaction between Lactococcus lactis NZ9000\\/pNZPNK and intestinal microflora was evaluated as a method to assess safety of genetically modified microorganisms (GMMs). L. lactis NZ9000\\/pNZPNK is one kind of GMM and able to produce the intracellular subtilisin NAT (nattokinase) under induction with nisin. The host strain L. lactis NZ9000 was a generally recognized as safe (GRAS) microorganism. Six groups of

Kai-Chien Lee; Chin-Feng Liu; Tzu-Hsing Lin; Tzu-Ming Pan



Genetic evidence for a protective role of the peritrophic matrix against intestinal bacterial infection in Drosophila melanogaster  

PubMed Central

The peritrophic matrix (PM) forms a layer composed of chitin and glycoproteins that lines the insect intestinal lumen. This physical barrier plays a role analogous to that of mucous secretions of the vertebrate digestive tract and is thought to protect the midgut epithelium from abrasive food particles and microbes. Almost nothing is known about PM functions in Drosophila, and its function as an immune barrier has never been addressed by a genetic approach. Here we show that the Drosocrystallin (Dcy) protein, a putative component of the eye lens of Drosophila, contributes to adult PM formation. A loss-of-function mutation in the dcy gene results in a reduction of PM width and an increase of its permeability. Upon bacterial ingestion a higher level of expression of antibacterial peptides was observed in dcy mutants, pointing to an influence of this matrix on bacteria sensing by the Imd immune pathway. Moreover, dcy-deficient flies show an increased susceptibility to oral infections with the entomopathogenic bacteria Pseudomonas entomophila and Serratia marcescens. Dcy mutant flies also succumb faster than wild type upon ingestion of a P. entomophila toxic extract. We show that this lethality is due in part to an increased deleterious action of Monalysin, a pore-forming toxin produced by P. entomophila. Collectively, our analysis of the dcy immune phenotype indicates that the PM plays an important role in Drosophila host defense against enteric pathogens, preventing the damaging action of pore-forming toxins on intestinal cells.

Kuraishi, Takayuki; Binggeli, Olivier; Opota, Onya; Buchon, Nicolas; Lemaitre, Bruno



Genetic evidence for a protective role of the peritrophic matrix against intestinal bacterial infection in Drosophila melanogaster.  


The peritrophic matrix (PM) forms a layer composed of chitin and glycoproteins that lines the insect intestinal lumen. This physical barrier plays a role analogous to that of mucous secretions of the vertebrate digestive tract and is thought to protect the midgut epithelium from abrasive food particles and microbes. Almost nothing is known about PM functions in Drosophila, and its function as an immune barrier has never been addressed by a genetic approach. Here we show that the Drosocrystallin (Dcy) protein, a putative component of the eye lens of Drosophila, contributes to adult PM formation. A loss-of-function mutation in the dcy gene results in a reduction of PM width and an increase of its permeability. Upon bacterial ingestion a higher level of expression of antibacterial peptides was observed in dcy mutants, pointing to an influence of this matrix on bacteria sensing by the Imd immune pathway. Moreover, dcy-deficient flies show an increased susceptibility to oral infections with the entomopathogenic bacteria Pseudomonas entomophila and Serratia marcescens. Dcy mutant flies also succumb faster than wild type upon ingestion of a P. entomophila toxic extract. We show that this lethality is due in part to an increased deleterious action of Monalysin, a pore-forming toxin produced by P. entomophila. Collectively, our analysis of the dcy immune phenotype indicates that the PM plays an important role in Drosophila host defense against enteric pathogens, preventing the damaging action of pore-forming toxins on intestinal cells. PMID:21896728

Kuraishi, Takayuki; Binggeli, Olivier; Opota, Onya; Buchon, Nicolas; Lemaitre, Bruno



Host resistance to an intragastric infection with Listeria monocytogenes in mice depends on cellular immunity and intestinal bacterial flora.  

PubMed Central

Suckling and adult mice were infected intragastrically with different doses of viable Listeria monocytogenes. The 50% lethal dose for the intragastric infection was 10(3.7) CFU for suckling mice, while adult mice were highly resistant and the 50% lethal dose was more than 10(9.3) CFU. When adult mice were infected intragastrically with 5 x 10(8) CFU of L. monocytogenes, no mice died. However, 35% of adult mice died when they were treated with cyclosporin A 1 day before infection. Although mice did not die when treated with an L. monocytogenes-resistant broad-spectrum cephalosporin, sodium cefbuperazone, before and during infection, the number of L. monocytogenes bacteria increased in the feces. The sodium cefbuperazone treatment of mice resulted in superinfection, i.e., a marked decrease of Escherichia coli and an increase of Enterococcus spp. in the intestines. Furthermore, host resistance against the intragastric infection markedly decreased when the mice were treated with both drugs. The growth of L. monocytogenes was augmented in the spleens, mesenteric lymph nodes, Peyer's patches, and feces, and the mortality of the mice was 65%. These results suggest that both cellular immunity and the intestinal bacterial flora are required for host resistance against oral L. monocytogenes infection.

Okamoto, M; Nakane, A; Minagawa, T



Deglycosylation of flavonoid and isoflavonoid glycosides by human small intestine and liver ?-glucosidase activity  

Microsoft Academic Search

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

Andrea J Day; M. Susan DuPont; Saxon Ridley; Mike Rhodes; Michael J. C Rhodes; Michael R. A Morgan; Gary Williamson



High taxonomic level fingerprint of the human intestinal microbiota by Ligase Detection Reaction - Universal Array approach  

Microsoft Academic Search

BACKGROUND: Affecting the core functional microbiome, peculiar high level taxonomic unbalances of the human intestinal microbiota have been recently associated with specific diseases, such as obesity, inflammatory bowel diseases, and intestinal inflammation. RESULTS: In order to specifically monitor microbiota unbalances that impact human physiology, here we develop and validate an original DNA-microarray (HTF-Microbi.Array) for the high taxonomic level fingerprint of

Marco Candela; Clarissa Consolandi; Marco Severgnini; Elena Biagi; Bianca Castiglioni; Beatrice Vitali; Gianluca De Bellis; Patrizia Brigidi



Comparative gene expression profiles of intestinal transporters in mice, rats and humans  

Microsoft Academic Search

We have studied gene expression profiles of intestinal transporters in model animals and humans. Total RNA was isolated from duodenum and the mRNA expression was measured using Affymetrix GeneChip oligonucleotide arrays. Detected genes from the intestine of mice, rats, and humans were about 60% of 22,690 sequences, 40% of 8739, and 47% of 12,559, respectively. A total of 86 genes

Hye-Ryoung Kim; Sung-Won Park; Hee-Jung Cho; Kyung-Ae Chae; Ji-Min Sung; Jin-Suk Kim; Christopher P. Landowski; Duxin Sun; A. M. Abd El-Aty; Gordon L. Amidon; Ho-Chul Shin



Longitudinal cell formation in the entire human small intestine is correlated with the localization of Hath1 and Klf4  

Microsoft Academic Search

Background  Double balloon endoscopy (DBE) enables the observation and collection of viable specimens from the entire intestine, thereby\\u000a allowing more detailed investigation of how the structure and function of the human small intestine are regulated. The present\\u000a study aimed to elucidate the regulation of cell formation in the human small intestine using biopsy specimens collected from\\u000a an entire individual small intestine

Michiko IwasakiKiichiro; Kiichiro Tsuchiya; Ryuichi Okamoto; Xiu Zheng; Yoshihito Kano; Eiko Okamoto; Eriko Okada; Akihiro Araki; Shinji Suzuki; Naoya Sakamoto; Keisuke Kitagaki; Takumi Akashi; Yoshinobu Eishi; Tetsuya Nakamura; Mamoru Watanabe



Characterization of intracellular pteroylpolyglutamate hydrolase (PPH) from human intestinal mucosa  

SciTech Connect

There are two forms of pteroylpolyglutamate hydrolase (PPH) in the human intestinal mucosa, one in the brush border membrane and the other intracellular; brush border PPH is an exopeptidase with optimal activity at pH 6.5 and a requirement for zinc. The presence study characterized human intracellular PPH and compared its properties to those of brush border PPH. Intracellular PPH was purified 30-fold. The enzyme had a MW of 75,000 by gel filtration, was optimally active at pH 4.5, and had an isoelectric point at pH 8.0. In contrast to brush border PPH, intracellular PPH was unstable at increasing temperatures, was unaffected by dialysis against chelating agents and showed no requirement for Zn/sup 2 +/. Using PteGlu/sub 2/(/sup 14/C)Glu as substrate, they demonstrated a K/sub m/ of 1.2 and increasing affinity for folates with longer glutamate chains. Intracellular PPH required the complete folic acid (PteGlu) moiety and a ..gamma..-glutamyl linkage for activity. Using ion exchange chromatography and an HPLC method to determine the hydrolytic products of the reaction, they found intracellular PPH could cleave both internal and terminal ..gamma..-glutamyl linkages, with PteGlu as an end product. After subcellular fractionation of the mucosa, PPH was found in the lysosomes. In summary, the distinct characteristics of brush border and intracellular PPH suggest that the two hydrolases serve different roles in folate metabolism.

Wang, T.T.Y.; Chandler, C.J.; Halsted, C.H.



Identification of the predominant antigenic epitopes in intestinal flora in IBD  

Microsoft Academic Search

The normal intestinal flora is required for the development of intestinal inflammation in animal models of inflammatory bowel disease (IBD). In humans, several studies indicated a potential association of Escherichia coli (E. coli) with IBD. In addition, we have shown that T-cell clones of IBD patients cross react toward different enteric bacterial species and thus likely respond to conserved bacterial

A Ergin; T Adam; K Büssow; A Thiel; J Sieper; R Duchmann



Fecal collection, ambient preservation, and DNA extraction for PCR amplification of bacterial and human markers from human feces.  


Feces contain intestinal bacteria and exfoliated epithelial cells that may provide useful information concerning gastrointestinal tract health. Intestinal bacteria that synthesize or metabolize potential carcinogens and produce anti-tumorigenic products may have relevance to colorectal cancer, the second most common cause of cancer deaths in the USA. To facilitate epidemiological studies relating bacterial and epithelial cell DNA and RNA markers, preservative/extraction methods suitable for self-collection and shipping of fecal samples at room temperature were tested. Purification and PCR amplification of fecal DNA were compared after preservation of stool samples in RNAlater (R) or Paxgene (P), or after drying over silica gel (S) or on Whatman FTA cards (W). Comparisons were made to samples frozen in liquid nitrogen (N2). DNA purification methods included Whatman (accompanying FTA cards), Mo-Bio Fecal (MB), Qiagen Stool (QS), and others. Extraction methods were compared for amount of DNA extracted, DNA amplifiable in a real-time SYBR-Green quantitative PCR format, and the presence of PCR inhibitors. DNA can be extracted after room temperature storage for five days from W, R, S and P, and from N2 frozen samples. High amounts of total DNA and PCR-amplifiable Bacteroides spp. DNA (34%+/-9% of total DNA) with relatively little PCR inhibition were especially obtained with QS extraction applied to R preserved samples (method QS-R). DNA for human reduced folate carrier (SLC19A1) genomic sequence was also detected in 90% of the QS-R extracts. Thus, fecal DNA is well preserved by methods suitable for self-collection that may be useful in future molecular epidemiological studies of intestinal bacteria and human cancer markers. PMID:18162191

Nechvatal, Jordan M; Ram, Jeffrey L; Basson, Marc D; Namprachan, Phanramphoei; Niec, Stephanie R; Badsha, Kawsar Z; Matherly, Larry H; Majumdar, Adhip P N; Kato, Ikuko



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


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

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



Morphology of Diagnostic Stages of Intestinal Parasites of Humans.  

National Technical Information Service (NTIS)

The diagnostic stages of intestinal parasites are differentiated on the basis of specific morphologic features that can be seen microscopically. Although Dientamoeba fragilis is a flagellate, morphologically, it resembles the amebae. Therefore, in this ma...

M. M. Brooke D. M. Melvin



Laminin receptor 37/67LR regulates adhesion and proliferation of normal human intestinal epithelial cells.  


Interactions between the cell basal membrane domain and the basement membrane are involved in several cell functions including proliferation, migration and differentiation. Intestinal epithelial cells can interact with laminin, a major intestinal basement membrane glycoprotein, via several cell-surface laminin-binding proteins including integrin and non-integrin receptors. The 37/67kDa laminin receptor (37/67LR) is one of these but its role in normal epithelial cells is still unknown. The aim of this study was to characterise the expression pattern and determine the main function of 37/67LR in the normal human small intestinal epithelium. Immunolocalization studies revealed that 37/67LR was predominantly present in the undifferentiated/proliferative region of the human intestinal crypt in both the immature and adult intestine. Using a human intestinal epithelial crypt (HIEC) cell line as experimental model, we determined that 37/67LR was expressed in proliferative cells in both the cytoplasmic and membrane compartments. Small-interfering RNA-mediated reduction of 37/67LR expression led to HIEC cell-cycle reduction and loss of the ability to adhere to laminin-related peptides under conditions not altering ribosomal function. Taken together, these findings indicate that 37/67LR regulates proliferation and adhesion in normal intestinal epithelial cells independently of its known association with ribosomal function. PMID:23991217

Khalfaoui, Taoufik; Groulx, Jean-François; Sabra, Georges; GuezGuez, Amel; Basora, Nuria; Vermette, Patrick; Beaulieu, Jean-François



Nerveless and gutsy: intestinal nutrient sensing from invertebrates to humans.  


The increasingly recognized role of gastrointestinal signals in the regulation of food intake, insulin production and peripheral nutrient storage has prompted a surge of interest in studying how the gastrointestinal tract senses and responds to nutritional information. Identification of metabolically important intestinal nutrient sensors could provide potential new drug targets for the treatment of diabetes, obesity and gastrointestinal disorders. From a more fundamental perspective, the study of intestinal chemosensation is revealing novel, non-neuronal modes of communication involving differentiated epithelial cells. It is also identifying signalling mechanisms downstream of not only canonical receptors but also nutrient transporters, thereby supporting a chemosensory role for "transceptors" in the intestine. This review describes known and proposed mechanisms of intestinal carbohydrate, protein and lipid sensing, best characterized in mammalian systems. It also highlights the potential of invertebrate model systems such as C. elegans and Drosophila melanogaster by summarizing known examples of molecular evolutionary conservation. Recently developed genetic tools in Drosophila, an emerging model system for the study of physiology and metabolism, allow the temporal, spatial and high-throughput manipulation of putative intestinal sensors. Hence, fruit flies may prove particularly suited to the study of the link between intestinal nutrient sensing and metabolic homeostasis. PMID:22248674

Miguel-Aliaga, Irene



Exopolysaccharides produced by probiotic strains modify the adhesion of probiotics and enteropathogens to human intestinal mucus.  


Exopolysaccharides (EPSs) are exocellular polymers present in the surface of many bacteria, including Lactobacillus and Bifidobacterium. The genome sequence of several strains revealed the presence of EPS-encoding genes. However, the physiological role that EPSs play in the bacterial ecology still remains uncertain. In this study, we have assessed the effect of EPSs produced by Lactobacillus rhamnosus GG, Bifidobacterium longum NB667, and Bifidobacterium animalis IPLA-R1 on the adhesion of probiotic and enteropathogen strains to human intestinal mucus. The EPS fraction GG had no significant effect on the adhesion of L. rhamnosus GG and B. animalis IPLA-R1. However, the EPS fractions NB667 and IPLA-R1 significantly reduced the adherence of both probiotic strains. In contrast, the three EPS fractions increased the adhesion of Enterobacter sakazakii ATCC 29544 and Escherichia coli NCTC 8603. Higher adherence of Salmonella enterica serovar Typhimurium ATCC 29631 and Clostridium difficile ATCC 9689 was detected in the presence of the EPS fractions GG and NB667. In general, these effects were obtained at EPS concentrations of up to 5 mg/ml, and they were EPS dose dependent. The competitive exclusion of probiotics in the presence of EPS could suggest the involvement of these biopolymers in the adhesion to mucus. The increase in the adherence of enteropathogens could be explained if components of the pathogen surface are able to bind to specific EPSs and the bound EPSs are able to adhere to mucus. To the best of our knowledge, this is the first work reporting the effect of EPSs from probiotics on bacterial adhesion properties. PMID:16924934

Ruas-Madiedo, Patricia; Gueimonde, Miguel; Margolles, Abelardo; de los Reyes-Gavilán, Clara G; Salminen, Seppo



Identification of urinary and intestinal bacterial metabolites of ellagitannin geraniin in rats.  


Hydrolyzable tannins, including ellagitannins, occur in foods such as berries and nuts. Various biological activities, including antioxidant, antiviral, and antitumor activities, have been noted and reported for ellagitannins, but the absorption and metabolism of purified ellagitannins are poorly understood. We describe herein the characterization of urinary and intestinal microbial metabolites in rats after the ingestion of ellagitannins. Urine samples were collected after oral administration of ellagitannins such as geraniin ( 1), corilagin ( 2), and their related polyphenols. The suspension of rat intestinal microflora was anaerobically incubated with ellagitannins. Each sample was separated by column chromatography and/or preparative HPLC to give seven metabolites, M1- M7. The structures of these metabolites were determined on the basis of spectroscopic data and chemical evidence. These compounds, except for M1, were characterized as ellagitannin metabolites for the first time. Furthermore, among four major metabolites ( M1- M4) in urine, M2 showed an antioxidant activity comparable to intact geraniin and related polyphenols. PMID:18163562

Ito, Hideyuki; Iguchi, Ayumu; Hatano, Tsutomu



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

Microsoft Academic Search

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

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



Vasoactive intestinal peptide (VIP) inhibits human renal cell carcinoma proliferation.  


Clear renal cell carcinoma (cRCC) is an aggressive and fatal neoplasm. The present work was undertaken to investigate the antiproliferative potential of vasoactive intestinal peptide (VIP) exposure on non-tumoral (HK2) and tumoral (A498, cRCC) human proximal tubular epithelial cell lines. Reverse transcription and semiquantitative PCR was used at the VIP mRNA level whereas enzyme immunoanalysis was performed at the protein level. Both renal cell lines expressed VIP as well as VIP/pituitary adenylate cyclase-activating peptide (VPAC) receptors whereas only HK2 cells expressed formyl peptide receptor-like 1 (FPRL-1). Receptors were functional, as shown by VIP stimulation of adenylyl cyclase activity. Treatment with 0.1?M VIP (24h) inhibited proliferation of A498 but not HK2 cells as based on a reduction in the incorporation of [(3)H]-thymidine and BrdU (5'-Br-2'-deoxyuridine), PCNA (proliferating-cell nuclear antigen) expression and STAT3 (signal transducer and activator of transcription 3) expression and activation. VPAC(1)-receptor participation was established using JV-1-53 antagonist and siRNA transfection. Growth-inhibitory response to VIP was related to the cyclic adenosine monophosphate (cAMP)/exchange protein directly activated by cAMP (EPAC)/phosphoinositide 3-kinase (PI3-K) signaling systems as shown by studies on adenylate cyclase stimulation, and using the EPAC-specific compound 8CPT-2Me-cAMP and specific kinase inhibitors such as H89, wortmannin and PD98059. The efficacy of VIP on the prevention of tumor progression was confirmed in vivo using xenografted athymic mouse. These actions support a potential role of this peptide and its agonists in new therapies for cRCC. PMID:22728770

Vacas, Eva; Fernández-Martínez, Ana B; Bajo, Ana M; Sánchez-Chapado, Manuel; Schally, Andrew V; Prieto, Juan C; Carmena, María J



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

PubMed Central

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

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



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

PubMed Central

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.

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



Characterization of two cysteine proteases secreted by Blastocystis ST7, a human intestinal parasite.  


Blastocystis spp. are unicellular anaerobic intestinal parasites of both humans and animals and the most prevalent ones found in human stool samples. Their association with various gastrointestinal disorders raises the questions of its pathogenicity and of the molecular mechanisms involved. Since secreted proteases are well-known to be implicated in intestinal parasite virulence, we intended to determine whether Blastocystis spp. possess such pathogenic factors. In silico analysis of the Blastocystis subtype 7 (ST7) genome sequence highlighted 22 genes coding proteases which were predicted to be secreted. We characterized the proteolytic activities in the secretory products of Blastocystis ST7 using specific protease inhibitors. Two cysteine proteases, a cathepsin B and a legumain, were identified in the parasite culture supernatant by gelatin zymographic SDS-PAGE gel and MS/MS analysis. These proteases might act on intestinal cells and disturb gut function. This work provides serious molecular candidates to link Blastocystis spp. and intestinal disorders. PMID:22402106

Wawrzyniak, Ivan; Texier, Catherine; Poirier, Philippe; Viscogliosi, Eric; Tan, Kevin S W; Delbac, Frédéric; El Alaoui, Hicham



Bacterial Type IV Secretion Systems in Human Disease  

PubMed Central

Summary Type IV secretion (T4S) systems are versatile machines involved in many processes relevant to bacterial virulence, such as horizontal DNA transfer and effector translocation into human cells. A recent Workshop organized by the International University of Andalousia (UNIA) in Baeza, Spain, covered most aspects of bacterial T4S relevant to human disease, ranging from the structural and mechanistic analysis of the T4S systems to the physiological roles of the translocated effector proteins in subverting cellular functions in infected humans. This review reports the highlights from this workshop, which include the first visualization of a T4S system core complex spanning both membranes of Gram-negative bacteria, the identification of the first host receptors for T4S systems, the identification and characterization of novel T4S effector proteins, the analysis of the molecular function of effector proteins in subverting human cellular functions, and an analysis of the role of T4S systems in the evolution of pathogenic bacteria. Our increasing knowledge of the biology of T4S improves our ability to exploit them as biotechnological tools or to use them as novel targets for a new generation of antimicrobials.

Llosa, Matxalen; Roy, Craig; Dehio, Christoph



Why is it Challenging to Predict Intestinal Drug Absorption and Oral Bioavailability in Human Using Rat Model  

Microsoft Academic Search

Purpose  To study the correlation of intestinal absorption for drugs with various absorption routes between human and rat, and to explore the underlying molecular mechanisms for the similarity in drug intestinal absorption and the differences in oral bioavailability between human and rat.Materials and Methods  The intestinal permeabilities of 14 drugs and three drug-like compounds with different absorption mechanisms in rat and human

Xianhua Cao; Seth T. Gibbs; Lanyan Fang; Heather A. Miller; Christopher P. Landowski; Ho-Chul Shin; Hans Lennernas; Yanqiang Zhong; Gordon L. Amidon; Lawrence X. Yu; Duxin Sun



Folate synthesized by bacteria in the human upper small intestine is assimilated by the host  

Microsoft Academic Search

BACKGROUND & AIMS: Some intestinal flora are known to synthesize folate. The aim of this study was to determine whether folate synthesized by small intestinal flora is assimilated by the human host. METHODS: Subjects with atrophic gastritis and healthy volunteers were studied before and after omeprazole administration. A double-lumen perfusion tube was placed in the duodenum. 3H-labeled P-aminobenzoic acid, a

E Camilo; J Zimmerman; JB Mason; B Golner; R Russell; J Selhub; IH Rosenberg



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 Central

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.

Allen, W D; Porter, P



Certain canine weakly beta-hemolytic intestinal spirochetes are phenotypically and genotypically related to spirochetes associated with human and porcine intestinal spirochetosis.  

PubMed Central

Four canine weakly beta-hemolytic intestinal spirochetes associated with intestinal spirochetosis (IS-associated WBHIS) were compared with IS-associated human and porcine WBHIS and the type species for Serpulina hyodysenteriae and S. innocens by using phenotypic and genotypic parameters. The IS-associated canine, human, and porcine WBHIS belonged to a phyletic group distinct from but related to previously described Serpulina type species.

Duhamel, G E; Muniappa, N; Mathiesen, M R; Johnson, J L; Toth, J; Elder, R O; Doster, A R



High taxonomic level fingerprint of the human intestinal microbiota by Ligase Detection Reaction - Universal Array approach  

PubMed Central

Background Affecting the core functional microbiome, peculiar high level taxonomic unbalances of the human intestinal microbiota have been recently associated with specific diseases, such as obesity, inflammatory bowel diseases, and intestinal inflammation. Results In order to specifically monitor microbiota unbalances that impact human physiology, here we develop and validate an original DNA-microarray (HTF-Microbi.Array) for the high taxonomic level fingerprint of the human intestinal microbiota. Based on the Ligase Detection Reaction-Universal Array (LDR-UA) approach, the HTF-Microbi.Array enables specific detection and approximate relative quantification of 16S rRNAs from 30 phylogenetically related groups of the human intestinal microbiota. The HTF-Microbi.Array was used in a pilot study of the faecal microbiota of eight young adults. Cluster analysis revealed the good reproducibility of the high level taxonomic microbiota fingerprint obtained for each of the subject. Conclusion The HTF-Microbi.Array is a fast and sensitive tool for the high taxonomic level fingerprint of the human intestinal microbiota in terms of presence/absence of the principal groups. Moreover, analysis of the relative fluorescence intensity for each probe pair of our LDR-UA platform can provide estimation of the relative abundance of the microbial target groups within each samples. Focusing the phylogenetic resolution at division, order and cluster levels, the HTF-Microbi.Array is blind with respect to the inter-individual variability at the species level.



Intestinal Immune Response to Human Cryptosporidium sp. Infection  

Microsoft Academic Search

Cryptosporidium is an obligate intracellular protozoan para- site that is a major cause of diarrheal illness worldwide. Cryp- tosporidium primarily infects the distal small intestine. Immu- nocompetent hosts control and eliminate the infection, which typically causes acute, self-limited watery diarrhea lasting 5 to 10 days. However, in patients with defects in cellular immune responses (e.g., AIDS, malnutrition, or defects in

Birte Pantenburg; Sara M. Dann; Heuy-Ching Wang; Prema Robinson; Alejandro Castellanos-Gonzalez; Dorothy E. Lewis; A. Clinton White



Mass chemotherapy for intestinal Taenia solium infection: effect on prevalence in humans and pigs  

Microsoft Academic Search

Mass treatment of the human population with niclosamide was carried out in 2 villages in rural Guatemala where Taenia solium was endemic, to determine how this would affect the epidemiology of the parasite. Intestinal taeniasis was diagnosed by microscopy and coproantigen testing, and porcine cysticercosis by a specific Western blot. Before mass treatment, the prevalence of human taeniasis was 3·5%;

J. C. Allan; M. Velasquez-Tohom; C. Fletes; R. Torres-Alvarez; G. Lopez-Virula; P. Yurrita; H. Soto de Alfaro; A. Rivera; J. Garcia-Noval



Use of EDTA and its derivatives for prevention and treatment of bacterial intestinal diseases of pigs and for increasing the effects of antibiotics exerted in such diseases  

US Patent & Trademark Office Database

The invention relates to the use of ethylenediamine tetraacetic acid (EDTA) and its derivatives, i.e. its salts and complexes for prevention and treatment of bacterial intestinal diseases of pigs and for increasing the effects of antibiotics exerted in such diseases. The invention also relates to compositions for animal husbandry, i.e. to veterinary compositions and to feeds and drinks which can be consumed by pigs, comprising EDTA or its derivatives.



Anti-apoptotic PI3K\\/Akt signaling by sodium\\/glucose transporter 1 reduces epithelial barrier damage and bacterial translocation in intestinal ischemia  

Microsoft Academic Search

Intestinal ischemia\\/reperfusion (I\\/R) causes mucosal barrier damage and bacterial translocation (BT), leading to septic complications. Previous in vitro studies showed that activation of sodium\\/glucose transporter 1 (SGLT1) prevented the epithelial apoptosis and permeability rise induced by microbial products. Our aim was to investigate whether luminal glucose uptake by SGLT1 protects against ischemia-induced epithelial cell death and barrier dysfunction, and to

Ching-Ying Huang; Jong-Kai Hsiao; Yen-Zhen Lu; Tsung-Chun Lee; Linda C-H Yu



Effect of probiotic or prebiotic supplementation on antibiotic therapy in the small intestinal bacterial overgrowth: a comparative evaluation.  


Bacterial intestinal overgrowth syndrome (SIBO) treatment is based on antibiotics. Probiotics have been shown to give similar results, whilst no study is available about prebiotics. This study evaluated the addition of probiotics or prebiotics to antibiotics on SIBO symptoms in a 6-month follow-up. We enrolled 40 patients (14 males and 26 females) reporting abdominal compliant without gastrointestinal diseases/alarm symptoms. SIBO was diagnosed by the agreement of lactulose and glucose breath tests. Patients were randomly divided into two groups homogeneous for sex and age: group 1 received Rifaximin 400 mg/day for 7 days/month followed by Lactobacillus casei for 7 days more and group 2 antibiotic followed by short chain fructo-oligosaccharides. All patients recorded a questionnaire for subjective symptom evaluation according to Rome III criteria and Bristol scale for stool characters before the study and after 6 months. Statistics: Student's t and Fisher's exact tests. In group 1, a significant improvement was obtained in 5 out of 6 symptoms, whilst in group 2 in 4 out of 6 symptoms (nausea and number of bowel movements failed to improve). Despite we observed a trend of probiotics to be more effective than prebiotics, the difference in the percentage of improved symptoms was not significant (83,3% vs 66.6%; p= 0.57). Our preliminary data show a good outcome with sequential antibioticprobiotic/ prebiotic administration in patients with SIBO. PMID:23244247

Rosania, Rosa; Giorgio, Floriana; Principi, Mariabeatrice; Amoruso, Annacinzia; Monno, Rosa; Di Leo, Alfredo; Ierardi, Enzo



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


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 Kt value of nateglinide (45.9 ?M) 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

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



Fecal transplant: a safe and sustainable clinical therapy for restoring intestinal microbial balance in human disease?  


Recent studies have suggested an association between intestinal microbiota composition and human disease, however causality remains to be proven. With hindsight, the application of fecal transplantation (FMT) does indeed suggest a causal relation between interfering with gut microbiota composition and a resultant cure of several disease states. In this review, we aim to show the available evidence regarding the involvement of intestinal microbiota and human (autoimmune) disease. Moreover, we refer to (mostly case report) studies showing beneficial or adverse effects of fecal transplantation on clinical outcomes in some of these disease states. If these findings can be substantiated in larger randomized controlled double blind trials also implementing gut microbiota composition before and after intervention, fecal transplantation might provide us with novel insights into causally related intestinal microbiota, that might be serve as future diagnostic and treatment targets in human disease. PMID:23768558

Vrieze, A; de Groot, P F; Kootte, R S; Knaapen, M; van Nood, E; Nieuwdorp, M



Tspan-1 interacts with the thiamine transporter-1 in human intestinal epithelial cells and modulates its stability.  


The human thiamine transporter-1 (hTHTR-1) contributes to intestinal thiamine uptake, and its function is regulated at both the transcriptional and posttranscriptional levels. Nothing, however, is known about the protein(s) that may interact with hTHTR-1 and affects its cell biology and physiology. We addressed this issue in the present investigation using a bacterial two-hybrid system to screen a human intestinal cDNA library with the complete coding sequence of hTHTR-1 as a bait. Our results showed that a member of the tetraspanin family of proteins, Tspan-1, interacts with hTHTR-1. Coimmunoprecipitation and glutathione S-transferase (GST)-pulldown assays confirmed the existence of such an interaction between hTspan-1 and hTHTR-1 in human intestinal epithelial Caco-2 cells. Furthermore, live cell confocal imaging demonstrated that hTspan-1 and hTHTR-1 colocalize in human intestinal epithelial HuTu-80 cells. The importance of the interaction between hTspan-1 and hTHTR-1 for cell biology of the thiamine transporter was examined in HuTu-80 cells stably expressing hTHTR-1. Coexpression of hTspan-1 in these cells led to a significant decrease in the rate of degradation of hTHTR-1 compared with cells expressing the hTHTR-1 alone; in fact the half-life of the hTHTR-1 protein was twice longer in the former cell type compared with the latter cell type (12 h vs. 6 h, respectively). This finding was also confirmed at the functional level when a significantly higher thiamine uptake was observed in cycloheximide-treated (6 h) cells expressing hTHTR-1 together with hTspan-1 compared with those expressing hTHTR-1 alone. These studies demonstrate for the first time that Tspan-1 is an interacting partner with hTHTR-1 and that this interaction affects hTHTR-1 stability. PMID:21836059

Nabokina, Svetlana M; Senthilkumar, Sundar Rajan; Said, Hamid M



Phase-variable expression of a family of glycoproteins imparts a dynamic surface to a symbiont in its human intestinal ecosystem  

PubMed Central

The recent report of the synthesis of glycoproteins by the abundant intestinal symbionts Bacteroides showed that these organisms use a novel bacterial enzyme to decorate their surfaces with a sugar residue derived from their environment. As a first step in understanding the importance of these glycoproteins to the bacteria and to the bacterial–host symbiosis, we identified and characterized the abundant glycoproteins of Bacteroides distasonis (proposed reclassification as Parabacteroides distasonis) [Sakamoto M, Benno Y (2006) Int J Syst Evol Microbiol 56:1599–1605]. Using lectin-affinity purification followed by tandem mass spectrometry, we identified a family of at least nine glycoproteins, similar only to the S-layer glycoproteins of Tannerella forsythia. Analysis of one of these purified glycoproteins demonstrated that the glycan is primarily a polymer of xylose, a monosaccharide rarely found in bacterial glycans. Even more unexpected was the finding that seven of nine of the glycoprotein promoters undergo DNA inversion, a process that we show is active in their endogenous human environment. Using cross-species functional assays, we show that a single serine family site-specific recombinase globally mediates the inversions of these glycoprotein promoters. This regulatory mechanism is similar to that of the Bacteroides fragilis capsular polysaccharides and establishes DNA inversion as a general and ancient means of regulation of glycan-containing surface molecules of these important human intestinal symbionts.

Fletcher, C. Mark; Coyne, Michael J.; Bentley, David L.; Villa, Otto F.; Comstock, Laurie E.



Construction and Identification of Bacterial Plasmids Containing Nucleotide Sequence for Human Leukocyte Interferon  

Microsoft Academic Search

Bacterial plasmids containing human leukocyte interferon sequences were constructed and identified. Identification was confirmed by correspondence of the nucleotide sequence with our amino acid sequence of human leukocyte interferon. The finding of bacterial recombinants containing distinct leukocyte interferon sequences is consistent with our purification of different leukocyte interferon species. We conclude that what has been designated human leukocyte interferon is,

Shuichiro Maeda; Russell McCandliss; Mitchell Gross; Alan Sloma; Philip C. Familletti; John M. Tabor; Marian Evinger; Warren P. Levy; Sidney Pestka



Poly-beta-hydroxybutyrate (PHB) increases growth performance and intestinal bacterial range-weighted richness in juvenile European sea bass, Dicentrarchus labrax.  


The bacterial storage polymer poly-beta-hydroxybutyrate (PHB) has the potential to be used as an alternative anti-infective strategy for aquaculture rearing. In this research, the effects of (partially) replacing the feed of European sea bass juveniles with PHB were investigated. During a 6-week trial period, the PHB showed the ability to act as an energy source for the fish. This indicated that PHB was degraded and used during gastrointestinal passage. The gut pH decreased from 7.7 to 7.2 suggesting that the presence of PHB in the gut led to the increased production of (short-chain fatty) acids. The diets supplemented with 2% and 5% PHB (w/w) induced a gain of the initial fish weight with a factor 2.4 and 2.7, respectively, relative to a factor 2.2 in the normal feed treatment. Simultaneously, these treatments showed the highest bacterial range-weighted richness in the fish intestine. Based on molecular analysis, higher dietary PHB levels induced larger changes in the bacterial community composition. From our results, it seems that PHB can have a beneficial effect on fish growth performance and that the intestinal bacterial community structure may be closely related to this phenomenon. PMID:20094715

De Schryver, Peter; Sinha, Amit Kumar; Kunwar, Prabesh Singh; Baruah, Kartik; Verstraete, Willy; Boon, Nico; De Boeck, Gudrun; Bossier, Peter



Identification of an intestine-specific promoter and inducible expression of bacterial ?-galactosidase in mammalian cells by a lac operon system  

PubMed Central

Background ?-galactosidase has been widely used in animal husbandry to reduce anti-nutritional factors (such as ?-galactoside) in feed. Intestine-specific and substrate inducible expression of ?-galactosidase would be highly beneficial for transgenic animal production. Methods To achieve the intestine-specific and substrate inducible expression of ?-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 ?-galactosidase expression and enzyme activity by isopropyl ?-D-1-thiogalactopyranoside (IPTG) and an ?-galactosidase substrate, ?-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 ?-galactosidase mRNA was decreased by 6-fold and ?-galactosidase activity was reduced by 8-fold. In line with our expectations, IPTG and ?-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 ?-galactosidase mRNA abundance (by about 5-fold) and ?-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.



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...


Heparan sulfate and syndecan-1 are essential in maintaining murine and human intestinal epithelial barrier function  

PubMed Central

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-?, TNF-?, 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-?, TNF-?, 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.

Bode, Lars; Salvestrini, Camilla; Park, Pyong Woo; Li, Jin-Ping; Esko, Jeffrey D.; Yamaguchi, Yu; Murch, Simon; Freeze, Hudson H.



Evaluation of rat intestinal absorption data and correlation with human intestinal absorption  

Microsoft Academic Search

The absorption of 111 drug and drug-like compounds was evaluated from 111 references based on the ratio of urinary excretion of drugs following oral and intravenous administration to intact rats and biliary excretion of bile duct-cannulated rats. Ninety-eight drug compounds for which both human and rat absorption data were available were selected for correlation analysis between the human and rat

Yuan H Zhao; Michael H Abraham; Joelle Le; Anne Hersey; Chris N Luscombe; Gordon Beck; Brad Sherborne; Ian Cooper



Intestinal Pseudo-Obstruction  


... cause diarrhea. Over time, the condition can cause bacterial infections, malnutrition, weight loss, and muscle problems in ... may include medications, such as antibiotics to treat bacterial infections, pain medication, and medication to treat intestinal ...


Identification of the transcriptional response of human intestinal mucosa to Lactobacillus plantarum WCFS1 in vivo  

PubMed Central

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.

Troost, Freddy J; van Baarlen, Peter; Lindsey, Patrick; Kodde, Andrea; de Vos, Willem M; Kleerebezem, Michiel; Brummer, Robert-Jan M



Frequency of Small Intestinal Bacterial Overgrowth in Patients with Irritable Bowel Syndrome and Chronic Non-Specific Diarrhea  

PubMed Central

Introduction Small intestinal bacterial overgrowth (SIBO) occurs in varying frequency in irritable bowel syndrome (IBS). We studied the frequency of SIBO in IBS and chronic non-specific diarrhea (CNSD). Methods 129 patients with IBS (Manning's criteria), 73 with CNSD (? 4 weeks diarrhea with two of these tests normal [urine D-xylose, fecal fat and duodenal biopsy]) and 51 healthy controls (HC) were evaluated for SIBO using glucose hydrogen breath test (GHBT). Diarrhea-predominant IBS (D-IBS) was grouped into CNSD. Rise in breath hydrogen 12 ppm above basal following 100 g glucose was diagnostic of SIBO. Results Of 129 patients with IBS, 7 were constipation (C-IBS), and 122 were of indeterminate type (I-IBS). Patients with IBS were younger than HC and CNSD (IBS vs. HC: 36.6 yr ± 11.4 vs. 44.1 yr ± 13.6, p = 0.001; IBS vs. CNSD: 36.6 yr ± 11.4 vs. 42 yr ± 14.5, p = 0.003). Patients with CNSD were comparable to HC in age (42 yr ± 14.5 vs. 44.1 yr ± 13.6, p = ns). Patients with IBS were more often male than HC [108/129 (83.7%) vs. 34/51 (66.7%) p = 0.02]; gender of CNSD and HC was comparable [male 39/73 (53.4%) vs. 34/51 (66.7%) p = ns]. SIBO was commoner in CNSD than HC [16 (21.9%) vs. 1 (2%), p = 0.003], but was comparable in IBS and HC [11 (8.5%) vs. 1 (2%), p = 0.18]. Patients with CNSD more often had SIBO than IBS [16 (21.9%) vs. 11 (8.5%), p = 0.007]. Conclusions SIBO was more common in CNSD including D-IBS than other types of IBS and HC.

Kumar, Sunil; Mehrotra, Mansi; Lakshmi, CP; Misra, Asha



Human ecology and behavior and sexually transmitted bacterial infections.  

PubMed Central

The three direct determinants of the rate of spread of sexually transmitted diseases (STDs) are sexual behaviors, the mean duration of infectiousness, and the mean efficiency of sexual transmission of each STD. Underlying ecological and behavioral factors that operate through one or more of these direct determinants lie on a continuum, ranging from those most proximate back to those more remote (in time or mechanism) from the direct determinants. Most remote and least modifiable are the historical stages of economic development that even today conspicuously influence patterns of sexual behavior. Next are the distribution and changing patterns of climate, hygiene, and population density; the global population explosion and stages of the demographic transition; and ongoing changes in human physiology (e.g., menarche at younger age) and culture (e.g., later marriage). More proximate on the continuum are war, migration, and travel; and current policies for economic development and social welfare. Most recent or modifiable are technologic and commercial product development (e.g., oral contraceptives); circumcision, condom, spermicide, and contraception practices; patterns of illicit drug use that influence sexual behaviors; and the accessibility, quality, and use of STD health care. These underlying factors help explain why the curable bacterial STDs are epidemic in developing countries and why the United States is the only industrialized country that has failed to control bacterial STDs during the AIDS era. Images

Holmes, K K



Effectiveness of dried Carica papaya seeds against human intestinal parasitosis: a pilot study.  


The tropical fruit Carica papaya and its seeds have proven antihelminthic and anti-amoebic activities. To determine the effectiveness of air-dried C. papaya seeds on human intestinal parasitosis, 60 asymptomatic Nigerian children with stool microscopic evidence of intestinal parasites received immediate doses (20 mL) of either an elixir composed with air-dried C. papaya seeds and honey (CPH) or honey alone (placebo) in two randomized treatment groups. Repeat stool microscopic examinations were conducted 7 days postintervention for intestinal parasites. Significantly more subjects given CPH elixir than those given honey had their stools cleared of parasites [23 of 30 (76.7%) vs. five of 30 (16.7%); z = 4.40, P = .0000109]. There were no harmful effects. The stool clearance rate for the various types of parasites encountered was between 71.4% and 100% following CPH elixir treatment compared with 0-15.4% with honey. Thus, air-dried C. papaya seeds are efficacious in treating human intestinal parasites and without significant side effects. Their consumption offers a cheap, natural, harmless, readily available monotherapy and preventive strategy against intestinal parasitosis, especially in tropical communities. Further and large-scale intervention studies to compare C. papaya with standard antiparasitic preparation are desirous. PMID:17472487

Okeniyi, John A O; Ogunlesi, Tinuade A; Oyelami, Oyeku A; Adeyemi, Lateef A



Biomechanical characterisation of fresh and cadaverous human small intestine: applications for abdominal trauma.  


Intestinal injuries are responsible for significant morbidity and mortality arising from trauma to the abdomen. The biomechanical characterisation of the small intestine allows for the understanding of the pathophysiological mechanisms responsible for these injuries. Studies reported in the literature focus principally on quasi-static tests, which do not take into account the stresses experienced during high kinetic trauma. In addition, the use of embalmed human tissue can alter the recorded response. The stress-strain curves from 43 tensile tests performed at 1 m/s were analysed. Samples were prepared from four fresh human intestines and from four embalmed cadaveric intestines. The data indicated a two-phase response, with each response consisting of a quasi-linear increase in the stress followed by an inflection in the curve before a peak preceding the loss of stress. The fresh tissue was more deformable than the embalmed tissue, and its first peak stress was lower (P = 0.034). A complementary histological analysis was performed. The results of the analysis enable an investigation of the response of the intestinal wall layers to stress as a two-layer structure and highlight the high sensitivity of the structure's mechanical behaviour to the speed of loading and the method of preservation. PMID:23054381

Bourgouin, Stéphane; Bège, Thierry; Masson, Catherine; Arnoux, Pierre-Jean; Mancini, Julien; Garcia, Stéphane; Brunet, Christian; Berdah, Stéphane V



Distribution of dominant T cell receptor beta chains in human intestinal mucosa  

PubMed Central

The majority of human intestinal intraepithelial lymphocytes (iIELs) are CD8+ T cells that use the T cell receptor (TCR)-alpha/beta. Previous studies have shown that iIELs isolated from segments of small intestine or colon contain one or several dominant alpha/beta T cell clones. It is not known whether these clones expand only locally in response to a particular antigen or whether they are widely distributed throughout the intestine. To address this question, iIELs were purified from near the proximal and distal margins in a series of intestinal resections for noninflammatory diseases. TCR-beta expression was then assessed by semiquantitative polymerase chain reaction amplification, analysis of N-region length, and DNA sequencing. The previously described oligoclonal expansion of iIELs was confirmed in each sample. Identical dominant clones were identified in the proximal and distal samples from most cases, including samples taken from sites as distant as the transverse and sigmoid colon or rectum. Distinct clones were found in only one case with samples from the terminal ileum and transverse colon. These results demonstrate that a relatively small number of widely dispersed T cell clones comprise the majority of cells in the human intestinal mucosa.



In vitro intestinal and hepatic metabolism of Di(2-ethylhexyl) phthalate (DEHP) in human and rat.  


Species and organ differences in the intrinsic clearance and the enzymes involved in the metabolism of DEHP were examined in subcellular fractions of the intestine and liver as well as by recombinant cytochrome P450 (CYP) isoforms of human and rat. Estimated clearance (CLint) of DEHP via esterase-mediated pathway in human intestine was 2.4-fold greater than that in human liver while its value in rat intestine was 1.7-fold less than that in rat liver. Ranks of CLint for CYP-mediated oxidation/dealkylation of MEHP were human liver>rat liver>human intestine>rat intestine. Estimates of CLint for the production of mono(2-ethyl-5-hydroxyhexyl) phthalate and mono(2-ethyl-5-oxohexyl) phthalate by human CYP2C9 1 were 4.2- and 2.6-fold greater than those by rat CYP2C6, respectively. Total CLint via hCYP2C9 3-mediated oxidation was 1.9- and 2.6-fold less than those by hCYP2C9 2 and 2C9 1, respectively. Estimated CLint for phthalic acid production by hCYP3A4 was 24.5 ?L nmol CYP(-1)min(-1) while it was continuously produced by rCYP2C6 and 3A2 via passive mechanism. These species/organ differences in major metabolic pathway and CYP isoforms should be considered for appraisal of the potential adverse health effects of DEHP. PMID:23545481

Choi, Kyoungju; Joo, Hyun; Campbell, Jerry L; Andersen, Melvin E; Clewell, Harvey J



Human Cytomegalovirus: Bacterial Artificial Chromosome (BAC) Cloning and Genetic Manipulation  

PubMed Central

Our understanding of human cytomegalovirus (HCMV) biology was long hindered by the inability to perform efficient viral genetic analysis. This hurdle was recently overcome when the genomes of multiple HCMV strains were cloned as infectious bacterial artificial chromosomes (BACs). The BAC system takes advantage of the single-copy F plasmid of E. coli that can stably carry large pieces of foreign DNA. In this system, a recombinant HCMV virus carrying a modified F plasmid is first generated in eukaryotic cells. Recombinant viral genomes are then isolated and recovered in E. coli as BAC clones. BAC-captured viral genomes can be manipulated using prokaryotic genetics, and recombinant virus can be reconstituted from BAC transfection in eukaryotic cells. The BAC reverse genetic system provides a reliable and efficient method to introduce genetic alterations into the viral genome in E.coli and subsequently analyze their effects on virus biology in eukaryotic cells.

Paredes, Anne M.; Yu, Dong



Casein Phosphopeptides Influence Calcium Uptake by Cultured Human Intestinal HT29 Tumor Cells1,2  

Microsoft Academic Search

We investigated the direct effects of casein phosphopeptides (CPP), which are formed by the proteolytic degradation of a- and b-caseins, on calcium uptake by human HT-29 intestinal tumor cells, which undergo an enterocytically oriented differentiation in culture. A commercial preparation containing a mixture of purified CPP and an individual CPP of 25 amino acids, both containing the characteristic Ca21 binding

Anita Ferraretto; Alessandra Signorile; Claudia Gravaghi; Amelia Fiorilli; Guido Tettamanti


A Model of Human Small Intestinal Absorptive Cells. 1. Transport Barrier  

Microsoft Academic Search

The Caco-2 cell culture model of human small intestinal absorptive cells was used to investigate transepithelial transport. Transport of permeability markers such as mannitol demonstrated that Caco-2 monolayers became less permeable with increasing age in culture. Cells were routinely used for transport studies between day 18 and day 32. A transport index was determined for each compound by calculating the

J. Nita Cogburn; Matthew G. Donovan; Charles S. Schasteen



Adaptive function of soil consumption: an in vitro study modeling the human stomach and small intestine  

Microsoft Academic Search

Despite occurring in a wide variety of taxa, deliberate soil consumption (geophagy) is a poorly understood behavior. In humans, geophagy is sometimes considered aberrant or a sign of metabolic dysfunction. However, geophagy is normally assigned an adaptive function in nonhuman primates and various other organisms. One hypothesis submits that clay-rich soil adsorbs intestinal insults, namely plant metabolites or diarrhoea-causing enterotoxins.

Nathaniel J. Dominy; Estelle Davoust; Mans Minekus



Oxidative Damage and Transforming Growth Factor ?1 Expression in Pretumoral and Tumoral Lesions of Human Intestine  

Microsoft Academic Search

The aim of this study was to evaluate a possible relationship between oxidative stress and transforming growth factor ?1 (TGF?1) expression in human colon adenocarcinoma. Crohn's disease, an inflammatory pathology of the intestine often regarded to as precancerous, was also examined. Indices of impaired redox balance were monitored in blood and in bioptic samples from 10 adult patients with adenocarcinoma

Elena Chiarpotto; Antonella Scavazza; Gabriella Leonarduzzi; Simonetta Camandola; Fiorella Biasi; Paolo Mello Teggia; Marcello Garavoglia; Antonio Robecchi; Alba Roncari; Giuseppe Poli



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 ...


Heavy metal toxicity following apical and basolateral exposure in the human intestinal cell line Caco-2  

Microsoft Academic Search

Caco-2 is a cell line, derived from a human colon carcinoma, that retains the ability to differentiate in culture into absorptive intestinal cells. Caco-2 cells were used to evaluate the toxicity of three heavy metals—the essential trace elements zinc and copper, and the xenobiotic cadmium. The cells were cultivated on permeable filters until differentiated and were then exposed to the

A. Rossi; R. Poverini; G. Di Lullo; A. Modesti; A. Modica; M. L. Scarino



Occurrence and activity of human intestinal bacteria involved in the conversion of dietary lignans  

Microsoft Academic Search

The human intestinal microbiota is necessary for the production of enterolignans from the dietary lignan secoisolariciresinol diglucoside (SDG). However, little is known about the bacteria that contribute to SDG conversion. Therefore, we aimed at describing the occurrence and activity of SDG metabolising bacteria. The data showed differences in conversion efficiency between SDG deglycosylating species, but SDG was completely deglycosylated within

Thomas Clavel; Daniela Borrmann; Annett Braune; Joël Doré; Michael Blaut



Short chain fatty acids in human large intestine, portal, hepatic and venous blood  

Microsoft Academic Search

Evidence for the occurrence of microbial breakdown of carbohydrate in the human colon has been sought by measuring short chain fatty acid (SCFA) concentrations in the contents of all regions of the large intestine and in portal, hepatic and peripheral venous blood obtained at autopsy of sudden death victims within four hours of death. Total SCFA concentration (mmol\\/kg) was low

J H Cummings; E W Pomare; W J Branch; C P Naylor; G T Macfarlane



Different patterns of cytokine regulation of phagocytosis and bacterial killing by human neutrophils  

Microsoft Academic Search

We describe here the capacity of human recombinant interleukin-1-beta (IL-1?), interferon-gamma (INF-?), interferon-alpha (INF-?), tumor necrosis factor-alpha (INF-?), interleukin-6 (IL-6) and interleukin-2 (IL-2) to modulate phagocytosis and bacterial killing by human neutrophils. IL-1?, INF-? and TNF-? enhance phagocytosis of bacteria but do not have consistent effect on bacterial killing. In contrast, IL-6 augments bacterial killing but not phagocytosis of bacteria

Dmitry V. Pechkovsky; Michael P. Potapnev; Oksana M. Zalutskaya



MicroRNAs determine human intestinal epithelial cell fate  

PubMed Central

MicroRNAs (miRNAs) are small, non-coding RNA molecules that post-transcriptionally regulate gene expression. Evidence has shown that miRNAs play important roles in various cellular processes, including proliferation, differentiation and survival. The intestinal epithelium is regenerated throughout life, and enterocytes undergo differentiation during migration along the crypt/villus axis. Our study aimed at establishing the expression profiles of miRNAs during intestinal epithelial cell (IEC) differentiation and determining a miRNA “signature” that distinguishes between small and large IECs. MiRNA arrays were employed to profile miRNA expression in two IEC models: the enterocyte-like Caco2-BBE and the colonocyte-like HT29-Cl.19A cell lines. Microarray data showed that in both cell lineages, the differentiated stage exhibited a different miRNA expression profile from undifferentiated stage. Interestingly, Caco2-BBE cells were distinguished from HT29-Cl.19A cells by their unique miRNA expression profile. Notably, HT29-Cl.19A cells exhibited down-regulation of miR-1269 and up-regulation of miR-99b and miR-125a-5p compared with Caco2-BBE cells. Most importantly, transfection of Caco2-BBE cells with mature miR-99b, mature miR-125a-5p and antisense of mature miR-1269 decreased growth rate and trans-epithelial resistance of the cells, indicating their shift toward HT29-Cl.19A cell phenotype. In conclusion, our study shows that miRNAs might play a role in determining the unique physiological characteristics of IECs.

Dalmasso, Guillaume; Nguyen, Hang Thi Thu; Yan, Yutao; Laroui, Hamed; Srinivasan, Shanthi; Sitaraman, Shanthi V; Merlin, Didier



Study of the Adhesion of Bifidobacterium bifidum MIMBb75 to Human Intestinal Cell Lines  

Microsoft Academic Search

The aim of this study was to investigate the adhesive phenotype of the human intestinal isolate Bifidobacterium bifidum MIMBb75 to human colon carcinoma cell lines. We have previously shown that the adhesion of this strain to Caco-2 cells is\\u000a mediated by an abundant surface lipoprotein named BopA. In this study, we found that this strain adheres to Caco-2 and HT-29

Simone Guglielmetti; Isabella Tamagnini; Mario Minuzzo; Stefania Arioli; Carlo Parini; Elena Comelli; Diego Mora



Human Intestinal Lumen and Mucosa-Associated Microbiota in Patients with Colorectal Cancer  

PubMed Central

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.

Ling, Zongxin; Tong, Xiaojuan; Xiang, Charlie



Importance of different CD44v6 expression in human gastric intestinal and diffuse type cancers for metastatic lymphogenic spreading  

Microsoft Academic Search

In 42 human gastric adenocarcinomas of intestinal (n=25) and diffuse types (n=17) the expression of CD44v6 splice variants was investigated immunohistochemically and compared with the pattern of lymphogenic tumor spreading. Distinct differences were observed between the two cancer types: 92% of intestinal-type tumors expressed CD44v6 as in the intestinal metaplasia in chronic atrophic gastritis, while v6 expression occurred in only

J. Dämmrich; H. P. Vollmers; K.-H. Heider; H.-K. Müller-Hermelink



Magnetoenterography (MENG): noninvasive measurement of bioelectric activity in human small intestine.  


The basic electrical rhythm (BER) of the gastrointestinal tract creates minute magnetic fields that have been measured in animals using a Superconducting QUantum Interference Device (SQUID) gradiometer. The aim of this study was to measure noninvasively the biomagnetic fields of human stomach and small intestine. Twenty-one human volunteers were studied using a 37-channel SQUID gradiometer positioned over the epigastrium and umbilicus. In one volunteer additional biomagnetic recordings were performed in order to map the spatial variation of the biomagnetic fields. Cyclical waveforms consistent with gastric BER [3.0+/-0.5 cycles per minute (cpm)] and small intestine BER (10.26+/-1.74 cpm) were seen in the epigastrium and umbilicus, respectively. The mapping study identified the expected frequency gradient (12.0 cpm in duodenum, 11.3 cpm in jejunum, to 9.7 cpm in ileum) within the small intestine. Noninvasive recordings of human gastric and small intestinal BER can be obtained using a SQUID gradiometer. PMID:9011432

Richards, W O; Bradshaw, L A; Staton, D J; Garrard, C L; Liu, F; Buchanan, S; Wikswo, J P



Human-derived probiotic Lactobacillus reuteri strains differentially reduce intestinal inflammation  

PubMed Central

Lactobacillus reuteri (L. reuteri) is a probiotic that inhibits the severity of enteric infections and modulates the immune system. Human-derived L. reuteri strains DSM17938, ATCC PTA4659, ATCC PTA 5289, and ATCC PTA 6475 have demonstrated strain-specific immunomodulation in cultured monocytoid cells, but information about how these strains affect inflammation in intestinal epithelium is limited. We determined the effects of the four different L. reuteri strains on lipopolysaccharide (LPS)-induced inflammation in small intestinal epithelial cells and in the ileum of newborn rats. IPEC-J2 cells (derived from the jejunal epithelium of a neonatal piglet) and IEC-6 cells (derived from the rat crypt) were treated with L. reuteri. Newborn rat pups were gavaged cow milk formula supplemented with L. reuteri strains in the presence or absence of LPS. Protein and mRNA levels of cytokines and histological changes were measured. We demonstrate that even though one L. reuteri strain (DSM 17938) did not inhibit LPS-induced IL-8 production in cultured intestinal cells, all strains significantly reduced intestinal mucosal levels of KC/GRO (?IL-8) and IFN-? when newborn rat pups were fed formula containing LPS ± L. reuteri. Intestinal histological damage produced by LPS plus cow milk formula was also significantly reduced by all four strains. Cow milk formula feeding (without LPS) produced mild gut inflammation, evidenced by elevated mucosal IFN-? and IL-13 levels, a process that could be suppressed by strain 17938. Other cytokines and chemokines were variably affected by the different strains, and there was no toxic effect of L. reuteri on intestinal cells or mucosa. In conclusion, L. reuteri strains differentially modulate LPS-induced inflammation. Probiotic interactions with both epithelial and nonepithelial cells in vivo must be instrumental in modulating intrinsic anti-inflammatory effects in the intestine. We suggest that the terms anti- and proinflammatory be used only to describe the effects of a probiotic in the living host.

Liu, Yuying; Fatheree, Nicole Y.; Mangalat, Nisha



Bacterial translocation secondary to small intestinal mucosal ischemia during cardiopulmonary bypass. Measurement by diamine oxidase and peptidoglycan  

Microsoft Academic Search

Objective: To demonstrate that small intestinal mucosal ischemia occurs during cardiopulmonary bypass by measuring serum diamine oxidase activity, an index of small intestinal mucosal ischemia, in perioerative patients undergoing cardiovascular surgery with and without cardiopulmonary bypass. Methods: Twelve successive patients who underwent coronary artery bypass grafting with cardiopulmonary bypass (Group I) were compared to 10 patients who underwent off-pump coronary

Nobuo Tsunooka; Kazutaka Maeyama; Yoshihiro Hamada; Hiroshi Imagawa; Shinji Takano; Yuji Watanabe; Kanji Kawachi



Folate uptake in the human intestine: promoter activity and effect of folate deficiency.  


The intestinal folate absorption process occurs via a specialized mechanism that involves the reduced folate carrier (RFC). In humans, multiple variants of the hRFC (driven by multiple promoters) have been identified with variant I being the prominent form expressed in the intestine. While it is known that promoter B (pB) of hRFC drives the expression of this variant, little is known about the minimal region required for basal activity of this promoter in human intestinal epithelial cells. Also not known is whether folate absorption in the human intestine is up-regulated during folate deficiency (as occur in animal studies), and if so, whether transcriptional mechanisms via activation of hRFC pB are involved in such regulation. To address these issues, we have used deletion constructs of the hRFC pB and determined their activity in two human intestinal epithelial cell lines: the colon-derived Caco-2 cells, and the duodenum-derived HuTu-80 cells. Our results showed that activity of hRFC pB to be significantly higher in Caco-2 cells compared to HuTu-80 cells, a finding that corresponds with a higher level of folate uptake and endogenous hRFC mRNA levels in the former compared to the latter cell type. The minimal region required for basal activity of hRFC pB in Caco-2 cells was found to be encoded in a sequence between -1088 and -1043, while in HuTu-80 cells it was encoded in a sequence between -1431 and -1088. Growing Caco-2 cells in a folate deficient medium led to a significant and specific up-regulation in folate uptake. This up-regulation was associated with a parallel increase in hRFC protein and mRNA levels, and in the activity of hRFC pB. The most responsive sequence of pB to the effect of folate deficiency was found to be encoded in a sequence between -2016 and -1431, i.e., outside the minimal region of the pB. These results show that different minimal regions for hRFC pB are utilized by different intestinal epithelial cells. In addition, folate-deficiency was found to up-regulate folate uptake by human intestinal epithelial cells and that this regulation involves activation of hRFC pB. PMID:12811835

Subramanian, Veedamali S; Chatterjee, Nabendu; Said, Hamid M



Adherence of Lactobacillus Species to Human Fetal Intestinal Cells1  

Microsoft Academic Search

Thirty-two lactobacilli were tested for ability to adhere to a human fetal in- testinal epithelial cell line. By an in vitro system, two adherence mechanisms were found. One mechanism, requiring calcium in the adherence reaction, was nonspecific and allowed all lactobacilli tested to adhere. The other system, not requiring calcium, was found in four strains, all human Lactobacillus acidopbilus isolates.

E. G. Kleeman; T. R. Klaenhammer



Monitoring and survival of Lactobacillus gasseri SBT2055 in the human intestinal tract.  


The monitoring and survival of Lactobacillus gasseri SBT2055 in the human intestinal tract was investigated with seven healthy subjects having a low number of fecal lactobacilli. An increase of fecal lactobacilli (10(3.2-5.2) CFU/g feces) was recognized after ingestion of yogurt with SBT2055 by the subjects. A high positive rate of L. gasseri in fecal lactobacilli detected from the subjects (over 70% at 2nd weeks of feeding) was also observed during the ingestion period using the species-specific PCR system. These findings indicate that the SBT2055 strain in yogurt survived in the human intestinal tract and was recovered from human feces. PMID:17116981

Takahashi, Hidetoshi; Fujita, Takashi; Suzuki, Yutaka; Benno, Yoshimi



Non-biting cyclorrhaphan flies (Diptera) as carriers of intestinal human parasites in slum areas of Addis Ababa, Ethiopia  

Microsoft Academic Search

A study was conducted to determine the role of non-biting cyclorrhaphan flies as carriers of intestinal parasites in slum areas of Addis Ababa from January 2004 to June 2004. A total of 9550 flies, comprising of at least seven species were collected from four selected sites and examined for human intestinal parasites using the formol–ether concentration method. The dominant fly

Sisay Getachew; Teshome Gebre-Michael; Berhanu Erko; Meshesha Balkew; Girmay Medhin



Absorption and metabolism of genistein and its five isoflavone analogs in the human intestinal Caco-2 model  

Microsoft Academic Search

The purposes of this study were to determine the effect of structural change on the intestinal disposition of isoflavones and to elucidate the mechanisms responsible for transport of phase II isoflavone conjugates. Transport and metabolism of six isoflavones (i.e., genistein, daidzein, glycitein, formononetin, biochanin A, and prunetin) were studied in the human intestinal Caco-2 model and mature Caco-2 cell lysate.

Jun Chen; Huimin Lin; Ming Hu



In vivo gene expression profiling of human intestinal epithelial cells: analysis by laser microdissection of formalin fixed tissues  

Microsoft Academic Search

BACKGROUND: The small intestinal epithelium mediates vital functions of nutrient absorption and host defense. The spatial organization of the epithelial cells along the crypt-villus axis segregates them into regions of specialized function. However, the differences in transcriptional programming and the molecular machinery that governs the migration, adhesion, and differentiation of intestinal epithelial cell lineages in humans remain under-explored. To increase

Michael D George; Jan Wehkamp; Robert J Kays; Christian M Leutenegger; Sadiah Sabir; Irina Grishina; Satya Dandekar; Charles L Bevins



Electromagnetic radiation from ingested sources in the human intestine between 150 MHz and 1.2 GHz  

Microsoft Academic Search

The conventional method of diagnosing disorders of the human gastro-intestinal (GI) tract is by sensors embedded in cannulae that are inserted through the anus, mouth, or nose. However, these cannulae cause significant patient discomfort and cannot be used in the small intestine. As a result, there is considerable ongoing work in developing wireless sensors that can be used in the

Lawrence C. Chirwa; Paul A. Hammond; Scott Roy; David R. S. Cumming



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.  


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 Gal?1-6-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 ?1,2-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

Iwamori, Masao; Iwamori, Yuriko; Adachi, Shigeki; Nomura, Taisei



Pathogenicity of human and porcine intestinal spirochetes in one-day-old specific-pathogen-free chicks: an animal model of intestinal spirochetosis.  

PubMed Central

One-day-old chicks were infected orally with two strains of weakly hemolytic spirochetes isolated from a human and a pig with intestinal spirochetosis. These spirochetosis both colonized birds, attached end-on to their cecal enterocytes, induced watery diarrhea, and significantly depressed growth rates. Cultures of Serpulina innocens failed to colonize the chicks.

Trott, D J; McLaren, A J; Hampson, D J



Exploring the Human Intestinal Microbiome in Health and Disease.  

National Technical Information Service (NTIS)

In this thesis, molecule tools were used to study bacteria inhabiting the gastrointestinal tract of humans. One aim was to determine whether certain lifestyle factors, such as an anthroposophic lifestyle, or living on a farm, had an impact on the bacteria...

J. Dicksved



Metabolomics analysis of Cistus monspeliensis leaf extract on energy metabolism activation in human intestinal cells.  


Energy metabolism is a very important process to improve and maintain health from the point of view of physiology. It is well known that the intracellular ATP production is contributed to energy metabolism in cells. Cistus monspeliensis is widely used as tea, spices, and medical herb; however, it has not been focusing on the activation of energy metabolism. In this study, C. monspeliensis was investigated as the food resources by activation of energy metabolism in human intestinal epithelial cells. C. monspeliensis extract showed high antioxidant ability. In addition, the promotion of metabolites of glycolysis and TCA cycle was induced by C. monspeliensis treatment. These results suggest that C. monspeliensis extract has an ability to enhance the energy metabolism in human intestinal cells. PMID:22523469

Shimoda, Yoichi; Han, Junkyu; Kawada, Kiyokazu; Smaoui, Abderrazak; Isoda, Hiroko



Cytotoxic activity of human lymphocytes against differentiated intestinal tumour cell lines.  

PubMed Central

The natural killer (NK) and lymphokine-activated killer (LAK) cytotoxic activity of human peripheral blood lymphocytes (PBL) against various human tumour cell lines from intestinal origin (WIDR, HT29, Caco-2) has been investigated. The differentiated Caco-2 cells were then used as a model to investigate the cytotoxic activity against enterocyte-like target cells. Caco-2 were seeded on polycarbonate filters and maintained in culture for at least 15 days to allow the differentiation and formation of tight junctions. The integrity of tight junctions was assayed by measuring [3H]mannitol flux from apical to basolateral compartment. Cytotoxic analysis showed that both differentiated and undifferentiated Caco-2 cells were similarly susceptible to NK and LAK activity. The capacity of cytotoxic lymphocytes to kill enterocyte-like cells with intact junctional complex may suggest a direct role of cytotoxic lymphocytes in causing intestinal lesions under inflammatory conditions.

Anelli, R; Placido, R; Sambuy, Y; Bach, S; Di Massimo, A; Colizzi, V



Metabolomics Analysis of Cistus monspeliensis Leaf Extract on Energy Metabolism Activation in Human Intestinal Cells  

PubMed Central

Energy metabolism is a very important process to improve and maintain health from the point of view of physiology. It is well known that the intracellular ATP production is contributed to energy metabolism in cells. Cistus monspeliensis is widely used as tea, spices, and medical herb; however, it has not been focusing on the activation of energy metabolism. In this study, C. monspeliensis was investigated as the food resources by activation of energy metabolism in human intestinal epithelial cells. C. monspeliensis extract showed high antioxidant ability. In addition, the promotion of metabolites of glycolysis and TCA cycle was induced by C. monspeliensis treatment. These results suggest that C. monspeliensis extract has an ability to enhance the energy metabolism in human intestinal cells.

Shimoda, Yoichi; Han, Junkyu; Kawada, Kiyokazu; Smaoui, Abderrazak; Isoda, Hiroko



Transglutaminase 2 expression is enhanced synergistically by interferon-? and tumour necrosis factor-? in human small intestine  

PubMed Central

Transglutaminase 2 (TG2) is expressed ubiquitously, has multiple physiological functions and has also been associated with inflammatory diseases, neurodegenerative disorders, autoimmunity and cancer. In particular, TG2 is expressed in small intestine mucosa where it is up-regulated in active coeliac disease (CD). The aim of this work was to investigate the induction of TG2 expression by proinflammatory cytokines [interleukin (IL)-1, IL-6, tumour necrosis factor (TNF)-?, interferon (IFN)-? and IL-15] and the signalling pathways involved, in human epithelial and monocytic cells and in intestinal tissue from controls and untreated CD patients. Here we report that IFN-? was the most potent inducer of TG2 expression in the small intestinal mucosa and in four [Caco-2, HT-29, Calu-6 and human acute monocytic leukaemia cell line (THP-1)] of five cell lines tested. The combination of TNF-? and IFN-? produced a strong synergistic effect. The use of selective inhibitors of signalling pathways revealed that induction of TG2 by IFN-? was mediated by phosphoinositide 3-kinase (PI3K), while c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) were required for TNF-? activation. Quantitative polymerase chain reaction (PCR), flow cytometry and Western blot analysis showed that TG2 expression was blocked completely when stimulation by either TNF-? or IFN-? was performed in the presence of nuclear factor (NF)-?B inhibitors (sulphasalazine and BAY-117082). TG2 was up-regulated substantially by TNF-? and IFN-? in intestinal mucosa in untreated CD compared with controls. This study shows that IFN-?, a dominant cytokine in intestinal mucosa in active CD, is the most potent inducer of TG2, and synergism with TNF-? may contribute to exacerbate the pathogenic mechanism of CD. Selective inhibition of signalling pathways may be of therapeutic benefit.

Bayardo, M; Punzi, F; Bondar, C; Chopita, N; Chirdo, F



Transglutaminase 2 expression is enhanced synergistically by interferon-? and tumour necrosis factor-? in human small intestine.  


Transglutaminase 2 (TG2) is expressed ubiquitously, has multiple physiological functions and has also been associated with inflammatory diseases, neurodegenerative disorders, autoimmunity and cancer. In particular, TG2 is expressed in small intestine mucosa where it is up-regulated in active coeliac disease (CD). The aim of this work was to investigate the induction of TG2 expression by proinflammatory cytokines [interleukin (IL)-1, IL-6, tumour necrosis factor (TNF)-?, interferon (IFN)-? and IL-15] and the signalling pathways involved, in human epithelial and monocytic cells and in intestinal tissue from controls and untreated CD patients. Here we report that IFN-? was the most potent inducer of TG2 expression in the small intestinal mucosa and in four [Caco-2, HT-29, Calu-6 and human acute monocytic leukaemia cell line (THP-1)] of five cell lines tested. The combination of TNF-? and IFN-? produced a strong synergistic effect. The use of selective inhibitors of signalling pathways revealed that induction of TG2 by IFN-? was mediated by phosphoinositide 3-kinase (PI3K), while c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) were required for TNF-? activation. Quantitative polymerase chain reaction (PCR), flow cytometry and Western blot analysis showed that TG2 expression was blocked completely when stimulation by either TNF-? or IFN-? was performed in the presence of nuclear factor (NF)-?B inhibitors (sulphasalazine and BAY-117082). TG2 was up-regulated substantially by TNF-? and IFN-? in intestinal mucosa in untreated CD compared with controls. This study shows that IFN-?, a dominant cytokine in intestinal mucosa in active CD, is the most potent inducer of TG2, and synergism with TNF-? may contribute to exacerbate the pathogenic mechanism of CD. Selective inhibition of signalling pathways may be of therapeutic benefit. PMID:22385244

Bayardo, M; Punzi, F; Bondar, C; Chopita, N; Chirdo, F



Nondigestible saccharides suppress the bacterial degradation of quercetin aglycone in the large intestine and enhance the bioavailability of quercetin glucoside in rats.  


Contribution of intestinal bacterial degradation of quercetin aglycone to the promotive effects of fructooligosaccharides and di-D-fructose anhydride III (DFAIII) on quercetin-3-O-beta-glucoside (Q3G) bioavailability was examined. Male Sprague-Dawley rats were fed 0.68% Q3G diets with or without 1.5% or 3% oligosaccharides for 2 weeks. Blood levels and urinary excretion of quercetin and methylquercetin conjugates, measured by methanol extraction and LC-MS analyses, were dose-dependently and adaptively increased by the oligosaccharide supplementation with increasing cecal fermentation (Experiment 1). Degradation of Q3G and quercetin aglycone by cecal bacteria in oligosaccharide-fed rats was much lower than that in the control rats using an anaerobic culture system (Experiment 2). Using the ligated intestinal sacs of anesthetized rats, we found that the cecum possessed high absorptive capacity for quercetin derivatives (Experiment 3). These results demonstrate that feeding of the oligosaccharides strongly suppresses the bacterial degradation of quercetin aglycone in the cecum, thus largely contributing to the increased bioavailability of Q3G. PMID:19807098

Matsukawa, Noriko; Matsumoto, Megumi; Shinoki, Aki; Hagio, Masahito; Inoue, Ryo; Hara, Hiroshi



Autoradiographic quantification of vasoactive intestinal peptide binding sites in sections from human blood mononuclear cell pellets  

SciTech Connect

Quantitative autoradiographic methods were utilized to characterize specific, high-affinity vasoactive intestinal peptide binding sites (Kd = 310 +/- 60 pmol/L; Bmax = 93 +/- 11 fmol/mg protein) in frozen sections obtained from a mononuclear cell pellet derived from 20 ml of human blood. The method is at least one order of magnitude more sensitive than conventional membrane binding techniques, and it has the potential for wide applications in studies of neuropeptide, biogenic amine, and drug binding in clinical samples.

Gutkind, J.S.; Kurihara, M.; Castren, E.; Saavedra, J.M.



Isolation of cholesterol-lowering lactic acid bacteria from human intestine for probiotic use  

Microsoft Academic Search

Cholesterol-lowering effect of lactic acid bacteria (LAB: Streptococcus, Lactobacillus and Bifidobacterium) is well- known. Thus, we investigated LAB isolated from human intestine on the cholesterol-lowering effect in vitro. Seven Streptococcus (61.1%), 11 Lactobacillus (71.8%) and 7 Bifidobacterium (27.9%) were isolated as acid (pH 2.5 and 3.0) and bile (0.3% oxgall) tolerant strains. Streptococcus HJS-1, Lactobacillus HJL-37 and Bifidobacterium HJB-4 were

Hyeong-Jun Lim; So-Young Kim; Wan-Kyu Lee


Integrin ?8?1 confers anoikis susceptibility to human intestinal epithelial crypt cells  

Microsoft Academic Search

We previously reported that integrin ?8?1 is expressed in human intestinal epithelial crypt cells (HIECs) and represents one of the major RGD-binding integrins expressed by these cells. Moreover, the depletion of ?8?1 affects vinculin, but not paxillin, localization at focal adhesion points. In the present study, we show that the integrin ?8 shRNA-mediated knockdown in HIECs leads to a decrease

Yannick D. Benoit; Jean-François Larrivée; Jean-François Groulx; Jana Stankova; Pierre H. Vachon; Jean-François Beaulieu



Electromagnetic Propagation From the Intestine-Ingested Source in the Human Body Model  

Microsoft Academic Search

Electromagnetic fields radiated from an intestine-ingested source in the human body model are calculated using the finite-difference time-domain (FDTD) method. The propagation characteristics of the vertically polarized components of the electric fields at the receiving points vertically placed on the model surface are analyzed in the frequency range of 100 MHz to 700 MHz. As the receiving point moves away

Ji-Hyun Jung; Sang-Wook Kim; Young-Sik Kim; Se-Yun Kim



Influence of Exposure Time on Gene Expression by Human Intestinal Epithelial Cells Exposed to Lactobacillus acidophilus  

PubMed Central

Analysis of global temporal gene expression by human intestinal cells when exposed to Lactobacillus acidophilus revealed induction of immune-related pathways and NF-?B target genes after a 1-h exposure, compared to a 4- or 8-h exposure. Additionally, an L. acidophilus derivative expressing covalently bound flagellin resulted in increased induction of il8, cxc1, and cxcl2 compared to the parent L. acidophilus.

O'Flaherty, Sarah



Animal models of intestinal nematode infections of humans.  


In this paper we discuss several established and potential animal models for human parasitic infection, with a focus on rodent, pig and primate models and the nematodes Ascaris, Trichuris and Toxocara spp. Firstly, we discuss the relevance of choosing a suitable animal host to fit the particular study hypothesis, and the interaction between mathematical modelling and animal models. Secondly, we review the use of animal models for the study of nutrition-parasite interaction, evaluation of treatment and control strategies, and bacteria-parasite interactions. We show that rodent, pig and primate models are all very useful in parasitological research, and that each model has its limitations. However, based on recent experience with the pig-Ascaris and pig-Trichuris models, a more extensive use of the pig-parasite model is advocated, especially for the study of the interaction between human malnutrition and helminth infection, and congenital helminth infection. PMID:11386694

Boes, J; Helwigh, A B



Shift from a mixed diet to a lactovegetarian diet: influence on some cancer-associated intestinal bacterial enzyme activities.  


This investigation studied the effects of a shift from a mixed diet to a lactovegetarian diet on some cancer-associated bacterial enzymes in human feces (beta-glucuronidase, beta-glucosidase, and sulphatase). Three months after the shift to the lactovegetarian diet, there was a significant decrease in beta-glucuronidase, beta-glucosidase, and sulphatase activities per gram feces wet weight (p less than 0.05, less than 0.05, and less than 0.001, respectively). In contrast, glucuronide and glucoside hydrolysis remained unchanged per gram dry weight, although sulphatase activity was still significantly lowered when expressed this way (p less than 0.01). However, the fecal excretion increased significantly (p less than 0.05). Part of the explanation for the decreased enzyme activities is obviously a dilution effect, because much of the increased fecal weight after the shift in diet was associated with a higher water content. The higher water content was probably due to a higher fiber intake (p less than 0.001). Thus, the results in this paper indicate that a change from a mixed diet to a lactovegetarian diet leads to a decrease in certain enzyme activities proposed to be risk factors for colon cancer. PMID:2128119

Johansson, G K; Ottova, L; Gustafsson, J A



Short chain fatty acid absorption by the human large intestine  

Microsoft Academic Search

Short chain fatty acid absorption from the human rectum has been studied in 46 subjects attending an obesity clinic, using a dialysis bag technique. From a mixed electrolyte solution, acetate concentrations fell from 97.0 to 64.2 mmol\\/l, and sodium from 97.8 to 85.1 mmol\\/l with respective net absorption rates of 8.1 and 5.2 mumol\\/cm2\\/h. From a solution with mixed short

N I McNeil; J H Cummings; W P James



Increase of Intestinal Bifidobacterium and Suppression of Coliform Bacteria with Short-Term Yogurt Ingestion  

Microsoft Academic Search

To determine whether ingestion of yogurt would alter human intestinal bacterial composition and whether Bi- fidobacterium numbers would increase in the intestine, 34 healthy volunteers were studied. The experimental period was 26 d, including an initial 8 d without yogurt, 10 d with three bottles (230 ml each) of AB yogurt per day (President Enterprise Corporation, Tainan, Tai- wan), and

R. M. Chen; J. J. Wu; S. C. Lee; A. H. Huang; H. M. Wu



Position preference on glucuronidation of mono-hydroxylflavones in human intestine.  


Extensive intestinal glucuronidation has been previously reported in both human and animals after oral administration of naturally occurred flavonoids. The present study aims to investigate the relationship between human intestinal glucuronidation activity and the position of hydroxyl substitution on flavonoids. Seven commercially available mono-hydroxyflavones (HF), namely 3-, 5-, 6-, 7-, 2'-, 3'- and 4'-mono-hydroxyflavones, were chosen as model compounds. Glucuronidation activity of the selected seven HFs was investigated by incubating each HF at various concentrations with human jejunum S9 at 37 degrees C for 10 min. The generated glucuronides were identified by HPLC/MS and quantified by HPLC/UV. Metabolic kinetics parameters including Km and Vmax of each HF were determined. The results demonstrated that the glucuronidation activity of 6- and 3'-mono-hydroxyflavones was much greater than that of 3-, 4'-, 7- and 2'-HF with 5-HF to be the lowest. The findings imply that nucleophilicity and stereo-conformation of OH substituents are crucial for the intestinal glucuronidation of flavonoids. PMID:16376382

Zhang, Li; Lin, Ge; Zuo, Zhong



Src family kinase inhibitor PP2 accelerates differentiation in human intestinal epithelial cells.  


The proto-oncogene Src is an important protein tyrosine kinase involved in signaling pathways that control cell adhesion, growth, migration and survival. Here, we investigated the involvement of Src family kinases (SFKs) in human intestinal cell differentiation. We first observed that Src activity peaked in early stages of Caco-2/15 cell differentiation. Inhibition of SFKs with PP2, a selective SFK inhibitor, accelerated the overall differentiation program. Interestingly, all polarization and terminal differentiation markers tested, including sucrase-isomaltase, lactase-phlorizin hydrolase and E and Li-cadherins were found to be significantly up-regulated after only 3 days of treatment in the newly differentiating cells. Further investigation of the effects of PP2 revealed a significant up-regulation of the two main intestinal epithelial cell-specific transcription factors Cdx2 and HNF1? and a reduction of polycomb PRC2-related epigenetic repressing activity as measured by a decrease in H3K27me3, two events closely related to the control of cell terminal differentiation in the intestine. Taken together, these data suggest that SFKs play a key role in the control of intestinal epithelial cell terminal differentiation. PMID:23274493

Seltana, Amira; Guezguez, Amel; Lepage, Manon; Basora, Nuria; Beaulieu, Jean-François



Species differences in hepatic and intestinal metabolic activities for 43 human cytochrome P450 substrates between humans and rats or dogs.  


Abstract 1. ??Prediction of human pharmacokinetics might be made more precise by using species with similar metabolic activities to humans. We had previously reported the species differences in intestinal and hepatic metabolic activities of 43 cytochrome P450 (CYP) substrates between cynomolgus monkeys and humans. However, the species differences between humans and rats or dogs had not yet been determined using comparable data sets with sufficient number of compounds. 2. ??Here, we investigated metabolic stabilities in intestinal and liver microsomes obtained from rats, dogs and humans using 43 substrates of human CYP1A2, CYP2J2, CYP2C, CYP2D6 and CYP3A. 3. ??Hepatic intrinsic clearance (CLint) values for most compounds in dogs were comparable to those in humans (within 10-fold), whereas in rats, those for the human CYP2D6 substrates were much higher and showed low correlation with humans. In dog intestine, as with human intestine, CLint values for almost all human CYP1A2, CYP2C, CYP2D6 substrates were not determined because they were very low. Intestinal CLint values for human CYP3A substrates in rats and dogs appeared to be lower for most of the compounds and showed moderate correlation with those in humans. 4. ??In conclusion, dogs showed the most similar metabolic activity to humans. PMID:23593983

Nishimuta, Haruka; Nakagawa, Tetsuya; Nomura, Naruaki; Yabuki, Masashi



[Effect of combined chemotherapy against human intestinal nematode eggs].  


The effect of a combination of albendazole and mebendazole was evaluated by stool examination in 7 patients with Ascaris lumbricoides eggs, 7 patients with Trichuris trichiura eggs and 9 patients with hookworm eggs. Albendazole and mebendazole were given at 300 mg and 375 mg, respectively. Both drugs were divided into 3 parts, one part b. id., and given in 1.5 days. The fecal eggs turned negative in all the patients with Ascaris infection in 3 days, while the fecal eggs were negative in all patients with Trichuris or hookworm infection in 5 days. The development rates of the eggs were remarkably lower post-treatment than pre-treatment. It was found that the ovicidal rates in human ascariasis, trichuriasis and ancylostomiasis were 98.8%, 100% and 100%, respectively on the second day following the initiation of treatment. The results showed that the worm-repelling and ovicidal effect of the combined chemotherapy was more evident. PMID:8044908

Yang, W P; Shen, Y P; Shao, J O; Dong, K; Zhong, T; Hu, Y L; Xu, Z L



Effects of Antibiotics on Bacterial Species Composition and Metabolic Activities in Chemostats Containing Defined Populations of Human Gut Microorganisms  

PubMed Central

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 ?g (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 ?g (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.

Newton, Dorothy F.; Macfarlane, George T.



Effects of antibiotics on bacterial species composition and metabolic activities in chemostats containing defined populations of human gut microorganisms.  


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 ?g (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 ?g (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

Newton, Dorothy F; Macfarlane, Sandra; Macfarlane, George T



Identification of isoquercitrin metabolites produced by human intestinal bacteria using UPLC-Q-TOF/MS.  


In this paper, ultraperformance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) and the MetaboLynx™ software combined with mass defect filtering were applied to identity the metabolites of isoquercitrin using an intestinal mixture of bacteria and 96 isolated strains from human feces. The human incubated samples collected for 72 h in the anaerobic incubator and extracted with ethyl acetate were analyzed by UPLC-Q-TOF/MS within 10 min. The parent compound and five metabolites were identified by eight isolated strains, including Bacillus sp. 17, Veillonella sp. 23 and 32 and Bacteroides sp. 40, 41, 56, 75 and 88 in vitro. The results indicate that quercetin, acetylated isoquercitrin, dehydroxylated isoquercitrin, hydroxylated quercetin and hydroxymethylated quercetin are the major metabolites of isoquercitrin. Furthermore, a possible metabolic pathway for the biotransformation of isoquercitrin was established in intestinal flora. This study will be helpful for understanding the metabolic route of isoquercitrin and the role of different intestinal bacteria in the metabolism of natural compounds. PMID:23018801

Lu, Linling; Qian, Dawei; Yang, Jing; Jiang, Shu; Guo, Jianming; Shang, Er-xin; Duan, Jin-ao



A basal gradient of Wnt and stem-cell number influences regional tumour distribution in human and mouse intestinal tracts  

PubMed Central

Objective Wnt signalling is critical for normal intestinal development and homeostasis. Wnt dysregulation occurs in almost all human and murine intestinal tumours and an optimal but not excessive level of Wnt activation is considered favourable for tumourigenesis. The authors assessed effects of pan-intestinal Wnt activation on tissue homeostasis, taking into account underlying physiological Wnt activity and stem-cell number in each region of the bowel. Design The authors generated mice that expressed temporally controlled, stabilised ?-catenin along the crypt–villus axis throughout the intestines. Physiological Wnt target gene activity was assessed in different regions of normal mouse and human tissue. Human intestinal tumour mutation spectra were analysed. Results In the mouse, ?-catenin stabilisation resulted in a graduated neoplastic response, ranging from dysplastic transformation of the entire epithelium in the proximal small bowel to slightly enlarged crypts of non-dysplastic morphology in the colorectum. In contrast, stem and proliferating cell numbers were increased in all intestinal regions. In the normal mouse and human intestines, stem-cell and Wnt gradients were non-identical, but higher in the small bowel than large bowel in both species. There was also variation in the expression of some Wnt modulators. Human tumour analysis confirmed that different APC mutation spectra are selected in different regions of the bowel. Conclusions There are variable gradients in stem-cell number, physiological Wnt activity and response to pathologically increased Wnt signalling along the crypt-villus axis and throughout the length of the intestinal tract. The authors propose that this variation influences regional mutation spectra, tumour susceptibility and lesion distribution in mice and humans.

Rodenas-Cuadrado, Pedro; Howarth, Kimberley; Lewis, Annabelle; Mallappa, Sreelakshmi; Segditsas, Stefania; Davis, Hayley; Jeffery, Rosemary; Rodriguez-Justo, Manuel; Keshav, Satish; Travis, Simon P L; Graham, Trevor A; East, James; Clark, Susan; Tomlinson, Ian P M



Interaction of Macrolide Antibiotics with Intestinally Expressed Human and Rat Organic Anion-Transporting Polypeptides  

PubMed Central

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 ?M, 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.

Lan, Tian; Rao, Anuradha; Haywood, Jamie; Davis, Charles B.; Han, Chao; Garver, Eric



Interaction of macrolide antibiotics with intestinally expressed human and rat organic anion-transporting polypeptides.  


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 (K(i)) values of 3.3 and 2.4 microM, 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

Lan, Tian; Rao, Anuradha; Haywood, Jamie; Davis, Charles B; Han, Chao; Garver, Eric; Dawson, Paul A



Azoreductase activity of anaerobic bacteria isolated from human intestinal microflora.  

PubMed Central

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

Rafii, F; Franklin, W; Cerniglia, C E



MOLECULAR, CELLULAR, AND DEVELOPMENTAL BIOLOGY Intestinal Bacterial Community and Growth Performance of Chickens Fed Diets Containing Antibiotics  

Microsoft Academic Search

This study was conducted to relate the per- formance of broiler chickens fed diets containing growth- promoting antibiotics to changes in the intestinal microbi- ota. The technique of denaturing gradient gel electropho- resis (DGGE) of amplicons of the region V3 of 16S rDNA was used to characterize the microbiota. Two experiments were conducted, one with broilers raised in battery cages

A. A. Pedroso; J. F. M. Menten; M. R. Lambais; A. M. C. Racanicci; F. A. Longo; J. O. B. Sorbara


Modeling the human intestinal mucin (MUC2) C-terminal cystine knot dimer.  


Intestinal mucus, a viscous secretion that lines the mucosa, is believed to be a barrier to absorption of many therapeutic compounds and carriers, and is known to play an important physiological role in controlling pathogen invasion. Nevertheless, there is as yet no clear understanding of the barrier properties of mucus, such as the nature of the molecular interactions between drug molecules and mucus components as well as those that govern gel formation. Secretory mucins, large and complex glycoprotein molecules, are the principal determinants of the viscoelastic properties of intestinal mucus. Despite the important role that mucins play in controlling transport and in diseases such as cystic fibrosis, their structures remain poorly characterized. The major intestinal secretory mucin gene, MUC2, has been identified and fully sequenced. The present study was undertaken to determine a detailed structure of the cysteine-rich region within the C-terminal end of human intestinal mucin (MUC2) via homology modeling, and explore possible configurations of a dimer of this cysteine-rich region, which may play an important role in governing mucus gel formation. Based on sequence-structure alignments and three-dimensional modeling, a cystine knot tertiary structure homologous to that of human chorionic gonadotropin (HCG) is predicted at the C-terminus of MUC2. Dimers of this C-terminal cystine knot (CTCK) were modeled using sequence alignment based on HCG and TGF-beta, followed by molecular dynamics and simulated annealing. Results support the formation of a cystine knot dimer with a structure analogous to that of HCG. PMID:21318237

Sadasivan, Vatsala D; Narpala, Sandeep R; Budil, David E; Sacco, Albert; Carrier, Rebecca L



Ganglioside composition of differentiated Caco-2 cells resembles human colostrum and neonatal rat intestine.  


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

Schnabl, Kareena L; Field, Catherine; Clandinin, M T



Human gut-on-a-chip inhabited by microbial flora that experiences intestinal peristalsis-like motions and flow.  


Development of an in vitro living cell-based model of the intestine that mimics the mechanical, structural, absorptive, transport and pathophysiological properties of the human gut along with its crucial microbial symbionts could accelerate pharmaceutical development, and potentially replace animal testing. Here, we describe a biomimetic 'human gut-on-a-chip' microdevice composed of two microfluidic channels separated by a porous flexible membrane coated with extracellular matrix (ECM) and lined by human intestinal epithelial (Caco-2) cells that mimics the complex structure and physiology of living intestine. The gut microenvironment is recreated by flowing fluid at a low rate (30 ?L h(-1)) producing low shear stress (0.02 dyne cm(-2)) over the microchannels, and by exerting cyclic strain (10%; 0.15 Hz) that mimics physiological peristaltic motions. Under these conditions, a columnar epithelium develops that polarizes rapidly, spontaneously grows into folds that recapitulate the structure of intestinal villi, and forms a high integrity barrier to small molecules that better mimics whole intestine than cells in cultured in static Transwell models. In addition, a normal intestinal microbe (Lactobacillus rhamnosus GG) can be successfully co-cultured for extended periods (>1 week) on the luminal surface of the cultured epithelium without compromising epithelial cell viability, and this actually improves barrier function as previously observed in humans. Thus, this gut-on-a-chip recapitulates multiple dynamic physical and functional features of human intestine that are critical for its function within a controlled microfluidic environment that is amenable for transport, absorption, and toxicity studies, and hence it should have great value for drug testing as well as development of novel intestinal disease models. PMID:22434367

Kim, Hyun Jung; Huh, Dongeun; Hamilton, Geraldine; Ingber, Donald E



Human ?2-glycoprotein I attenuates mouse intestinal ischemia/reperfusion induced injury and inflammation  

PubMed Central

Intestinal ischemia-reperfusion (IR)-induced injury results from a complex cascade of inflammatory components. In the mouse model of intestinal IR, the serum protein, ?2-glycoprotein I (?2-GPI) binds to the cell surface early in the cascade. The bound ?2-GPI undergoes a conformational change which exposes a neoantigen recognized by naturally occurring antibodies and initiates the complement cascade. We hypothesized that providing additional antigen with exogenous ?2-GPI would alter IR-induced tissue injury. Administration of human but not mouse ?2-GPI attenuated IR-induced tissue damage and prostaglandin E2 production indicating a physiological difference between ?2-GPI isolated from the two species. To investigate whether structural features were responsible for this physiological difference, we compared the chemical, physical and biochemical properties of the two proteins. Despite possessing 76% amino acid identity and 86% sequence homology, we found that mouse ?2-GPI differs from the human protein in size, carbohydrate chain location, heterogeneity and secondary structural content. These data suggest that the structural differences result in mouse Ab recognition of soluble human but not mouse ?2-GPI and attenuated IR-induced injury. We conclude that caution should be exercised in interpreting results obtained by using human ?2-GPI in a mouse model.

Tomasi, Maurizio; Hiromasa, Yasuaki; Pope, Michael R.; Gudlur, Sushanth; Tomich, John M.; Fleming, Sherry D.



Bacterial pathogens: from natural ecosystems to human hosts.  


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

Martínez, José L



Bacterial dissemination and metabolic changes in rats induced by endotoxemia following intestinal E. coli overgrowth are reduced by ornithine alpha-ketoglutarate administration.  


The efficacy of ornithine alpha-ketoglutarate (OKG) in preventing bacterial translocation and dissemination, metabolic disorders and changes in mucosal enzyme activities was assessed in a model of bacterial translocation in rats. Antibiotic decontamination was performed 4 d before intragastric inoculation with an Escherichia coli strain (10(10) bacteria/kg body). Two days later, the rats were given either a lipopolysaccharide (LPS) 0127:B8 or a saline injection and were deprived of food for 24 h. Enteral nutrition, [Osmolite, 880 kJ/(kg. d)] supplemented with either OKG (LPS + OKG) or glycine (Saline + Gly or LPS + Gly), was then given for 2 d. Urinary total nitrogen losses and 3-methylhistidine excretion were determined daily. On killing at d 3, bacterial translocation to the mesenteric lymph nodes (MLN) and dissemination to the spleen and liver were evaluated, jejunal mucosa enzyme activities were assayed and tissue free amino acids in muscles were measured. Endotoxin induced translocation from the gut lumen to the MLN in all groups, whereas dissemination occurred only in LPS-treated rats. OKG significantly reduced dissemination of the bacteria in the spleen. 3-Methylhistidine excretion was greater in the LPS + Gly group (+25%, P: < 0.05) than in either the LPS + OKG or Saline + Gly group. The group fed the OKG-enriched diet had higher muscular glutamine, ornithine and arginine concentrations than did the Gly-supplemented groups (P: < 0.05). Intestinal sucrase and aminopeptidase activities were higher in the LPS + OKG group than in the LPS + Gly group (-30%, P: < 0.05). OKG supplementation limits bacterial dissemination and metabolic changes after injury in rats and thus may be useful in the prevention of gut-derived sepsis in critically ill patients. PMID:11110843

Schlegel, L; Coudray-Lucas, C; Barbut, F; Le Boucher, J; Jardel, A; Zarrabian, S; Cynober, L



The identification of a bacterial strain BGI-1 isolated from the intestinal flora of Blattella germanica, and its anti-entomopathogenic fungi activity.  


A bacterial strain BGI-1 was isolated from the gut of German cockroaches (Blattella germanica L.) and was identified as Bacillus subtilis based on 16S rDNA sequence and morphological, physiological, and biochemical characters. The strain BGI-1 inhibited the growth of Beauveria bassiana; the diameter of the inhibition zone exceeded 30 mm. Vesicles were observed in B. bassiana hyphae on the edge of the inhibition zone. Fermentation of BGI-1 reduced the conidial germination rate by 12%. Further studies demonstrated that B. bassiana infections in German cockroaches orally treated with the extracts of BGI-1 fermentation were significantly weakened. Cumulative mortality rate was 49.5% in the treatment group at the 20 d, while that of the control group was 62.3%. The study intends to understand the relationship between the intestinal flora and the cockroach. Those microbes with anti-entomopathogenic fungi activity might contribute to resisting the infection of pathogenic fungi. PMID:23448013

Huang, Y H; Wang, X J; Zhang, F; Huo, X B; Fu, R S; Liu, J J; Sun, W B; Kang, D M; Jing, X



D-cycloserine uses an active transport mechanism in the human intestinal cell line Caco 2.  

PubMed Central

In a previous study we have shown that cultured epithelial cell lines can be used to measure the transepithelial passage of antimicrobial agents across the intestine and to obtain information on the mechanisms of transport utilized and predict the bioavailability of the antimicrobial agents after oral administration. In particular, among the drugs investigated, D-cycloserine had been shown to be transported in a polarized manner only in the intestinal cells. In the present work, further characterization of the transport of D-cycloserine in the human intestinal cell line Caco 2 has shown that this occurs in the apical-to-basolateral direction by an active mechanism which is energy dependent but only partially sodium dependent. Competition studies have also indicated that the transport of D-cycloserine occurs via a carrier for imino acids, amino acids with aliphatic side chains (L-Ala, D-Ala, and beta Ala), and L-Trp, L-Tyr, L-Cys, and alpha-amino isobutyric acid. This system may correspond to a proton-dependent system for L-proline and beta-alanine recently described for Caco 2 cells. In contrast with the cephalosporins, which are taken up by the Caco 2 cells via a dipeptide carrier, D-cycloserine transport cannot be inhibited by either cephalexin (a member of the class of cephalosporins) or dipeptides.

Ranaldi, G; Islam, K; Sambuy, Y



Identification of NF-?B Modulation Capabilities within Human Intestinal Commensal Bacteria  

PubMed Central

The intestinal microbiota plays an important role in modulation of mucosal immune responses. To seek interactions between intestinal epithelial cells (IEC) and commensal bacteria, we screened 49 commensal strains for their capacity to modulate NF-?B. We used HT-29/kb-seap-25 and Caco-2/kb-seap-7 intestinal epithelial cells and monocyte-like THP-1 blue reporter cells to measure effects of commensal bacteria on cellular expression of a reporter system for NF-?B. Bacteria conditioned media (CM) were tested alone or together with an activator of NF-?B to explore its inhibitory potentials. CM from 8 or 10 different commensal species activated NF-?B expression on HT-29 and Caco-2 cells, respectively. On THP-1, CM from all but 5 commensal strains stimulated NF-?B. Upon challenge with TNF-? or IL-1?, some CM prevented induced NF-?B activation, whereas others enhanced it. Interestingly, the enhancing effect of some CM was correlated with the presence of butyrate and propionate. Characterization of the effects of the identified bacteria and their implications in human health awaits further investigations.

Lakhdari, Omar; Tap, Julien; Beguet-Crespel, Fabienne; Le Roux, Karine; de Wouters, Tomas; Cultrone, Antonietta; Nepelska, Malgorzata; Lefevre, Fabrice; Dore, Joel; Blottiere, Herve M.



Transport of quercetin di-sodium salt in the human intestinal epithelial Caco-2 cell monolayer 139  

Microsoft Academic Search

Summary  Quercetin di-sodium salt (QDS), a water-soluble derivative of quercetin (Q), is a potent free radical scavenger. The aim of\\u000a this study was to examine thein vitro intestinal transport of QDS compared to that of Q using the Caco-2 human intestinal epithelial cell line. The apical (A)\\u000a to basolateral (B) transport of QDS was found to be higher than the B

H. A. Milane; A. Al Ahmad; M. Naitchabane; T. F. Vandamme; L. Jung; G. Ubeaud



Modulation of bacterial translocation in mice mediated through lactose and human milk oligosaccharides.  


Massive resection of the small intestine in infants is imposed to the regulation of several intestinal pathological situations, as intestinal adaptation cannot be relied upon. Many nutritional disturbances are occurring following surgery procedure. In this vein, long-term parenteral feeding is adopt to improve prognosis not always successfully. Clostridia and more specifically Clostridium perfringens, are suspected to participate in the physiopathology of the rising situation. In order to investigate the effect of lactose and human milk neutral oligosaccharides (HMNOs) on Clostridia, germfree mice were inoculated either with enterotoxigenic C.perfringens strain isolated from a patient with NEC, or with a human microbiota harboring C.clostridioforme group(HF). In this vein, different doses of lactose were administrated during 2 weeks in adult mice on an attempt to evaluate the lactase activity. Intake of lactose (70 g/L) and HMNOs (7 g/L) in C.perfringens monoassociated mice induced mortality within a week. In HF mice, no mortality was observed. An increase in Clostridia occurrence was observed in the median ileum after intake of 7 g lactose (p = 0.017). Higher clostridial numbers occurred in caecum following intake of 70 g lactose (p < 0.05) and HMNOs (p < 0.025). Bifidobacteria were found increased from distal ileum to colon following 70 g of lactose intake, whereas they decreased in the caecum of mice drinking lower lactose concentrations. Finally, bacteremia was more frequent in 70 g lactose/L mice (p < 0.02), whereas at lower doses of lactose bifidobacterial translocation was observed. As a result, human milk oligosaccharides could favor clostridial population when reaching the lower intestine. The shortness of the small intestine in infants underwent massive intestinal resection seems to be associated to an incomplete breakdown of lactose. Enteral feeds formulas deprived in lactose would be more suitable in enteral feeding of infants. PMID:21939778

Mielcarek, C; Romond, P C; Romond, M B; Bezirtzoglou, E



Parenteral antibiotics and selective intestinal decontamination do not prevent enteric bacterial overgrowth or translocation observed in a swine model of small bowel transplantation.  


Alterations in the luminal microflora and increased intestinal translocation have been reported to occur following experimental and clinical small bowel transplantation (SBT). Selective intestinal decontamination (SID) has been used to prevent luminal overgrowth and bacterial translocation. Despite the wide use of SID in clinical SBT, there are no data supporting its usefulness in this situation. Thus, the aim of this investigation was to examine the effects of cyclosporine A (CsA) and SID upon bacterial overgrowth and translocation in a swine model of SBT. Nineteen Large White female pigs weighing 30 +/- 2 kg underwent a total orthotopic SBT and were randomly allocated to one of the following experimental groups as follows: Group 1 (No. 8) CSA 25 mg/kg body weight (b.w.)/day administered subcutaneously and Cefazolin 2 g/day im. Group 2 (No. 6) received the identical immunosuppression but the Cefazolin 2 g/day im was discontinued on the 5th Postoperative Day (pod) and switched to a SID regimen consisting of Vancomycin, 1 g, Nystatin, 500,000 IU, Colistin, 1,500,000 IU, and Tobramycin, 100 mg, given through a gastrostomy tube. Group 3 (No. 5) received no immunosuppression but antibiotic consisting of Cefazolin 2 g im/day. Group 4 (No. 7) underwent a small bowel autotransplantation. Group 4 received SID as in group 2 but no immunosuppression was given. Finally, 17 normal animals were sham-operated and were used as normal controls (N group). The animals in groups 1, 2, and 4 were sacrificed on the 29th pod. Those in group 3 were sacrificed on the 7th pod.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7723317

Biffi, R; Privitera, G; Matinato, C; Pozzi, S; Marzona, L; De Rai, P; Andreoni, B; Tiberio, G; Frezza, E; Van Thiel, D H



Decreased Gastric Bacterial Killing and Up-Regulation of Protective Genes in Small Intestine in Gastrin-Deficient Mouse  

Microsoft Academic Search

Gastrin regulates gastric acid secretion, believed to be primarily responsible for killing ingested microbes. We examined gastric killing of gavaged E. coli in gastrin-deficient mice, which have decreased gastric acid production. Additionally, the expression of intestinal genes involved in epithelial protection were analyzed: the mucus layer glycoprotein muclin, the polymeric Ig receptor, trefoil factor 3, and small proline-rich protein 2a

Francis J. Sun; Simran Kaur; Donna Ziemer; Snigdha Banerjee; Linda C. Samuelson; Robert C. De Lisle



Maternal Stress is Associated With Bacterial Vaginosis in Human Pregnancy  

Microsoft Academic Search

Objectives: Maternal infection, particularly bacterial vaginosis (BV) in pregnancy, is one of the leading causes of adverse perinatal outcomes. The determinants of individual differences in susceptibility, or vulnerability, to maternal infections are poorly understood. This study examines whether chronic maternal stress predisposes women to infection during pregnancy, and if so, whether the effects of chronic stress on infection are independent

Jennifer F. Culhane; Virginia Rauh; Kelly Farley McCollum; Vijaya K. Hogan; Kathy Agnew; Pathik D. Wadhwa



Comparative effects of dietary nucleoside-nucleotide mixture and its components on endotoxin induced bacterial translocation and small intestinal injury in protein deficient mice.  

PubMed Central

BACKGROUND--Nucleoside-nucleotide mixture has been shown to improve gut morphology and reduce the incidence of bacterial translocation in protein deficient mice. AIMS--To compare the reparative effect of nucleoside-nucleotide mixture and their individual components on maintenance of gut integrity and bacterial translocation based on their differential metabolism and utilisation. METHODS--ICR (CD-1) mice were randomised into eight groups of 10 animals each and fed 20% casein diet (control), protein free diet, or protein free diet supplemented with 3 M cytidine, uridine, thymidine, inosine, guanosine monophosphate, or nucleoside-nucleotide mixture for four weeks. On the fourth week, each mouse was injected lipopolysaccharide intraperitoneally (50 micrograms/500 microliters) and the incidence of bacterial translocation, caecal bacterial populations, and the ileal histology, noted 48 hours later. RESULTS--The death rate in the control group was 40% compared with 10% in the nucleoside-nucleotide mixture and 20% each in the individual components groups, respectively. Bacterial translocation to the mesenteric lymph node did occur in 100% of the surviving mice fed the control diet in comparison with 44% (nucleoside-nucleotide), 50% (cytidine), 75% (thymidine), 75% (uridine), 63% (inosine), and 63% (guanosine monophosphate). Histologically, the damage to the gut was more distinct in the protein free diet group. Villous height, crypt depth, and wall thickness in the nucleoside-nucleotide mixture group mean (SEM) (5.01 (0.34); 0.87 (0.14); 0.33 (0.10)), were respectively, higher compared with the protein free diet (3.34 (0.34); 0.61 (0.03); 0.18 (0.04)) group. In the cytidine group, crypt depth (0.86) (0.08)), and wall thickness (0.30 (0.002)) were higher. The same measurements in the components groups tended to be higher than the protein free diet group. Caecal bacterial populations were, however, similar in all groups. CONCLUSIONS--These results suggest that dietary nucleosides and nucleotides are essential nutrients for intestinal repair; nucleotides or cytidine provide a better response. Images Figure 1

Adjei, A A; Yamauchi, K; Chan, Y C; Konishi, M; Yamamoto, S



Molecular regulation of the intestinal epithelial barrier: implication in human diseases.  


Intestinal barrier dysfunction is implicated in the development of various clinical diseases. While the study of intestinal barrier function has traditionally emphasized the impact of intestinal microflora and bacteria, the rapid development of molecular and cellular techniques has helped the recent transition of the field to the molecular regulation of the intestinal epithelial barrier. In this review, we summarized several aspects of recent progress on the molecular regulation of the intestinal epithelial barrier, ranging from the extrinsic factors such as probiotics, intrinsic protein effectors including the tight junction proteins, intestinal alkaline phosphatase and protein phosphatase 2A, to intestinal cell subsets such as intestinal intraepithelial lymphocytes and intestinal stem cells. Further investigations into the detailed mechanisms underlying the molecular regulation of the intestinal epithelial barrier will enable our manipulation of the factors and cell subsets involved to develop effective approaches to treat intestinal barrier dysfunction associated diseases. PMID:21622211

Liu, Zhihua; Shi, Chenzhang; Yang, Jianjun; Zhang, Peng; Ma, Yanlei; Wang, Feng; Qin, Huanlong



Involvement of TRAIL/TRAIL-receptors in human intestinal cell differentiation.  


Despite the fact that tumor necrosis factor (TNF)-related apoptosis inducing ligand (TRAIL) and its receptors (TRAIL-Rs) are expressed in intestinal mucosa, little is known about the biological role of this system in intestinal cell physiology. The expression of surface TRAIL and TRAIL-R1, -R2, -R3, -R4 were examined by flow cytometry in the immortalized human cell line tsFHI under culture conditions promoting growth or growth arrest and expression of differentiated traits. A progressive increase of surface TRAIL expression paralleled tsFHI differentiation, consistently with immunohistochemistry analysis showing an increase of TRAIL immunostaining along the crypt-villus axis in normal jejuneal mucosa. In spite of the presence of TRAIL-R1 and TRAIL-R2 "death receptors," recombinant TRAIL was not cytotoxic for tsFHI cells. Exposure of tsFHI to recombinant TRAIL rather increased/anticipated the expression levels of the cyclin-dependent kinase inhibitors p21 and p27, which mediate the induction of growth arrest and the stabilization of differentiated traits, respectively, as well as of the canonical differentiation marker DPPIV. The differentiation inducing activity of TRAIL was abolished by pre-incubation with a Fc-TRAIL-R2 chimera. On the other hand, TRAIL did not significantly modulate the levels of osteoprotegerin (OPG), CXCL8/IL-8, CXCL9/MIG, and CXCL10/IP10 spontaneously released or induced by inflammatory cytokines. Taken together, these data suggest that TRAIL might act as a paracrine trophic cytokine on intestinal epithelium, promoting intestinal cell differentiation. PMID:16245299

Rimondi, Erika; Secchiero, Paola; Quaroni, Andrea; Zerbinati, Carlotta; Capitani, Silvano; Zauli, Giorgio



Extracellular nucleotides inhibit oxalate transport by human intestinal Caco-2-BBe cells through PKC-? activation.  


Nephrolithiasis remains a major health problem in Western countries. Seventy to 80% of kidney stones are composed of calcium oxalate, and small changes in urinary oxalate affect risk of kidney stone formation. Intestinal oxalate secretion mediated by the anion exchanger SLC26A6 plays an essential role in preventing hyperoxaluria and calcium oxalate nephrolithiasis, indicating that understanding the mechanisms regulating intestinal oxalate transport is critical for management of hyperoxaluria. Purinergic signaling modulates several intestinal processes through pathways including PKC activation, which we previously found to inhibit Slc26a6 activity in mouse duodenal tissue. We therefore examined whether purinergic stimulation with ATP and UTP affects oxalate transport by human intestinal Caco-2-BBe (C2) cells. We measured [¹?C]oxalate uptake in the presence of an outward Cl? gradient as an assay of Cl?/oxalate exchange activity, ?50% of which is mediated by SLC26A6. We found that ATP and UTP significantly inhibited oxalate transport by C2 cells, an effect blocked by the PKC inhibitor Gö-6983. Utilizing pharmacological agonists and antagonists, as well as PKC-? knockdown studies, we observed that ATP inhibits oxalate transport through the P2Y? receptor, PLC, and PKC-?. Biotinylation studies showed that ATP inhibits oxalate transport by lowering SLC26A6 surface expression. These findings are of potential relevance to pathophysiology of inflammatory bowel disease-associated hyperoxaluria, where supraphysiological levels of ATP/UTP are expected and overexpression of the P2Y? receptor has been reported. We conclude that ATP and UTP inhibit oxalate transport by lowering SLC26A6 surface expression in C2 cells through signaling pathways including the P2Y? purinergic receptor, PLC, and PKC-?. PMID:23596171

Amin, Ruhul; Sharma, Sapna; Ratakonda, Sireesha; Hassan, Hatim A



Functional modulation of human intestinal epithelial cell responses by Bifidobacterium infantis and Lactobacillus salivarius  

PubMed Central

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)-?B 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)-? 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-?B 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-? 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.

O'Hara, Ann M; O'Regan, Padraig; Fanning, Aine; O'Mahony, Caitlin; MacSharry, John; Lyons, Anne; Bienenstock, John; O'Mahony, Liam; Shanahan, Fergus



The metabolism of lithocholic acid-3alpha-sulfate by human intestinal microflora.  


Lithocholic acid-3alpha-sulfate is metabolized by human intestinal microflora to nonpolar metabolites which have been partially purified by Sephadex LH-20 chromatography. These metabolites were characterized by thin layer and gas liquid chromatography as well as combined gas liquid chromatography-mass spectrometry. The chromatographic properties of one of the metabolites are consistent with those described for a delta2- or delta3-cholenate. The formation of cholenates by the microflora may represent a retoxification of the sulfate ester of lithocholic acid. PMID:634046

Kelsey, M I; Muschik, G M; Sexton, S A



Comparative study on cancer cell apoptosis between gastric and intestinal-type human gastric carcinoma  

Microsoft Academic Search

Summary  Apoptosis of cancer cells between the gastric and intestinal-type human gastric carcinoma were compared in terms of the expression\\u000a of oncogene MDM2 and CD68, the histological types, the infiltration depth, and lymph node metastasis. Terminal deoxynucleotidyl\\u000a trans-ferase-mediated dUTP-biotin nick end-labeling (TUNEL) assay was employed to stain apoptotic cells. Histochemical method(AB-PAS)\\u000a was applied to stain mucus that is neutral or acidic

Limin Liu; Shengjun Lu; Qingshan Chen; Heping Xiao; Yongrong Mao



RGD-Dependent Epithelial Cell-Matrix Interactions in the Human Intestinal Crypt.  


Interactions between the extracellular matrix (ECM) and integrin receptors trigger structural and functional bonds between the cell microenvironment and the cytoskeleton. Such connections are essential for adhesion structure integrity and are key players in regulating transduction of specific intracellular signals, which in turn regulate the organization of the cell microenvironment and, consequently, cell function. The RGD peptide-dependent integrins represent a key subgroup of ECM receptors involved in the maintenance of epithelial homeostasis. Here we review recent findings on RGD-dependent ECM-integrin interactions and their roles in human intestinal epithelial crypt cells. PMID:22988499

Benoit, Yannick D; Groulx, Jean-François; Gagné, David; Beaulieu, Jean-François



Role of intestinal epithelial cells in the host secretory response to infection by invasive bacteria. Bacterial entry induces epithelial prostaglandin h synthase-2 expression and prostaglandin E2 and F2alpha production.  

PubMed Central

Increased intestinal fluid secretion is a protective host response after enteric infection with invasive bacteria that is initiated within hours after infection, and is mediated by prostaglandin H synthase (PGHS) products in animal models of infection. Intestinal epithelial cells are the first host cells to become infected with invasive bacteria, which enter and pass through these cells to initiate mucosal, and ultimately systemic, infection. The present studies characterized the role of intestinal epithelial cells in the host secretory response after infection with invasive bacteria. Infection of cultured human intestinal epithelial cell lines with invasive bacteria, but not noninvasive bacteria, is shown to induce the expression of one of the rate-limiting enzymes for prostaglandin formation, PGHS-2, and the production of PGE2 and PGF2alpha. Furthermore, increased PGHS-2 expression was observed in intestinal epithelial cells in vivo after infection with invasive bacteria, using a human intestinal xenograft model in SCID mice. In support of the physiologic importance of epithelial PGHS-2 expression, supernatants from bacteria-infected intestinal epithelial cells were shown to increase chloride secretion in an in vitro model using polarized epithelial cells, and this activity was accounted for by PGE2. These studies define a novel autocrine/paracrine function of mediators produced by intestinal epithelial cells in the rapid induction of increased fluid secretion in response to intestinal infection with invasive bacteria.

Eckmann, L; Stenson, W F; Savidge, T C; Lowe, D C; Barrett, K E; Fierer, J; Smith, J R; Kagnoff, M F



The human TLR4 variant D299G mediates inflammation-associated cancer progression in the intestinal epithelium  

PubMed Central

Homeostatic TLR4 signaling protects the intestinal epithelium in health. Evidence suggests that perturbed TLR4 signaling is linked to carcinogenesis. We have recently demonstrated that the common human TLR4 variant D299G exerts pro-inflammatory effects and drives malignant tumor progression in human colon cancer.



Temporal Variability of Human Vaginal Bacteria and Relationship with Bacterial Vaginosis  

Microsoft Academic Search

BackgroundLittle is known about short-term bacterial fluctuations in the human vagina. This study used PCR to assess the variability in concentrations of key vaginal bacteria in healthy women and the immediate response to antibiotic treatment in women with bacterial vaginosis (BV).Methodology\\/Principal FindingsTwenty-two women assessed for BV using Amsel's criteria were evaluated daily for 7 or 14 days, then at 2,

Sujatha Srinivasan; Congzhou Liu; Caroline M. Mitchell; Tina L. Fiedler; Katherine K. Thomas; Kathy J. Agnew; Jeanne M. Marrazzo; David N. Fredricks; Adam J. Ratner



Short-term effect of dietary yeast nucleotide supplementation on small intestinal enzyme activities, bacterial populations and metabolites and ileal nutrient digestibilities in newly weaned pigs.  


In previous studies, dietary nucleotides have been shown to improve performance in single-stomached animals by promoting the renewal of small intestine epithelial cells and by influencing the activity and composition of the microbial community in the digestive tract. The present experiment was carried out with 12 barrows weaned at the age of 18 days and fitted with a simple T-cannula at the distal ileum. To determine short-term effects of dietary yeast nucleotides, the piglets received a grain-soybean meal-based basal diet with or without supplementation of 1 g/kg of a dried yeast product containing free nucleotides. Dietary supplementation with yeast did not affect bacterial numbers in the ileum as well as ileal concentrations of individual short-chain fatty acids (SCFA), total SCFA and total lactic acid (p > 0.05). Moreover, there was no effect of supplemental yeast nucleotides on ileal ?-amylase, leucine amino peptidase, maltase and lactase activities (p > 0.05), as well as on ileal dry matter, crude protein and crude fibre digestibilities (p > 0.05). In conclusion, short-term supplementation with dietary yeast nucleotides did not affect microbial metabolite concentrations, bacterial numbers and enzyme activities in the ileal digesta as well as ileal nutrient digestibilities of newly weaned pigs. PMID:21797935

Sauer, N; Eklund, M; Roth, S; Rink, F; Jezierny, D; Bauer, E; Mosenthin, R



Incorporation of a non-human glycan mediates human susceptibility to a bacterial toxin  

SciTech Connect

AB{sub 5} toxins comprise an A subunit that corrupts essential eukaryotic cell functions, and pentameric B subunits that direct target-cell uptake after binding surface glycans. Subtilase cytotoxin (SubAB) is an AB{sub 5} toxin secreted by Shiga toxigenic Escherichia coli (STEC), which causes serious gastrointestinal disease in humans. SubAB causes haemolytic uraemic syndrome-like pathology in mice through SubA-mediated cleavage of BiP/GRP78, an essential endoplasmic reticulum chaperone. Here we show that SubB has a strong preference for glycans terminating in the sialic acid N-glycolylneuraminic acid (Neu5Gc), a monosaccharide not synthesized in humans. Structures of SubB-Neu5Gc complexes revealed the basis for this specificity, and mutagenesis of key SubB residues abrogated in vitro glycan recognition, cell binding and cytotoxicity. SubAB specificity for Neu5Gc was confirmed using mouse tissues with a human-like deficiency of Neu5Gc and human cell lines fed with Neu5Gc. Despite lack of Neu5Gc biosynthesis in humans, assimilation of dietary Neu5Gc creates high-affinity receptors on human gut epithelia and kidney vasculature. This, and the lack of Neu5Gc-containing body fluid competitors in humans, confers susceptibility to the gastrointestinal and systemic toxicities of SubAB. Ironically, foods rich in Neu5Gc are the most common source of STEC contamination. Thus a bacterial toxin's receptor is generated by metabolic incorporation of an exogenous factor derived from food.

Byres, Emma; Paton, Adrienne W.; Paton, James C.; Löfling, Jonas C.; Smith, David F.; Wilce, Matthew C.J.; Talbot, Ursula M.; Chong, Damien C.; Yu, Hai; Huang, Shengshu; Chen, Xi; Varki, Nissi M.; Varki, Ajit; Rossjohn, Jamie; Beddoe, Travis (Emory-MED); (UCD); (Adelaide); (Monash)



Incorporation of a non-human glycan mediates human susceptibility to a bacterial toxin.  


AB(5) toxins comprise an A subunit that corrupts essential eukaryotic cell functions, and pentameric B subunits that direct target-cell uptake after binding surface glycans. Subtilase cytotoxin (SubAB) is an AB(5) toxin secreted by Shiga toxigenic Escherichia coli (STEC), which causes serious gastrointestinal disease in humans. SubAB causes haemolytic uraemic syndrome-like pathology in mice through SubA-mediated cleavage of BiP/GRP78, an essential endoplasmic reticulum chaperone. Here we show that SubB has a strong preference for glycans terminating in the sialic acid N-glycolylneuraminic acid (Neu5Gc), a monosaccharide not synthesized in humans. Structures of SubB-Neu5Gc complexes revealed the basis for this specificity, and mutagenesis of key SubB residues abrogated in vitro glycan recognition, cell binding and cytotoxicity. SubAB specificity for Neu5Gc was confirmed using mouse tissues with a human-like deficiency of Neu5Gc and human cell lines fed with Neu5Gc. Despite lack of Neu5Gc biosynthesis in humans, assimilation of dietary Neu5Gc creates high-affinity receptors on human gut epithelia and kidney vasculature. This, and the lack of Neu5Gc-containing body fluid competitors in humans, confers susceptibility to the gastrointestinal and systemic toxicities of SubAB. Ironically, foods rich in Neu5Gc are the most common source of STEC contamination. Thus a bacterial toxin's receptor is generated by metabolic incorporation of an exogenous factor derived from food. PMID:18971931

Byres, Emma; Paton, Adrienne W; Paton, James C; Löfling, Jonas C; Smith, David F; Wilce, Matthew C J; Talbot, Ursula M; Chong, Damien C; Yu, Hai; Huang, Shengshu; Chen, Xi; Varki, Nissi M; Varki, Ajit; Rossjohn, Jamie; Beddoe, Travis



Incorporation of a non-human glycan mediates human susceptibility to a bacterial toxin  

PubMed Central

AB5 toxins comprise an A subunit that corrupts essential eukaryotic cell functions, and pentameric B subunits that direct target cell uptake after binding surface glycans. Subtilase cytotoxin (SubAB) is an AB5 toxin secreted by Shiga toxigenic Escherichia coli (STEC)1, which causes serious gastrointestinal disease in humans2. SubAB causes haemolytic uraemic syndrome-like pathology in mice3 via SubA-mediated cleavage of BiP/GRP78, an essential endoplasmic reticulum chaperone4. Here we show that SubB has a strong preference for glycans terminating in the sialic acid N-glycolylneuraminic acid (Neu5Gc), a monosaccharide not synthesised in humans. Structures of SubB-Neu5Gc complexes revealed the basis for this specificity, and mutagenesis of key SubB residues abrogated in vitro glycan recognition, cell binding and cytotoxicity. SubAB specificity for Neu5Gc was confirmed using mouse tissues with a human-like deficiency of Neu5Gc and human cell lines fed with Neu5Gc. Despite human lack of Neu5Gc biosynthesis, assimilation of dietary Neu5Gc creates high-affinity receptors on human gut epithelia and kidney vasculature. This, together with the human lack of Neu5Gc-containing body fluid competitors, confers susceptibility to the gastrointestinal and systemic toxicities of SubAB. Ironically, foods rich in Neu5Gc are the most common source of STEC contamination. Thus a bacterial toxin’s receptor is generated by metabolic incorporation of an exogenous factor derived from food.

Byres, Emma; Paton, Adrienne W.; Paton, James C.; Lofling, Jonas C.; Smith, David F.; Wilce, Matthew C.J.; Talbot, Ursula M.; Chong, Damien C.; Yu, Hai; Huang, Shengshu; Chen, Xi; Varki, Nissi M.; Varki, Ajit; Rossjohn, Jamie; Beddoe, Travis



Oxidative stress enhances IL-8 and inhibits CCL20 production from intestinal epithelial cells in response to bacterial flagellin.  


Intestinal epithelial cells act as innate immune sentinels, as the first cells that encounter diarrheal pathogens. They use pattern recognition molecules such as the Toll-like receptors (TLRs) to identify molecular signals found on microbes but not host cells or food components. TLRs cannot generally distinguish the molecular signals on pathogenic bacteria from those found in commensals, yet under healthy conditions epithelial immune responses are kept in check. We hypothesized that, in the setting of tissue damage or stress, intestinal epithelial cells would upregulate their responses to TLR ligands to reflect the greater need for immediate protection against pathogens. We treated Caco-2 cells with the TLR5 agonist flagellin in the presence or absence of H(2)O(2) and measured chemokine production and intracellular signaling pathways. H(2)O(2) increased flagellin-induced IL-8 (CXCL8) production in a dose-dependent manner. This was associated with synergistic phosphorylation of p38 MAP kinase and with prolonged I-kappaB degradation and NF-kappaB activation. The H(2)O(2)-mediated potentiation of IL-8 production required the activity of p38, tyrosine kinases, phospholipase Cgamma, and intracellular calcium, but not protein kinase C or protein kinase D. H(2)O(2) prolonged and augmented NF-kappaB activation by flagellin. In contrast to IL-8, CCL20 (MIP3alpha) production by flagellin was reduced by H(2)O(2), and this effect was not calcium dependent. Oxidative stress biases intestinal epithelial responses to flagellin, leading to increased production of IL-8 and decreased production of CCL20. This suggests that epithelial cells are capable of sensing the extracellular environment and adjusting their antimicrobial responses accordingly. PMID:20595617

Ivison, Sabine M; Wang, Ce; Himmel, Megan E; Sheridan, Jared; Delano, Jonathan; Mayer, Matt L; Yao, Yu; Kifayet, Arnawaz; Steiner, Theodore S



The High Affinity IgE Receptor Fc?RI Is Expressed by Human Intestinal Epithelial Cells  

PubMed Central

Background IgE antibodies play a paramount role in the pathogenesis of various intestinal disorders. To gain insights in IgE-mediated pathophysiology of the gut, we investigated the expression of the high affinity IgE receptor Fc?RI in human intestinal epithelium. Methodology/Principal Findings Fc?RI ?-chain, as detected by immunohistochemistry, was positive in epithelial cells for eight of eleven (8/11) specimens from colon cancer patients and 5/11 patients with inflammation of the enteric mucosa. The Fc?RI? positive epithelial cells co-expressed Fc?RI?, whereas with one exception, none of the samples was positive for the ?-chain in the epithelial layer. The functionality of Fc?RI was confirmed in situ by human IgE binding. In experiments with human intestinal tumor cell lines, subconfluent Caco-2/TC7 and HCT-8 cells were found to express the ?- and ?-chains of Fc?RI and to bind IgE, whereas confluent cells were negative for ?-chains. Conclusions/Significance Our data provide the first evidence that the components of a functional Fc?RI are in vitro expressed by the human intestinal epithelial cells depending on differentiation and, more importantly, in situ in epithelia of patients with colon cancer or gastrointestinal inflammations. Thus, a contribution of Fc?RI either to immunosurveillance or pathophysiology of the intestinal epithelium is suggested.

Starkl, Philipp; Bevins, Charles L.; Scheiner, Otto; Boltz-Nitulescu, George; Wrba, Fritz; Jensen-Jarolim, Erika



The Intestine Plays a Substantial Role in Human Vitamin B6 Metabolism: A Caco-2 Cell Model  

PubMed Central

Background Vitamin B6 is present in various forms (vitamers) in the diet that need to be metabolized to pyridoxal phosphate (PLP), the active cofactor form of vitamin B6. In literature, the liver has been reported to be the major site for this conversion, whereas the exact role of the intestine remains to be elucidated. Objective To gain insight into the role of the intestine in human vitamin B6 metabolism. Materials and Methods Expression of the enzymes pyridoxal kinase (PK), pyridox(am)ine phosphate oxidase (PNPO) and PLP-phosphatase was determined in Caco-2 cells and in lysates of human intestine. Vitamin B6 uptake, conversion and excretion were studied in polarized Caco-2 cell monolayers. B6 vitamer concentrations (pyridoxine (PN), pyridoxal (PL), PLP, pyridoxamine (PM), pyridoxamine phosphate (PMP)) and pyridoxic acid (PA) were quantified by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) using stable isotope-labeled internal standards. Results The enzymatic system involved in vitamin B6 metabolism (PK, PNPO and PLP-phosphatase) is fully expressed in Caco-2 cells as well as in human intestine. We show uptake of PN, PM and PL by Caco-2 cells, conversion of PN and PM into PL and excretion of all three unphosphorylated B6 vitamers. Conclusion We demonstrate, in a Caco-2 cell model, that the intestine plays a substantial role in human vitamin B6 metabolism.

Albersen, Monique; Bosma, Marjolein; Knoers, Nine V. V. A. M.; de Ruiter, Berna H. B.; Diekman, Eugene F.; de Ruijter, Jessica; Visser, Wouter F.; de Koning, Tom J.; Verhoeven-Duif, Nanda M.



Cyclic nucleotides regulate collagen production by human intestinal smooth muscle cells.  


The effect of cyclic nucleotides on collagen production by human intestinal smooth muscle cells was examined in vitro. Cholera toxin and isobutylmethylxanthine, agents that elevate cyclic adenosine monophosphate, caused selective inhibition of collagen production when cells were exposed to these agents for 24-72 h. Exposure for 6 h inhibited noncollagen protein synthesis without effects on collagen production. Forskolin similarly inhibited collagen production, decreasing relative collagen synthesis 40% at 10 microM and 60% at 100 microM. After 48 h of exposure to cholera toxin and isobutylmethylxanthine, levels of cyclic adenosine monophosphate had increased in a concentration-dependent manner. The effect of cyclic nucleotide analogues was also examined. Dibutyryl cyclic adenosine monophosphate inhibited collagen production, whereas dibutyryl cyclic guanosine monophosphate increased collagen production by 65%. This effect was maximal at a concentration of 10 microM. These observations suggest that cyclic adenosine monophosphate has a significant effect on collagen production by human intestinal smooth muscle cells in vitro and may play a role in the modulation of collagen production by these cells in vivo. PMID:2469616

Perr, H A; Graham, M F; Diegelmann, R F; Downs, R W



Cockroaches as carriers of human intestinal parasites in two localities in Ethiopia.  


A study was undertaken to assess the role of cockroaches as potential carriers of human intestinal parasites in Addis Ababa and Ziway, Ethiopia. A total of 6480 cockroaches were trapped from the two localities from October 2006 to March 2007. All the cockroaches trapped in Addis Ababa (n=2240) and almost 50% (2100/4240) of those trapped in Ziway were identified as Blattella germanica. The rest of the cockroaches trapped in Ziway were identified as Periplaneta brunnea (24.52%), Pycnoscelus surinamensis (16.03%) and Supella longipalpa (9.90%). Microscopic examination of the external body washes of pooled cockroaches and individual gut contents revealed that cockroaches are carriers of Entamoeba coli and Entamoeba histolytica/dispar cysts as well as Enterobius vermicularis, Trichuris trichiura, Taenia spp. and Ascaris lumbricoides ova. Besides their role as a nuisance, the present study further confirms that cockroaches serve as carriers of human intestinal parasites. The possible association of cockroaches with allergic conditions such as asthma is also discussed. Hence, appropriate control measures should be taken particularly to make hotels and residential areas free of cockroaches as they represent a health risk. PMID:18579170

Kinfu, Addisu; Erko, Berhanu



Human intestinal epithelial cells express functional cytokine receptors sharing the common gamma c chain of the interleukin 2 receptor.  

PubMed Central

Interleukin (IL) 2 signaling requires the dimerization of the IL-2 receptor beta (IL-2R beta) and common gamma (gamma c) chains. The gamma is also a component of the receptors for IL-4, IL-7, and IL-9. To assess the extent and role of the receptor signal transducing system utilizing the gamma c chain on human intestinal epithelial cells, the expression of gamma c, IL-2R beta, and receptor chains specific for IL-4, IL-7, and IL-9 was assessed by reverse transcription-coupled PCR on human intestinal epithelial cell lines and on isolated primary human intestinal epithelial cells. Caco-2, HT-29, and T-84 cells were found to express transcripts for the gamma c and IL-4R chains constitutively. IL-2R beta chain expression was demonstrated in Caco-2 and HT-29 but not in T-84 cells. None of the cell lines expressed mRNA for the IL-2R alpha chain. After stimulation with epidermal growth factor for 24 h Caco-2, HT-29, and T-84 cells expressed transcripts for IL-7R. In addition, Caco-2 and HT-29 cells expressed mRNA for the IL-9R. Receptors for IL-2, IL-4, IL-7, and IL-9 on intestinal epithelial cells lines appeared to be functional; stimulation with these cytokines caused rapid tyrosine phosphorylation of proteins. The relevance of the observations in intestinal epithelial cell lines for intestinal epithelial function in vivo was supported by the demonstration of transcripts for gamma c, IL-2R beta, IL-4R, IL-7R, and IL-9R in primary human intestinal epithelial cells. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7

Reinecker, H C; Podolsky, D K



Molecular mechanisms involved in the adaptive regulation of human intestinal biotin uptake: A study of the hSMVT system.  


Biotin, a water-soluble micronutrient, is vital for cellular functions, including growth and development. The human intestine utilizes the human sodium-dependent multivitamin transporter (hSMVT) for biotin uptake. Evidence exists showing that the intestinal biotin uptake process is adaptively regulated during biotin deficiency. Nothing, however, is known about molecular mechanism(s) involved during this adaptive regulation. This study compared two human-derived intestinal epithelial cell lines (HuTu-80 and Caco-2) during biotin-deficient or biotin-sufficient states and with an approach that assessed carrier-mediated biotin uptake, hSMVT protein and RNA levels, RNA stability, and hSMVT promoter activity. The results showed that during biotin deficiency, a significant and specific upregulation in carrier-mediated biotin uptake occurred in both human intestinal epithelial cell lines and that this increase was associated with an induction in protein and mRNA levels of hSMVT. The increase in mRNA levels was not due to an increase in RNA stability but was associated with an increase in activity of the hSMVT promoter in transfected human intestinal cells. Using promoter deletion constructs and mutational analysis in transiently transfected HuTu-80 and Caco-2 cells, a biotin deficiency-responsive region was mapped to a 103-bp area within the hSMVT promoter that contains gut-enriched Kruppel-like factor (GKLF) sites that confer the response to biotin deficiency. These results confirm that human intestinal biotin uptake is adaptively regulated and provide novel evidence demonstrating that the upregulation is not mediated via changes in hSMVT RNA stability but rather is due to transcriptional regulatory mechanism(s) that likely involve GKLF sites in the hSMVT promoter. PMID:16959947

Reidling, Jack C; Nabokina, Svetlana M; Said, Hamid M



Transport of Chitosan-DNA nanoparticles in human intestinal M-cell model versus normal intestinal enterocytes  

PubMed Central

Oral vaccination is one of the most promising applications of polymeric nanoparticles. Using two different in vitro cellular models to partially reproduce the characteristics of intestinal enterocytes and M-cells, this study demonstrates that nanoparticle transport through the M-cell co-culture model is 5 fold that of the intestinal epithelial monolayer, with at least 80% of the chitosan-DNA nanoparticles uptaken in the first 30 minutes. Among the properties of nanoparticles studied, ligand decoration has the most dramatic effect on the transcytosis rate: transferrin modification enhances transport through both models by 3–5 fold. The stability of the nanoparticles also affects transport kinetics. Factors which de-stabilize the nanoparticles, such as low charge (N/P) ratio and addition of serum, result in aggregation and in turn decreases transport efficiency. Of these stability factors, luminal pH is of great interest as an increase in pH from 5.5 to 6.4 and 7.4 leads to a 3 and 10 fold drop in nanoparticle transport respectively. Since soluble chitosan can act as an enhancer to increase paracellular transport by up to 60%, this decrease is partially attributed to the soluble chitosan precipitating near neutral pH. The implication that chitosan-DNA nanoparticles are more stable in the upper regions of the small intestine suggests that higher uptake rates may occur in the duodenum compared to the ileum and the colon.

Kadiyala, Irina; Loo, Yihua; Roy, Krishnendu; Rice, Janet; Leong, Kam W.



Morphine Induces Bacterial Translocation in Mice by Compromising Intestinal Barrier Function in a TLR-Dependent Manner  

PubMed Central

Opiates are among the most prescribed drugs for pain management. However, morphine use or abuse results in significant gut bacterial translocation and predisposes patients to serious infections with gut origin. The mechanism underlying this defect is still unknown. In this report, we investigated the mechanisms underlying compromised gut immune function and bacterial translocation following morphine treatment. We demonstrate significant bacterial translocation to mesenteric lymph node (MLN) and liver following morphine treatment in wild-type (WT) animals that was dramatically and significantly attenuated in Toll-like receptor (TLR2 and 4) knockout mice. We further observed significant disruption of tight junction protein organization only in the ileum but not in the colon of morphine treated WT animals. Inhibition of myosin light chain kinase (MLCK) blocked the effects of both morphine and TLR ligands, suggesting the role of MLCK in tight junction modulation by TLR. This study conclusively demonstrates that morphine induced gut epithelial barrier dysfunction and subsequent bacteria translocation are mediated by TLR signaling and thus TLRs can be exploited as potential therapeutic targets for alleviating infections and even sepsis in morphine-using or abusing populations.

Meng, Jingjing; Yu, Haidong; Ma, Jing; Wang, Jinghua; Banerjee, Santanu; Charboneau, Rick; Barke, Roderick A.; Roy, Sabita



Dysfunctions at human intestinal barrier by water-borne protozoan parasites: lessons from cultured human fully differentiated colon cancer cell lines.  


Some water-borne protozoan parasites induce diseases through their membrane-associated functional structures and virulence factors that hijack the host cellular molecules and signalling pathways leading to structural and functional lesions in the intestinal barrier. In this Microreview we analyse the insights on the mechanisms of pathogenesis of Entamoeba intestinalis, Giardia and Cryptosporidium observed in the human colon carcinoma fully differentiated colon cancer cell lines, cell subpopulations and clones expressing the structural and functional characteristics of highly specialized fully differentiated epithelial cells lining the intestinal epithelium and mimicking structurally and functionally an intestinal barrier. PMID:23437821

Liévin-Le Moal, Vanessa



Tryptophan from human milk induces oxidative stress and upregulates the Nrf-2-mediated stress response in human intestinal cell lines.  


Chemical screening of digested human milk protein using the oxygen radical absorbance capacity (ORAC(FL)) antioxidant assay confirmed the presence of a peptide fraction (PF23) with high antioxidant activity [5.53 mmol Trolox equivalents (TE)/g] that contained tryptophan as a main component. We evaluated the effects of both PF23 and tryptophan alone on the modulation of oxidative stress in cultured intestinal cells using a dichlorofluorescein diacetate probe. Despite the high ORAC(FL) value, PF23 enhanced (P < 0.05) 2, 2'-azobis (2-amidinopropane) dihydrochloride (peroxyl radical generator)-induced intracellular oxidation in the Caco-2 human adenocarcinoma cell line, suggesting prooxidant activity. Compared to selected peptide fractions with relatively lower ORAC(FL) values, PF23 induced oxidative stress more than all other peptide fractions tested (P < 0.05) and contained more tryptophan than the others (P < 0.05). Similar prooxidant activity was observed for tryptophan when it was added to culture medium for both the Caco-2 cells and FHs 74 Int primary fetal enterocytes, while also exhibiting a high ORAC(FL) value (9.69 mmol TE/g). The effect of tryptophan that involves activation of the Nrf-2 pathway and transcription of antioxidant enzymes was therefore investigated in FHs 74 Int cells. Exposure of infant intestinal cells to tryptophan resulted in Nrf-2 activation and an increase in the gene transcript level of glutathione peroxidase 2. We conclude that tryptophan-induced oxidative stress associated with tryptophan-containing milk peptides induces an adaptive response that involves the activation of the antioxidant responsive signaling pathway in intestinal cells. PMID:21677072

Elisia, Ingrid; Tsopmo, Apollinaire; Friel, James K; Diehl-Jones, William; Kitts, David D



Consumption of milk from transgenic goats expressing human lysozyme in the mammary gland results in the modulation of intestinal microflora  

Microsoft Academic Search

Lysozyme is a key antimicrobial component of human milk that has several health-promoting functions including the development\\u000a of a healthy intestinal tract. However, levels of lysozyme in the milk of dairy animals are negligible. We have generated\\u000a transgenic dairy goats that express human lysozyme (HLZ) in their milk in an attempt to deliver the benefits of human milk\\u000a in a

Elizabeth A. Maga; Richard L. Walker; Gary B. Anderson; James D. Murray



Mechanism of riboflavine uptake by Caco-2 human intestinal epithelial cells.  


The cellular and molecular regulation of intestinal absorption of the water-soluble vitamin riboflavine (RF) is poorly understood. The availability of a suitable in vitro cultured system that possesses the transport characteristics of the native intestinal absorptive cells would provide a powerful means to address this issue. In this study, we examined RF uptake by the human-derived cultured Caco-2 intestinal epithelial cells. RF uptake was Na+ and pH independent and occurred without metabolic alterations of the transported RF. Initial rate of RF uptake was temperature dependent and saturable as a function of concentration at 37 degrees C but not at 4 degrees C (apparent Michaelis constant = 0.30 +/- 0.03 microM, maximal velocity = 209.90 +/- 24.40 protein-1.3 min-1). Unlabeled RF, lumiflavine, 8-amino-riboflavine, isoriboflavine, and lumichrome in the incubation solution caused significant inhibition of RF uptake. RF uptake was also energy dependent and was sensitive to the inhibitory effect of sulfhydryl group reagents. The membrane transport inhibitor amiloride, but not 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid, 4-acetamide-4'-isothiocyanostilbene-2,2'-disulfonic acid, furosemide, or probenecid, inhibited RF uptake in a competitive (inhibitory constant = 0.48 mM) and reversible manner. Growing Caco-2 monolayers in a RF-deficient and oversupplemented media caused significant up- and downregulation of RF uptake, respectively. These results demonstrate the existence of a carrier-mediated system for RF uptake by Caco-2 cells and provide new information regarding amiloride sensitivity, involvement of sulfhydryl groups, and up- and downregulation by the substrate level and clarify the controversy regarding the role of Na+ in the uptake process.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8304455

Said, H M; Ma, T Y



Cholinergic signaling inhibits oxalate transport by human intestinal T84 cells  

PubMed Central

Urolithiasis remains a very common disease in Western countries. Seventy to eighty percent of kidney stones are composed of calcium oxalate, and minor changes in urinary oxalate affect stone risk. Intestinal oxalate secretion mediated by anion exchanger SLC26A6 plays a major constitutive role in limiting net absorption of ingested oxalate, thereby preventing hyperoxaluria and calcium oxalate urolithiasis. Using the relatively selective PKC-? inhibitor rottlerin, we had previously found that PKC-? activation inhibits Slc26a6 activity in mouse duodenal tissue. To identify a model system to study physiologic agonists upstream of PKC-?, we characterized the human intestinal cell line T84. Knockdown studies demonstrated that endogenous SLC26A6 mediates most of the oxalate transport by T84 cells. Cholinergic stimulation with carbachol modulates intestinal ion transport through signaling pathways including PKC activation. We therefore examined whether carbachol affects oxalate transport in T84 cells. We found that carbachol significantly inhibited oxalate transport by T84 cells, an effect blocked by rottlerin. Carbachol also led to significant translocation of PKC-? from the cytosol to the membrane of T84 cells. Using pharmacological inhibitors, we observed that carbachol inhibits oxalate transport through the M3 muscarinic receptor and phospholipase C. Utilizing the Src inhibitor PP2 and phosphorylation studies, we found that the observed regulation downstream of PKC-? is partially mediated by c-Src. Biotinylation studies revealed that carbachol inhibits oxalate transport by reducing SLC26A6 surface expression. We conclude that carbachol negatively regulates oxalate transport by reducing SLC26A6 surface expression in T84 cells through signaling pathways including the M3 muscarinic receptor, phospholipase C, PKC-?, and c-Src.

Cheng, Ming; Aronson, Peter S.



Intestinal microbiology in early life: specific prebiotics can have similar functionalities as human-milk oligosaccharides.  


Human milk is generally accepted as the best nutrition for newborns and has been shown to support the optimal growth and development of infants. On the basis of scientific insights from human-milk research, a specific mixture of nondigestible oligosaccharides has been developed, with the aim to improve the intestinal microbiota in early life. The mixture has been extensively studied and has been shown to be safe and to have potential health benefits that are similar to those of human milk. The specific mixture of short-chain galacto-oligosaccharides and long-chain fructo-oligosaccharides has been found to affect the development of early microbiota and to increase the Bifidobacterium amounts as observed in human-milk-fed infants. The resulting gut ecophysiology is characterized by high concentrations of lactate, a slightly acidic pH, and specific short-chain fatty acid profiles, which are high in acetate and low in butyrate and propionate. Here, we have summarized the main findings of dietary interventions with these specific oligosaccharides on the gut microbiota in early life. The gut ecophysiology in early life may have consequences for the metabolic, immunologic, and even neurologic development of the child because reports increasingly substantiate the important function of gut microbes in human health. This review highlights major findings in the field of early gut colonization and the potential impact of early nutrition in healthy growth and development. PMID:23824728

Oozeer, Raish; van Limpt, Kees; Ludwig, Thomas; Ben Amor, Kaouther; Martin, Rocio; Wind, Richèle D; Boehm, Günther; Knol, Jan



Role of Intestinal Microbiota in Transformation of Bismuth and Other Metals and Metalloids into Volatile Methyl and Hydride Derivatives in Humans and Mice  

Microsoft Academic Search

The present study shows that feces samples of 14 human volunteers and isolated gut segments of mice (small intestine, cecum, and large intestine) are able to transform metals and metalloids into volatile derivatives ex situ during anaerobic incubation at 37°C and neutral pH. Human feces and the gut of mice exhibit highly productive mechanisms for the formation of the toxic

Klaus Michalke; Annette Schmidt; Britta Huber; Jorg Meyer; Margareta Sulkowski; Alfred V. Hirner; Jens Boertz; Frank Mosel; Philip Dammann; Gero Hilken; Hans J. Hedrich; Martina Dorsch; Albert W. Rettenmeier; Reinhard Hensel



Protamine selectively inhibits collagen synthesis by human intestinal smooth muscle cells and other mesenchymal cells.  


Collagen synthesis is a major function of human intestinal smooth muscle (HISM) cells and contributes to intestinal fibrosis in chronic inflammatory bowel disease. As an extension of previous in vitro studies of the role of heparin in regulating HISM cell proliferation and collagen synthesis, the effect of protamine sulfate was studied. Protamine decreased collagen production by 50% in confluent and proliferating cultures. This effect was concentration-dependent and was selective for collagen in that neither noncollagen production nor DNA accumulation in the culture plates was affected. Other human mesenchymal cells which produce collagen, such as dermal fibroblasts and aortic smooth muscle cells, responded to protamine in a similar fashion. Protamine has a strong cationic charge and is rich in lysine and arginine. To determine which of these properties was important in decreasing collagen production, the effect of protamine was compared to that of other polyionic compounds. Poly-L-lysine decreased collagen production to a lesser degree than protamine. Poly-L-arginine was toxic to the cells. Poly-L-glutamic acid, which has an opposite charge to protamine, had no effect. These findings suggest that both the number and the arrangement of lysyl residues, in addition to positive charge, are important. Binding assays demonstrated that protamine did not inhibit collagen production by binding to ascorbate in the culture medium. Electrophoretic separation and chromatography of collagen types expressed following protamine treatment showed that the ratio of type I to type III collagen remained 2:1. This observation suggests that suppression of collagen production is not specific to a particular collagen type. The selective inhibition of collagen production by protamine provides an important tool to study the regulation of collagen production in human cells and may also provide potential therapy of fibrotic disorders. PMID:2777885

Perr, H A; Drucker, D E; Cochran, D L; Diegelmann, R F; Lindblad, W J; Graham, M F



Vitamin A metabolism in the human intestinal Caco-2 cell line  

SciTech Connect

The human intestinal Caco-2 cell line, described as enterocyte-like in a number of studies, was examined for its ability to carry out the metabolism of vitamin A normally required in the absorptive process. Caco-2 cells contained cellular retinol-binding protein II, a protein which is abundant in human villus-associated enterocytes and may play an important role in the absorption of vitamin A. Microsomal preparations from Caco-2 cells contained retinal reductase, acyl-CoA-retinol acyltransferase (ARAT), and lecithin-retinol acyltransferase (LRAT) activites, which have previously been proposed to be involved in the metabolism of dietary vitamin A in the enterocyte. When intact Caco-2 cells were provided with {beta}-carotene, retinyl acetate, or retinyl acetate, or retinol, synthesis of retinyl palmitoleate, oleate, palmitate, and small amounts of stearate resulted. However, exogenous retinyl palmitate or stearate was not used by Caco-2 cells as a source of retinol for ester synthesis. While there was a disproportionate synthesis of monoenoic fatty acid esters of retinol in Caco-2 cells compared to the retinyl esters typically found in human chylomicrons or the esters normally synthesized in rat intestine, the pattern was consistent with the substantial amount of unsaturated fatty acids, particularly 18:1 and 16:1, found in the sn-1 position of Caco-2 microsomal phosphatidylcholine, the fatty acyl donor for LRAT. Both ARAT and LRAT have been proposed to be responsible for retinyl ester synthesis in the enterocyte. These data suggest the LRAT may be the physiologically important enzyme for the esterification of retinol in Caco-2 cells.

Quick, T.C.; Ong, D.E. (Vanderbilt Univ. School of Medicine, Nashville, TN (USA))



Characterization of Slackia exigua Isolated from Human Wound Infections, Including Abscesses of Intestinal Origin ?  

PubMed Central

Eleven clinical strains isolated from infected wound specimens were subjected to polyphasic taxonomic analysis. Sequence analysis of the 16S rRNA gene showed that all 11 strains were phylogenetically related to Slackia exigua. Additionally, conventional and biochemical tests of 6 of the 11 strains were performed as supplementary methods to obtain phenotypic identification by comparison with the phenotypes of the relevant type strains. S. exigua has been considered an oral bacterial species in the family Coriobacteriaceae. This organism is fastidious and grows poorly, so it may easily be overlooked. The 16S rRNA gene sequences and the biochemical characteristics of four of the S. exigua strains isolated for this study from various infections indicative of an intestinal source were almost identical to those of the validated S. exigua type strain from an oral source and two of the S. exigua strains from oral sources evaluated in this study. Thus, we show for the first time that S. exigua species can be isolated from extraoral infections as well as from oral infections. The profiles of susceptibility to selected antimicrobials of this species were also investigated for the first time.

Kim, Keun-Sung; Rowlinson, Marie-Claire; Bennion, Robert; Liu, Chengxu; Talan, David; Summanen, Paula; Finegold, Sydney M.



Up-regulating the human intestinal microbiome using whole plant foods, polyphenols, and/or fiber.  


Whole plant foods, including fruit, vegetables, and whole grain cereals, protect against chronic human diseases such as heart disease and cancer, with fiber and polyphenols thought to contribute significantly. These bioactive food components interact with the gut microbiota, with gut bacteria modifying polyphenol bioavailability and activity, and with fiber, constituting the main energy source for colonic fermentation. This paper discusses the consequences of increasing the consumption of whole plant foods on the gut microbiota and subsequent implications for human health. In humans, whole grain cereals can modify fecal bacterial profiles, increasing relative numbers of bifidobacteria and lactobacilli. Polyphenol-rich chocolate and certain fruits have also been shown to increase fecal bifidobacteria. The recent FLAVURS study provides novel information on the impact of high fruit and vegetable diets on the gut microbiota. Increasing whole plant food consumption appears to up-regulate beneficial commensal bacteria and may contribute toward the health effects of these foods. PMID:22607578

Tuohy, Kieran M; Conterno, Lorenza; Gasperotti, Mattia; Viola, Roberto



Structure, biosynthesis, and glycosylation of human small intestinal maltase-glucoamylase.  


Maltase-glucoamylase (MGA) was immunoprecipitated from detergent extracts of brush border membranes of the human small intestinal mucosa. Electrophoretic analysis of the precipitates under denaturing conditions revealed a single polypeptide of Mr = 335,000 in the presence or absence of reducing agents. Cross-linking of brush border membranes with the homobifunctional reagent dithiobis(succinimidylpropionate) did not result in considerable changes in the electrophoretic pattern of MGA. In contrast, aminopeptidase N, used in these studies as a control glycoprotein of the brush border membrane revealed dimeric structures of its single subunit in the presence of dithiobis(succinimidylpropionate). These data suggest that MGA is expressed in the human small intestinal brush border as a monomeric polypeptide. The biosynthesis of MGA was studied by pulse-labeling of human intestinal biopsy specimens or mucosal explants in organ culture. Continuous labeling with [35S]methionine for 30 min revealed a single polypeptide high mannose precursor of Mr = 285,000 (MGAh) which matures after 4 h of labeling to the Mr = 335,000 as judged by the susceptibility of these two forms to endo-beta-N-acetylglucosaminidase H. Owing to the absence of pancreatic secretions in the culture medium and the isolation of an identical species from nonlabeled mucosa, this result indicates that the Mr = 335,000 does not undergo an in situ extracellular cleavage by intraluminal proteases. Further, biosynthetically labeled, intracellularly cleaved polypeptides corresponding to the high mannose precursor or mature forms of MGA were not detected. The mature form of MGA (MGAm) bears in addition to N-linked glycans also O-glycosidically linked oligosaccharides. In fact, endo-beta-N-acetylglucosaminidase F/glycopeptidase F treatment of MGAm followed by chemical deglycosylation with trifluoromethanesulfonic acid revealed approximately 35,000 daltons of O-linked sugars. Furthermore, MGAm as well as its N-linked sugars-depleted form bound to Helix pomatia lectin which has specificity toward Gal-GalNAc structures. In addition, the data were suggestive of a post-translational O-glycosylation of the molecule since (i) the high mannose precursor of MGA did not bind to H. pomatia lectin and (ii) its endo-beta-N-acetylglucosaminidase H or endo-beta-N-acetylglucosaminidase F/glycopeptidase F form displayed an apparent molecular weight similar to that obtained upon endo-beta-N-acetylglucosaminidase F/glycopeptidase F/trifluoromethanesulfonic acid deglycosylation. Finally, pulse-chase experiments revealed a relatively slow rate of post-translational processing of MGA in comparison to aminopeptidase N.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:3143729

Naim, H Y; Sterchi, E E; Lentze, M J



Interferon Gamma-Dependent Intestinal Pathology Contributes to the Lethality in Bacterial Superantigen-Induced Toxic Shock Syndrome  

PubMed Central

Toxic shock syndrome (TSS) caused by the superantigen exotoxins of Staphylococcus aureus and Streptococcus pyogenes is characterized by robust T cell activation, profound elevation in systemic levels of multiple cytokines, including interferon-? (IFN-?), followed by multiple organ dysfunction and often death. As IFN-? possesses pro- as well as anti-inflammatory properties, we delineated its role in the pathogenesis of TSS. Antibody-mediated in vivo neutralization of IFN-? or targeted disruption of IFN-? gene conferred significant protection from lethal TSS in HLA-DR3 transgenic mice. Following systemic high dose SEB challenge, whereas the HLA-DR3.IFN-?+/+ mice became sick and succumbed to TSS, HLA-DR3.IFN-??/? mice appeared healthy and were significantly protected from SEB-induced lethality. SEB-induced systemic cytokine storm was significantly blunted in HLA-DR3.IFN-??/? transgenic mice. Serum concentrations of several cytokines (IL-4, IL-10, IL-12p40 and IL-17) and chemokines (KC, rantes, eotaxin and MCP-1) were significantly lower in HLA-DR3.IFN-??/? transgenic mice. However, SEB-induced T cell expansion in the spleens was unaffected and expansion of SEB-reactive TCR V?8+ CD4+ and CD8+ T cells was even more pronounced in HLA-DR3.IFN-??/? transgenic mice when compared to HLA-DR3.IFN-?+/+ mice. A systematic histopathological examination of several vital organs revealed that both HLA-DR3.IFN-?+/+ and HLA-DR3.IFN-??/? transgenic mice displayed comparable severe inflammatory changes in lungs, and liver during TSS. Remarkably, whereas the small intestines from HLA-DR3.IFN-?+/+ transgenic mice displayed significant pathological changes during TSS, the architecture of small intestines in HLA-DR3.IFN-??/? transgenic mice was preserved. In concordance with these histopathological changes, the gut permeability to macromolecules was dramatically increased in HLA-DR3.IFN-?+/+ but not HLA-DR3.IFN-??/? mice during TSS. Overall, IFN-? seemed to play a lethal role in the immunopathogenesis of TSS by inflicting fatal small bowel pathology. Our study thus identifies the important role for IFN-? in TSS.

Tilahun, Ashenafi Y.; Holz, Marah; Wu, Tsung-Teh; David, Chella S.; Rajagopalan, Govindarajan



XBP1 links ER stress to intestinal inflammation and confers genetic risk for human inflammatory bowel disease  

PubMed Central

Summary Inflammatory bowel disease (IBD) has been attributed to aberrant mucosal immunity to the intestinal microbiota. The transcription factor XBP1, a key component of the endoplasmic reticulum (ER) stress response, is required for development and maintenance of secretory cells and linked to JNK activation. We report that XBP1 deletion in intestinal epithelial cells (IEC) results in spontaneous enteritis and increased susceptibility to induced colitis secondary to both Paneth cell deficiency and overactive responses of the intestinal epithelial cell (IEC) to the IBD-inducers, TNF? and flagellin. An association of XBP1 variants with human IBD was identified and replicated (rs35873774, P-value 1.6×10?5) with novel, private hypomorphic variants identified as susceptibility factors. Hence, intestinal inflammation can originate solely from XBP1 abnormalities in IEC thus linking cell-specific ER stress to the induction of organ-specific inflammation. We report the first mouse model of spontaneous intestinal inflammation arising from alterations in a genetic risk factor for human IBD.

Kaser, Arthur; Lee, Ann-Hwee; Franke, Andre; Glickman, Jonathan N.; Zeissig, Sebastian; Tilg, Herbert; Nieuwenhuis, Edward E.S.; Higgins, Darren E.; Schreiber, Stefan; Glimcher, Laurie H.; Blumberg, Richard S.



Enterohemorrhagic Escherichia coli induce attaching and effacing lesions and hemorrhagic colitis in human and bovine intestinal xenograft models.  


Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is an important cause of diarrhea, hemorrhagic colitis and hemolytic uremic syndrome in humans worldwide. The two major virulence determinants of EHEC are the Shiga toxins (Stx) and the type III secretion system (T3SS), including the injected effectors. Lack of a good model system hinders the study of EHEC virulence. Here, we investigated whether bovine and human intestinal xenografts in SCID mice can be useful for studying EHEC and host tissue interactions. Fully developed, germ-free human and bovine small intestine and colon were established by subcutaneous transplantation of human and bovine fetal gut into SCID mice. Xenografts were allowed to develop for 3-4 months and thereafter were infected by direct intraluminal inoculation of Stx-negative derivatives of EHEC O157:H7, strain EDL933. The small intestine and colon xenografts closely mimicked the respective native tissues. Upon infection, EHEC induced formation of typical attaching and effacing lesions and tissue damage that resembled hemorrhagic colitis in colon xenografts. By contrast, xenografts infected with an EHEC mutant deficient in T3SS remained undamaged. Furthermore, EHEC did not attach to or damage the epithelium of small intestinal tissue, and these xenografts remained intact. EHEC damaged the colon in a T3SS-dependent manner, and this model is therefore useful for studying the molecular details of EHEC interactions with live human and bovine intestinal tissue. Furthermore, we demonstrate that Stx and gut microflora are not essential for EHEC virulence in the human gut. PMID:20959635

Golan, Lilach; Gonen, Erez; Yagel, Simcha; Rosenshine, Ilan; Shpigel, Nahum Y



Enterohemorrhagic Escherichia coli induce attaching and effacing lesions and hemorrhagic colitis in human and bovine intestinal xenograft models  

PubMed Central

SUMMARY Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is an important cause of diarrhea, hemorrhagic colitis and hemolytic uremic syndrome in humans worldwide. The two major virulence determinants of EHEC are the Shiga toxins (Stx) and the type III secretion system (T3SS), including the injected effectors. Lack of a good model system hinders the study of EHEC virulence. Here, we investigated whether bovine and human intestinal xenografts in SCID mice can be useful for studying EHEC and host tissue interactions. Fully developed, germ-free human and bovine small intestine and colon were established by subcutaneous transplantation of human and bovine fetal gut into SCID mice. Xenografts were allowed to develop for 3–4 months and thereafter were infected by direct intraluminal inoculation of Stx-negative derivatives of EHEC O157:H7, strain EDL933. The small intestine and colon xenografts closely mimicked the respective native tissues. Upon infection, EHEC induced formation of typical attaching and effacing lesions and tissue damage that resembled hemorrhagic colitis in colon xenografts. By contrast, xenografts infected with an EHEC mutant deficient in T3SS remained undamaged. Furthermore, EHEC did not attach to or damage the epithelium of small intestinal tissue, and these xenografts remained intact. EHEC damaged the colon in a T3SS-dependent manner, and this model is therefore useful for studying the molecular details of EHEC interactions with live human and bovine intestinal tissue. Furthermore, we demonstrate that Stx and gut microflora are not essential for EHEC virulence in the human gut.

Golan, Lilach; Gonen, Erez; Yagel, Simcha; Rosenshine, Ilan; Shpigel, Nahum Y.



Bacterial steroidogenesis by periodontal pathogens and the effect of bacterial enzymes on steroid conversions by human gingival fibroblasts in culture.  


Studies were performed to investigate the effect of microbial culture supernatants of periodontal pathogens on the metabolism of radiolabelled testosterone in the presence or absence of human gingival fibroblasts. Subgingival plaque samples were obtained on paper points from 3 sites with probing depth values of 6-8 mm. Samples were incubated with 14C-testosterone for 24 h in brain heart infusion (BHI) broth. Similar incubations were also carried out with strains of A. actinomycetemcomitans, P. Intermedius and P. gingivalis to study the metabolism of radiolabelled testosterone by these periodontal pathogens. At the end of a 24 h incubation period with fibroblasts and supernatants or sonicates, the radioactive metabolites were extracted with ethyl acetate, evaporated and subjected to thin layer chromatography. The separated metabolites were quantified by scanning the radioactive plates using a Berthold linear analyser. When three sub-gingival plaque samples were incubated with radiolabelled testosterone there were 50-fold, 10-12-fold and 15-17-fold increases in 5 alpha-dihydrotestosterone (DHT) synthesis over 4-androstenedione production in these mixed microbial cultures. The two strains of P. intermedius produced 3- and 20-fold increases in 4-androstenedione production and DHT synthesis respectively. Both strains of A. actinomycetemcomitans and P. gingivalis showed 3-4-fold and 12-28-fold increases respectively in 4-androstenedione synthesis over that of DHT. Culture supernatants of P. intermedius and P. gingivalis caused 3-fold and 2-fold increases in DHT synthesis by fibroblasts over controls. There was little change in the case of the third pathogen. Since DHT has implications on matrix synthesis by fibroblasts in the environment of plaque associated inflammatory periodontal disease, bacterial metabolism and the effect of bacterial supernatants on human gingival fibroblasts can influence the degree of inflammatory repair. PMID:7776153

Soory, M



Bacterial vaginosis is associated with uterine cervical human papillomavirus infection: a meta-analysis  

Microsoft Academic Search

BACKGROUND: Bacterial vaginosis (BV), an alteration of vaginal flora involving a decrease in Lactobacilli and predominance of anaerobic bacteria, is among the most common cause of vaginal complaints for women of childbearing age. It is well known that BV has an influence in acquisition of certain genital infections. However, association between BV and cervical human papillomavirus (HPV) infection has been

Evy Gillet; Joris FA Meys; Hans Verstraelen; Carolyne Bosire; Philippe De Sutter; Marleen Temmerman; Davy Vanden Broeck



Changes in predominant bacterial populations in human faeces with age and with Clostridium difficile infection  

Microsoft Academic Search

The bacterial composition of human faeces can vary greatly with factors such as age and disease, although relatively few studies have monitored these events, particularly at species level. In this investigation, bacteria were isolated from faecal samples from healthy young adults and elderly subjects, and elderly patients with Clostridium difficile- associated diarrhoea (CDAD). The organisms were identified to species level




Human small intestinal epithelial cells constitutively express the key elements for antigen processing and the production of exosomes  

Microsoft Academic Search

In humans, the small intestinal epithelial cells (IEC) have a high constitutive expression of MHC class II (MHC II), and contains lysosomes. The IEC also contains MHC II rich multivesicular compartments and has been shown to produce exosomes. This suggests a role for the IEC in antigen processing and presentation either directly or indirectly by the production of exosomes. However,

X. P. Lin; N. Almqvist; E. Telemo



Growth-promoting Effect, Biological Activity, and Binding of Insulin in Human Intestinal Cancer Cells in Culture1  

Microsoft Academic Search

The biological action and binding of insulin were tested in two human intestinal cancer cell lines originating from the duodenum (HUTU 80) and the colon (HT 29). After serum deprivation for 24 hr, insulin stimulated cell division and the incorporation of labeled precursors into RNA, protein, and DMA for both cell lines. The action on the RNA and protein was

Jean-Pierre Cezard; Marie-Elisabeth Forgue-Lafitte; Marie-Claude Chamblier; Gabriel E. Rosselin


Secretor Genotype (FUT2 gene) Is Strongly Associated with the Composition of Bifidobacteria in the Human Intestine  

Microsoft Academic Search

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

Pirjo Wacklin; Harri Mäkivuokko; Noora Alakulppi; Janne Nikkilä; Heli Tenkanen; Jarkko Räbinä; Jukka Partanen; Kari Aranko; Jaana Mättö



A Drug Absorption Model Based on the Mucus Layer Producing Human Intestinal Goblet Cell Line HT29-H  

Microsoft Academic Search

A new drug absorption model based on monolayers of the human intestinal goblet cell line HT29-H grown on permeable filters has been characterized. HT29-H cells have been shown (a) to form monolayers of mature goblet cells under standard cell culture conditions, (b) to secrete mucin molecules, (c) to produce a mucus layer that covers the apical cell surface, and (d)

Agneta Wikman; Johan Karlsson; Ingemar Carlstedt; Per Artursson



Human intestinal bacterium, strain END-2 is responsible for demethylation as well as lactonization during plant lignan metabolism.  


A human intestinal bacterium, strain END-2, which enantioselectively oxidizes (+)-enterodiol (END) to (+)-enterolactone (ENL) through enterolactol is also responsible for demethylation during plant lignan metabolism. A free hydroxyl group adjacent to the methoxy group is required for demethylation. The bacterium transformed (+)- and (-)-secoisolariciresinol to (+)-ENL and (-)-END, respectively, by co-incubation with strain ARC-1, which is responsible for dehydroxylation. PMID:20686246

Jin, Jong-Sik; Hattori, Masao



Sodium Caprate Elicits Dilatations in Human Intestinal Tight Junctions and Enhances Drug Absorption by the Paracellular Route  

Microsoft Academic Search

The effects of the absorption enhancer sodium caprate on human intestinal epithelial cells were investigated using Caco-2 cell monolayers. The effects on epithelial integrity and drug transport are dependent on time and concentration and are decreased by Ca2+, most likely through the formation of Ca22+ soaps. Morphological data indicate that exposure to sodium caprate results in cytoskeletal changes and in

Eva Karin Anderberg; Tuulikki Lindmark; Per Artursson



Endocytosis in absorptive cells of cultured human small-intestinal tissue: Horseradish peroxidase, lactoperoxidase, and ferritin as markers  

Microsoft Academic Search

The occurrence of endocytotic mechanisms in human small intestinal absorptive cells was investigated by culturing biopsy specimens in the presence of horseradish peroxidase (HRP), lactoperoxidase (LPO), and ferritin. The results indicate that both HRP and LPO entered the cells by apical endocytosis, after which they were transported via apical vesicles and tubules to the lysosome-like bodies. Ferritin, which showed a

J. Blok; A. A. Mulder-Stapel; L. A. Ginsel; W. Th. Daems




EPA Science Inventory

Giardia lamblia trophozoites specifically colonize the upper human small intestine which is normally serum-free, but grow in vitro only in medium supplemented with serum or serum fractions. Recently, biliary lipids were shown to support the growth of G. lamblia without serum. Now...


The effect of oral administration of calcium and magnesium on intestinal oxalate absorption in humans.  


Calcium oxalate (CaOx) urolithiasis is the most common urinary stone disease (70-75 % of all stones consist of CaOx in countries with western diet). Oxalate is the most lithogenic substance in CaOx crystallisation in urine. Oxalate is either synthesized within the body or absorbed from food. As oxalate is not metabolized in the human body, it appears unchanged in urine. Conventional analysis methods cannot distinguish between endogenous and exogenous oxalate. Our [13C2]oxalate absorption test enabled measurement of intestinal oxalate absorption and quantification of the influence of Ca- and Mg-supplementation on it. The effects of the oral administration of these supplements were compared in order to obtain valid data for recommendations for CaOx urolithiasis patients. A 10 mmol supplement of both ions decreased the oxalate absorption significantly, calcium being more than twice as effective. PMID:15370283

Voss, Susanne; Zimmermann, Diana J; Hesse, Albrecht; von Unruh, Gerd E



Automatic segmentation and classification of human intestinal parasites from microscopy images.  


Human intestinal parasites constitute a problem in most tropical countries, causing death or physical and mental disorders. Their diagnosis usually relies on the visual analysis of microscopy images, with error rates that may range from moderate to high. The problem has been addressed via computational image analysis, but only for a few species and images free of fecal impurities. In routine, fecal impurities are a real challenge for automatic image analysis. We have circumvented this problem by a method that can segment and classify, from bright field microscopy images with fecal impurities, the 15 most common species of protozoan cysts, helminth eggs, and larvae in Brazil. Our approach exploits ellipse matching and image foresting transform for image segmentation, multiple object descriptors and their optimum combination by genetic programming for object representation, and the optimum-path forest classifier for object recognition. The results indicate that our method is a promising approach toward the fully automation of the enteroparasitosis diagnosis. PMID:22328170

Suzuki, Celso T N; Gomes, Jancarlo F; Falcão, Alexandre X; Papa, João P; Hoshino-Shimizu, Sumie



Predicting the impact of diet and enzymopathies on human small intestinal epithelial cells  

PubMed Central

Small intestinal epithelial cells (sIECs) have a significant share in whole body metabolism as they perform enzymatic digestion and absorption of nutrients. Furthermore, the diet plays a key role in a number of complex diseases including obesity and diabetes. The impact of diet and altered genetic backgrounds on human metabolism may be studied by using computational modeling. A metabolic reconstruction of human sIECs was manually assembled using the literature. The resulting sIEC model was subjected to two different diets to obtain condition-specific metabolic models. Fifty defined metabolic tasks evaluated the functionalities of these models, along with the respective secretion profiles, which distinguished between impacts of different dietary regimes. Under the average American diet, the sIEC model resulted in higher secretion flux for metabolites implicated in metabolic syndrome. In addition, enzymopathies were analyzed in the context of the sIEC metabolism. Computed results were compared with reported gastrointestinal (GI) pathologies and biochemical defects as well as with biomarker patterns used in their diagnosis. Based on our simulations, we propose that (i) sIEC metabolism is perturbed by numerous enzymopathies, which can be used to study cellular adaptive mechanisms specific for such disorders, and in the identification of novel co-morbidities, (ii) porphyrias are associated with both heme synthesis and degradation and (iii) disturbed intestinal gamma-aminobutyric acid synthesis may be linked to neurological manifestations of various enzymopathies. Taken together, the sIEC model represents a comprehensive, biochemically accurate platform for studying the function of sIEC and their role in whole body metabolism.

Sahoo, Swagatika; Thiele, Ines



Role of ascorbic acid in procollagen expression and secretion by human intestinal smooth muscle cells.  


The role of ascorbate in the production and secretion of procollagen by human intestinal smooth muscle cells and the conditions in culture for optimal ascorbate bioefficacy were studied. Procollagen synthesis and secretion were determined by the incubation of cells with L-[5-3H]proline, and the quantitation of radiolabelled procollagen bands in the cell layer and the culture medium by polyacrylamide slab gel electrophoresis and densitometry. When cells were cultured without ascorbate in the culture medium, procollagen secretion into the medium was 75% less than in cells receiving fresh ascorbate daily. In the cell layer, in contrast, procollagen accumulation was fourfold greater in the scorbutic cells than in the ascorbate-replete cells. These findings contrasted with those in a control line of scorbutic human dermal fibroblasts in which a 95% decrease in procollagen secretion was not associated with any procollagen accumulation in the cells. In the intestinal smooth muscle cells, the absence of ascorbate resulted in a 25 and 50% decrease in steady-state levels of procollagen I and III mRNA, respectively, compared to a 40 and 75% decrease in fibroblasts. Heat inactivation of the serum in the culture medium augmented the promotion of procollagen secretion by ascorbate two- to fourfold. L-ascorbate phosphate did not increase the activity of L-ascorbate when replaced in medium either daily or every 4 days, and its efficacy was not augmented by serum heat inactivation. The changing of culture medium induced collagen secretion in the absence of ascorbate, but this process was markedly enhanced by ascorbate and induced a transient decrease in the steady-state levels of both procollagen and nonprocollagen mRNAs. The predominant action of L-ascorbate on HISM cells in vitro is to promote procollagen secretion and not procollagen synthesis. L-ascorbate-phosphate is not an adequate substitute for L-ascorbate in this cell line. PMID:7822432

Graham, M F; Willey, A; Adams, J; Yager, D; Diegelmann, R F



Role of hydrogen peroxide in ACh-induced dilation of human submucosal intestinal microvessels.  


The endothelium plays an important role in maintaining vascular homeostasis by synthesizing and releasing several mediators of vasodilation, which include prostacyclin (PGI(2)), nitric oxide, and endothelium-derived hyperpolarizing factor (EDHF). We have recently defined the role of nitric oxide and PGI(2) in the dilation of submucosal intestinal arterioles from patients with normal bowel function. However, significant endothelium-dependent dilator capacity to ACh remained after inhibiting both these mediators. The current study was designed to examine the potential role of EDHF in human intestinal submucosal arterioles. ACh elicited endothelium-dependent relaxation in the presence of inhibitors of nitric oxide synthase and cyclooxygenase (23 +/- 10%, n = 6). This ACh-induced relaxation was inhibited and converted to constriction by catalase (-53 +/- 10%, n = 6) or KCl (-30 +/- 3%, n = 7), whereas 17-octadecynoic acid and 6-(2-propargylloxyphenyl) hexanoic acid, two inhibitors of cytochrome P450 monooxygenase, had no significant effect (3 +/- 1% and 20 +/- 8%, n = 5, respectively). Exogenous H(2)O(2) elicited dose-dependent relaxation of intact microvessels (52 +/- 10%, n = 7) but caused frank vasoconstriction in arterioles denuded of endothelium (-73 +/- 8%, n = 7). ACh markedly increased the dichlorofluorescein fluorescence in intact arterioles in the presence of nitric oxide synthase and cyclooxygenase inhibitors compared with control and compared with catalase-treated microvessels (363.6 +/- 49, 218.8 +/- 10.6, 221.9 +/- 27.9, respectively, P < 0.05 ANOVA, n = 5 arbitrary units). No changes in the dichlorofluorescein fluorescence were recorded in vessels treated with ACh alone. These results indicate that endothelial production of H(2)O(2) occurs in response to ACh in human gut mucosal arterioles but that H(2)O(2) is not an EDHF in this tissue. Rather, we speculate that it stimulates the release of a chemically distinct EDHF. PMID:15345486

Hatoum, Ossama A; Binion, David G; Miura, Hiroto; Telford, Gordon; Otterson, Mary F; Gutterman, David D



Functional bacterial opsonic activity of human amniotic fluid  

SciTech Connect

There are some data to suggest that amniotic fluid protects the fetus from invasion by pathogenic bacteria. To examine methods by which amniotic fluid may offer such protection, quantitative antibody, complement activity, and functional opsonic capacity were measured. Immunoglobulins were measured by laser nephelometry and total hemolytic complement was determined by radial diffusion; results suggested activity adequate for bactericidal capacity. The chemiluminescence assay was used to quantitate the functional interaction between polymorphonuclear leukocytes and E. coli, group B streptococci (GBS), or zymosan particles preopsonized with amniotic fluid obtained at different stages of gestation. Results were compared to those for normal serum. Data were analyzed by evaluation of the initial slope, area under the curve, and peak chemiluminescence response. Opsonic activity of amniotic fluid for E. coli and GBS was demonstrated, with E. coli showing greater reactivity (maximum . 15,000 to 25,000 cpm) than GBS (10,000 to 20,000 cpm). Specific, as well as nonspecific, opsonic activity was demonstrated by absorption of amniotic fluid with killed bacteria. Concentration of amniotic fluid did not result in an increase in chemiluminescent activity, which demonstrates that optimal opsonic activity already exists. The classical and alternate pathways of complement were assessed for E. coli and GBS. Preterm amniotic fluid did not differ in response from that of amniotic fluid obtained from term pregnancies. This study demonstrates that amniotic fluid can provide the fetus with protection from bacterial pathogens and delineates mechanisms for such protection.

Cone, M.J.; Steele, R.W.; Marmer, D.J.; Hill, D.E.



Homeostatic regulation of zinc transporters in the human small intestine by dietary zinc supplementation  

PubMed Central

Background: The role of intestinal transporter regulation in optimising nutrient absorption has been studied extensively in rodent and cell line models but not in human subjects. Aims: The aim of the present study was to investigate the response in vivo of zinc transporters in the human enterocyte to dietary zinc supplementation. Subjects: Eighteen patients who had previously undergone ileostomy, all free of any symptoms of inflammatory bowel disease. Methods: Subjects took a daily zinc supplement of 25 mg for 14 days in a double blind, placebo controlled, crossover trial. The effect of the supplement on expression in ileal biopsies of the zinc transporters SLC30A1, SLC30A4, SLC30A5, SLC39A1, SLC39A4, and metallothionein was measured by reverse transcription-polymerase chain reaction RT-PCR. Expression of SLC30A1, SLC30A5, and SLC39A4 was also examined by immunoblotting. Results: The zinc supplement reduced SLC30A1 mRNA (1.4-fold) together with SLC30A1, SLC30A5, and SLC39A4 protein (1.8-fold, 3.7-fold, and to undetectable levels, respectively) in ileal mucosa and increased metallothionein mRNA (1.7-fold). The supplement had no effect on expression of SLC30A4 or SLC39A1 mRNA. Localisation of SLC30A5 at the apical human enterocyte/colonocyte membrane and also at the apical membrane of Caco-2 cells was demonstrated by immunohistochemistry. Commensurate with these observations in zinc supplemented human subjects, SLC30A1, SLC30A5, and SLC39A4 mRNA and protein were reduced in Caco-2 cells cultured at 200 ?M compared with 100 ?M zinc. Conclusions: These observations indicate that, in response to variations in dietary zinc intakes, regulated expression of plasma membrane zinc transporters in the human intestine contributes to maintenance of zinc status.

Cragg, R A; Phillips, S R; Piper, J M; Varma, J S; Campbell, F C; Mathers, J C; Ford, D



Responsiveness of intestinal epithelial cell lines to lipopolysaccharide is correlated with Toll-like receptor 4 but not Toll-like receptor 2 or CD14 expression  

Microsoft Academic Search

Background and aims. Luminal bacteria have been implicated in the pathogenesis of inflammatory bowel diseases. Exposure of intestinal epithelial cells (IEC) to bacterial components potentially initiates intestinal inflammation by release of chemokines and recruitment of inflammatory cells. We analyzed receptor expression and signaling pathways involved in activation of human primary IEC and carcinoma-derived cell lines by lipopolysaccharide (LPS). Materials and

Ulrich Böcker; Oleksandr Yezerskyy; Peter Feick; Tobias Manigold; Asit Panja; Uwe Kalina; Frank Herweck; Siegbert Rossol; Manfred V. Singer



Construction and Characterization of a Human Bacterial Artificial Chromosome Library  

Microsoft Academic Search

We have constructed an arrayed human genomic BAC library with approximately 4× coverage that is represented by 96,000 BAC clones with average insert size of nearly 140 kb. A new BAC vector that allows color-based positive screening to identify transformants with inserts has increased BAC cloning efficiency. The library was gridded onto hybridization filters at high density for efficient identification

Ung-Jin Kim; Bruce W. Birren; Tatiana Slepak; Valeria Mancino; Cecilie Boysen; Hyung-Lyun Kang; Melvin I. Simon; Hiroaki Shizuya



Flagellated bacterial nanorobots for medical interventions in the human body  

Microsoft Academic Search

We show that a combination of various types of nanorobots will prove to be more important as we attend to enhance targeting in the smallest blood vessels found in the human microvasculature. As such, various interdependent concepts for the implementation of these different types of medical bio-nanorobots including nanorobots propelled in the microvasculature by flagellated bacteria to target deep regions

Sylvain Martel; Ouajdi Felfoul; M. Mohammadi



Vasoactive Intestinal Peptide Induction by Ciliary Neurotrophic Factor in Donor Human Corneal Endothelium in situ  

PubMed Central

After peripheral nerve axotomy, vasoactive intestinal peptide (VIP) gene expression is upregulated in neurons, whereas ciliary neurotrophic factor (CNTF) accumulates extracellularly at the lesion site. Although CNTF-induced VIP gene expression has been reported in cultured sympathetic neurons and neuroblastoma cells, it still remains to be determined if CNTF and VIP play interrelated roles in nerve injury. The corneal endothelium, like sympathetic neurons, derives from the neural crest. Previously, we demonstrated that a sublethal-level of oxidative stress induces CNTF release from corneal endothelial (CE) cells in situ. Here, we show that human CE cells express the 53kDa ligand-binding ? subunit of the CNTF receptor (CNTFR?). We further demonstrate that CNTF induces VIP immunoreactivity in human donor corneas. To determine if the increase in VIP immunoreactivity was reflected by an increase in gene expression, donor human corneas were bisected and treated with CNTF or vehicle, and analyzed by real-time RT-qPCR. Two experiments using different sets of bisected corneas indicated that CNTF induced increases in VIP mRNA levels of 6.5-fold ±2.2 (N=7 corneas) and 2.3-fold ±0.6 (N=10 corneas), (mean±SEM), respectively. Whereas VIP is produced as a CE autocrine factor against oxidative stress, the present study suggested that oxidative stress-released CNTF plays a role in protecting CE cells against oxidative stress injury by upregulating VIP expression.

Koh, Shay-Whey M.; Guo, Yan; Bernstein, Steve L.; Waschek, James A.; Liu, Xiuhuai; Symes, Aviva J



In vitro metabolism of quazepam in human liver and intestine and assessment of drug interactions.  


The study was carried out to identify and characterize kinetically the cytochrome P450 (CYP) enzymes responsible for the major metabolite formation of quazepam. In in vitro studies using human liver and intestinal microsomes and cDNA-expressed human CYP and FMO isoenzymes, quazepam was rapidly metabolized mainly by CYP3A4 and to a minor extent by CYP2C9, CYP2C19 and FMO1 to 2-oxoquazepam (OQ), which was then further biotransformed to N-desalkyl-2-oxoquazepam (DOQ) and to 3-hydroxy-2-oxoquazepam (HOQ) mainly by CYP3A4 and CYP2C9. CYP3A4 is the enzyme predominantly responsible for all the metabolic pathways of quazepam. Itraconazole inhibited the formation of OQ from quazepam, HOQ from OQ and DOQ from OQ in human liver microsomes with Ki values of 8.40, 0.08 and 0.39 microM, respectively. However, the Ki for OQ formation was greater than the peak plasma itraconazole concentration following a clinically relevant 200-mg oral dose to healthy volunteers. In addition, CYP2C9 and CYP2C19 inhibitors failed to inhibit OQ formation from quazepam. In conclusion, clinically relevant drug interaction with CYP inhibitors seem unlikely for the major metabolic pathway of quazepam to OQ. PMID:15801544

Miura, M; Ohkubo, T


Differential modulation of human intestinal bifidobacterium populations after consumption of a wild blueberry (Vaccinium angustifolium) drink.  


Bifidobacteria are gaining increasing interest as health-promoting bacteria. Nonetheless, the genus comprises several species, which can exert different effects on human host. Previous studies showed that wild blueberry drink consumption could selectively increase intestinal bifidobacteria, suggesting an important role for the polyphenols and fiber present in wild blueberries. This study evaluated the modulation of the most common and abundant bifidobacterial taxonomic groups inhabiting the human gut in the same fecal samples. The analyses carried out showed that B. adolescentis, B. breve, B. catenulatum/pseudocatelulatum, and B. longum subsp. longum were always present in the group of subjects enrolled, whereas B. bifidum and B. longum subsp. infantis were not. Furthermore, it was found that the most predominant bifidobacterial species were B. longum subsp. longum and B. adolescentis. The results obtained revealed a high interindividual variability; however, a significant increase of B. longum subsp. infantis cell concentration was observed in the feces of volunteers after the wild blueberry drink treatment. This bifidobacterial group was shown to possess immunomodulatory abilities and to relieve symptoms and promote the regression of several gastrointestinal disorders. Thus, an increased cell concentration of B. longum subsp. infantis in the human gut could be considered of potential health benefit. In conclusion, wild blueberry consumption resulted in a specific bifidogenic effect that could positively affect certain populations of bifidobacteria with demonstrated health-promoting properties. PMID:23883473

Guglielmetti, Simone; Fracassetti, Daniela; Taverniti, Valentina; Del Bo', Cristian; Vendrame, Stefano; Klimis-Zacas, Dorothy; Arioli, Stefania; Riso, Patrizia; Porrini, Marisa



Fermentation of mucin by bifidobacteria from rectal samples of humans and rectal and intestinal samples of animals  

Microsoft Academic Search

Bifidobacteria (246 strains in total) were isolated from rectal samples of infants and adult humans and animals, and from\\u000a intestinal samples of calves. Twenty-five strains grew well on mucin: 20 from infants, two from adults, and three from goatlings.\\u000a Poor or no growth on mucin was observed in 156 bifidobacterial strains of animal origin. The difference between human and\\u000a animal

J. Killer; M. Marounek



Gene expression in human small intestinal mucosa in vivo is mediated by iron-induced oxidative stress.  


Iron-induced oxidative stress in the small intestine may alter gene expression in the intestinal mucosa. The present study aimed to determine which genes are mediated by an iron-induced oxidative challenge in the human small intestine. Eight healthy volunteers [22 yr(SD2)] were tested on two separate occasions in a randomized crossover design. After duodenal tissue sampling by gastroduodenoscopy, a perfusion catheter was inserted orogastrically to perfuse a 40-cm segment of the proximal small intestine with saline and, subsequently, with either 80 or 400 mg of iron as ferrous gluconate. After the intestinal perfusion, a second duodenal tissue sample was obtained. Thiobarbituric acid-reactive substances, an indicator of lipid peroxidation, in intestinal fluid samples increased significantly and dose dependently at 30 min after the start of perfusion with 80 or 400 mg of iron, respectively (P < 0.001). During the perfusion with 400 mg of iron, the increase in thiobarbituric acid-reactive substances was accompanied by a significant, momentary rise in trolox equivalent antioxidant capacity, an indicator of total antioxidant capacity (P < 0.05). The expression of 89 gene reporters was significantly altered by both iron interventions. Functional mapping showed that both iron dosages mediated six distinct processes. Three of those processes involved G-protein receptor coupled pathways. The other processes were associated with cell cycle, complement activation, and calcium channels. Iron administration in the small intestine induced dose-dependent lipid peroxidation and a momentary antioxidant response in the lumen, mediated the expression of at least 89 individual gene reporters, and affected at least six biological processes. PMID:16464976

Troost, Freddy J; Brummer, Robert-Jan M; Haenen, Guido R M M; Bast, Aalt; van Haaften, Rachel I; Evelo, Chris T; Saris, Wim H M



[Bacterial Infection as a Cause of Infertility in Humans].  


Microorganisms which are present in the human urogenital tract may be involved in the development of inflammatory changes negatively affecting the genitals in both men and women. Pathological conditions due to inflammatory alterations may result in complete loss of fertility. Infections of the urogenital tract are responsible for 15% of all cases of infertility in couples. Negative impact on the human reproduction is mainly caused by direct damage to the genital tract mucosa by metabolic products of microorganisms or by induction of pro-inflammatory responses of the body. Another mechanism is indirect impact of microorganisms on the genital function. Moreover, the effect of bacteria on spermatogenesis and semen quality is important in men. Infections mainly caused by Chlamydia trachomatis or Neisseria gonorrhoeae represent the greatest risk in terms of permanent consequences for human reproduction. As for other sexually transmitted disorders, such as infections caused by Gardnerella vaginalis, urogenital mycoplasmas or ureaplasmas, the link between infection and infertility has been intensively researched. PMID:23768092

Radek, Sleha; Vanda, Boštíková; Miloslav, Salavec; Petra, Mosio; Eva, Kusáková; Rudolf, Kukla; Jaroslava, Mazurová; Miroslav, Spli?o



EP Receptor Expression in Human Intestinal Epithelium and Localization Relative to the Stem Cell Zone of the Crypts  

PubMed Central

There is substantial evidence for PGE2 affecting intestinal epithelial proliferation. PGE2 is also reported to be involved in the regulation of growth and differentiation in adult stem cells, both effects mediated by binding to EP-receptors. We have used the Lgr5 as a marker to scrutinize EP-receptor and COX expression in human intestinal epithelial cells with focus on the stem cell area of the crypts. Normal tissue from ileum and colon, but also duodenal biopsies from patients with untreated celiac disease, were investigated by immunohistochemistry and RT-PCR. The combination of fresh flash-frozen tissue and laser microdissection made it possible to isolate RNA from the epithelial cell layer, only. In the small intestine, Lgr5 labels cells are in the +4 position, while in the colon, Lgr5 positive cells are localized to the crypt bottoms. Epithelial crypt cells of normal small intestine expressed neither EP-receptor mRNA nor COX1/2. However, crypt cells in tissue from patients with untreated celiac disease expressed EP2/4 receptor and COX1 mRNA. In the colon, the situation was different. Epithelial crypt cells from normal colon were found to express EP2/4 receptor and COX1/2 transcripts. Thus, there are distinct differences between normal human small intestine and colon with regard to expression of EP2/4 receptors and COX1/2. In normal colon tissue, PGE2-mediated signaling through EP-receptors 2/4 could be involved in regulation of growth and differentiation of the epithelium, while the lack of EP-receptor expression in the small intestinal tissue exclude the possibility of a direct effect of PGE2 on the crypt epithelial cells.

Fosnes, Kjetil; Jacobsen, Morten; Lea, Tor



Bacterial and human peptidylarginine deiminases: targets for inhibiting the autoimmune response in rheumatoid arthritis?  

PubMed Central

Peptidylarginine deiminases (PADs) convert arginine within a peptide (peptidylarginine) into peptidylcitrulline. Citrullination by human PADs is important in normal physiology and inflammation. Porphyromonas gingivalis, a major pathogen in periodontitis, is the only prokaryote described to possess PAD. P. gingivalis infection may generate citrullinated peptides, which trigger anti-citrullinated peptide antibodies. In susceptible individuals, host protein citrullination by human PADs in the joint probably perpetuates antibody formation, paving the way for the development of chronic arthritis. Blockades of bacterial and human PADs may act as powerful novel therapies by inhibiting the generation of the antigens that trigger and sustain autoimmunity in rheumatoid arthritis.



An In Vitro Study on Bacterial Growth Interactions and Intestinal Epithelial Cell Adhesion Characteristics of Probiotic Combinations  

Microsoft Academic Search

The aims of this study were to examine long-term growth interactions of five probiotic strains (Lactobacillus casei 01, Lactobacillus plantarum HA8, Lactobacillus rhamnosus GG, Lactobacillus reuteri ATCC 55730 and Bifidobacterium lactis Bb12) either alone or in combination with Propionibacterium jensenii 702 in a co-culture system and to determine their adhesion ability to human colon adenocarcinoma cell line Caco-2. Growth\\u000a patterns

Mahta MoussaviMichelle; Michelle Catherine Adams



Regulation of expression of human intestinal bile acid-binding protein in Caco-2 cells.  

PubMed Central

Molecular mechanisms of the bile acid active transport system in the ileal enterocytes remain unknown. We examined whether bile acids affect human enterocyte gene expression of intestinal bile acid-binding protein (I-BABP), a component of this transport system. Differentiated Caco-2 cells were incubated in the presence of human bile, bile acids or other lipids. The level of I-BABP expression was evaluated by Northern and Western blot analyses. A 24 h incubation of Caco-2 cells in a medium containing either bile or bile acids resulted in a remarkable 7.5-fold increase in the I-BABP mRNA level over the control level. Neither cholesterol, palmitic acid, phosphatidylcholine nor cholestyramine treated bile showed any difference in I-BABP mRNA expression from the control. Bile acid treatment increased the level of I-BABP mRNA in Caco-2 cells in a time- and dose-dependent manner. Western blot analysis showed that this induction led to increase in cytosolic I-BABP. Chenodeoxycholic acid and deoxycholic acid showed greater induction effects than other hydrophilic bile acids, including their own glycine conjugates. Pretreatment by actinomycin D or cycloheximide completely inhibited the up-regulation of I-BABP expression by bile acid. Bile acids, especially lipophilic bile acids, increase the I-BABP expression in Caco-2-cells, suggesting that luminal bile acids play an important role in regulating the I-BABP gene expression.

Kanda, T; Foucand, L; Nakamura, Y; Niot, I; Besnard, P; Fujita, M; Sakai, Y; Hatakeyama, K; Ono, T; Fujii, H



Human Pancreatic Secretory Trypsin Inhibitor Stabilizes Intestinal Mucosa against Noxious Agents  

PubMed Central

Pancreatic secretory trypsin inhibitor (PSTI) is a serine protease inhibitor, expressed in gut mucosa, whose function is unclear. We, therefore, examined the effects of PSTI on gut stability and repair. Transgenic mice overexpressing human PSTI within the jejunum (FABPi?1178 to +28 hPSTI construct) showed no change in baseline morphology or morphometry but reduced indomethacin-induced injury in overexpressing hPSTI region by 42% (P < 0.01). Systemic recombinant hPSTI did not affect baseline morphology or morphometry but truncated injurious effects in prevention and recovery rat models of dextran-sodium-sulfate-induced colitis. In vitro studies showed PSTI stimulated cell migration but not proliferation of human colonic carcinoma HT29 or immortalized mouse colonic YAMC cells. PSTI also induced changes in vectorial ion transport (short-circuit current) when added to basolateral but not apical surfaces of polarized monolayers of Colony-29 cells. Restitution and vectorial ion transport effects of PSTI were dependent on the presence of a functioning epidermal growth factor (EGF) receptor because cells with a disrupted (EGFR?/? immortalized cells) or neutralized (EGFR blocking antibodies or tyrosine kinase inhibitor) receptor prevented these effects. PSTI also reduced the cytokine release of lipopolysaccharide-stimulated dendritic cells. We conclude that administration of PSTI may provide a novel method of stabilizing intestinal mucosa against noxious agents and stimulating repair after injury.

Marchbank, Tania; Mahmood, Asif; Fitzgerald, Anthony J.; Domin, Jan; Butler, Matt; Goodlad, Robert A.; Elia, George; Cox, Helen M.; van Heel, David A.; Ghosh, Subrata; Playford, Raymond J.



Effect of broad-spectrum parenteral antibiotics on "colonization resistance" of intestinal microflora of humans.  

PubMed Central

Studies with animals have shown that the normal intestinal microflora protects against colonization by new strains ("colonization resistance") and that this protective effect may be related to the anaerobic component of the microflora. However, colonization resistance has not been shown in humans. We administered cefoxitin, piperacillin, cefoperazone, and aztreonam intravenously to healthy subjects for 9 days and monitored the acquisition of new isolates in the fecal flora. Seven of sixteen antibiotic-treated subjects but none of four untreated controls became colonized by gram-negative bacilli. However, there was no correlation between colonization and the particular drug given or the extent of suppression of anaerobes or of any other component of the fecal microflora. Cefoxitin and piperacillin were associated with the greatest increases in the numbers of drug-resistant bacteria and in fecal beta-lactamase content. The results of this study support the concept that colonization resistance occurs in humans and is diminished by antibiotic administration but fail to support the hypothesis that resistance is related to the anaerobic microflora.

Barza, M; Giuliano, M; Jacobus, N V; Gorbach, S L



Transgenic mice containing intestinal fatty acid-binding protein-human growth hormone fusion genes exhibit correct regional and cell-specific expression of the reporter gene in their small intestine  

Microsoft Academic Search

The rat intestinal fatty acid binding protein (I-FABP) gene exhibits cell-specific as well as regional differences in its expression within the continuously regenerating small intestinal epithelium. To investigate the underlying mechanisms, we linked portions of its 5' nontranscribed domain to the human growth hormone (hGH) gene and analyzed expression of the hGH reporter in transgenic mice by RNA blot, solution

D. A. Sweetser; S M Hauft; P C Hoppe; E H Birkenmeier; J I Gordon



CARD15\\/NOD2 functions as an antibacterial factor in human intestinal epithelial cells  

Microsoft Academic Search

Background & Aims: Mutations in the CARD15\\/NOD2 gene, a putative intracellular pattern recognition receptor, have been linked to the risk for Crohn's disease. Because intestinal epithelial cells play a role as the barrier to luminal microorganisms, we investigated the expression and function of CARD15\\/NOD2 in intestinal epithelial cells. Methods: Expression of CARD15\\/NOD2 messenger RNA (mRNA) in intestinal epithelial cell lines

Tadakazu Hisamatsu; Manabu Suzuki; Hans-Christian Reinecker; William J. Nadeau; Beth A. McCormick; Daniel K. Podolsky



Nanoparticle formulation of a poorly soluble cannabinoid receptor 1 antagonist improves absorption by rat and human intestine.  


The inclusion of nanoparticles dispersed in a hydrophilic matrix is one of the formulation strategies to improve the bioavailability of orally administered Biopharmaceutics Classification System (BCS) class II and IV drugs by increasing their dissolution rate in the intestine. To confirm that the increased dissolution rate results in increased bioavailability, in vitro and in vivo animal experiments are performed, however, translation to the human situation is hazardous. In this study, we used a range of in vitro and ex vivo methods, including methods applying human tissue, to predict the in vivo oral bioavailability of a model BCS class II CB-1 antagonist, formulated as a nanoparticle solid dispersion. The enhanced dissolution rate from the nanoparticle formulation resulted in an increased metabolite formation in both rat and human precision-cut intestinal slices, suggesting increased uptake and intracellular drug concentration in the enterocytes. In Ussing chamber experiments with human tissue, both the metabolite formation and apical efflux of the metabolite were increased for the nanoparticulate solid dispersion compared with a physical mixture, in line with the results in intestinal slices. The pharmacokinetics of the different formulations was studied in rats in vivo. The nanoparticle formulation indeed improved the absorption of the cannabinoid receptor 1 (CB-1) antagonist and the delivery into the brain compared with the physical mixture. In conclusion, the combined approach provides a valuable set of tools to investigate the effects of formulation on the absorption of poorly soluble compounds in human intestine and may provide relevant information on the oral bioavailability in humans early in the development process. PMID:23733277

Siissalo, Sanna; de Waard, Hans; de Jager, Marina H; Hayeshi, Rose; Frijlink, Henderik W; Hinrichs, Wouter L J; Dinter-Heidorn, Heike; van Dam, Annie; Proost, Johannes H; Groothuis, Geny M M; de Graaf, Inge A M



A Novel Method for the Establishment of a Pure Population of Nontransformed Human Intestinal Primary Epithelial Cell (HIPEC) Lines in Long Term Culture  

Microsoft Academic Search

A novel method for generating nontransformed human intestinal primary epithelial cell (HIPEC) lines in an in vitro culture system is reported here. Although several groups have reported the development of nontransformed intestinal epithelial cells (IEC) lines (Deveney et al, 1996; Latella et al, 1996; Pang et al, 1996; Perreault and Beaulieu, 1998), it still had been difficult to find an

Asit Panja



Bacterial adaptation to the gut environment favors successful colonization  

PubMed Central

Rodent models harboring a simple yet functional human intestinal microbiota provide a valuable tool to study the relationships between mammals and their bacterial inhabitants. In this study, we aimed to develop a simplified gnotobiotic mouse model containing 10 easy-to-grow bacteria, readily available from culture repositories, and of known genome sequence, that overall reflect the dominant commensal bacterial makeup found in adult human feces. We observed that merely inoculating a mix of fresh bacterial cultures into ex-germ free mice did not guarantee a successful intestinal colonization of the entire bacterial set, as mice inoculated simultaneously with all strains only harbored 3 after 21 d. Therefore, several inoculation procedures were tested and levels of individual strains were quantified using molecular tools. Best results were obtained by inoculating single bacterial strains into individual animals followed by an interval of two weeks before allowing the animals to socialize to exchange their commensal microbes. Through this procedure, animals were colonized with almost the complete bacterial set (9/10). Differences in the intestinal composition were also reflected in the urine and plasma metabolic profiles, where changes in lipids, SCFA, and amino acids were observed. We conclude that adaptation of bacterial strains to the host’s gut environment (mono-colonization) may predict a successful establishment of a more complex microbiota in rodents.

Rezzonico, Enea; Mestdagh, Renaud; Delley, Michele; Combremont, Severine; Dumas, Marc-Emmanuel; Holmes, Elaine; Nicholson, Jeremy; Bibiloni, Rodrigo



Group A Streptococcus transcriptome dynamics during growth in human blood reveals bacterial adaptive and survival strategies.  


The molecular basis for bacterial responses to host signals during natural infections is poorly understood. The gram-positive bacterial pathogen group A Streptococcus (GAS) causes human mucosal, skin, and life-threatening systemic infections. During the transition from a throat or skin infection to an invasive infection, GAS must adapt to changing environments and host factors. To better understand how GAS adapts, we used transcript profiling and functional analysis to investigate the transcriptome of a wild-type serotype M1 GAS strain in human blood. Global changes in GAS gene expression occur rapidly in response to human blood exposure. Increased transcription was observed for many genes that likely enhance bacterial survival, including those encoding superantigens and host-evasion proteins regulated by a multiple gene activator called Mga. GAS also coordinately expressed genes involved in proteolysis, transport, and catabolism of oligopeptides to obtain amino acids in this protein-rich host environment. Comparison of the transcriptome of the wild-type strain to that of an isogenic deletion mutant (DeltacovR) mutated in the two-component regulatory system designated CovR-CovS reinforced the hypothesis that CovR-CovS has an important role linking key biosynthetic, catabolic, and virulence functions during transcriptome restructuring. Taken together, the data provide crucial insights into strategies used by pathogenic bacteria for thwarting host defenses and surviving in human blood. PMID:15681829

Graham, Morag R; Virtaneva, Kimmo; Porcella, Stephen F; Barry, William T; Gowen, Brian B; Johnson, Claire R; Wright, Fred A; Musser, James M



Molecular mechanisms of superoxide production by complex III: A bacterial versus human mitochondrial comparative case study.  


In this mini review, we briefly survey the molecular processes that lead to reactive oxygen species (ROS) production by the respiratory complex III (CIII or cytochrome bc1). In particular, we discuss the "forward" and "reverse" electron transfer pathways that lead to superoxide generation at the quinol oxidation (Qo) site of CIII, and the components that affect these reactions. We then describe and compare the properties of a bacterial (Rhodobacter capsulatus) mutant enzyme producing ROS with its mitochondrial (human cybrids) counterpart associated with a disease. The mutation under study is located at a highly conserved tyrosine residue of cytochrome b (Y302C in R. capsulatus and Y278C in human mitochondria) that is at the heart of the quinol oxidation (Qo) site of CIII. Similarities of the major findings of bacterial and human mitochondrial cases, including decreased catalytic activity of CIII, enhanced ROS production and ensuing cellular responses and damages, are remarkable. This case illustrates the usefulness of undertaking parallel and complementary studies using biologically different yet evolutionarily related systems, such as ?-proteobacteria and human mitochondria. It progresses our understanding of CIII mechanism of function and ROS production, and underlines the possible importance of supra-molecular organization of bacterial and mitochondrial respiratory chains (i.e., respirasomes) and their potential disease-associated protective roles. This article is part of a Special Issue entitled: Respiratory complex III and related bc complexes. PMID:23542447

Lanciano, Pascal; Khalfaoui-Hassani, Bahia; Selamoglu, Nur; Ghelli, Anna; Rugolo, Michela; Daldal, Fevzi



Host response to respiratory bacterial pathogens as identified by integrated analysis of human gene expression data.  


Respiratory bacterial pathogens are one of the leading causes of infectious death in the world and a major health concern complicated by the rise of multi-antibiotic resistant strains. Therapeutics that modulate host genes essential for pathogen infectivity could potentially avoid multi-drug resistance and provide a wider scope of treatment options. Here, we perform an integrative analysis of published human gene expression data generated under challenges from the gram-negative and Gram-positive bacteria pathogens, Pseudomonas aeruginosa and Streptococcus pneumoniae, respectively. We applied a previously described differential gene and pathway enrichment analysis pipeline to publicly available host mRNA GEO datasets resulting from exposure to bacterial infection. We found 72 canonical human pathways common between four GEO datasets, representing P. aeruginosa and S. pneumoniae. Although the majority of these pathways are known to be involved with immune response, we found several interesting new interactions such as the SUMO1 pathway that might have a role in bacterial infections. Furthermore, 36 host-bacterial pathways were also shared with our previous results for respiratory virus host gene expression. Based on our pathway analysis we propose several drug-repurposing opportunities supported by the literature. PMID:24086587

Smith, Steven B; Magid-Slav, Michal; Brown, James R



Host Response to Respiratory Bacterial Pathogens as Identified by Integrated Analysis of Human Gene Expression Data  

PubMed Central

Respiratory bacterial pathogens are one of the leading causes of infectious death in the world and a major health concern complicated by the rise of multi-antibiotic resistant strains. Therapeutics that modulate host genes essential for pathogen infectivity could potentially avoid multi-drug resistance and provide a wider scope of treatment options. Here, we perform an integrative analysis of published human gene expression data generated under challenges from the gram-negative and Gram-positive bacteria pathogens, Pseudomonas aeruginosa and Streptococcus pneumoniae, respectively. We applied a previously described differential gene and pathway enrichment analysis pipeline to publicly available host mRNA GEO datasets resulting from exposure to bacterial infection. We found 72 canonical human pathways common between four GEO datasets, representing P. aeruginosa and S. pneumoniae. Although the majority of these pathways are known to be involved with immune response, we found several interesting new interactions such as the SUMO1 pathway that might have a role in bacterial infections. Furthermore, 36 host-bacterial pathways were also shared with our previous results for respiratory virus host gene expression. Based on our pathway analysis we propose several drug-repurposing opportunities supported by the literature.

Smith, Steven B.; Magid-Slav, Michal; Brown, James R.



Microbiota/Host Crosstalk Biomarkers: Regulatory Response of Human Intestinal Dendritic Cells Exposed to Lactobacillus Extracellular Encrypted Peptide  

PubMed Central

The human gastrointestinal tract is exposed to a huge variety of microorganisms, either commensal or pathogenic; at this site, a balance between immunity and immune tolerance is required. Intestinal dendritic cells (DCs) control the mechanisms of immune response/tolerance in the gut. In this paper we have identified a peptide (STp) secreted by Lactobacillus plantarum, characterized by the abundance of serine and threonine residues within its sequence. STp is encoded in one of the main extracellular proteins produced by such species, which includes some probiotic strains, and lacks cleavage sites for the major intestinal proteases. When studied in vitro, STp expanded the ongoing production of regulatory IL-10 in human intestinal DCs from healthy controls. STp-primed DC induced an immunoregulatory cytokine profile and skin-homing profile on stimulated T-cells. Our data suggest that some of the molecular dialogue between intestinal bacteria and DCs may be mediated by immunomodulatory peptides, encoded in larger extracellular proteins, secreted by commensal bacteria. These peptides may be used for the development of nutraceutical products for patients with IBD. In addition, this kind of peptides seem to be absent in the gut of inflammatory bowel disease patients, suggesting a potential role as biomarker of gut homeostasis.

Al-Hassi, Hafid O.; Mann, Elizabeth R.; Urdaci, Maria C.; Knight, Stella C.; Margolles, Abelardo



Microbiota/host crosstalk biomarkers: regulatory response of human intestinal dendritic cells exposed to Lactobacillus extracellular encrypted peptide.  


The human gastrointestinal tract is exposed to a huge variety of microorganisms, either commensal or pathogenic; at this site, a balance between immunity and immune tolerance is required. Intestinal dendritic cells (DCs) control the mechanisms of immune response/tolerance in the gut. In this paper we have identified a peptide (STp) secreted by Lactobacillus plantarum, characterized by the abundance of serine and threonine residues within its sequence. STp is encoded in one of the main extracellular proteins produced by such species, which includes some probiotic strains, and lacks cleavage sites for the major intestinal proteases. When studied in vitro, STp expanded the ongoing production of regulatory IL-10 in human intestinal DCs from healthy controls. STp-primed DC induced an immunoregulatory cytokine profile and skin-homing profile on stimulated T-cells. Our data suggest that some of the molecular dialogue between intestinal bacteria and DCs may be mediated by immunomodulatory peptides, encoded in larger extracellular proteins, secreted by commensal bacteria. These peptides may be used for the development of nutraceutical products for patients with IBD. In addition, this kind of peptides seem to be absent in the gut of inflammatory bowel disease patients, suggesting a potential role as biomarker of gut homeostasis. PMID:22606249

Bernardo, David; Sánchez, Borja; Al-Hassi, Hafid O; Mann, Elizabeth R; Urdaci, María C; Knight, Stella C; Margolles, Abelardo



Effect of selective PKC isoform activation and inhibition on TNF-?-induced injury and apoptosis in human intestinal epithelial cells  

PubMed Central

We have investigated the effects of specific PKC isoforms in TNF-? mediated cellular damage using a human intestinal cell line (SCBN). TNF-? treatment induced a decrease in the extent of intestinal cellular viability as determined by a formazan-based assay and an increase in the apoptotic index as assessed by immunohistology. These changes in cellular integrity were found to be related to the degradation of I-?B?, mobilization of NF-?B and release of mitochondrial cytochrome c. TNF-? treatment also induced the activation of selective PKC isoforms which were associated with the decrease in cellular viability and an increase of cellular apoptosis. Nonselective PKC antagonists, such as GF109203X and Gö6976 as well as isoform-selective PKC-inhibiting peptides would reverse the cellular injury as well as reduce the degradation of I-?B? and mitochondrial cytochrome c release. These effects were most highly correlated with changes in PKC? and ? primarily. Intestinal cellular injury could be induced by treating cells with agonists selective for PKC? and ? mainly. In conclusion, this study has shown that TNF-? treatment can induce the activation of PKC? and ? in the human intestinal cell line, SCBN, and this response is closely associated with an increase in cellular damage and apoptosis. PKC? and ? primarily mediate the release of mitochondrial cytochrome c and degradation of I-?B? and hence mobilization of NF-?B, which are responsible for the pathway leading to cell injury.

Chang, Q; Tepperman, B L



Loss of Rab25 promotes the development of intestinal neoplasia in mice and is associated with human colorectal adenocarcinomas  

PubMed Central

Transformation of epithelial cells is associated with loss of cell polarity, which includes alterations in cell morphology as well as changes in the complement of plasma membrane proteins. Rab proteins regulate polarized trafficking to the cell membrane and therefore represent potential regulators of this neoplastic transition. Here we have demonstrated a tumor suppressor function for Rab25 in intestinal neoplasia in both mice and humans. Human colorectal adenocarcinomas exhibited reductions in Rab25 expression independent of stage, with lower Rab25 expression levels correlating with substantially shorter patient survival. In wild-type mice, Rab25 was strongly expressed in cells luminal to the proliferating cells of intestinal crypts. While Rab25-deficient mice did not exhibit gross pathology, ApcMin/+ mice crossed onto a Rab25-deficient background showed a 4-fold increase in intestinal polyps and a 2-fold increase in colonic tumors compared with parental ApcMin/+ mice. Rab25-deficient mice had decreased ?1 integrin staining in the lateral membranes of villus cells, and this pattern was accentuated in Rab25-deficient mice crossed onto the ApcMin/+ background. Additionally, Smad3+/– mice crossed onto a Rab25-deficient background demonstrated a marked increase in colonic tumor formation. Taken together, these results suggest that Rab25 may function as a tumor suppressor in intestinal epithelial cells through regulation of protein trafficking to the cell surface.

Nam, Ki Taek; Lee, Hyuk-Joon; Smith, J. Joshua; Lapierre, Lynne A.; Kamath, Vidya P.; Chen, Xi; Aronow, Bruce J.; Yeatman, Timothy J.; Bhartur, Sheela G.; Calhoun, Benjamin C.; Condie, Brian; Manley, Nancy R.; Beauchamp, R. Daniel; Coffey, Robert J.; Goldenring, James R.



Identification of Bacterial DNA Markers for the Detection of Human Fecal Pollution in Water? †  

PubMed Central

We used genome fragment enrichment and bioinformatics to identify several microbial DNA sequences with high potential for use as markers in PCR assays for detection of human fecal contamination in water. Following competitive solution-phase hybridization of total DNA from human and pig fecal samples, 351 plasmid clones were sequenced and were determined to define 289 different genomic DNA regions. These putative human-specific fecal bacterial DNA sequences were then analyzed by dot blot hybridization, which confirmed that 98% were present in the source human fecal microbial community and absent from the original pig fecal DNA extract. Comparative sequence analyses of these sequences suggested that a large number (43.5%) were predicted to encode bacterial secreted or surface-associated proteins. Deoxyoligonucleotide primers capable of annealing to a subset of 26 of the candidate sequences predicted to encode factors involved in interactions with host cells were then used in the PCR and did not amplify markers in DNA from any additional pig fecal specimens. These 26 PCR assays exhibited a range of specificity in tests with 11 other animal sources, with more than half amplifying markers only in specimens from dogs or cats. Four assays were more specific, detecting markers only in specimens from humans, including those from 18 different human populations examined. We then demonstrated the potential utility of these assays by using them to detect human fecal contamination in several impacted watersheds.

Shanks, Orin C.; Domingo, Jorge W. Santo; Lu, Jingrang; Kelty, Catherine A.; Graham, James E.



Assessment of the mode of action underlying development of rodent small intestinal tumors following oral exposure to hexavalent chromium and relevance to humans.  


Abstract Chronic exposure to high concentrations of hexavalent chromium (Cr(VI)) in drinking water causes intestinal adenomas and carcinomas in mice, but not in rats. Cr(VI) causes damage to intestinal villi and crypt hyperplasia in mice after only one week of exposure. After two years of exposure, intestinal damage and crypt hyperplasia are evident in mice (but not rats), as are intestinal tumors. Although Cr(VI) has genotoxic properties, these findings suggest that intestinal tumors in mice arise as a result of chronic mucosal injury. To better understand the mode of action (MOA) of Cr(VI) in the intestine, a 90-day drinking water study was conducted to collect histological, biochemical, toxicogenomic and pharmacokinetic data in intestinal tissues. Using MOA analyses and human relevance frameworks proposed by national and international regulatory agencies, the weight of evidence supports a cytotoxic MOA with the following key events: (a) absorption of Cr(VI) from the intestinal lumen, (b) toxicity to intestinal villi, (c) crypt regenerative hyperplasia and (d) clonal expansion of mutations within the crypt stem cells, resulting in late onset tumorigenesis. This article summarizes the data supporting each key event in the MOA, as well as data that argue against a mutagenic MOA for Cr(VI)-induced intestinal tumors. PMID:23445218

Thompson, Chad M; Proctor, Deborah M; Suh, Mina; Haws, Laurie C; Kirman, Christopher R; Harris, Mark A



Assessment of the mode of action underlying development of rodent small intestinal tumors following oral exposure to hexavalent chromium and relevance to humans  

PubMed Central

Chronic exposure to high concentrations of hexavalent chromium (Cr(VI)) in drinking water causes intestinal adenomas and carcinomas in mice, but not in rats. Cr(VI) causes damage to intestinal villi and crypt hyperplasia in mice after only one week of exposure. After two years of exposure, intestinal damage and crypt hyperplasia are evident in mice (but not rats), as are intestinal tumors. Although Cr(VI) has genotoxic properties, these findings suggest that intestinal tumors in mice arise as a result of chronic mucosal injury. To better understand the mode of action (MOA) of Cr(VI) in the intestine, a 90-day drinking water study was conducted to collect histological, biochemical, toxicogenomic and pharmacokinetic data in intestinal tissues. Using MOA analyses and human relevance frameworks proposed by national and international regulatory agencies, the weight of evidence supports a cytotoxic MOA with the following key events: (a) absorption of Cr(VI) from the intestinal lumen, (b) toxicity to intestinal villi, (c) crypt regenerative hyperplasia and (d) clonal expansion of mutations within the crypt stem cells, resulting in late onset tumorigenesis. This article summarizes the data supporting each key event in the MOA, as well as data that argue against a mutagenic MOA for Cr(VI)-induced intestinal tumors.

Proctor, Deborah M.; Suh, Mina; Haws, Laurie C.; Kirman, Christopher R.; Harris, Mark A.



Small intestinal physiology and pathophysiology.  


The small intestine, like the rest of the gastrointestinal tract, is an intelligent organ. It generates a wide variety of motor patterns to meet motility requirements in different situations. Its basic motor function after a meal is to mix the chyme with exocrine and intestinal secretions, agitate its contents to uniformly and evenly expose them to the mucosal surface, and to propel them distally at a rate that allows optimal absorption of food components, and reabsorption of bile. Most of these functions are performed by individual phasic contractions. In humans, the phasic contractions are largely disorganized in time and space. These contractions may cause mixing and agitation of luminal contents with slow distal propulsion. Occasionally, an individual contraction of large amplitude and long duration migrates over several centimeters and may rapidly propel the contents over this distance. In general, the spatial and temporal relationships of individual phasic contractions become less organized distally, resulting in a slower propulsion rate in the distal small intestine than in the proximal small intestine. The migrating clustered contractions generated after a meal may also be propulsive, but because of their unpredictable and irregular occurrence, their precise role in postprandial propulsion is incompletely understood. Rapidly migrating contractions may occur when the electrical control activity is obliterated by pharmacologic agents or during parasitic infections. Their effects on motility are not known yet. Between meals, when digestion is complete, the small intestine generates migrating motor complexes that help keep the small intestine clean by dislodging debris from the villi and dumping them into the colon. This may prevent decay of these materials in the small intestine and limit their contribution to bacterial overgrowth. Giant migrating contractions may perform a similar function in the distal small intestine as well as return any refluxed fecal material back to the colon. However, the major role of giant migrating contractions may be, in pathologic states, associated with abdominal cramping and diarrhea. Giant migrating contractions are associated with mass movements. Vomiting is preceded by a retrograde giant contraction. This contraction rapidly empties the contents of the proximal half of small intestine into the stomach in preparation for vomitus expulsion by contraction of abdominal and diaphragmatic muscles. The three basic mechanisms of control of spatial and temporal patterns of contractions are myogenic, neural, and chemical.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:2668175

Sarna, S K; Otterson, M F



Fibronectin-degrading activity in human crevicular fluid, gingival explants culture medium and bacterial plaques.  


125I-fibronectin was incubated with extracts having presumably a proteolytic activity. Plaque from children without gingivitis, plaque from adults with chronic periodontitis, human gingival fluid and pooled culture media of human gingival explants were studied. Proteolysis was usually faster with plaque from patients with adult periodontitis than with plaque from children without gingivitis and the inhibition tests showed that several enzymes were implicated in the process. For the culture medium of gingival explants, the electrophoretic profile of the digestion products of fibronectin was different and showed a decreased activity. Nevertheless the gingival fluid gave a very similar degradation to bacterial plaque. The sulcular content was able to assume enzymatic activity capable of destroying fibronectin. These sulcular activities could be important for bacterial colonisation of sulcular surfaces and perhaps also for fibronectin destruction of periodontal tissues. PMID:3049569

Pellat, B; Planchenault, T; Keil-Dlouha, V; Pellerin, C



Adherence to and invasion of human intestinal cells by arcobacter species and their virulence genotypes.  


The genus Arcobacter is composed of 17 species which have been isolated from various sources. Of particular interest are A. butzleri, A. cryaerophilus, and A. skirrowii, as these have been associated with human cases of diarrhea, the probable transmission routes being through the ingestion of contaminated drinking water and food. To date, only limited studies of virulence traits in this genus have been undertaken. The present study used 60 Arcobacter strains isolated from different sources, representing 16 of the 17 species of the genus, to investigate their ability to adhere to and invade the human intestinal cell line Caco-2. In addition, the presence of five putative virulence genes (ciaB, cadF, cj1349, hecA, and irgA) was screened for in these strains by PCR. All Arcobacter species except A. bivalviorum and Arcobacter sp. strain W63 adhered to Caco-2 cells, and most species (10/16) were invasive. The most invasive species were A. skirrowii, A. cryaerophilus, A. butzleri, and A. defluvii. All invasive strains were positive for ciaB (encoding a putative invasion protein). Other putative virulence genes were present in other species, i.e., A. butzleri (cadF, cj1349, irgA, and hecA), A. trophiarum (cj1349), A. ellisii (cj1349), and A. defluvii (irgA). No virulence genes were detected in strains which showed little or no invasion of Caco-2 cells. These results indicate that many Arcobacter species are potential pathogens of humans and animals. PMID:23770897

Levican, Arturo; Alkeskas, Aldukali; Günter, Claudia; Forsythe, Stephen J; Figueras, María José



A Bacterial Artificial Chromosome Library for Sequencing the Complete Human Genome  

Microsoft Academic Search

A 30-fold redundant human bacterial artificial chromosome (BAC) library with a large average insert size (178 kb) has been constructed to provide the intermediate substrate for the international genome sequencing effort. The DNA was obtained from a single anonymous volunteer, whose identity was protected through a double-blind donor selection protocol. DNA fragments were generated by partial digestion with EcoRI (library

Kazutoyo Osoegawa; Aaron G. Mammoser; Chenyan Wu; Eirik Frengen; Changjiang Zeng; Joseph J. Catanese; Pieter J. de Jong



Effect of Dexamethasone and ACC on Bacterial Induced Mucin Expression in Human Airway Mucosa  

Microsoft Academic Search

Gram-negative bacteria can stimulate mucin production, but exces- sive mucus supports bacterial infection and consequently leads to airway obstruction. Therefore, the effect of dexamethasone (DEX) and the antioxidant acetyl-cysteine (ACC) on bacteria-induced mucus expression was investigated. Explanted human airway mu- cosa and mucoepidermoid cells (Calu-3) were stimulated with lipopolysaccharide (LPS) or PAM3 (a synthetic lipoprotein). DEX or ACCwereaddedtoeitherLPS-orPAM3-stimulatedairwaymucosaor Calu-3 cells.

Hans-Peter Hauber; Torsten Goldmann; Ekkehard Vollmer; Barbara Wollenberg



Bacterial ?-galactosidase and human dystrophin genes are expressed in mouse skeletal muscle fibers after ballistic transfection  

Microsoft Academic Search

Ballistic transfection, based on cell and tissue bombardment by the tungsten and gold microparticles covered with the gene DNA, was used for the delivery of a bacterial ?-galactosidase and a full-length cDNA copy of the human dystrophin genes into mouse skeletal muscles. CMV-lacZ, SV40-lacZ, LTR-lacZneo and full-length cDNA dystrophin (pDMD-1, approximately 16 kb) in eukaryotic expression vector pJ OMEGA driven

Alexander V. Zelenin; Victor A. Kolesnikov; Olga A. Tarasenko; Ramin A. Shafei; Inessa A. Zelenina; Vyacheslav V. Mikhailov; Maria L. Semenova; Dmitry V. Kovalenko; Olga V. Artemyeva; Tatyana E. Ivaschenko; Oleg V. Evgrafov; George Dickson; Vladislav S. Baranovand



Evidence for Dendritic Cell-Dependent CD4+ T Helper-1 Type Responses to Commensal Bacteria in Normal Human Intestinal Lamina Propria  

PubMed Central

Reactivity of lamina propria (LP) T cells to commensal bacteria has been demonstrated in animal models of inflammatory bowel disease (IBD) and in humans with IBD, but few studies have evaluated the function of such cells in normal individuals. LP mononuclear cells (LPMC) were disaggregated from healthy human intestinal tissue and cultured with heat-killed commensal and pathogenic bacteria. CD3+CD4+ IFN-?-producing (Th1) cells reactive to commensal bacteria were demonstrated at frequencies ranging from 0.05 to 2.28% in LPMC. Bacteria-specific Th1 responses were inhibited by anti-HLA-DR antibodies and chloroquine exposure, were enriched in LP relative to peripheral blood, and expressed effector memory cell markers. Bacteria-specific CD4+ T cell proliferation in vitro was dependent on the presence of LP dendritic cells (DCs), which produced proinflammatory cytokines upon bacterial exposure. These results suggest that bacteria-reactive DCs and CD4+ T cells in normal LP have substantial pro-inflammatory potential that is revealed upon disaggregation in vitro.

Howe, Rawleigh; Dillon, Stephanie; Rogers, Lisa; McCarter, Martin; Kelly, Caleb; Gonzalez, Ricardo; Madinger, Nancy; Wilson, Cara C.



Staphylococcus aureus adheres to human intestinal mucus but can be displaced by certain lactic acid bacteria  

Microsoft Academic Search

There is increasing evidence that Staphylococcus aureus may colonize the intestinal tract, especially among hospitalized patients. As Staph. aureus has been found to be associated with certain gastrointestinal diseases, it has become important to study whether this bacterium can colonize the intestinal tract and if so, whether it is possible to prevent colonization. Adhesion is the first step in colonization;

Satu Vesterlund; Matti Karp; Seppo Salminen; Arthur C. Ouwehand



Effect of Acute Hyperglycemia on Intestinal Gas Transit and Tolerance in Nondiabetic Humans  

Microsoft Academic Search

Background: Acute hyperglycemia usually inhibits gastrointestinal motility and hyperinsulinemia may contribute to specific inhibitory effects. However, the influences on postprandial intestinal gas dynamics have not been investigated. Aims: To compare effects of euglycemic hyperinsulinemia and acute fasting hyperglycemia on intestinal gas dynamics in nondiabetics. Methods: On 3 separate days, 10 healthy volunteers were evaluated in randomized order with duodenal glucose,

Hermann Harder; Ana C. Hernando-Harder; Andreas Franke; Heinz-Juergen Krammer; Manfred V. Singer



Postabsorptive Plasma Citrulline Concentration Is a Marker of Absorptive Enterocyte Mass and Intestinal Failure in Humans  

Microsoft Academic Search

Background & Aims: No blood marker assessing the functional absorptive bowel length has been identified. Plasma citrulline, a nonprotein amino acid produced by intestinal mucosa, is one candidate. We tested this hypothesis in adult patients with the short-bowel syndrome, whose condition can lead to intestinal failure. Methods: In 57 patients, after a minimal follow-up of 2 years subsequent to final



Variations in metabolism of the soy isoflavonoid daidzein by human intestinal microfloras from different individuals  

Microsoft Academic Search

Isoflavonoids found in legumes, such as soybeans, are converted by intestinal bacteria to metabolites that might have increased or decreased estrogenic activity. Variation in the effects of dietary isoflavonoids among individuals has been attributed to differences in their metabolism by intestinal bacteria. To investigate this variation, the metabolism of the isoflavonoid daidzein by bacteria from ten fecal samples, provided at

Fatemeh Rafii; Christy Davis; Thomas M. Heinze; Richard D. Beger



Human small intestinal contractions and aboral traction forces during fasting and after feeding  

Microsoft Academic Search

Small intestinal intraluminal pressure activity and aboral traction forces were explored in 19 healthy volunteers using a combined manometry and traction force detecting assembly sited in the upper small intestine. Each aboral traction event was classified as being associated with either a propagating or a stationary contraction and its force measured. During phase I no contractions or traction events were

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



Disease-Dependent Adhesion of Lactic Acid Bacteria to the Human Intestinal Mucosa  

Microsoft Academic Search

Their adhesion to the intestinal mucosa is considered one of the main reasons for the beneficial health effects of specific lactic acid bacteria (LAB). However, the influence of disease on the mucosal adhesion is largely unknown. Adhesion of selected LAB to resected colonic tissue and mucus was determined in patients with three major intestinal diseases (i.e., diverticulitis, rectal carcinoma, and

Arthur C. Ouwehand; Seppo Salminen; Peter J. Roberts; Jari Ovaska; Eeva Salminen



In vitro antibacterial potential of Eugenia jambolana seed extracts against multidrug-resistant human bacterial pathogens.  


The present study was carried out to evaluate the possible in vitro antibacterial potential of extracts of Eugenia jambolana seeds against multidrug-resistant human bacterial pathogens. Agar well diffusion and microbroth dilution assay methods were used for antibacterial susceptibility testing. Kill-kinetics study was done to know the rate and extent of bacterial killing. Phytochemical analysis and TLC-bioautography were performed by colour tests to characterize the putative compounds responsible for this antibacterial activity. Cytotoxic potential was evaluated on human erythrocytes by haemolytic assay method and acute oral toxicity study was done in mice. The plant extracts demonstrated varying degrees of strain specific antibacterial activity against all the test isolates. Further, ethyl acetate fraction obtained from fractionation of most active ethanol extract showed maximum antibacterial effect against all the test isolates. Phytochemical analysis and TLC-bioautography of ethyl acetate fraction revealed that phenolics were the major active phytoconstituents. Ethyl acetate fraction also demonstrated no haemolytic activity on human erythrocytes and no gross behavioural changes as well as toxic symptoms were observed in mice at recommended dosage level. The results provide justification for the use of E. jambolana in folk medicine to treat various infectious diseases and may contribute to the development of novel antimicrobial agents for the treatment of infections caused by these drug-resistant bacterial pathogens. PMID:22444436

Bag, Anwesa; Bhattacharyya, Subir Kumar; Pal, Nishith Kumar; Chattopadhyay, Rabi Ranjan



Intestinal epithelial barrier function in liver cirrhosis: an extensive review of the literature.  


Recent evidence suggests that translocation of bacteria and bacterial products, such as endotoxin from the intestinal lumen into the systemic circulation is a contributing factor in the pathogenesis of chronic liver diseases and the development of complications in cirrhosis. In addition to alterations in the intestinal microbiota and immune system, dysfunction of the intestinal epithelial barrier may be an important factor facilitating bacterial translocation. This review aims to provide an overview of the current evidence of intestinal epithelial barrier dysfunction in human chronic liver diseases and cirrhosis, and to discuss possible contributing factors and mechanisms. Data suggest the presence of intestinal epithelial barrier dysfunction in patients with chronic liver diseases, but are more convincing in patients with cirrhosis, especially in those with complications. The barrier dysfunction can result from both direct and indirect effects of aetiological factors, such as alcohol and obesity, which can cause chronic liver diseases and ultimately cirrhosis. On the other hand characteristics of cirrhosis itself, including portal hypertension, alterations in the intestinal microbiota, inflammation and oxidative stress can affect barrier function of both small and large intestine and may contribute to the development