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Sample records for prebiotic modulated transgenomic

  1. Evolutionary transgenomics: prospects and challenges

    PubMed Central

    Correa, Raul; Baum, David A.

    2015-01-01

    Many advances in our understanding of the genetic basis of species differences have arisen from transformation experiments, which allow us to study the effect of genes from one species (the donor) when placed in the genetic background of another species (the recipient). Such interspecies transformation experiments are usually focused on candidate genes – genes that, based on work in model systems, are suspected to be responsible for certain phenotypic differences between the donor and recipient species. We suggest that the high efficiency of transformation in a few plant species, most notably Arabidopsis thaliana, combined with the small size of typical plant genes and their cis-regulatory regions allow implementation of a screening strategy that does not depend upon a priori candidate gene identification. This approach, transgenomics, entails moving many large genomic inserts of a donor species into the wild type background of a recipient species and then screening for dominant phenotypic effects. As a proof of concept, we recently conducted a transgenomic screen that analyzed more than 1100 random, large genomic inserts of the Alabama gladecress Leavenworthia alabamica for dominant phenotypic effects in the A. thaliana background. This screen identified one insert that shortens fruit and decreases A. thaliana fertility. In this paper we discuss the principles of transgenomic screens and suggest methods to help minimize the frequencies of false positive and false negative results. We argue that, because transgenomics avoids committing in advance to candidate genes it has the potential to help us identify truly novel genes or cryptic functions of known genes. Given the valuable knowledge that is likely to be gained, we believe the time is ripe for the plant evolutionary community to invest in transgenomic screens, at least in the mustard family Brassicaceae where many species are amenable to efficient transformation. PMID:26579137

  2. Prebiotic fiber modulation of the gut microbiota improves risk factors for obesity and the metabolic syndrome

    PubMed Central

    Parnell, Jill A.; Reimer, Raylene A.

    2013-01-01

    Prebiotic fibers are non-digestible carbohydrates that promote the growth of beneficial bacteria in the gut. Prebiotic consumption may benefit obesity and associated co-morbidities by improving or normalizing the dysbiosis of the gut microbiota. We evaluated the dose response to a prebiotic diet on the gut microbiota, body composition and obesity associated risk factors in lean and genetically obese rats. Prebiotic fibers increased Firmicutes and decreased Bacteroidetes, a profile often associated with a leaner phenotype. Bifidobacteria and Lactobacillus numbers also increased. Changes in the gut microbiota correlated with energy intake, glucose, insulin, satiety hormones, and hepatic cholesterol and triglyceride accumulation. Here we provide a comprehensive analysis evaluating the results through the lens of the gut microbiota. Salient, new developments impacting the interpretation and significance of our data are discussed. We propose that prebiotic fibers have promise as a safe and cost-effective means of modulating the gut microbiota to promote improved host:bacterial interactions in obesity and insulin resistance. Human clinical trials should be undertaken to confirm these effects. PMID:22555633

  3. Modulation of Gut Microbiota-Brain Axis by Probiotics, Prebiotics, and Diet.

    PubMed

    Liu, Xiaofei; Cao, Shangqing; Zhang, Xuewu

    2015-09-16

    There exists a bidirectional communication system between the gastrointestinal tract and the brain. Increasing evidence shows that gut microbiota can play a critical role in this communication; thus, the concept of a gut microbiota and brain axis is emerging. Here, we review recent findings in the relationship between intestinal microbes and brain function, such as anxiety, depression, stress, autism, learning, and memory. We highlight the advances in modulating brain development and behavior by probiotics, prebiotics, and diet through the gut microbiota-brain axis. A variety of mechanisms including immune, neural, and metabolic pathways may be involved in modulation of the gut microbiota-brain axis. We also discuss some future challenges. A deeper understanding of the relationship between the gut bacteria and their hosts is implicated in developing microbial-based therapeutic strategies for brain disorders. PMID:26306709

  4. Prebiotics Modulate the Effects of Antibiotics on Gut Microbial Diversity and Functioning in Vitro

    PubMed Central

    Johnson, Laura P.; Walton, Gemma E.; Psichas, Arianna; Frost, Gary S.; Gibson, Glenn R.; Barraclough, Timothy G.

    2015-01-01

    Intestinal bacteria carry out many fundamental roles, such as the fermentation of non-digestible dietary carbohydrates to produce short chain fatty acids (SCFAs), which can affect host energy levels and gut hormone regulation. Understanding how to manage this ecosystem to improve human health is an important but challenging goal. Antibiotics are the front line of defence against pathogens, but in turn they have adverse effects on indigenous microbial diversity and function. Here, we have investigated whether dietary supplementation—another method used to modulate gut composition and function—could be used to ameliorate the side effects of antibiotics. We perturbed gut bacterial communities with gentamicin and ampicillin in anaerobic batch cultures in vitro. Cultures were supplemented with either pectin (a non-fermentable fibre), inulin (a commonly used prebiotic that promotes the growth of beneficial bacteria) or neither. Although antibiotics often negated the beneficial effects of dietary supplementation, in some treatment combinations, notably ampicillin and inulin, dietary supplementation ameliorated the effects of antibiotics. There is therefore potential for using supplements to lessen the adverse effects of antibiotics. Further knowledge of such mechanisms could lead to better therapeutic manipulation of the human gut microbiota. PMID:26053617

  5. Prebiotics Modulate the Effects of Antibiotics on Gut Microbial Diversity and Functioning in Vitro.

    PubMed

    Johnson, Laura P; Walton, Gemma E; Psichas, Arianna; Frost, Gary S; Gibson, Glenn R; Barraclough, Timothy G

    2015-06-01

    Intestinal bacteria carry out many fundamental roles, such as the fermentation of non-digestible dietary carbohydrates to produce short chain fatty acids (SCFAs), which can affect host energy levels and gut hormone regulation. Understanding how to manage this ecosystem to improve human health is an important but challenging goal. Antibiotics are the front line of defence against pathogens, but in turn they have adverse effects on indigenous microbial diversity and function. Here, we have investigated whether dietary supplementation--another method used to modulate gut composition and function--could be used to ameliorate the side effects of antibiotics. We perturbed gut bacterial communities with gentamicin and ampicillin in anaerobic batch cultures in vitro. Cultures were supplemented with either pectin (a non-fermentable fibre), inulin (a commonly used prebiotic that promotes the growth of beneficial bacteria) or neither. Although antibiotics often negated the beneficial effects of dietary supplementation, in some treatment combinations, notably ampicillin and inulin, dietary supplementation ameliorated the effects of antibiotics. There is therefore potential for using supplements to lessen the adverse effects of antibiotics. Further knowledge of such mechanisms could lead to better therapeutic manipulation of the human gut microbiota. PMID:26053617

  6. Modulating the microbiota in inflammatory bowel diseases: prebiotics, probiotics or faecal transplantation?

    PubMed

    Verbeke, Kristin A; Boesmans, Leen; Boets, Eef

    2014-11-01

    Crohn's disease (CD) and ulcerative colitis (UC) are the two major phenotypes of inflammatory bowel diseases (IBD) which constitute a spectrum of chronic, debilitating diseases characterised by a relapsing inflammation of the intestinal mucosal lining. Evidence from a variety of disciplines implicates the intestinal microbiota in the pathogenesis of idiopathic IBD and their complications, including pouchitis. Many studies have reported a dysbiosis in IBD, characterised by a decrease in diversity, a decreased abundance of some dominant commensal members (such as Clostridium IV and XIVa) and an increase in detrimental bacteria (such as sulphate reducing bacteria and Escherichia coli). Therapies such as prebiotics and probiotics aim to selectively manipulate the intestinal microbiota and have been evaluated as an attractive therapeutic option with few side effects. The multispecies product VSL#3 was found effective in preventing and maintaining remission in pouchitis, whereas both VSL#3 and E. coli Nissle were effective in maintaining remission in UC. A more drastic approach to restore the composition of the microbiota and correct the underlying imbalance is a faecal microbiota transplantation (FMT). FMT has been successfully applied to treat patients with even recalcitrant Clostridium difficile infection. Particularly in UC, the majority of studies suggest that FMT may be an effective treatment option although the evidence is still limited. It is anticipated that our increasing knowledge on the composition and function of the intestinal microbiota components will allow in the future for a better selection of highly performing bacteria with specific functions required for specific benefits. PMID:24969143

  7. Prebiotics and calcium bioavailability.

    PubMed

    Cashman, Kevin

    2003-03-01

    A prebiotic substance has been defined as a non-digestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or activity of one or a limited number of bacteria in the colon. Therefore, compared to probiotics, which introduce exogenous bacteria into the colonic microflora, a prebiotic aims at stimulating the growth of one or a limited number of the potentially health-promoting indigenous micro-organisms, thus modulating the composition of the natural ecosystem. In recent years, increasing attention has been focussed on the possible beneficial effects of prebiotics, such as enhanced resistance to invading pathogens, improved bowel function, anti-colon cancer properties, lipid lowering action, improved calcium bioavailability, amongst others. The objective of this review is to critically assess the available data on the effects of prebiotics on calcium bioavailability, and place it in the context of human physiology and, when possible, explain the underlying cellular and molecular mechanisms. The review will also try to highlight future areas of research that may help in the evaluation of prebiotics as potential ingredients for functional foods aimed at enhancing calcium bioavailability and protecting against osteoporosis. PMID:12691259

  8. Exposure to a galactooligosaccharides/inulin prebiotic mix at different developmental time points differentially modulates immune responses in mice.

    PubMed

    Gourbeyre, Pascal; Desbuards, Nicolas; Grémy, Guilaine; Le Gall, Sophie; Champ, Martine; Denery-Papini, Sandra; Bodinier, Marie

    2012-12-01

    Prebiotics constitute emerging tools to alleviate immune pathologies. This study aimed to evaluate the effect of prebiotic exposure during perinatal and postweaning periods on immune and gut regulations. Mice were fed either a galactooligosaccharides/inulin prebiotic mix-enriched diet or a control diet during the perinatal and/or postweaning periods. Biomarkers related to gut barrier function (SCFA, heat shock proteins, zonula occludens protein-1, and mucin-2) and immune mechanisms (IgA, IgE, IgG1, IgG2a, IL-10, TGF-β, IL-4, IL-17A, and IFN-γ) were analyzed. The milk of dams fed the prebiotic diet was more concentrated in both IgA and TGF-β when prebiotics were introduced during both the perinatal and postweaning periods; IL-10, IgA, and IgG2a were increased in pups; and expression of intestinal markers was more pronounced. Postweaning exposure to prebiotics alone induced higher INF-γ and TGF-β levels, whereas IgA levels fell. Combined exposure periods (perinatal/postweaning) to prebiotics increased tolerance-related immunoglobulins in pups and reinforced gut barrier functions. PMID:23145871

  9. Prebiotic chirality

    NASA Astrophysics Data System (ADS)

    Mekki-Berrada, Ali

    Bringing closer phospholipids each other on a bilayer of liposome, causes their rotation around their fatty acids axis, generating a force which brings closer the two sheets of the bilayer. In this theoretical study I show that for getting the greater cohesion of the liposome, by these forces, the serine in the hydrophilic head must have a L chirality. In the case where the hydrophilic head is absent amino acids with L chirality could contribute to this cohesion by taking the place of L-serine. Some coenzymes having a configuration similar to ethanolamine may also contribute. This is the case of pyridoxamine, thiamine and tetrahydrofolic acid. The grouping of amino acids of L chirality and pyridoxamine on the wall could initialize the prebiotic metabolism of these L amino acids only. This would explain the origin of the homo-chirality of amino acids in living world. Furthermore I show that in the hydrophilic head, the esterification of glycerol-phosphate by two fatty acids go through the positioning of dihydroxyacetone-phosphate and L-glyceraldehyde-3-phosphate, but not of D-glyceraldehyde-3-phosphate, prior their hydrogenation to glycerol-3- phosphate. The accumulation of D-glyceraldehyde-3-phosphate in the cytoplasm displace the thermodynamic equilibria towards the synthesis of D-dATP from D-glyceraldehyde-3-phosphate, acetaldehyde and prebiotic adenine, a reaction which does not require a coenzyme in the biotic metabolism. D-dATP and thiamine, more prebiotic metabolism of L-amino acids on the wall, would initialize D-pentoses phosphate and D-nucleotides pathways from the reaction of D-glyceraldehyde-3-phosphate + dihydroxyacetone-phosphate + prebiotic nucleic bases. The exhaustion of the prebiotic glyceraldehyde (racemic) and the nascent biotic metabolism dominated by D-glyceraldehyde-3-phosphate, would explain the origin of homo-chirality of sugars in living world. References: http://en.wikiversity.org/wiki/Prebiotic_chirality

  10. Prebiotic Petroleum

    NASA Astrophysics Data System (ADS)

    Ali, Mekki-Berrada

    2014-12-01

    This short communication summarizes a global and continuous reflection on the origins of life. "Prebiotic Petroleum" assumes that " the class of most complex molecules of life that may have geochemical and abiotic origin is the class of fatty acids with long aliphatic chains" and proposes a physical process for the formation of liposomes. Developments following the workshop start from the idea that the liposomes also acquire ion exchange channels physically during their forming process.

  11. Prebiotic petroleum.

    PubMed

    Ali, Mekki-Berrada

    2014-12-01

    This short communication summarizes a global and continuous reflection on the origins of life. "Prebiotic Petroleum" assumes that "the class of most complex molecules of life that may have geochemical and abiotic origin is the class of fatty acids with long aliphatic chains" and proposes a physical process for the formation of liposomes. Developments following the workshop start from the idea that the liposomes also acquire ion exchange channels physically during their forming process. PMID:25743765

  12. Prebiotics and gut microbiota in chickens.

    PubMed

    Pourabedin, Mohsen; Zhao, Xin

    2015-08-01

    Prebiotics are non-digestible feed ingredients that are metabolized by specific members of intestinal microbiota and provide health benefits for the host. Fermentable oligosaccharides are best known prebiotics that have received increasing attention in poultry production. They act through diverse mechanisms, such as providing nutrients, preventing pathogen adhesion to host cells, interacting with host immune systems and affecting gut morphological structure, all presumably through modulation of intestinal microbiota. Currently, fructooligosaccharides, inulin and mannanoligosaccharides have shown promising results while other prebiotic candidates such as xylooligosaccharides are still at an early development stage. Despite a growing body of evidence reporting health benefits of prebiotics in chickens, very limited studies have been conducted to directly link health improvements to prebiotic-dependent changes in the gut microbiota. This article visits the current knowledge of the chicken gastrointestinal microbiota and reviews most recent publications related to the roles played by prebiotics in modulation of the gut microbiota and immune functions. Progress in this field will help us better understand how the gut microbiota contributes to poultry health and productivity, and support the development of new prebiotic products as an alternative to in-feed antibiotics. PMID:26208530

  13. Modulation of the gut microbiota by nutrients with prebiotic properties: consequences for host health in the context of obesity and metabolic syndrome

    PubMed Central

    2011-01-01

    The gut microbiota is increasingly considered as a symbiotic partner for the maintenance of health. The homeostasis of the gut microbiota is dependent on host characteristics (age, gender, genetic background…), environmental conditions (stress, drugs, gastrointestinal surgery, infectious and toxic agents…). Moreover, it is dependent on the day-to-day dietary changes. Experimental data in animals, but also observational studies in obese patients, suggest that the composition of the gut microbiota is a factor characterizing obese versus lean individuals, diabetic versus non diabetic patients, or patients presenting hepatic diseases such as non alcoholic steatohepatitis. Interestingly, the changes in the gut microbes can be reversed by dieting and related weight loss. The qualitative and quantitative changes in the intake of specific food components (fatty acids, carbohydrates, micronutrients, prebiotics, probiotics), have not only consequences on the gut microbiota composition, but may modulate the expression of genes in host tissues such as the liver, adipose tissue, intestine, muscle. This in turn may drive or lessen the development of fat mass and metabolic disturbances associated with the gut barrier function and the systemic immunity. The relevance of the prebiotic or probiotic approaches in the management of obesity in humans is supported by few intervention studies in humans up to now, but the experimental data obtained with those compounds help to elucidate novel potential molecular targets relating diet with gut microbes. The metagenomic and integrative metabolomic approaches could help elucidate which bacteria, among the trillions in human gut, or more specifically which activities/genes, could participate to the control of host energy metabolism, and could be relevant for future therapeutic developments. PMID:21995448

  14. Prebiotics: why definitions matter.

    PubMed

    Hutkins, Robert W; Krumbeck, Janina A; Bindels, Laure B; Cani, Patrice D; Fahey, George; Goh, Yong Jun; Hamaker, Bruce; Martens, Eric C; Mills, David A; Rastal, Robert A; Vaughan, Elaine; Sanders, Mary Ellen

    2016-02-01

    The prebiotic concept was introduced twenty years ago, and despite several revisions to the original definition, the scientific community has continued to debate what it means to be a prebiotic. How prebiotics are defined is important not only for the scientific community, but also for regulatory agencies, the food industry, consumers and healthcare professionals. Recent developments in community-wide sequencing and glycomics have revealed that more complex interactions occur between putative prebiotic substrates and the gut microbiota than previously considered. A consensus among scientists on the most appropriate definition of a prebiotic is necessary to enable continued use of the term. PMID:26431716

  15. Prebiotics: why definitions matter

    PubMed Central

    Hutkins, Robert W; Krumbeck, Janina A; Bindels, Laure B; Cani, Patrice D; Fahey, George; Goh, Yong Jun; Hamaker, Bruce; Martens, Eric C; Mills, David A; Rastal, Robert A; Vaughan, Elaine; Sanders, Mary Ellen

    2015-01-01

    The prebiotic concept was introduced twenty years ago, and despite several revisions to the original definition, the scientific community has continued to debate what it means to be a prebiotic. How prebiotics are defined is important not only for the scientific community, but also for regulatory agencies, the food industry, consumers and healthcare professionals. Recent developments in community-wide sequencing and glycomics have revealed that more complex interactions occur between putative prebiotic substrates and the gut microbiota than previously considered. A consensus among scientists on the most appropriate definition of a prebiotic is necessary to enable continued use of the term. PMID:26431716

  16. Probiotics, prebiotics and colorectal cancer prevention.

    PubMed

    Ambalam, Padma; Raman, Maya; Purama, Ravi Kiran; Doble, Mukesh

    2016-02-01

    Colorectal cancer (CRC), the third major cause of mortality among various cancer types in United States, has been increasing in developing countries due to varying diet and dietary habits and occupational hazards. Recent evidences showed that composition of gut microbiota could be associated with the development of CRC and other gut dysbiosis. Modulation of gut microbiota by probiotics and prebiotics, either alone or in combination could positively influence the cross-talk between immune system and microbiota, would be beneficial in preventing inflammation and CRC. In this review, role of probiotics and prebiotics in the prevention of CRC has been discussed. Various epidemiological and experimental studies, specifically gut microbiome research has effectively improved the understanding about the role of probiotics and microbial treatment as anticarcinogenic agents. A few human studies support the beneficial effect of probiotics and prebiotics; hence, comprehensive understanding is urgent to realize the clinical applications of probiotics and prebiotics in CRC prevention. PMID:27048903

  17. Probiotics, prebiotics and synbiotics- a review.

    PubMed

    Pandey, Kavita R; Naik, Suresh R; Vakil, Babu V

    2015-12-01

    The health benefits imparted by probiotics and prebiotics as well as synbiotics have been the subject of extensive research in the past few decades. These food supplements termed as functional foods have been demonstrated to alter, modify and reinstate the pre-existing intestinal flora. They also facilitate smooth functions of the intestinal environment. Most commonly used probiotic strains are: Bifidobacterium, Lactobacilli, S. boulardii, B. coagulans. Prebiotics like FOS, GOS, XOS, Inulin; fructans are the most commonly used fibers which when used together with probiotics are termed synbiotics and are able to improve the viability of the probiotics. Present review focuses on composition and roles of Probiotics, Prebiotics and Synbiotics in human health. Furthermore, additional health benefits like immune-modulation, cancer prevention, inflammatory bowel disease etc. are also discussed. Graphical abstractPictorial summary of health benefits imparted by probiotics, prebiotics and synbiotics. PMID:26604335

  18. Probiotics, prebiotics, and synbiotics.

    PubMed

    de Vrese, Michael; Schrezenmeir, J

    2008-01-01

    . Prevention of respiratory tract infections (common cold, influenza) and other infectious diseases as well as treatment of urogenital infections. Insufficient or at most preliminary evidence exists with respect to cancer prevention, a so-called hypocholesterolemic effect, improvement of the mouth flora and caries prevention or prevention or therapy of ischemic heart diseases or amelioration of autoimmune diseases (e.g. arthritis). A prebiotic is "a selectively fermented ingredient that allows specific changes, both in the composition and/or activity in the gastrointestinal microflora that confers benefits upon host well being and health", whereas synergistic combinations of pro- and prebiotics are called synbiotics. Today, only bifidogenic, non-digestible oligosaccharides (particularly inulin, its hydrolysis product oligofructose, and (trans)galactooligosaccharides), fulfill all the criteria for prebiotic classification. They are dietary fibers with a well-established positive impact on the intestinal microflora. Other health effects of prebiotics (prevention of diarrhoea or obstipation, modulation of the metabolism of the intestinal flora, cancer prevention, positive effects on lipid metabolism, stimulation of mineral adsorption and immunomodulatory properties) are indirect, i.e. mediated by the intestinal microflora, and therefore less-well proven. In the last years, successful attempts have been reported to make infant formula more breast milk-like by the addition of fructo- and (primarily) galactooligosaccharides. PMID:18461293

  19. The International Scientific Conference on Probiotics and Prebiotics.

    PubMed

    Madsen, Karen

    2011-10-01

    The 5th International Scientific Conference on Probiotics and Prebiotics was held in the Doubletree Hotel in Kosice, Slovakia, and highlighted current advances in the research and use of probiotics and prebiotics in both animal and human health. The conference attracted academic and industry representatives from over 35 countries and facilitated networking between research scientists and industry. A poster session was on display throughout the entire meeting. Over the course of the 3-day symposium, 12 sessions addressed issues related to the use of probiotics and prebiotics in the prevention and treatment of chronic and infectious diseases, their effects on host immune function and how they may modulate existing gut microbes. PMID:21910573

  20. Prebiotic mechanisms, functions and application

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In October 2012, a group of scientists met at the 10th Meeting of the International Scientific Association of Probiotics and Prebiotics (ISAPP) in Cork, Ireland to discuss issues surrounding prebiotics and their development. This article summarises outputs from the meeting. Various prebiotic defin...

  1. Prebiotic synthesis of histidine

    NASA Technical Reports Server (NTRS)

    Shen, C.; Yang, L.; Miller, S. L.; Oro, J.

    1990-01-01

    The prebiotic formation of histidine (His) has been accomplished experimentally by the reaction of erythrose with formamidine followed by a Strecker synthesis. In the first step of this reaction sequence, the formation of imidazole-4-acetaldehyde took place by the condensation of erythrose and formamidine, two compounds that are known to be formed under prebiotic conditions. In a second step, the imidazole-4-acetaldehyde was converted to His, without isolation of the reaction products by adding HCN and ammonia to the reaction mixture. LC, HPLC, thermospray liquid chromatography-mass spectrometry, and tandem mass spectrometry were used to identify the product, which was obtained in a yield of 3.5% based on the ratio of His/erythrose. This is a new chemical synthesis of one of the basic amino acids which had not been synthesized prebiotically until now.

  2. Prebiotic chemistry in clouds

    NASA Technical Reports Server (NTRS)

    Oberbeck, Verne R.; Marshall, John; Shen, Thomas

    1991-01-01

    The chemical evolution hypothesis of Woese (1979), according to which prebiotic reactions occurred rapidly in droplets in giant atmospheric reflux columns was criticized by Scherer (1985). This paper proposes a mechanism for prebiotic chemistry in clouds that answers Scherer's concerns and supports Woese's hypothesis. According to this mechanism, rapid prebiotic chemical evolution was facilitated on the primordial earth by cycles of condensation and evaporation of cloud drops containing clay condensation nuclei and nonvolatile monomers. For example, amino acids supplied by, or synthesized during entry of meteorites, comets, and interplanetary dust, would have been scavenged by cloud drops containing clay condensation nuclei and would be polymerized within cloud systems during cycles of condensation, freezing, melting, and evaporation of cloud drops.

  3. Emergent Sources of Prebiotics: Seaweeds and Microalgae.

    PubMed

    de Jesus Raposo, Maria Filomena; de Morais, Alcina Maria Miranda Bernardo; de Morais, Rui Manuel Santos Costa

    2016-02-01

    In recent years, scientists have become aware that human microbiota, in general, and gut microbiota, in particular, play a major role in human health and diseases, such as obesity and diabetes, among others. A large number of evidence has come to light regarding the beneficial effects, either for the host or the gut microbiota, of some foods and food ingredients or biochemical compounds. Among these, the most promising seem to be polysaccharides (PS) or their derivatives, and they include the dietary fibers. Some of these PS can be found in seaweeds and microalgae, some being soluble fibers, such as alginates, fucoidans, carrageenans and exopolysaccharides, that are not fermented, at least not completely, by colonic microbiota. This review gives an overview of the importance of the dietary fibers, as well as the benefits of prebiotics, to human health. The potential of the PS from marine macro- and microalgae to act as prebiotics is discussed, and the different techniques to obtain oligosaccharides from PS are presented. The mechanisms of the benefits of fiber, in general, and the types and benefits of algal fibers in human health are highlighted. The findings of some recent studies that present the potential effects of prebiotics on animal models of algal biomass and their extracts, as well as oligo- and polysaccharides, are presented. In the future, the possibility of using prebiotics to modulate the microbiome, and, consequently, prevent certain human diseases is foreseen. PMID:26828501

  4. Emergent Sources of Prebiotics: Seaweeds and Microalgae

    PubMed Central

    de Jesus Raposo, Maria Filomena; de Morais, Alcina Maria Miranda Bernardo; de Morais, Rui Manuel Santos Costa

    2016-01-01

    In recent years, scientists have become aware that human microbiota, in general, and gut microbiota, in particular, play a major role in human health and diseases, such as obesity and diabetes, among others. A large number of evidence has come to light regarding the beneficial effects, either for the host or the gut microbiota, of some foods and food ingredients or biochemical compounds. Among these, the most promising seem to be polysaccharides (PS) or their derivatives, and they include the dietary fibers. Some of these PS can be found in seaweeds and microalgae, some being soluble fibers, such as alginates, fucoidans, carrageenans and exopolysaccharides, that are not fermented, at least not completely, by colonic microbiota. This review gives an overview of the importance of the dietary fibers, as well as the benefits of prebiotics, to human health. The potential of the PS from marine macro- and microalgae to act as prebiotics is discussed, and the different techniques to obtain oligosaccharides from PS are presented. The mechanisms of the benefits of fiber, in general, and the types and benefits of algal fibers in human health are highlighted. The findings of some recent studies that present the potential effects of prebiotics on animal models of algal biomass and their extracts, as well as oligo- and polysaccharides, are presented. In the future, the possibility of using prebiotics to modulate the microbiome, and, consequently, prevent certain human diseases is foreseen. PMID:26828501

  5. Health benefits of prebiotic fibers.

    PubMed

    Meyer, Diederick

    2015-01-01

    This chapter describes the various compounds that can act as prebiotic fibers: their structure, occurrence, production, and physiological effects (health effects) will be presented. The basis for the description is the latest definitions for dietary fibers and for prebiotics. Using as much as possible data from human studies, both the fiber and the prebiotic properties will be described of a variety of compounds. Based on the presented data the latest developments in the area of prebiotics, fibers and gut and immune health will be discussed in more detail as they show best what the potential impact of prebiotics on health of the human host might be. PMID:25624035

  6. Prebiotic effects: metabolic and health benefits.

    PubMed

    Roberfroid, Marcel; Gibson, Glenn R; Hoyles, Lesley; McCartney, Anne L; Rastall, Robert; Rowland, Ian; Wolvers, Danielle; Watzl, Bernhard; Szajewska, Hania; Stahl, Bernd; Guarner, Francisco; Respondek, Frederique; Whelan, Kevin; Coxam, Veronique; Davicco, Marie-Jeanne; Léotoing, Laurent; Wittrant, Yohann; Delzenne, Nathalie M; Cani, Patrice D; Neyrinck, Audrey M; Meheust, Agnes

    2010-08-01

    a prebiotic effect has tentatively been investigated for potential health benefits. The prebiotic effect has been shown to associate with modulation of biomarkers and activity(ies) of the immune system. Confirming the studies in adults, it has been demonstrated that, in infant nutrition, the prebiotic effect includes a significant change of gut microbiota composition, especially an increase of faecal concentrations of bifidobacteria. This concomitantly improves stool quality (pH, SCFA, frequency and consistency), reduces the risk of gastroenteritis and infections, improves general well-being and reduces the incidence of allergic symptoms such as atopic eczema. Changes in the gut microbiota composition are classically considered as one of the many factors involved in the pathogenesis of either inflammatory bowel disease or irritable bowel syndrome. The use of particular food products with a prebiotic effect has thus been tested in clinical trials with the objective to improve the clinical activity and well-being of patients with such disorders. Promising beneficial effects have been demonstrated in some preliminary studies, including changes in gut microbiota composition (especially increase in bifidobacteria concentration). Often associated with toxic load and/or miscellaneous risk factors, colon cancer is another pathology for which a possible role of gut microbiota composition has been hypothesised. Numerous experimental studies have reported reduction in incidence of tumours and cancers after feeding specific food products with a prebiotic effect. Some of these studies (including one human trial) have also reported that, in such conditions, gut microbiota composition was modified (especially due to increased concentration of bifidobacteria). Dietary intake of particular food products with a prebiotic effect has been shown, especially in adolescents, but also tentatively in postmenopausal women, to increase Ca absorption as well as bone Ca accretion and bone

  7. Struvite and prebiotic phosphorylation.

    NASA Technical Reports Server (NTRS)

    Handschuh, G. J.; Orgel, L. E.

    1973-01-01

    Struvite rather than apatite or amorphous calcium phosphate is precipitated when phosphate is added to seawater containing more than 0.01M NH4+ ions. Struvite may have precipitated from evaporating seawater on the primitive earth, and may have been important for prebiotic phosphorylation.

  8. Fate of prebiotic adenine.

    PubMed

    Cohn, C A; Hansson, T K; Larsson, H S; Sowerby, S J; Holm, N G

    2001-01-01

    Equilibrium adsorption isotherm data for the purine base adenine has been obtained on several prebiotically relevant minerals by frontal analysis using water as a mobile phase. Adenine is far displaced toward adsorption on pyrite (FeS2), quartz (SiO2), and pyrrhotite (FeS), but somewhat less for magnetite (Fe3O4) and forsterite (Mg2SiO4). The prebiotic prevalence of these minerals would have allowed them to act as a sink for adenine; removal from the aqueous phase would confer protection from hydrolysis as well, establishing a nonequilibrium thermodynamic framework for increased adenine synthesis. Our results provide evidence that adsorption phenomena may have been critical for the primordial genetic architecture. PMID:12448980

  9. Analysis of Prebiotic Oligosaccharides

    NASA Astrophysics Data System (ADS)

    Sanz, M. L.; Ruiz-Matute, A. I.; Corzo, N.; Martínez-Castro, I.

    Carbohydrates and more specifically prebiotics, are complex mixtures of isomers with different degrees of polymerization (DP), monosaccharide units and/or glycosidic linkages. Many efforts are focused on the search for new products and the determination of their biological activity. However, the study of their chemical structure is fundamental to both acquire a basic knowledge of the carbohydrate and to increase the understanding of the mechanisms for their metabolic effect.

  10. Prebiotic activation processes.

    NASA Technical Reports Server (NTRS)

    Lohrmann, R.; Orgel, L. E.

    1973-01-01

    Questions regarding the combination of amino acids and ribonucleotides to polypeptides and polynucleotides are investigated. Each of the reactions considered occurs in the solid state in plausible prebiotic conditions. Together they provide the basis for a unified scheme of amino acid and nucleotide activation. Urea, imidazole and Mg(++) are essential catalytic components of the reaction mixtures. However, these compounds could probably be replaced by other organic molecules.

  11. Application of prebiotics in infant foods.

    PubMed

    Veereman-Wauters, Gigi

    2005-04-01

    The rationale for supplementing an infant formula with prebiotics is to obtain a bifidogenic effect and the implied advantages of a 'breast-fed-like' flora. So far, the bifidogenic effect of oligofructose and inulin has been demonstrated in animals and in adults, of oligofructose in infants and toddlers and of a long-chain inulin (10 %) and galactooligosaccharide (90 %) mixture in term and preterm infants. The addition of prebiotics to infant formula softens stools but other putative effects remain to be demonstrated. Studies published post marketing show that infants fed a long-chain inulin/galactooligosaccharide mixture (0.8 g/dl) in formula grow normally and have no side-effects. The addition of the same mixture at a concentration of 0.8 g/dl to infant formula was therefore recognized as safe by the European Commission in 2001 but follow-up studies were recommended. It is thought that a bifidogenic effect is beneficial for the infant host. The rising incidence in allergy during the first year of life may justify the attempts to modulate the infant's flora. Comfort issues should not be confused with morbidity and are likely to be multifactorial. The functional effects of prebiotics on infant health need further study in controlled intervention trials. PMID:15877896

  12. Intestinal infections and prebiotics: the roles of oligosaccharides in promoting health

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Prebiotic oligosaccharides exert activity against pathogens partly by stimulating the growth and/or activity of commensal bacteria that provide health benefits (lower pH, bacteriocin production, immune system modulation, competitive exclusion). This review describes alternative mechanisms of action...

  13. Prebiotics and synbiotics: concepts and nutritional properties.

    PubMed

    Roberfroid, M B

    1998-10-01

    The main role of diet is to provide enough nutrients to meet the requirements of a balanced diet, while giving the consumer a feeling of satisfaction and well-being. The most recent knowledge in bioscience supports the hypothesis that diet also controls and modulates various functions in the body, and, in doing so, contributes to the state of good health necessary to reduce the risk of some diseases. It is such an hypothesis which is at the origin both of the concept of 'functional food' and the development of a new scientific discipline of 'functional food science'. In the context of this paper the potential 'functional foods' to be discussed are the prebiotics and the synbiotics. The prebiotics developed so far are the non-digestible oligosaccharides and especially the non-digestible fructans among which chicory fructans play a major role. The chicory fructans are beta (2-1) fructo-oligosaccharides classified as natural food ingredients. They positively affect various physiological functions in such a way that they are already or may, in the future, be classified as functional food ingredients for which claims of functional effects or of disease risk reduction might become authorized. They are classified as prebiotic and have been shown to induce an increase in the number of bifidobacteria in human faecal flora. As part of a synbiotic-type product, they are already bifidogenic at a dose of 2.75 g/d and the effect lasts for at least 7 weeks. The other potential functional effects are on the bioavailability of minerals, but also, and more systemically, on the metabolism of lipids. Potential health benefits may concern reduction of the risk of intestinal infectious diseases, cardiovascular disease, non-insulin-dependent diabetes, obesity, osteoporosis and cancer. However, except for the prebiotic effect, and tentatively the improvement of calcium bioavailability, the evidence to support such effects is still missing in humans though hypotheses already exist to

  14. A Prebiotic Synthesis of Pterins.

    PubMed

    Marín-Yaseli, Margarita R; Mompeán, Cristina; Ruiz-Bermejo, Marta

    2015-09-21

    The genesis of life on Earth is a hypothesis of evolutionary science that can be, at least partially, tested experimentally. The prebiotic synthesis of cofactors or coenzymes is a poorly explored issue, likely because their formation under plausible prebiotic conditions is not clear. In this sense, it has been proposed that the cofactors are "molecular fossils" of an early phase of life. In contrast, Eschenmoser and Loewenthal suggested a prebiotic hydrocyanic origin of cofactor building blocks. In the present paper, the formation of a set of pterins from cyanide polymerizations is demonstrated, showing that the main structure of some cofactors can be prebiotically formed. Indeed, it was observed that aqueous aerosols additionally increase the relative composition for pterins in the insoluble NH4CN polymers synthesized. The novel identification of pterins in NH4CN polymers, together with the previous detection of other important biomonomers, indicates that cyanide polymerizations were essential in the early state of prebiotic chemistry. PMID:26256284

  15. Variations in prebiotic oligosaccharide fermentation by intestinal lactic acid bacteria.

    PubMed

    Endo, Akihito; Nakamura, Saki; Konishi, Kenta; Nakagawa, Junichi; Tochio, Takumi

    2016-01-01

    Prebiotic oligosaccharides confer health benefits on the host by modulating the gut microbiota. Intestinal lactic acid bacteria (LAB) are potential targets of prebiotics; however, the metabolism of oligosaccharides by LAB has not been fully characterized. Here, we studied the metabolism of eight oligosaccharides by 19 strains of intestinal LAB. Among the eight oligosaccharides used, 1-kestose, lactosucrose and galactooligosaccharides (GOSs) led to the greatest increases in the numbers of the strains tested. However, mono- and disaccharides accounted for more than half of the GOSs used, and several strains only metabolized the mono- and di-saccharides in GOSs. End product profiles indicated that the amounts of lactate produced were generally consistent with the bacterial growth recorded. Oligosaccharide profiling revealed the interesting metabolic manner in Lactobacillus paracasei strains, which metabolized all oligosaccharides, but left sucrose when cultured with fructooligosaccharides. The present study clearly indicated that the prebiotic potential of each oligosaccharide differs. PMID:26888650

  16. Phosphorus in prebiotic chemistry

    PubMed Central

    Schwartz, Alan W

    2006-01-01

    The prebiotic synthesis of phosphorus-containing compounds—such as nucleotides and polynucleotides—would require both a geologically plausible source of the element and pathways for its incorporation into chemical systems on the primitive Earth. The mineral apatite, which is the only significant source of phosphate on Earth, has long been thought to be problematical in this respect due to its low solubility and reactivity. However, in the last decade or so, at least two pathways have been demonstrated which would circumvent these perceived problems. In addition, recent results would seem to suggest an additional, extraterrestrial source of reactive phosphorus. It appears that the ‘phosphorus problem’ is no longer the stumbling block which it was once thought to be. PMID:17008215

  17. Prebiotic photosynthetic reactions.

    PubMed

    Chittenden, G J; Schwartz, A W

    1981-01-01

    Historically, numerous attempts have been made to mimic - by means of inorganic model reactions - the photosynthetic fixation of CO2 by green plants. The literature in this field is strewn with claims and counter-claims. Two factors have led us to reexamine this subject: firstly; doubts concerning the highly reducing model for the atmosphere of the primitive Earth and secondly; recent results which demonstrate that photoreductive fixation is feasable on a suitable catalytic surface, for both CO2 and N2. The latter observation is of particular interest due to the well-known susceptibility of NH3 to photolytic destruction. Our review of the literature leads us to suggest that similar processes would have been plausible for the primitive Earth and could have been prebiotic precursors to an early development of CO2-fixing autotrophs. PMID:6791723

  18. Effect of Probiotics/Prebiotics on Cattle Health and Productivity

    PubMed Central

    Uyeno, Yutaka; Shigemori, Suguru; Shimosato, Takeshi

    2015-01-01

    Probiotics/prebiotics have the ability to modulate the balance and activities of the gastrointestinal (GI) microbiota, and are, thus, considered beneficial to the host animal and have been used as functional foods. Numerous factors, such as dietary and management constraints, have been shown to markedly affect the structure and activities of gut microbial communities in livestock animals. Previous studies reported the potential of probiotics and prebiotics in animal nutrition; however, their efficacies often vary and are inconsistent, possibly, in part, because the dynamics of the GI community have not been taken into consideration. Under stressed conditions, direct-fed microbials may be used to reduce the risk or severity of scours caused by disruption of the normal intestinal environment. The observable benefits of prebiotics may also be minimal in generally healthy calves, in which the microbial community is relatively stable. However, probiotic yeast strains have been administered with the aim of improving rumen fermentation efficiency by modulating microbial fermentation pathways. This review mainly focused on the benefits of probiotics/prebiotics on the GI microbial ecosystem in ruminants, which is deeply involved in nutrition and health for the animal. PMID:26004794

  19. Dietary prebiotics: Current status and new definition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In November 2008, a group of scientists met at the 6th Meeting of the International Scientific Association of Probiotics and Prebiotics (ISAPP) in London, Ontario. The aim was to discuss the functionality of prebiotics. As a result of this, it was decided that the prebiotic field as it stands is dom...

  20. Probiotics and prebiotics: immunological and clinical effects in allergic disease.

    PubMed

    Tang, Mimi L K

    2009-01-01

    The intestinal microbiota plays an important role in immune development and may play a role in the development of allergic disorders. Manipulation of the intestinal microbiota may therefore offer an approach to the prevention or treatment of allergic diseases. Probiotics and prebiotics, used alone or together (synbiotics), can influence the intestinal microbiota and modulate immune responses in vitro and in vivo. Clinical studies suggest a potential role for selected probiotics (alone or in combination with prebiotics) in the prevention of atopic eczema. A prenatal component of treatment appears important for beneficial effects. Effects are dependent upon the specific bacteria and characteristics of the study population. One study reported beneficial effects for prebiotics in the prevention of eczema in high-risk infants, however, further studies are required to confirm this. The use of probiotics in the treatment of allergic disease is less promising. A Cochrane meta-analysis concluded that probiotics are not effective for the treatment of atopic dermatitis. Probiotic effects in the treatment of asthma and allergic rhinitis are conflicting. Probiotics, prebiotics and synbiotics offer potential treatments for the prevention of atopic eczema; however, there is currently insufficient evidence to recommend their use in clinical practice. Studies to clarify the optimal dose, bacterial species/strains, whether there is added benefit with synbiotics, the optimal timing for intervention, and the patient populations who would benefit most from such therapies are warranted. PMID:19710525

  1. Prebiotic inulin: Useful dietary adjuncts to manipulate the livestock gut microflora

    PubMed Central

    Samanta, A.K.; Jayapal, Natasha; Senani, S.; Kolte, A.P.; Sridhar, Manpal

    2013-01-01

    In recent years, there has been a growing appreciation on the relevance of gastrointestinal microflora in both ruminants and non-ruminants owing to revelation of their role in several physiological functions including digestion, nutrient utilization, pathogen exclusion, gastrointestinal development, immunity system, gut gene expression and quality of animal products. The ban imposed on the use of antibiotics and hormones in feed has compelled animal researchers in finding an alternative which could overcome the issues of conventional feed additives. Though the concept of prebiotic was evolved keeping in mind the gastrointestinal flora of human beings, presently animal researchers are exploring the efficiency of prebiotic (inulin) for modulating the gut ecosystem of both ruminants and non-ruminants. It was revealed that prebiotic inulin is found to exhibit desirable changes in the gut of non-ruminants like poultry, swine, rabbit etc for augmenting gut health and improvement of product quality. Similarly, in ruminants the prebiotic reduces rumen ammonia nitrogen, methane production, increase microbial protein synthesis and live weight gains in calves. Unlike other feed additives, prebiotic exhibits its effect in multipronged ways for overall increase in the performances of the animals. In coming days, it is expected that prebiotics could be the part of diets in both ruminants and non-ruminants for enabling modulation of gut microflora vis a vis animals productivity in ecological ways. PMID:24159277

  2. Gut microbiota: Ganoderma lucidum, a new prebiotic agent to treat obesity?

    PubMed

    Delzenne, Nathalie M; Bindels, Laure B

    2015-10-01

    Modulation of the gut microbiota is one of the promising tools to tackle obesity. Chang and colleagues have recently shown that an extract of the mushroom Ganoderma lucidum, a traditional remedy in Asia, can reduce obesity in mice by modulating the gut microbiota, thereby exerting a prebiotic effect. PMID:26284561

  3. Catalysis and prebiotic RNA synthesis

    NASA Technical Reports Server (NTRS)

    Ferris, James P.

    1993-01-01

    The essential role of catalysis for the origins of life is discussed. The status of the prebiotic synthesis of 2',5'- and 3'5'-linked oligomers of RNA is reviewed. Examples of the role of metal ion and mineral catalysis in RNA oligomer formation are discussed.

  4. Probiotics and prebiotics in pediatrics.

    PubMed

    Thomas, Dan W; Greer, Frank R

    2010-12-01

    This clinical report reviews the currently known health benefits of probiotic and prebiotic products, including those added to commercially available infant formula and other food products for use in children. Probiotics are supplements or foods that contain viable microorganisms that cause alterations of the microflora of the host. Use of probiotics has been shown to be modestly effective in randomized clinical trials (RCTs) in (1) treating acute viral gastroenteritis in healthy children; and (2) preventing antibiotic-associated diarrhea in healthy children. There is some evidence that probiotics prevent necrotizing enterocolitis in very low birth weight infants (birth weight between 1000 and 1500 g), but more studies are needed. The results of RCTs in which probiotics were used to treat childhood Helicobacter pylori gastritis, irritable bowel syndrome, chronic ulcerative colitis, and infantile colic, as well as in preventing childhood atopy, although encouraging, are preliminary and require further confirmation. Probiotics have not been proven to be beneficial in treating or preventing human cancers or in treating children with Crohn disease. There are also safety concerns with the use of probiotics in infants and children who are immunocompromised, chronically debilitated, or seriously ill with indwelling medical devices. Prebiotics are supplements or foods that contain a nondigestible food ingredient that selectively stimulates the favorable growth and/or activity of indigenous probiotic bacteria. Human milk contains substantial quantities of prebiotics. There is a paucity of RCTs examining prebiotics in children, although there may be some long-term benefit of prebiotics for the prevention of atopic eczema and common infections in healthy infants. Confirmatory well-designed clinical research studies are necessary. PMID:21115585

  5. Impact of prebiotics and probiotics on skin health.

    PubMed

    Al-Ghazzewi, F H; Tester, R F

    2014-06-01

    This review discusses the role of pre- and probiotics with respect to improving skin health by modulating the cutaneous microbiota. The skin ecosystem is a complex environment covered with a diverse microbiota community. These are classified as either transient or resident, where some are considered as beneficial, some essentially neutral and others pathogenic or at least have the capacity to be pathogenic. Colonisation varies between different parts of the body due to different environmental factors. Pre- and probiotic beneficial effects can be delivered topically or systemically (by ingestion). The pre- and probiotics have the capacity to optimise, maintain and restore the microbiota of the skin in different ways. Topical applications of probiotic bacteria have a direct effect at the site of application by enhancing the skin natural defence barriers. Probiotics as well as resident bacteria can produce antimicrobial peptides that benefit cutaneous immune responses and eliminate pathogens. In cosmetic formulations, prebiotics can be applied to the skin microbiota directly and increase selectively the activity and growth of beneficial 'normal' skin microbiota. Little is known about the efficacy of topically applied prebiotics. Nutritional products containing prebiotics and/or probiotics have a positive effect on skin by modulating the immune system and by providing therapeutic benefits for atopic diseases. This review underlines the potential use of pre- and probiotics for skin health. PMID:24583611

  6. Prebiotics in Companion and Livestock Animal Nutrition

    NASA Astrophysics Data System (ADS)

    Barry, Kathleen A.; Vester, Brittany M.; Fahey, George C.

    Prebiotic supplementation of animal diets began in an attempt to increase concentrations of beneficial intestinal microbiota. It was understood that prebiotics inhibited growth of intestinal pathogens and decreased concentrations of stool odor-causing metabolites. Since the use of prebiotics began, several countries have banned the use of antimicrobials in livestock animal feeds, and several more have placed restrictions on the quantity of antimicrobials that can be used. Prebiotic supplementation has become increasingly popular as the body of evidence supporting its use continues to grow. As this literature expands, the number of potential prebiotic substances has grown beyond those that are naturally occurring, such as those found in chicory and yeast products, to include a large number of synthetic or chemically/enzymatically manufactured prebiotics.

  7. [Prebiotics: concept, properties and beneficial effects].

    PubMed

    Corzo, N; Alonso, J L; Azpiroz, F; Calvo, M A; Cirici, M; Leis, R; Lombó, F; Mateos-Aparicio, I; Plou, F J; Ruas-Madiedo, P; Rúperez, P; Redondo-Cuenca, A; Sanz, M L; Clemente, A

    2015-01-01

    Prebiotics are non-digestible food ingredients (oligosaccharides) that reach the colon and are used as substrate by microorganisms producing energy, metabolites and micronutrients used for the host; in addition they also stimulate the selective growth of certain beneficial species (mainly bifidobacteria and lactobacilli) in the intestinal microbiota. In this article, a multidisciplinary approach to understand the concept of prebiotic carbohydrates, their properties and beneficial effects in humans has been carried out. Definitions of prebiotics, reported by relevant international organizations and researchers, are described. A comprehensive description of accepted prebiotics having strong scientific evidence of their beneficial properties in humans (inulin-type fructans, FOS, GOS, lactulose and human milk oligosaccharides) is reported. Emerging prebiotics and those which are in the early stages of study have also included in this study. Taken into account that the chemical structure greatly influences carbohydrates prebiotic properties, the analytical techniques used for their analysis and characterization are discussed. In vitro and in vivo models used to evaluate the gastrointestinal digestion, absorption resistance and fermentability in the colon of prebiotics as well as major criteria to design robust intervention trials in humans are described. Finally, a comprehensive summary of the beneficial effects of prebiotics for health at systemic and intestinal levels is reported. The research effort on prebiotics has been intensive in last decades and has demonstrated that a multidisciplinary approach is necessary in order to claim their health benefits. PMID:25659062

  8. Spectroscopy of Isolated Prebiotic Nucleobases

    NASA Technical Reports Server (NTRS)

    Svadlenak, Nathan; Callahan, Michael P.; Ligare, Marshall; Gulian, Lisa; Gengeliczki, Zsolt; Nachtigallova, Dana; Hobza, Pavel; deVries, Mattanjah

    2011-01-01

    We use multiphoton ionization and double resonance spectroscopy to study the excited state dynamics of biologically relevant molecules as well as prebiotic nucleobases, isolated in the gas phase. Molecules that are biologically relevant to life today tend to exhibit short excited state lifetimes compared to similar but non-biologically relevant analogs. The mechanism is internal conversion, which may help protect the biologically active molecules from UV damage. This process is governed by conical intersections that depend very strongly on molecular structure. Therefore we have studied purines and pyrimidines with systematic variations of structure, including substitutions, tautomeric forms, and cluster structures that represent different base pair binding motifs. These structural variations also include possible alternate base pairs that may shed light on prebiotic chemistry. With this in mind we have begun to probe the ultrafast dynamics of molecules that exhibit very short excited states and search for evidence of internal conversions.

  9. Tolerance of probiotics and prebiotics.

    PubMed

    Marteau, Philippe; Seksik, Philippe

    2004-07-01

    The clinical efficacy of probiotics and prebiotics has been proved in several clinical settings. The authors review their proved or potential side effects. Probiotics as living microorganisms may theoretically be responsible for 4 types of side effects in susceptible individuals: infections, deleterious metabolic activities, excessive immune stimulation, and gene transfer. Very few cases of infection have been observed. These occurred mainly in very sick patients who received probiotic drugs because of severe medical conditions. Prebiotics exert an osmotic effect in the intestinal lumen and are fermented in the colon. They may induce gaseousness and bloating. Abdominal pain and diarrhea only occur with large doses. An increase in gastroesophageal reflux has recently been associated with large daily doses. Tolerance depends on the dose and individual sensitivity factors (probably the presence of irritable bowel syndrome or gastroesophageal reflux), and may be an adaptation to chronic consumption. PMID:15220662

  10. Coacervates as prebiotic chemical reactors

    NASA Astrophysics Data System (ADS)

    Kolb, Vera M.; Swanson, Mercedes; Menger, Fredric M.

    2012-10-01

    Coacervates are colloidal systems that are comprised of two immiscible aqueous layers, the colloid-rich layer, so-called coacervate, and the colloid-poor layer, so-called equilibrium liquid. Although immiscible, the two phases are both water-rich. Coacervates are important for prebiotic chemistry, but also have various practical applications, notably as transport vehicles of personal care products and pharmaceuticals. Our objectives are to explore the potential of coacervates as prebiotic chemical reactors. Since the reaction medium in coacervates is water, this creates a challenge, since most organic reactants are not water-soluble. To overcome this challenge we are utilizing recent Green Chemistry examples of the organic reactions in water, such as the Passerini reaction. We have investigated this reaction in two coacervate systems, and report here our preliminary results.

  11. Cashew juice containing prebiotic oligosaccharides.

    PubMed

    da Silva, Isabel Moreira; Rabelo, Maria Cristiane; Rodrigues, Sueli

    2014-09-01

    The enzyme dextransucrase in a medium containing sucrose and an acceptor as substrate synthesizes prebiotics oligosaccharides. The cashew apple juice works as a source of acceptors because it is rich in glucose and fructose (enzyme acceptors). The use of cashew apple juice becomes interesting because it aims at harnessing the peduncle of the cashew that is wasted during the nut processing, which is the product of greater economic expression. The production of dextransucrase enzyme was done by fermentative process by inoculating the bacterium Leuconostoc mesenteroides NRRL B512F into a culture medium containing sucrose as the only carbon source. Thus, the aim of this work was the production of prebiotic oligosaccharides by enzymatic process with addition of the dextransucrase enzyme to the clarified cashew apple juice. Dextran yield was favored by the combination of low concentrations of sucrose and reducing sugars. The formation of oligosaccharides was favored by increasing the concentration of reducing sugars and by the combination of high concentrations of sucrose and reducing sugars, the highest concentration of oligosaccharides obtained was 104.73 g/L and the qualitative analysis showed that at concentrations of 25 g/L and 75 g/L of sucrose and reducing sugar, respectively, it is possible to obtain oligosaccharides of degree of polymerization up to 12. The juice containing prebiotic oligosaccharide is a potential new functional beverage. PMID:25190866

  12. Was Ferrocyanide a Prebiotic Reagent?

    NASA Technical Reports Server (NTRS)

    Keefe, Anthony D.; Miller, Stanley L.

    1996-01-01

    Hydrogen cyanide is the starting material for a diverse array of prebiotic syntheses, including those of amino acids and purines. Hydrogen cyanide also reacts with ferrous ions to give ferrocyanide, and so it is possible that ferrocyanide was common in the early ocean. This can only be true if the hydrogen cyanide concentration was high enough and the rate of reaction of cyanide with ferrous ions was fast enough. We show experimentally that the rate of formation of ferrocyanide is rapid even at low concentrations of hydrogen cyanide in the pH range 6-8, and therefore an equilibrium calculation is valid. The equilibrium concentrations of ferrocyanide are calculated as a function of hydrogen cyanide concentration, pH and temperature. The steady state concentration of hydrogen cyanide depends on the rate of synthesis by electric discharges and ultraviolet light and the rate of hydrolysis, which depends on pH and temperature. Our conclusions show that ferrocyanide was a major species in the prebiotic ocean only at the highest production rates of hydrogen cyanide in a strongly reducing atmosphere and at temperatures of 0 C or less, although small amounts would have been present at lower hydrogen cyanide production rates. The prebiotic application of ferrocyanide as a source of hydrated electrons, as a photochemical replication process, and in semi-permeable membranes is discussed.

  13. Imitating prebiotic homochirality on Earth.

    PubMed

    Breslow, Ronald; Levine, Mindy; Cheng, Zhan-Ling

    2010-02-01

    We show how the amino acids needed on prebiotic earth in their homochiral L form can be produced by a reaction of L-alpha-methyl amino acids-that have been identified in the Murchison meteorite-with alpha-keto acids under credible prebiotic conditions. When they are simply heated together they perform a process of decarboxylative transamination but with almost no chiral transfer, and that in the wrong direction, producing D-amino acids from the L-alpha-methyl amino acids. With copper ion a square planar complex with two of the reaction intermediates is formed, and now there is the desired L to L transformation, producing small enantioexcesses of the normal L-amino acids. We also show how these can be amplified, not by making more of the L form but by increasing its concentration in water solution. The process can start with a miniscule excess and in one step generate water solutions with L/D ratios in the over 90% region. Kinetic processes can exceed the results from equilibria. We have also examined such amplifications with ribonucleosides, and have shown that initial modest excesses of the D-nucleosides can be amplified to afford water solutions with D to L ratios in the high 90's. We have shown that the homochiral compound has two effects on the solubility of the racemate. On one hand it decreases the solubility of the racemate by its role in the solubility product, as a theoretical equation predicts. On the other hand, it increases the solubility of the racemate by changing the nature of the solvent, acting as a cosolvent with the water. This explains why the amplification, while large, is not as large as the simple theoretical equation predicts. Thus when credible examples are produced where small enantioexcesses of D-ribose are created under credible prebiotic conditions, the prerequisites for the RNA world will have been exemplified. PMID:19911303

  14. The prebiotic synthesis of oligonucleotides

    NASA Technical Reports Server (NTRS)

    Oro, J.; Stephen-Sherwood, E.

    1974-01-01

    This paper is primarily a review of recent developments in the abiotic synthesis of nucleotides, short chain oligonucleotides, and their mode of replication in solution. It also presents preliminary results from this laboratory on the prebiotic synthesis of thymidine oligodeoxynucleotides. A discussion, based on the physicochemical properties of RNA and DNA oligomers, relevant to the molecular evolution of these compounds leads to the tentative hypothesis that oligodeoxyribonucleotides of about 12 units may have been of sufficient length to initiate a self replicating coding system. Two models are suggested to account for the synthesis of high molecular weight oligomers using short chain templates and primers.

  15. [Autochthonous microbiota, probiotics and prebiotics].

    PubMed

    Suárez, Juan Evaristo

    2015-01-01

    The autochthonous microbiota is the community of microorganisms that colonizes the skin and mucosal surfaces. The symbiosis is, generally, mutualistic but it can become parasitic due to immune response alterations. The skin microbiota includes bacteria (95%), lipophilic fungi and mites. In the digestive apparatus, each cavity presents its own microbiota, which reaches its target organ during the perinatal period, originating complex and stable communities (homeostasis). The vaginal microbiota varies with the endocrine activity, significantly increasing during the fertile and pregnancy periods, when lactobacilli are the most abundant organisms. Four are the main benefits of the autochthonous microbiota: i) delivery of essential nutrients, such as vitamins and some amino acids; ii) utilization of undigestible diet components, the colonic microbiota degrades complex glycans and fulfils almost 20% of the calories present in a normal diet; iii) development of the immune system: the continuous contact with the immune system maintains it alert and in good shape to repel pathogens efficaciously and iv) microbial antagonism, hinders colonization of our mucosal surfaces by alochthonous, potentially pathogenic, organisms. This works through three mechanisms: colonization interference, production of antimicrobials and co-aggregation with the potential pathogens. The microbiota can, sporadically, produce damages: opportunistic endogenous infections and generation of carcinogenic compounds. Probiotics are "live microorganisms that when administered in adequate amounts, confer a health benefit to the consumer". Prebiotics are undigestible glycans that enhance the growth or activity of the intestinal microbiota, thus generating a health benefit. Synbiotics are mixes of probiotics and prebiotics that exert a synergistic health effect. PMID:25659048

  16. Attempted prebiotic synthesis of pseudouridine

    NASA Technical Reports Server (NTRS)

    Dworkin, J. P.; Miller, S. L. (Principal Investigator)

    1997-01-01

    Pseudouridine is a modified base found in all tRNA and rRNA. Hence, it is reasonable to think that pseudouridine was important in the early evolution, if not the origin, of life. Since uracil reacts rapidly with formaldehyde and other aldehydes at the C-5 position, it is plausible that pseudouridine could be synthesized in a similar way by the reaction of the C-5 of uracil with the C-1 of ribose. The determining factor is whether the ribose could react with the uracil faster than ribose decomposes. However, both rates are determined by the amount of free aldehyde in the ribose. Various plausible prebiotic reactions were investigated and none showed pseudouridine above the detection limit (<0.01%). Only unreacted uracil and ribose decomposition products could be observed. Thus the rate of addition of ribose to uracil is much slower than the decomposition of ribose under any reasonable prebiotic conditions. Unless efficient non-biological catalysts for any of these reactions exist, pseudouridine would not have been synthesized to any significant extent without the use of biologically produced enzymes.

  17. Prebiotics: A Potential Treatment Strategy for the Chemotherapy-damaged Gut?

    PubMed

    Wang, Hanru; Geier, Mark S; Howarth, Gordon S

    2016-04-25

    Mucositis, characterized by ulcerative lesions along the alimentary tract, is a common consequence of many chemotherapy regimens. Chemotherapy negatively disrupts the intestinal microbiota, resulting in increased numbers of potentially pathogenic bacteria, such as Clostridia and Enterobacteriaceae, and decreased numbers of "beneficial" bacteria, such as Lactobacilli and Bifidobacteria. Agents capable of restoring homeostasis in the bowel microbiota could, therefore, be applicable to mucositis. Prebiotics are indigestible compounds, commonly oligosaccharides, that seek to reverse chemotherapy-induced intestinal dysbiosis through selective colonization of the intestinal microbiota by probiotic bacteria. In addition, evidence is emerging that certain prebiotics contribute to nutrient digestibility and absorption, modulate intestinal barrier function through effects on mucin expression, and also modify mucosal immune responses, possibly via inflammasome-mediated processes. This review examines the known mechanisms of prebiotic action, and explores their potential for reducing the severity of chemotherapy-induced mucositis in the intestine. PMID:25162145

  18. Prebiotics to fight diseases: reality or fiction?

    PubMed

    Di Bartolomeo, F; Startek, J B; Van den Ende, W

    2013-10-01

    Bacteria living in the gastrointestinal tract are crucial for human health and disease occurrence. Increasing the beneficial intestinal microflora by consumption of prebiotics, which are 'functional foods', could be an elegant way to limit the number and incidence of disorders and to recover from dysbiosis or antibiotic treatments. This review focuses on the short-chain low-digestible carbohydrates (LDCs) which are metabolized by gut microbiota serving as energy source, immune system enhancers or facilitators of mineral uptake. Intake of foods containing LDCs can improve the state of health and may prevent diseases as for example certain forms of cancer. Given the large number of different molecules belonging to LDCs, we focused our attention on fructans (inulin, fructo-oligosaccharides), galacto-oligosaccharides and resistant starches and their therapeutic and protective applications. Evidence is accumulating that LDCs can inhibit bacterial and viral infections by modulating host defense responses and by changing the interactions between pathogenic and beneficial bacteria. Animal studies and studies on small groups of human subjects suggest that LDCs might help to counteract colorectal cancer, diabetes and metabolic syndrome. The action mechanisms of LDCs in the human body might be broader than originally thought, perhaps also including reactive oxygen species scavenging and signaling events. PMID:23280537

  19. Prebiotic synthesis of histidyl-histidine

    NASA Technical Reports Server (NTRS)

    Shen, C.; Mills, T.; Oro, J.

    1990-01-01

    Histidyl-histidine (His-His) has been synthesized in a yield of up to 14.4% under plausible prebiotic conditions using histidine (His), cyanamide, and 4-amino-5-imidazole carboxamide. A trace amount of His trimer was also detected. Because the imidazole group of His is involved in a number of important enzymatic reactions, and His-His has been shown to catalyze the prebiotic synthesis of glycyl-glycine, we expect this work will stimulate further studies on the catalytic activities of simple His-containing peptides in prebiotic reactions.

  20. Potentially Prebiotic Syntheses of Condensed Phosphates

    NASA Technical Reports Server (NTRS)

    Keefe, Anthony D.; Miller, Stanley L.

    1996-01-01

    In view of the importance of a prebiotic source of high energy phosphates, we have investigated a number of potentially prebiotic processes to produce condensed phosphates from orthophosphate and cyclic trimetaphosphate from tripolyphosphate. The reagents investigated include polymerizing nitriles, acid anhydrides, lactones, hexamethylene tetramine and carbon suboxide. A number of these processes give substantial yields of pyrophosphate from orthophosphate and trimetaphosphate from tripolyphosphate. Although these reactions may have been applicable in local areas, they are not sufficiently robust to have been of importance in the prebiotic open ocean.

  1. Prebiotics, probiotics, and synbiotics affect mineral absorption, bone mineral content, and bone structure.

    PubMed

    Scholz-Ahrens, Katharina E; Ade, Peter; Marten, Berit; Weber, Petra; Timm, Wolfram; Açil, Yahya; Glüer, Claus-C; Schrezenmeir, Jürgen

    2007-03-01

    Several studies in animals and humans have shown positive effects of nondigestible oligosaccharides (NDO) on mineral absorption and metabolism and bone composition and architecture. These include inulin, oligofructose, fructooligosaccharides, galactooligosaccharides, soybean oligosaccharide, and also resistant starches, sugar alcohols, and difructose anhydride. A positive outcome of dietary prebiotics is promoted by a high dietary calcium content up to a threshold level and an optimum amount and composition of supplemented prebiotics. There might be an optimum composition of fructooligosaccharides with different chain lengths (synergy products). The efficacy of dietary prebiotics depends on chronological age, physiological age, menopausal status, and calcium absorption capacity. There is evidence for an independent probiotic effect on facilitating mineral absorption. Synbiotics, i.e., a combination of probiotics and prebiotics, can induce additional effects. Whether a low content of habitual NDO would augment the effect of dietary prebiotics or synbiotics remains to be studied. The underlying mechanisms are manifold: increased solubility of minerals because of increased bacterial production of short-chain fatty acids, which is promoted by the greater supply of substrate; an enlargement of the absorption surface by promoting proliferation of enterocytes mediated by bacterial fermentation products, predominantly lactate and butyrate; increased expression of calcium-binding proteins; improvement of gut health; degradation of mineral complexing phytic acid; release of bone-modulating factors such as phytoestrogens from foods; stabilization of the intestinal flora and ecology, also in the presence of antibiotics; stabilization of the intestinal mucus; and impact of modulating growth factors such as polyamines. In conclusion, prebiotics are the most promising but also best investigated substances with respect to a bone-health-promoting potential, compared with probiotics

  2. Effect of in ovo-delivered prebiotics and synbiotics on lymphoid-organs' morphology in chickens.

    PubMed

    Madej, J P; Stefaniak, T; Bednarczyk, M

    2015-06-01

    Prebiotics and probiotics, either alone or together (synbiotics), can influence the intestinal microbiota and modulate the immune response. We aimed to investigate the effects of prebiotic and synbiotic administration during the early stage of development on the histological structures of central (bursa of Fabricius and thymus) and peripheral (spleen) lymphatic organs in broilers. We used 800 hatching eggs from meat-type hens (Ross 308). Prebiotics and synbiotics were administered in ovo into the air chamber of chicken eggs at d 12 incubation, as follows: prebiotic inulin (Pre1), Bi2tos (Pre2), a synbiotic composed of inulin and Lactococcus lactis subsp. lactis IBB SL1 (Syn1), a synbiotic composed of Bi2tos and L. lactis subsp. cremoris IBB SC1 (Syn2), or physiological saline (control group, C). In ovo delivery of prebiotics and synbiotics had no adverse effect on the development of the immune system in exposed chickens. Administration of Bi2tos with L. lactis subsp. cremoris (Syn2) decreased the cortex/medulla ratio in the thymus and slowed the development of the cortex in bursal follicles on d 21 posthatching, with consequent impacts on the primary lymphatic organs. The above treatment also stimulated germinal centers' formation in the spleens of 21- and 35-day-old chickens, indicating enhanced B-cell proliferation in secondary lymphatic organs. Syn2 also caused an age-dependent increase in the spleen/bursa of Fabricius ratio. In conclusion, the in ovo administration of pre- and synbiotics at d 12 incubation can modulate the central and peripheral lymphatic organ development in broilers. This effect is more pronounced after synbiotic treatment than in prebiotic-treated groups. PMID:25877410

  3. Mechanisms of Prebiotic Impact on Health

    NASA Astrophysics Data System (ADS)

    Steed, H.; Macfarlane, S.

    Prebiotics were originally defined as non-digestible food ingredients that beneficially affect the host by selectively stimulating the growth and/or activities of one or a limited number of bacteria in the colon, thereby improving host health (Gibson and Roberfroid, 1995). However, a more recent definition is that “A prebiotic is a selectively fermented ingredient that allows specific changes, both in the composition and/or activity in the gastrointestinal microbiota that confers benefits upon host wellbeing and health” (Gibson et al., 2004). The principal concept associated with both of these definitions is that the prebiotic has a selective effect on the microbiota that results in an improvement in the health of the host. Common prebiotics in use include inulins, fructo-oligosaccharides (FOS), galacto-oligosaccharides (GOS), soya-oligosaccharides, xylo-oligosaccharides, pyrodextrins, isomalto-oligosaccharides and lactulose. The majority of studies carried out to date have focused on inulin, FOS and GOS (Macfarlane et al., 2008).

  4. Prebiotics as immunostimulants in aquaculture: a review.

    PubMed

    Song, Seong Kyu; Beck, Bo Ram; Kim, Daniel; Park, John; Kim, Jungjoon; Kim, Hyun Duk; Ringø, Einar

    2014-09-01

    Prebiotics are indigestible fibers that increase beneficial gut commensal bacteria resulting in improvements of the host's health. The beneficial effects of prebiotics are due to the byproducts generated from their fermentation by gut commensal bacteria. In this review, the direct effects of prebiotics on the innate immune system of fish are discussed. Prebiotics, such as fructooligosaccharide, mannanoligosaccharide, inulin, or β-glucan, are called immunosaccharides. They directly enhance innate immune responses including: phagocytic activation, neutrophil activation, activation of the alternative complement system, increased lysozyme activity, and more. Immunosaccharides directly activate the innate immune system by interacting with pattern recognition receptors (PRR) expressed on innate immune cells. They can also associate with microbe associated molecular patterns (MAMPs) to activate innate immune cells. However, the underlying mechanisms involved in innate immune cell activation need to be further explored. Many studies have indicated that immunosaccharides are beneficial to both finfish and shellfish. PMID:24973515

  5. Prebiotic condensation reactions using cyanamide

    NASA Technical Reports Server (NTRS)

    Sherwood, E.; Nooner, D. W.; Eichberg, J.; Epps, D. E.; Oro, J.

    1978-01-01

    Condensation reactions in cyanamide, 4-amino-5-imidazole-carboxamide and cyanamide, imidazole systems under dehydrating conditions at moderate temperatures (60 to 100 deg C) were investigated. The cyanamide, imidazole system was used for synthesis of palmitoylglycerols from ammonium palmitate and glycerol. With the addition of deoxythymidine to the former system, P1, P2-dideoxythymidine 5 prime-phosphate was obtained; the same cyanamide, 4-amino-5-imidazole-carboxamide system was used to synthesize deoxythymidine oligonucleotides using deoxythymidine 5 prime-phosphate and deoxythymidine 5 prime-triphosphate, and peptides using glycine, phenylalanine or isoleucine with adenosine 5 prime-triphosphate. The pH requirements for these reactions make their prebiotic significance questionable; however, it is conceivable that they could occur in stable pockets of low interlayer acidity in a clay such as montmorillonite.

  6. Life's chirality from prebiotic environments

    NASA Astrophysics Data System (ADS)

    Gleiser, Marcelo; Walker, Sara Imari

    2012-10-01

    A key open question in the study of life is the origin of biomolecular homochirality: almost every life-form on Earth has exclusively levorotary amino acids and dextrorotary sugars. Will the same handedness be preferred if life is found elsewhere? We review some of the pertinent literature and discuss recent results suggesting that life's homochirality resulted from sequential chiral symmetry breaking triggered by environmental events. In one scenario, autocatalytic prebiotic reactions undergo stochastic fluctuations due to environmental disturbances, in a mechanism reminiscent of evolutionary punctuated equilibrium: short-lived destructive events may lead to long-term enantiomeric excess. In another, chiral-selective polymerization reaction rates influenced by environmental effects lead to substantial chiral excess even in the absence of autocatalysis. Applying these arguments to other potentially life-bearing platforms has implications to the search for extraterrestrial life: we predict that a statistically representative sampling of extraterrestrial stereochemistry will be racemic (chirally neutral) on average.

  7. The prebiotic chemistry of nucleotides

    NASA Technical Reports Server (NTRS)

    Ferris, J. P.; Yanagawa, H.; Hagan, W. J., Jr.

    1984-01-01

    Diminosuccinonitrile (DISN), formed by the oxidation of diaminomaleonitrile, has been investigated as a potential prebiotic phosphorylating agent. DISN affects the cyclization of 3'-adenosine monophosphate to adenosine 2',3'-cyclic phosphate in up to 39 percent yield. The mechanism of this reaction was investigated. The DISN-mediated phosphorylation of uridine to uridine monophosphate does not proceed efficiencly in aqueous solution. The reaction of DISN with uridine-5'-phosphate and uridine results in the formation of 2,2'-anhydronucleotides and 2,2'-anhydronucleosides respectively, and other reaction products resulting from an initial reaction at the 2'- and 3'-hydroxyl groups. The clay mineral catalysis of the cyclization of adenosine-3'-phosphate was investigated using homoionic montmorillonites.

  8. Prebiotic homochirality as a critical phenomenon.

    PubMed

    Gleiser, Marcelo; Thorarinson, Joel

    2006-12-01

    The development of prebiotic homochirality on early-Earth or another planetary platform may be viewed as a critical phenomenon. It is shown, in the context of spatio-temporal polymerization reaction networks, that environmental effects--be they temperature surges or other external disruptions--may destroy any net chirality previously produced. In order to understand the emergence of prebiotic homochirality it is important to model the coupling of polymerization reaction networks to different planetary environments. PMID:17120129

  9. Differential responses of gut microbiota to the same prebiotic formula in oligotrophic and eutrophic batch fermentation systems

    PubMed Central

    Long, Wenmin; Xue, Zhengsheng; Zhang, Qianpeng; Feng, Zhou; Bridgewater, Laura; Wang, Linghua; Zhao, Liping; Pang, Xiaoyan

    2015-01-01

    The same prebiotics have produced inconsistent effects on microbiota when evaluated in different batch fermentation studies. To understand the reasons behind these discrepancies, we compared impact of one prebiotic formula on the same inoculated fecal microbiota in two frequently used batch systems: phosphate-buffered saline (PBS, oligotrophic) and basal culture medium (BCM, eutrophic). The microbiota was monitored using 454 pyrosequencing. Negative controls (no prebiotic) of both systems showed significant shifts in the microbiota during fermentation, although their pH remained relatively stable, especially in BCM, with increases in Bilophila and Escherichia/Shigella but a decrease in Faecalibacterium. We identified prebiotic responders via redundancy analysis by including both baseline and negative controls. The key positive and negative responders in the two systems were very different, with only 8 consistently modulated OTUs (7 of the 28 positive responders and 1 of the 35 negative responders). Moreover, some OTUs within the same genus responded to the prebiotic in opposite ways. Therefore, to obtain a complete in vitro evaluation of the modulatory effects of a prebiotic on microbiota, it is necessary to use both oligotrophic and eutrophic systems, compare treatment groups with both baseline and negative controls, and analyze the microbiota changes down to the OTU level. PMID:26305380

  10. Evaluation of the prebiotic potential of arabinoxylans from brewer's spent grain.

    PubMed

    Reis, Sofia F; Gullón, Beatriz; Gullón, Patricia; Ferreira, Susana; Maia, Cláudio J; Alonso, José L; Domingues, Fernanda C; Abu-Ghannam, Nissreen

    2014-11-01

    Arabinoxylans (AX) consumption has been related to the treatment and prevention of cardiovascular diseases, type II diabetes, colorectal cancer and obesity. The beneficial health effects are conferred through gut microbiota modulation, and therefore, they have been proposed as potential slowly fermentable prebiotic candidates. As the mechanisms are not yet well understood, the prebiotic potential of AX from brewer's spent grain (BSG) has been investigated. Two types of AX from BSG (AX1 and AX2) of different length and branching averages were fermented with human faecal inocula and compared to fermented cultures containing a commercial prebiotic (fructooligosaccharide (FOS)) and cultures with no added carbohydrate (control). Results demonstrated that the AX were extensively metabolised after 48 h of fermentation. The pH decreased along fermentation and the lowest value was achieved in AX1 cultures. The production of short chain fatty acids (SCFA) was higher in AX cultures than in cultures containing FOS and controls, with AX1 presenting the highest concentrations. The stimulatory effect of beneficial bacteria was higher in AX cultures, and AX2 presented the highest positive effect. Prebiotic potential of AX from BSG was confirmed by the production of SCFA and the modulation of gut microbiota, especially by the high increase in bifidobacteria populations. PMID:25117549

  11. Antigenotoxic activity of lactic acid bacteria, prebiotics, and products of their fermentation against selected mutagens.

    PubMed

    Nowak, Adriana; Śliżewska, Katarzyna; Otlewska, Anna

    2015-12-01

    Dietary components such as lactic acid bacteria (LAB) and prebiotics can modulate the intestinal microbiota and are thought to be involved in the reduction of colorectal cancer risk. The presented study measured, using the comet assay, the antigenotoxic activity of both probiotic and non-probiotic LAB, as well as some prebiotics and the end-products of their fermentation, against fecal water (FW). The production of short chain fatty acids by the bacteria was quantified using HPLC. Seven out of the ten tested viable strains significantly decreased DNA damage induced by FW. The most effective of them were Lactobacillus mucosae 0988 and Bifidobacterium animalis ssp. lactis Bb-12, leading to a 76% and 80% decrease in genotoxicity, respectively. The end-products of fermentation of seven prebiotics by Lactobacillus casei DN 114-001 exhibited the strongest antigenotoxic activity against FW, with fermented inulin reducing genotoxicity by 75%. Among the tested bacteria, this strain produced the highest amounts of butyrate in the process of prebiotic fermentation, and especially from resistant dextrin (4.09 μM/mL). Fermented resistant dextrin improved DNA repair by 78% in cells pre-treated with 6.8 μM methylnitronitrosoguanidine (MNNG). Fermented inulin induced stronger DNA repair in cells pre-treated with mutagens (FW, 25 μM hydrogen peroxide, or MNNG) than non-fermented inulin, and the efficiency of DNA repair after 120 min of incubation decreased by 71%, 50% and 70%, respectively. The different degrees of genotoxicity inhibition observed for the various combinations of bacteria and prebiotics suggest that this effect may be attributable to carbohydrate type, SCFA yield, and the ratio of the end-products of prebiotic fermentation. PMID:26404012

  12. Development of a bread delivery vehicle for dietary prebiotics to enhance food functionality targeted at those with metabolic syndrome

    PubMed Central

    Costabile, Adele; Walton, Gemma E; Tzortzis, George; Vulevic, Jelena; Charalampopoulos, Dimitris; Gibson, Glenn R

    2015-01-01

    Prebiotics are dietary carbohydrates that favourably modulate the gut microbiota. The aims of the present study were to develop a functional prebiotic bread using Bimuno®, (galactooligosaccharide (B-GOS) mixture), for modulation of the gut microbiota in vitro in individuals at risk of metabolic syndrome. A control bread, (no added prebiotic) and positive control bread (containing equivalent carbohydrate to B-GOS bread) were also developed. A 3-stage continuous in vitro colonic model was used to assess prebiotic functionality of the breads. Bacteria were quantified by fluorescence in situ hybridization and short chain fatty acids by gas chromatography. Ion-exchange chromatography was used to determine GOS concentration after bread production. Following B-GOS bread fermentation numbers of bifidobacteria and lactobacilli were significantly higher compared to controls. There was no significant degradation of B-GOS during bread manufacture, indicating GOS withstood the manufacturing process. Furthermore, based on previous research, increased bifidobacteria and butyrate levels could be of benefit to those with obesity related conditions. Our findings support utilization of prebiotic enriched bread for improving gastrointestinal health. PMID:26099034

  13. Prebiotic Synthesis of Diaminopyrimidine and Thiocytosine

    NASA Technical Reports Server (NTRS)

    Robertson, Michael P.; Levy, Matthew; Miller, Stanley L.

    1996-01-01

    The reaction of guanidine hydrochloride with cyanoacetaldehyde gives high yields (40-85%) of 2,4-diaminopyrimidine under the concentrated conditions of a drying lagoon model of prebiotic synthesis, in contrast to the low yields previously obtained under more dilute conditions. The prebiotic source of cyanoacetaldehyde, cyanoacetylene, is produced from electric discharges under reducing conditions. The effect of pH and concentration of guanidine hydrochloride on the rate of synthesis and yield of diaminopyrimidine were investigated, as well as the hydrolysis of diaminopyrimidine to cytosine, isocytosine, and uracil. Thiourea also reacts with cyanoacetaldehyde to give 2-thiocytosine, but the pyrimidine yields are much lower than with guanidine hydrochloride or urea. Thiocytosine hydrolyzes to thiouracil and cytosine and then to uracil. This synthesis would have been a significant prebiotic source of 2-thiopyrimidines and 5-substituted derivatives of thiouracil, many of which occur in tRNA. The applicability of these results to the drying lagoon model of prebiotic synthesis was tested by dry-down experiments where dilute solutions of cyanoacetaldehyde, guanidine hydrochloride, and 0.5 M NaCl were evaporated over varying periods of time. The yields of diaminopyrimidine varied from 1 to 7%. These results show that drying lagoons and beaches may have been major sites of prebiotic syntheses.

  14. Prebiotic Evolution of Nitrogen Compounds

    NASA Technical Reports Server (NTRS)

    Arrhenius, G.

    1999-01-01

    Support from this four year grant has funded our research on two general problems. One involves attempts to model the abiotic formation of simple source compounds for functional biomolecules, their concentration from dilute state in the hydrosphere and, in several cases, surface induced reactions to form precursor monomers for bioactive end products (refs. 1-5). Because of the pervasiveness and antiquity of phosphate based biochemistry and the catalytic activity of RNA we have exploring the hypothesis of an RNA World as an early stage in the emergence of life. This concept is now rather generally considered, but has been questioned due to the earlier lack of an experimentally demonstrated successful scheme for the spontaneous formation of ribose phosphate, the key backbone molecule in RNA. That impediment has now been removed. This has been achieved by demonstrating probable sources of activated (condensed) highly soluble and strongly sorbed phosphates in nature (Refs. 1,2) and effective condensation of aldehyde phosphates to form ribose phosphate in high yield (ref.6), thereby placing the RNA World concept on a somewhat safer experimental footing. Like all work in this field these experiments are oversimplifications that largely ignore competing side reactions with other compounds expected to be present. None the less our choice of experimental conditions aim at selective processes that eliminate interfering reactions. We have also sought to narrow the credibility gap by simulating geophysically and geochemically plausible conditions surrounding the putative prebiotic reactions.

  15. Probiotics and prebiotics and health in ageing populations.

    PubMed

    Duncan, Sylvia H; Flint, Harry J

    2013-05-01

    In healthy adults microbial communities that colonise different regions of the human colon contribute nutrients and energy to the host via the fermentation of non-digestible dietary components in the large intestine. A delicate balance of microbial species is required to maintain healthy metabolism and immune function. Disturbance in this microbial balance can have negative consequences for health resulting in elevated inflammation and infection, that are contributory factors in diabetes and cancer. There is a growing awareness that the microbial balance in the colon may become increasingly perturbed with aging and therefore hasten the onset of certain diseases. Societal and dietary factors influence microbial community composition both in the short and long term in the elderly (>65 years old) whilst immunosenescence may also be linked to a perturbed distal gut microbiota and frailty in the elderly. Significant progress has been made in defining some of the dominant members of the microbial community in the healthy large intestine and in identifying their roles in metabolism. There is therefore an urgent need for better awareness of the impact of diet, prebiotic and probiotic strategies in driving human colonic microbial composition in order to understand the possibilities for maintaining healthy gut function and well-being in an increasingly elderly population. Here we review gut microbial changes associated with aging and how diet, prebiotics and probiotics may modulate the gut microbiota to maintain health in the elderly. PMID:23489554

  16. Probiotics and prebiotics in ulcerative colitis.

    PubMed

    Derikx, Lauranne A A P; Dieleman, Levinus A; Hoentjen, Frank

    2016-02-01

    The intestinal microbiota is one of the key players in the etiology of ulcerative colitis. Manipulation of this microflora with probiotics and prebiotics is an attractive strategy in the management of ulcerative colitis. Several intervention studies for both the induction and maintenance of remission in ulcerative colitis patients have been performed. Most of these studies evaluated VSL#3 or E. Coli Nissle 1917 and in general there is evidence for efficacy of these agents for induction and maintenance of remission. However, studies are frequently underpowered, lack a control group, and are very heterogeneous investigating different probiotic strains in different study populations. The absence of well-powered robust randomized placebo-controlled trials impedes the widespread use of probiotics and prebiotics in ulcerative colitis. However, given the promising results that are currently available, probiotics and prebiotics may find their way to the treatment algorithm for ulcerative colitis in the near future. PMID:27048897

  17. Prebiotically Important Molecules in Orion KL

    NASA Astrophysics Data System (ADS)

    Kuan, Yi-Jehng; Chuang, Yo-Ling

    Many interstellar, complex organic molecules are known to be prebiotically important and have essential functions in terrestrial biochemistry. Observations of complex organic molecular species in molecular clouds can thus enable us to test the origin of the primitive organic material found in the Solar System. Interstellar pyrimidine and glycine, the building block of nucleic acid and the simplest amino acid, respectively, are key molecules for astrobiology and were both detected in meteorites and comets. Although the formation of prebiotic molecules in extraterrestrial environments and their contribution to prebiotic chemistry and the origin of life remains unsettled, the connection between interstellar organic chemistry, meteoritic pyrimidines and amino acids, and the emergence of life on the early Earth would be strengthened with the discovery of interstellar pyrimidine and glycine. We have therefore observed the Orion KL hot molecular core to search for interstellar pyrimidine and for the confirmation of interstellar glycine using the ALMA array. We will present some of the encouraging, positive results.

  18. Prebiotics as gut microflora management tools.

    PubMed

    Gibson, Glenn R

    2008-07-01

    Functional foods is an often-used term applied to dietary ingredients that serve to improve consumer health. Over the last few decades, these foods have gained in popularity with sales continuing to increase rapidly. Recent scientific, and some lay, reports have shown the popularity of both probiotics and prebiotics. These serve to elicit changes in the gut microbiota composition that increase populations of purported beneficial gut bacterial genera, for example, lactobacilli or bifidobacteria. Probiotics use live microbial feed additions, whereas prebiotics target indigenous flora components. As gastrointestinal disorders are prevalent in terms of human health, both probiotics and prebiotics serve an important role in the prophylactic management of various acute and chronic gut derived conditions. Examples include protection from gastroenteritis and some inflammatory conditions. PMID:18542038

  19. Probiotics, prebiotics and immunomodulation of gut mucosal defences: homeostasis and immunopathology.

    PubMed

    Hardy, Holly; Harris, Jennifer; Lyon, Eleanor; Beal, Jane; Foey, Andrew D

    2013-06-01

    Probiotics are beneficial microbes that confer a realistic health benefit on the host, which in combination with prebiotics, (indigestible dietary fibre/carbohydrate), also confer a health benefit on the host via products resulting from anaerobic fermentation. There is a growing body of evidence documenting the immune-modulatory ability of probiotic bacteria, it is therefore reasonable to suggest that this is potentiated via a combination of prebiotics and probiotics as a symbiotic mix. The need for probiotic formulations has been appreciated for the health benefits in "topping up your good bacteria" or indeed in an attempt to normalise the dysbiotic microbiota associated with immunopathology. This review will focus on the immunomodulatory role of probiotics and prebiotics on the cells, molecules and immune responses in the gut mucosae, from epithelial barrier to priming of adaptive responses by antigen presenting cells: immune fate decision-tolerance or activation? Modulation of normal homeostatic mechanisms, coupled with findings from probiotic and prebiotic delivery in pathological studies, will highlight the role for these xenobiotics in dysbiosis associated with immunopathology in the context of inflammatory bowel disease, colorectal cancer and hypersensitivity. PMID:23760057

  20. Probiotics, Prebiotics and Immunomodulation of Gut Mucosal Defences: Homeostasis and Immunopathology

    PubMed Central

    Hardy, Holly; Harris, Jennifer; Lyon, Eleanor; Beal, Jane; Foey, Andrew D.

    2013-01-01

    Probiotics are beneficial microbes that confer a realistic health benefit on the host, which in combination with prebiotics, (indigestible dietary fibre/carbohydrate), also confer a health benefit on the host via products resulting from anaerobic fermentation. There is a growing body of evidence documenting the immune-modulatory ability of probiotic bacteria, it is therefore reasonable to suggest that this is potentiated via a combination of prebiotics and probiotics as a symbiotic mix. The need for probiotic formulations has been appreciated for the health benefits in “topping up your good bacteria” or indeed in an attempt to normalise the dysbiotic microbiota associated with immunopathology. This review will focus on the immunomodulatory role of probiotics and prebiotics on the cells, molecules and immune responses in the gut mucosae, from epithelial barrier to priming of adaptive responses by antigen presenting cells: immune fate decision—tolerance or activation? Modulation of normal homeostatic mechanisms, coupled with findings from probiotic and prebiotic delivery in pathological studies, will highlight the role for these xenobiotics in dysbiosis associated with immunopathology in the context of inflammatory bowel disease, colorectal cancer and hypersensitivity. PMID:23760057

  1. Prebiotics and Probiotics and Oral Health

    NASA Astrophysics Data System (ADS)

    Meurman, J. H.

    The first part of this chapter describes the unique characteristics of the mouth with special emphasis on the oral microbiota. Next, the highly prevalent dental diseases are briefly described together with more rare but still important diseases and symptoms of the mouth. Prevention and treatment of oral and dental diseases are also discussed focusing on aspects considered important with respect to the potential application of prebiotics and probiotics. The second part of the chapter then concentrates on research data on prebiotics and probiotics in the oral health perspective, ending up with conclusions and visions for future research.

  2. Probiotics, prebiotics and antioxidants as functional foods.

    PubMed

    Grajek, Włodzimierz; Olejnik, Anna; Sip, Anna

    2005-01-01

    The term "functional foods" comprises some bacterial strains and products of plant and animal origin containing physiologically active compounds beneficial for human health and reducing the risk of chronic diseases. Among the best known functional compounds probiotics, prebiotics and natural antioxidants should be given as examples. These substances can be obtained by biotechnological methods and by extraction from plant or animal tissues. PMID:16086074

  3. Are Polyphosphates or Phosphate Esters Prebiotic Reagents?

    NASA Technical Reports Server (NTRS)

    Keefe, Anthony D.; Miller, Stanley L.

    1995-01-01

    It is widely held that there was a phosphate compound in prebiotic chemistry that played the role of adenosine triphosphate and that the first living organisms had ribose-phosphate in the backbone of their genetic material. However, there are no known efficient prebiotic synthesis of high-energy phosphates or phosphate esters. We review the occurrence of phosphates in nature, the efficiency of the volcanic synthesis of P4O10, the efficiency of polyphosphate synthesis by heating phosphate minerals under geological conditions, and the use of high-energy organic compounds such as cyanamide or hydrogen cyanide. These are shown to be inefficient processes especially when the hydrolysis of the polyphosphates is taken into account. For example, if a whole atmosphere of methane or carbon monoxide were converted to cyanide which somehow synthesized polyphosphates quantitatively, the polyphosphate concentration in the ocean would still have been insignificant. We also attempted to find more efficient high-energy polymerizing agents by spark discharge syntheses, but without success. There may still be undiscovered robust prebiotic syntheses of polyphosphates, or mechanisms for concentrating them, but we conclude that phosphate esters may not have been constituents of the first genetic material. Phosphoanhydrides are also unlikely as prebiotic energy sources.

  4. Manufacture of Prebiotics from Biomass Sources

    NASA Astrophysics Data System (ADS)

    Gullón, Patricia; Gullón, Beatriz; Moure, Andrés; Alonso, José Luis; Domínguez, Herminia; Parajó, Juan Carlos

    Biomass from plant material is the most abundant and widespread renewable raw material for sustainable development, and can be employed as a source of polymeric and oligomeric carbohydrates. When ingested as a part of the diet, some biomass polysaccharides and/or their oligomeric hydrolysis products are selectively fermented in the colon, causing prebiotic effects.

  5. Quantification of prebiotics in commercial infant formulas.

    PubMed

    Sabater, Carlos; Prodanov, Marin; Olano, Agustín; Corzo, Nieves; Montilla, Antonia

    2016-03-01

    Since breastfeeding is not always possible, infant formulas (IFs) are supplemented with prebiotic oligosaccharides, such as galactooligosaccharides (GOS) and/or fructooligosaccharides (FOS) to exert similar effects to those of the breast milk. Nowadays, a great number of infant formulas enriched with prebiotics are disposal in the market, however there are scarce data about their composition. In this study, the combined use of two chromatographic methods (GC-FID and HPLC-RID) for the quantification of carbohydrates present in commercial infant formulas have been used. According to the results obtained by GC-FID for products containing prebiotics, the content of FOS, GOS and GOS/FOS was in the ranges of 1.6-5.0, 1.7-3.2, and 0.08-0.25/2.3-3.8g/100g of product, respectively. HPLC-RID analysis allowed quantification of maltodextrins with degree of polymerization (DP) up to 19. The methodology proposed here may be used for routine quality control of infant formula and other food ingredients containing prebiotics. PMID:26471520

  6. Insight into the prebiotic concept: lessons from an exploratory, double blind intervention study with inulin-type fructans in obese women

    PubMed Central

    Dewulf, Evelyne M; Cani, Patrice D; Claus, Sandrine P; Fuentes, Susana; Puylaert, Philippe GB; Neyrinck, Audrey M; Bindels, Laure B; de Vos, Willem M; Gibson, Glenn R; Thissen, Jean-Paul; Delzenne, Nathalie M

    2013-01-01

    Objective To highlight the contribution of the gut microbiota to the modulation of host metabolism by dietary inulin-type fructans (ITF prebiotics) in obese women. Methods A double blind, placebo controlled, intervention study was performed with 30 obese women treated with ITF prebiotics (inulin/oligofructose 50/50 mix; n=15) or placebo (maltodextrin; n=15) for 3 months (16 g/day). Blood, faeces and urine sampling, oral glucose tolerance test, homeostasis model assessment and impedancemetry were performed before and after treatment. The gut microbial composition in faeces was analysed by phylogenetic microarray and qPCR analysis of 16S rDNA. Plasma and urine metabolic profiles were analysed by 1H-NMR spectroscopy. Results Treatment with ITF prebiotics, but not the placebo, led to an increase in Bifidobacterium and Faecalibacterium prausnitzii; both bacteria negatively correlated with serum lipopolysaccharide levels. ITF prebiotics also decreased Bacteroides intestinalis, Bacteroides vulgatus and Propionibacterium, an effect associated with a slight decrease in fat mass and with plasma lactate and phosphatidylcholine levels. No clear treatment clustering could be detected for gut microbial analysis or plasma and urine metabolomic profile analyses. However, ITF prebiotics led to subtle changes in the gut microbiota that may importantly impact on several key metabolites implicated in obesity and/or diabetes. Conclusions ITF prebiotics selectively changed the gut microbiota composition in obese women, leading to modest changes in host metabolism, as suggested by the correlation between some bacterial species and metabolic endotoxaemia or metabolomic signatures. PMID:23135760

  7. Prebiotic Chemistry: Geochemical Context and Reaction Screening

    PubMed Central

    Cleaves, Henderson James

    2013-01-01

    The origin of life on Earth is widely believed to have required the reactions of organic compounds and their self- and/or environmental organization. What those compounds were remains open to debate, as do the environment in and process or processes by which they became organized. Prebiotic chemistry is the systematic organized study of these phenomena. It is difficult to study poorly defined phenomena, and research has focused on producing compounds and structures familiar to contemporary biochemistry, which may or may not have been crucial for the origin of life. Given our ignorance, it may be instructive to explore the extreme regions of known and future investigations of prebiotic chemistry, where reactions fail, that will relate them to or exclude them from plausible environments where they could occur. Come critical parameters which most deserve investigation are discussed. PMID:25369745

  8. Prussian Blue as a Prebiotic Reagent

    NASA Astrophysics Data System (ADS)

    Ruiz-Bermejo, M.; Menor-Salván, C.; Osuna-Esteban, S.; Veintemillas-Verdaguer, S.

    2009-12-01

    Ferrocyanide has been proposed as a potential prebiotic reagent and the complex salt Prussian Blue, Fe4[Fe(CN)6]3, might be an important reservoir of HCN, in the early Earth. HCN is considered the main precursor of amino acids and purine and pyrimidine bases under prebiotic conditions. Recently, we observed the formation of Prussian Blue in spark discharge experiments using saline solutions of ferrous chloride, FeCl2. Using Prussian Blue as starting material in ammonium suspensions, we obtained organic compounds containing nitrogen. These results seem to indicate that Prussian Blue could have been first, a sink of HCN, and then in subsequent reactions, triggered by pH fluctuations, it might have lead to organic life precursors.

  9. Prebiotic chemistry in the solar system

    NASA Astrophysics Data System (ADS)

    Raulin, Francois

    1990-11-01

    Forty years of experimental studies in prebiotic chemistry are summarized. Most of the building blocks of the living systems have been synthesized in conditions plausible to conditions found on the primitive Earth. The starting ingredients belong to two complementary classes: volatile organics, and their non volatile oligomers. They may have been formed in the atmosphere on the primitive Earth and/or imported by extraterrestrial sources. Organic molecules are found in meteorites, comets, in the giant planets and several of their satellites. Again this chemistry presents two complementary aspects. With a dense reduced atmosphere rich in organic compounds in gas and aerosol phases, Titan appears to be a natural laboratory for studying prebiotic chemistry on a planetary scale.

  10. Prebiotic significance of the Maillard reaction

    NASA Astrophysics Data System (ADS)

    Kolb, Vera M.; Bajagic, Milica; Zhu, William; Cody, George D.

    2005-09-01

    The Maillard reaction was studied from a prebiotic point of view. We have shown that the Maillard reaction between ribose and common amino acids occurs readily in the solid state at 65°C. The C-13 NMR spectra of the solid insoluble Maillard products of ribose and serine, or alanine or isoleucine were compared to the spectrum of the insoluble organic carbon on Murchison.

  11. Prebiotic RNA Synthesis by Montmorillonite Catalysis

    NASA Astrophysics Data System (ADS)

    Jheeta, Sohan; Joshi, Prakash C.

    2014-08-01

    This review summarizes our recent findings on the role of mineral salts in prebiotic RNA synthesis, which is catalyzed by montmorillonite clay minerals. The clay minerals not only catalyze the synthesis of RNA but also facilitate homochiral selection. Preliminary data of these findings have been presented at the "Horizontal Gene Transfer and the Last Universal Common Ancestor (LUCA)" conference at the Open University, Milton Keynes, UK, 5-6 September 2013. The objective of this meeting was to recognize the significance of RNA in LUCA. We believe that the prebiotic RNA synthesis from its monomers must have been a simple process. As a first step, it may have required activation of the 5'-end of the mononucleotide with a leaving group, e.g., imidazole in our model reaction (Figure 1). Wide ranges of activating groups are produced from HCN under plausible prebiotic Earth conditions. The final step is clay mineral catalysis in the presence of mineral salts to facilitate selective production of functional RNA. Both the clay minerals and mineral salts would have been abundant on early Earth. We have demonstrated that while montmorillonite (pH 7) produced only dimers from its monomers in water, addition of sodium chloride (1 M) enhanced the chain length multifold, as detected by HPLC. The effect of monovalent cations on RNA synthesis was of the following order: Li+ > Na+ > K+. A similar effect was observed with the anions, enhancing catalysis in the following order: Cl- > Br- > I-. The montmorillonite-catalyzed RNA synthesis was not affected by hydrophobic or hydrophilic interactions. We thus show that prebiotic synthesis of RNA from its monomers was a simple process requiring only clay minerals and a small amount of salt.

  12. Prebiotic RNA Synthesis by Montmorillonite Catalysis

    PubMed Central

    Jheeta, Sohan; Joshi, Prakash C.

    2014-01-01

    This review summarizes our recent findings on the role of mineral salts in prebiotic RNA synthesis, which is catalyzed by montmorillonite clay minerals. The clay minerals not only catalyze the synthesis of RNA but also facilitate homochiral selection. Preliminary data of these findings have been presented at the “Horizontal Gene Transfer and the Last Universal Common Ancestor (LUCA)” conference at the Open University, Milton Keynes, UK, 5–6 September 2013. The objective of this meeting was to recognize the significance of RNA in LUCA. We believe that the prebiotic RNA synthesis from its monomers must have been a simple process. As a first step, it may have required activation of the 5'-end of the mononucleotide with a leaving group, e.g., imidazole in our model reaction (Figure 1). Wide ranges of activating groups are produced from HCN under plausible prebiotic Earth conditions. The final step is clay mineral catalysis in the presence of mineral salts to facilitate selective production of functional RNA. Both the clay minerals and mineral salts would have been abundant on early Earth. We have demonstrated that while montmorillonite (pH 7) produced only dimers from its monomers in water, addition of sodium chloride (1 M) enhanced the chain length multifold, as detected by HPLC. The effect of monovalent cations on RNA synthesis was of the following order: Li+ > Na+ > K+. A similar effect was observed with the anions, enhancing catalysis in the following order: Cl− > Br− > I−. The montmorillonite-catalyzed RNA synthesis was not affected by hydrophobic or hydrophilic interactions. We thus show that prebiotic synthesis of RNA from its monomers was a simple process requiring only clay minerals and a small amount of salt. PMID:25370375

  13. [The effect of prebiotics on lipid metabolism].

    PubMed

    Marti del Moral, A; Moreno-Aliaga, M J; Martínez Hernández, J Alfredo

    2003-01-01

    Prebiotics were defined in 1995 as non-digestible food ingredients beneficially affecting the host by stimulating the growth and/or activity of one or more bacteria in the colon, thus improving health. The proliferation of certain bacteria by fermentation of non-digestible carbohydrates has been shown to be able to inhibit the colonization of the intestine by pathogens, thus giving a protective effect vis-à-vis acute or chronic intestinal disorders. The fermentation of prebiotics may promote some specific physiological functions through the release of metabolites from the bacteria, especially short chain fatty acids (acetate, propionate, butyrate, lactate, etc.) into the lumen of the intestine. Short chain fatty acids may act directly or indirectly (by modifying the pH) on intestinal cells and may be involved in the control of various processes such as the proliferation of mucosa, inflammation, colorectal carcinogenesis, mineral absorption and the elimination of nitrogenated compounds. Curiously, numerous papers have hinted at the possibility that prebiotics may have systemic physiological effects that are related to beneficial effects on lipid metabolism and various cardiovascular risk factors. PMID:12884473

  14. Prebiotic properties of potato starch dextrins.

    PubMed

    Barczyńska, Renata; Śliżewska, Katarzyna; Libudzisz, Zdzisława; Kapuśniak, Kamila; Kapuśniak, Janusz

    2015-01-01

    The objective of the present study was to compare the prebiotic properties of starch dextrins, that is, resistant dextrins obtained from potato starch in the process of simultaneous thermolysis and chemical modification, which were selected based on previous research. Both prepared dextrins met the definition criterion of dietary fiber and also the basic prebiotic criterion - they were not degraded by the digestive enzymes of the initial sections of the gastrointestinal tract. The growth of probiotic lactobacilli and bifidobacteria, as well as Escherichia coli, Enterococcus, Bacteroides, and Clostridium strains isolated from feces of healthy people, showed that both studied dextrins were utilized as a source of assimilable carbon and energy by the strains. Furthermore, better growth (higher numbers of cells) counts of probiotic bacteria than those of fecal isolates indicated that the studied resistant dextrins showed a selective effect. Both dextrins might be considered as substances with prebiotic properties due to their chemical and physical properties and selectivity towards the studied probiotic bacterial strains. PMID:26400889

  15. Prebiotic network evolution: six key parameters.

    PubMed

    Nghe, Philippe; Hordijk, Wim; Kauffman, Stuart A; Walker, Sara I; Schmidt, Francis J; Kemble, Harry; Yeates, Jessica A M; Lehman, Niles

    2015-12-01

    The origins of life likely required the cooperation among a set of molecular species interacting in a network. If so, then the earliest modes of evolutionary change would have been governed by the manners and mechanisms by which networks change their compositions over time. For molecular events, especially those in a pre-biological setting, these mechanisms have rarely been considered. We are only recently learning to apply the results of mathematical analyses of network dynamics to prebiotic events. Here, we attempt to forge connections between such analyses and the current state of knowledge in prebiotic chemistry. Of the many possible influences that could direct primordial network, six parameters emerge as the most influential when one considers the molecular characteristics of the best candidates for the emergence of biological information: polypeptides, RNA-like polymers, and lipids. These parameters are viable cores, connectivity kinetics, information control, scalability, resource availability, and compartmentalization. These parameters, both individually and jointly, guide the aggregate evolution of collectively autocatalytic sets. We are now in a position to translate these conclusions into a laboratory setting and test empirically the dynamics of prebiotic network evolution. PMID:26490759

  16. Fiber and prebiotics: mechanisms and health benefits.

    PubMed

    Slavin, Joanne

    2013-04-01

    The health benefits of dietary fiber have long been appreciated. Higher intakes of dietary fiber are linked to less cardiovascular disease and fiber plays a role in gut health, with many effective laxatives actually isolated fiber sources. Higher intakes of fiber are linked to lower body weights. Only polysaccharides were included in dietary fiber originally, but more recent definitions have included oligosaccharides as dietary fiber, not based on their chemical measurement as dietary fiber by the accepted total dietary fiber (TDF) method, but on their physiological effects. Inulin, fructo-oligosaccharides, and other oligosaccharides are included as fiber in food labels in the US. Additionally, oligosaccharides are the best known "prebiotics", "a selectively fermented ingredient that allows specific changes, both in the composition and/or activity in the gastrointestinal microflora that confers benefits upon host well-bring and health." To date, all known and suspected prebiotics are carbohydrate compounds, primarily oligosaccharides, known to resist digestion in the human small intestine and reach the colon where they are fermented by the gut microflora. Studies have provided evidence that inulin and oligofructose (OF), lactulose, and resistant starch (RS) meet all aspects of the definition, including the stimulation of Bifidobacterium, a beneficial bacterial genus. Other isolated carbohydrates and carbohydrate-containing foods, including galactooligosaccharides (GOS), transgalactooligosaccharides (TOS), polydextrose, wheat dextrin, acacia gum, psyllium, banana, whole grain wheat, and whole grain corn also have prebiotic effects. PMID:23609775

  17. Multispecies population dynamics of prebiotic compositional assemblies.

    PubMed

    Markovitch, Omer; Lancet, Doron

    2014-09-21

    Present life portrays a two-tier phenomenology: molecules compose supramolecular structures, such as cells or organisms, which in turn portray population behaviors, including selection, evolution and ecological dynamics. Prebiotic models have often focused on evolution in populations of self-replicating molecules, without explicitly invoking the intermediate molecular-to-supramolecular transition. Here, we explore a prebiotic model that allows one to relate parameters of chemical interaction networks within molecular assemblies to emergent population dynamics. We use the graded autocatalysis replication domain (GARD) model, which simulates the network dynamics within amphiphile-containing molecular assemblies, and exhibits quasi-stationary compositional states termed compotype species. These grow by catalyzed accretion, divide and propagate their compositional information to progeny in a replication-like manner. The model allows us to ask how molecular network parameters influence assembly evolution and population dynamics parameters. In 1000 computer simulations, each embodying different parameter set of the global chemical interaction network parameters, we observed a wide range of behaviors. These were analyzed by a multi species logistic model often used for analyzing population ecology (r-K or Lotka-Volterra competition model). We found that compotypes with a larger intrinsic molecular repertoire show a higher intrinsic growth (r) and lower carrying capacity (K), as well as lower replication fidelity. This supports a prebiotic scenario initiated by fast-replicating assemblies with a high molecular diversity, evolving into more faithful replicators with narrower molecular repertoires. PMID:24831416

  18. Distant Site Effects of Ingested Prebiotics.

    PubMed

    Collins, Stephanie; Reid, Gregor

    2016-01-01

    The gut microbiome is being more widely recognized for its association with positive health outcomes, including those distant to the gastrointestinal system. This has given the ability to maintain and restore microbial homeostasis a new significance. Prebiotic compounds are appealing for this purpose as they are generally food-grade substances only degraded by microbes, such as bifidobacteria and lactobacilli, from which beneficial short-chain fatty acids are produced. Saccharides such as inulin and other fructo-oligosaccharides, galactooligosaccharides, and polydextrose have been widely used to improve gastrointestinal outcomes, but they appear to also influence distant sites. This review examined the effects of prebiotics on bone strength, neural and cognitive processes, immune functioning, skin, and serum lipid profile. The mode of action is in part affected by intestinal permeability and by fermentation products reaching target cells. As the types of prebiotics available diversify, so too will our understanding of the range of microbes able to degrade them, and the extent to which body sites can be impacted by their consumption. PMID:27571098

  19. [Infant formulas supplemented with prebiotics: intestinal microbiota and immune responses].

    PubMed

    Fanaro, S; Vigi, V

    2008-06-01

    It is well known that the type of feeding influences the composition of the gut microflora after birth. Human milk favours the growth of a ''bifidus flora'' which, according to several evidences, may activate the immune system and defend from pathogens. Breast milk oligosaccharides, which are involved in many functional effects both at local and systemic level, are thought to stimulate the growth of health promoting microbes, such as bifidobacteria, and may ultimately influence the immune system. In accordance with this current working hypothesis, dietary modulation of the gut microbiota to obtain a ''bifidus flora'' also in bottle-fed infants may be a useful way to stimulate immunological functions and to harbour a biological barrier against pathogens. In several clinical trials prebiotic oligosaccharides have been used to mimic the beneficial effects of breast milk oligosaccharides. A mixture of oligosaccharides has shown its efficacy in stimulating the establishment of a ''bifidus flora'', with stools closer to those found in breast-fed infants. Several experimental data also indicate that oligosaccharides might modulate the immune system and contribute to the improvement of the protective properties of infant formulas. PMID:18487978

  20. Towards microbial fermentation metabolites as markers for health benefits of prebiotics.

    PubMed

    Verbeke, Kristin A; Boobis, Alan R; Chiodini, Alessandro; Edwards, Christine A; Franck, Anne; Kleerebezem, Michiel; Nauta, Arjen; Raes, Jeroen; van Tol, Eric A F; Tuohy, Kieran M

    2015-06-01

    Available evidence on the bioactive, nutritional and putative detrimental properties of gut microbial metabolites has been evaluated to support a more integrated view of how prebiotics might affect host health throughout life. The present literature inventory targeted evidence for the physiological and nutritional effects of metabolites, for example, SCFA, the potential toxicity of other metabolites and attempted to determine normal concentration ranges. Furthermore, the biological relevance of more holistic approaches like faecal water toxicity assays and metabolomics and the limitations of faecal measurements were addressed. Existing literature indicates that protein fermentation metabolites (phenol, p-cresol, indole, ammonia), typically considered as potentially harmful, occur at concentration ranges in the colon such that no toxic effects are expected either locally or following systemic absorption. The endproducts of saccharolytic fermentation, SCFA, may have effects on colonic health, host physiology, immunity, lipid and protein metabolism and appetite control. However, measuring SCFA concentrations in faeces is insufficient to assess the dynamic processes of their nutrikinetics. Existing literature on the usefulness of faecal water toxicity measures as indicators of cancer risk seems limited. In conclusion, at present there is insufficient evidence to use changes in faecal bacterial metabolite concentrations as markers of prebiotic effectiveness. Integration of results from metabolomics and metagenomics holds promise for understanding the health implications of prebiotic microbiome modulation but adequate tools for data integration and interpretation are currently lacking. Similarly, studies measuring metabolite fluxes in different body compartments to provide a more accurate picture of their nutrikinetics are needed. PMID:26156216

  1. Combining prebiotics with probiotic bacteria can enhance bacterial growth and secretion of bacteriocins.

    PubMed

    Pranckutė, Raminta; Kaunietis, Arnoldas; Kuisienė, Nomeda; Čitavičius, Donaldas J

    2016-08-01

    There is a growing interest in supporting human health by using prebiotics, such as oligosaccharides, and beneficial bacteria, also called probiotics. Combining these two components we can develop synbiotics. In order to create successful combination of synbiotic it is very important to evaluate the influence of prebiotic oligosaccharides to probiotic bacteria and their behavior, such as growth and secretion of health related biomolecules, including bacteriocins. In this study seven type strains of probiotic bacteria (five Lactobacillus sp. and two Lactococcus sp.) and two Lactobacillus sp. strains, isolated from probiotic yoghurt, were cultivated with various commercially available and extracted oligosaccharides (OS). The aim of this study was to evaluate the influence of these OS on type and isolated bacterial strains growth and antibacterial activity. Obtained results suggest that combination of certain OS with probiotic strains may considerably improve their growth and/or antibacterial activity. We also determined the antibacterial activity spectrum of investigated strains with combination of OS against common food borne pathogens. Results of this work show that prebiotic OS can be useful for modulating probiotic bacteria growth, antibacterial activity and even specificity of this activity. PMID:27181578

  2. Transcriptional analysis of prebiotic uptake and catabolism by Lactobacillus acidophilus NCFM.

    PubMed

    Andersen, Joakim Mark; Barrangou, Rodolphe; Hachem, Maher Abou; Lahtinen, Sampo J; Goh, Yong-Jun; Svensson, Birte; Klaenhammer, Todd R

    2012-01-01

    The human gastrointestinal tract can be positively modulated by dietary supplementation of probiotic bacteria in combination with prebiotic carbohydrates. Here differential transcriptomics and functional genomics were used to identify genes in Lactobacillus acidophilus NCFM involved in the uptake and catabolism of 11 potential prebiotic compounds consisting of α- and β-linked galactosides and glucosides. These oligosaccharides induced genes encoding phosphoenolpyruvate-dependent sugar phosphotransferase systems (PTS), galactoside pentose hexuronide (GPH) permease, and ATP-binding cassette (ABC) transporters. PTS systems were upregulated primarily by di- and tri-saccharides such as cellobiose, isomaltose, isomaltulose, panose and gentiobiose, while ABC transporters were upregulated by raffinose, Polydextrose, and stachyose. A single GPH transporter was induced by lactitol and galactooligosaccharides (GOS). The various transporters were associated with a number of glycoside hydrolases from families 1, 2, 4, 13, 32, 36, 42, and 65, involved in the catabolism of various α- and β-linked glucosides and galactosides. Further subfamily specialization was also observed for different PTS-associated GH1 6-phospho-β-glucosidases implicated in the catabolism of gentiobiose and cellobiose. These findings highlight the broad oligosaccharide metabolic repertoire of L. acidophilus NCFM and establish a platform for selection and screening of both probiotic bacteria and prebiotic compounds that may positively influence the gastrointestinal microbiota. PMID:23028535

  3. Prebiotic Potential of a Maize-Based Soluble Fibre and Impact of Dose on the Human Gut Microbiota

    PubMed Central

    Costabile, Adele; Deaville, Eddie R.; Morales, Agustin Martin; Gibson, Glenn R.

    2016-01-01

    Dietary management of the human gut microbiota towards a more beneficial composition is one approach that may improve host health. To date, a large number of human intervention studies have demonstrated that dietary consumption of certain food products can result in significant changes in the composition of the gut microbiota i.e. the prebiotic concept. Thus the prebiotic effect is now established as a dietary approach to increase beneficial gut bacteria and it has been associated with modulation of health biomarkers and modulation of the immune system. Promitor™ Soluble Corn Fibre (SCF) is a well-known maize-derived source of dietary fibre with potential selective fermentation properties. Our aim was to determine the optimum prebiotic dose of tolerance, desired changes to microbiota and fermentation of SCF in healthy adult subjects. A double-blind, randomised, parallel study was completed where volunteers (n = 8/treatment group) consumed 8, 14 or 21 g from SCF (6, 12 and 18 g/fibre delivered respectively) over 14-d. Over the range of doses studied, SCF was well tolerated Numbers of bifidobacteria were significantly higher for the 6 g/fibre/day compared to 12g and 18g/fibre delivered/day (mean 9.25 and 9.73 Log10 cells/g fresh faeces in the pre-treatment and treatment periods respectively). Such a numerical change of 0.5 Log10 bifidobacteria/g fresh faeces is consistent with those changes observed for inulin-type fructans, which are recognised prebiotics. A possible prebiotic effect of SCF was therefore demonstrated by its stimulation of bifidobacteria numbers in the overall gut microbiota during a short-term intervention. PMID:26731113

  4. Prebiotic Potential of a Maize-Based Soluble Fibre and Impact of Dose on the Human Gut Microbiota.

    PubMed

    Costabile, Adele; Deaville, Eddie R; Morales, Agustin Martin; Gibson, Glenn R

    2016-01-01

    Dietary management of the human gut microbiota towards a more beneficial composition is one approach that may improve host health. To date, a large number of human intervention studies have demonstrated that dietary consumption of certain food products can result in significant changes in the composition of the gut microbiota i.e. the prebiotic concept. Thus the prebiotic effect is now established as a dietary approach to increase beneficial gut bacteria and it has been associated with modulation of health biomarkers and modulation of the immune system. Promitor™ Soluble Corn Fibre (SCF) is a well-known maize-derived source of dietary fibre with potential selective fermentation properties. Our aim was to determine the optimum prebiotic dose of tolerance, desired changes to microbiota and fermentation of SCF in healthy adult subjects. A double-blind, randomised, parallel study was completed where volunteers (n = 8/treatment group) consumed 8, 14 or 21 g from SCF (6, 12 and 18 g/fibre delivered respectively) over 14-d. Over the range of doses studied, SCF was well tolerated Numbers of bifidobacteria were significantly higher for the 6 g/fibre/day compared to 12 g and 18 g/fibre delivered/day (mean 9.25 and 9.73 Log10 cells/g fresh faeces in the pre-treatment and treatment periods respectively). Such a numerical change of 0.5 Log10 bifidobacteria/g fresh faeces is consistent with those changes observed for inulin-type fructans, which are recognised prebiotics. A possible prebiotic effect of SCF was therefore demonstrated by its stimulation of bifidobacteria numbers in the overall gut microbiota during a short-term intervention. PMID:26731113

  5. Wholegrain oat-based cereals have prebiotic potential and low glycaemic index.

    PubMed

    Connolly, M L; Tuohy, K M; Lovegrove, J A

    2012-12-28

    Population studies show a positive association between increased dietary intake of wholegrains and reduced risk of cardiometabolic disorders. Consumption of wholegrain food has been associated with lower blood glucose and therefore may contribute to a low-glycaemic load diet. The ability to mediate a prebiotic modulation of gut microbiota has recently been suggested to have an inverse correlation with risk of cardiometabolic disease. To date very little work has been carried out on the functionality of wholegrain breakfast cereals in terms of glycaemic response or impact on gut microbiota. An investigation into identifying wholegrain-based breakfast cereals demonstrating both low glycaemic index (GI) and prebiotic attributes was performed. After in vitro digestion, cereal samples were supplemented to pH-controlled anaerobic batch cultures of the human faecal microbiota. Total bacteria populations increased significantly (P < 0·05) in all treated cultures, and the fermentation of a wholegrain oat cluster cereal was associated with proliferation of the Bifidobacterium genus (P = 0·02). Smaller, but significant increases in the Bifidobacterium genus were observed for a further four oat-based cereals. Significant increases in the Lactobacillus-Enterococcus group were observed for granola (P = 0·01), 100 % wholegrain aggregate (P = 0·04) and 70 % wholegrain loops (P = 0·01). Cereals demonstrating prebiotic potential were selected for GI determination in twelve healthy subjects. The wholegrain oat aggregate cereal achieved the lowest GI value (40), three other cereals ranged between 44 and 74, with instant porridge resulting in a GI value similar to the standard glucose control. The present study suggests that wholegrain oat-based breakfast cereals may be prebiotics and have the potential to have low GI. PMID:22360862

  6. A Prebiotic Formula Improves the Gastrointestinal Bacterial Flora in Toddlers

    PubMed Central

    Chen, Ya-Ling; Liao, Fang-Hsuean

    2016-01-01

    We aimed to investigate the effect of enriched 3-prebiotic formula (including inulin, fructooligosaccharides, and galactooligosaccharides) on toddler gut health by measuring fecal microbiota. Our results revealed that the consumption of 3-prebiotic formula three times per day giving total intake of 1.8 g prebiotic ingredients significantly showed the increased number of probiotic Bifidobacterium spp. colonies and the reduced populations of both C. perfringens and total anaerobic bacteria on the fecal bacterial flora in toddlers at 18~36 months. In addition, total organic acids in the fecal samples significantly increased which improves the utilization of bifidus under acidic conditions after consumption of the 3-prebiotic formula. Therefore, using the formula enriched with prebiotic may maintain gut health in toddlers. PMID:27403155

  7. Effect of prebiotics on the fecal microbiota of elderly volunteers after dietary supplementation of Bacillus coagulans GBI-30, 6086.

    PubMed

    Nyangale, Edna P; Farmer, Sean; Keller, David; Chernoff, David; Gibson, Glenn R

    2014-12-01

    In advancing age, gut populations of beneficial microbes, notably Bifidobacterium spp., show a marked decline. This contributes to an environment less capable of maintaining homoeostasis. This in vitro investigation studied the possible synergistic effects of probiotic supplementation in modulating the gut microbiota enabling prebiotic therapy to in elderly persons. Single stage batch culture anaerobic fermenters were used and inoculated with fecal microbiota obtained from volunteers after taking a 28 day treatment of Bacillus coagulans GBI-30, 6086 (GanedenBC30 (BC30)) or a placebo. The response to prebiotic supplements fructooligosaccharides (FOS) and galactooligosaccharides (GOS) in the fermenters was assessed. Bacterial enumeration was carried out using fluorescent in situ hybridisation and organic acids measured by gas chromatography. Baseline populations of Faecalibacterium prausnitzii, Clostridium lituseburense and Bacillus spp. were significantly higher in those having consumed BC30 compared to the placebo. Both prebiotics increased populations of several purportedly beneficial bacterial groups in both sets of volunteers. Samples from volunteers having ingested the BC30 also increased populations of C. lituseburense, Eubacterium rectale and F. prausnitzii more so than in persons who had consumed the placebo, this also resulted in significantly higher concentrations of butyrate, acetate and propionate. This shows that consumption of BC30 and subsequent use of prebiotics resulted in elevated populations of beneficial genres of bacteria as well as organic acid production. PMID:25219857

  8. Efficacy of a novel prebiotic and a commercial probiotic in reducing mortality and production losses due to cold stress/Escherichia coli challenge in broiler chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Prebiotics consisting of resistant starch may alter intestinal ecology, thus modulating inflammation and increasing intestinal health through increased cecal production of short chain fatty acids. Probiotics may directly alter the intestinal microbiome resulting in the same effects. Trials 1, 2, and...

  9. Cold prebiotic evolution, tunneling, chirality and exobiology

    SciTech Connect

    Goldanskii, V.I.

    1996-07-01

    The extra-terrestrial scenario of the origin of life suggested by Svante Arrhenius (1) as the {open_quote}panspermia{close_quote} hypothesis was revived by the discovery of a low-temperature quantum limit of a chemical reaction rate caused by the molecular tunneling (2). Entropy factors play no role near absolute zero, and slow molecular tunneling can lead to the exothermic formation of quite complex molecules. Interstellar grains or particles of cometary tails could serve as possible cold seeds of life, with acetic acid, urea and products of their polycondensation as quasi-equilibrium intermediates. Very cold solid environment hinders racemization and stabilizes optical activity under conditions typical for outer space. Neither {open_quote}advantage{close_quote} factors can secure the evolutionary formation of chiral purity of initial prebiotic monomeric medium{emdash}even being temporary achieved it cannot be maintained at subsequent stages of prebiotic evolution because of counteraction of {open_quote}enantioselective pressure{close_quote}. Only bifurcational mechanism of the formation of prebiotic homochiral{emdash}monomeric and afterwards polymeric{emdash}medium and its subsequent transformation in {open_quote}homochiral chemical automata{close_quote} ({open_quote}biological big bang{close_quote}{emdash}passage from {open_quote}stochastic{close_quote} to {open_quote}algorithmic{close_quote} chemistry) is possible and can be realized. Extra-terrestrial (cold, solid phase) scenarios of the origin of life seem to be more promising from that point of view than terrestrial (warm) scenarios. Within a scheme of five main stages of prebiological evolution some problems important for further investigation are briefly discussed. {copyright} {ital 1996 American Institute of Physics.}

  10. Asymmetric spatiotemporal evolution of prebiotic homochirality.

    PubMed

    Gleiser, Marcelo

    2007-06-01

    The role of asymmetry on the evolution of prebiotic homochirality is investigated in the context of autocatalytic polymerization reaction networks. A model featuring enantiometric cross-inhibition and chiral bias is used to study the diffusion equations controlling the spatiotemporal development of left and right-handed domains. Bounds on the chiral bias are obtained based on present-day constraints on the emergence of life on early Earth. The viability of biasing mechanisms such as weak neutral currents and circularly polarized UV light is discussed. The results can be applied to any hypothetical planetary platform. PMID:17131085

  11. Antibiotics, probiotics and prebiotics in IBD.

    PubMed

    Bernstein, Charles N

    2014-01-01

    The dysbiosis theory of inflammatory bowel disease (IBD) posits that there is an alteration in the gut microbiome as an important underpinning of disease etiology. It stands to reason then, that administering agents that could impact on the balance of microbes on the gut could be impactful on the course of IBD. Herein is a review of the controlled trials undertaken to assess the use of antibiotics that would kill or suppress potentially injurious microbes, probiotics that would overpopulate the gut with potentially beneficial microbes or prebiotics that provide a metabolic substrate that enhances the growth of potentially beneficial microbes. With regard to antibiotics, the best data are for the use of nitroimadoles postoperatively in Crohn's disease (CD) to prevent disease recurrence. Otherwise, the data are limited with the regard to any lasting benefit of antibiotics sustaining remission in either CD or ulcerative colitis (UC). A recent meta-analysis concluded that antibiotics are superior to placebo at inducing remission in CD or UC, although the meta-analysis grouped a variety of antibiotics with different spectra of activity. Despite the absence of robust clinical trial data, antibiotics are widely used to treat perineal fistulizing CD and acute and chronic pouchitis. Probiotics have not been shown to have a beneficial role in CD. However, Escherichia coli Nissle 1917 has comparable effects to low doses of mesalamine in maintaining remission in UC. VSL#3, a combination of 8 microbes, has been shown to have an effect in inducing remission in UC and preventing pouchitis. Prebiotics have yet to be shown to have an effect in any form of IBD, but to date controlled trials have been small. The use of antibiotics should be balanced against the risks they pose. Even probiotics may pose some risk and should not be assumed to be innocuous especially when ingested by persons with a compromised epithelial barrier. Prebiotics may not be harmful but may cause

  12. What do we need for prebiotic chemistry?

    NASA Astrophysics Data System (ADS)

    Danger, G.; Duvernay, F.; Borget, F.; Theule, P.; Chiavassa, T.; le Sergeant d'Hendecourt, L.; Robert, P.

    2014-04-01

    Since the Miller Urey experiment, the prebiotic chemistry has been mainly focused on the search of organic matter formation (e.g. amino acids, nucleic bases) that can take a part in the emergence of living organisms. However, fewer researches have been performed on the specific processes that have to develop for obtaining an evolution of these organic matter toward living organisms. In this contribution, by taking the example of amino acids, we will try to understand what could be these processes and in which conditions they could emerge.

  13. Prebiotic chemistry and nucleic acid replication

    NASA Technical Reports Server (NTRS)

    Orgel, L. E.; Lohrmann, R.

    1974-01-01

    Recent work is reviewed on some reactions that could have occurred on the primitive earth and that could have played a part in the evolution of a self-replicating system. The transition from the primitive atmosphere to the simplest replicating molecules is considered in four stages: (1) the formation of a 'prebiotic soup' of organic precursors, including the purine and pyrimidine bases and the pentose sugars; (2) the condensation of these precursors and inorganic phosphate to form monomeric nucleotides and activated nucleotide derivatives; (3) the polymerization of nucleotide derivatives to oligonucleotides; and (4) the complementary replication of oligonucleotides in a template-directed process that depends on Watson-Crick base pairing.

  14. Initialization of metabolism in prebiotic petroleum

    NASA Astrophysics Data System (ADS)

    Mekki-Berrada, Ali

    The theoretical and bibliographical work on the geochemical origin of life, which I present here, it works on the assumption that: "The class of more complex molecules of life that can have a geochemical and abiotic origin is the class of fatty acid with long aliphatic chain". This idea comes from the controversy over the abiotic oil industry, and the first measurements of abiotic oil at mid-ocean ridges (Charlou J.L. et al. 2002, Proskurowski G. et al. 2008). To go further and propose a comprehensive experimentation on the origin of life, I propose in this article the idea that the prebiotic soup or prebiotic petroleum would stem from the diagenesis of the gas clathrates/sediments mixture. Gas, H2S H2 N2 CH4 CO2, are produced at mid-ocean ridges, and at large-scale at the seafloor, by serpentinization. Sediments contain hydrogenophosphates as a source of phosphate and minerals to the surface catalysis. Extreme conditions experienced by some prokaryotes and pressures and temperatures of submarine oilfields of fossil petroleum are close. The hydrostatic pressure is around 1.5 kbar and the temperature is below 150 °C. This experiment I propose is quite feasible today since these conditions are used: In research and exploration of fossil petroleum; In the field of organic chemistry called "green chemistry" and where temperatures remain low and the pressure can reach 10 kbar; to study the biology of prokaryotes living in the fossil petroleum of industrial interest, these studies are quite comparable to experiment with prebiotic oil; Finally, this experiment can be based on research on abiotic CH4 on Mars and abiotic hydrocarbons on Titan. The next step in the theoretical research of the origin of life is the abiotic synthesis of liposomes. Abiotic synthesis liposomes just requires synthesis of glycerol and ethanolamine (or serine) esterifying the phosphate and fatty acid. The state of research on the abiotic synthesis of these molecules shows that synthesis of

  15. Mechanistic possibilities in prebiotic thiophosphate chemistry

    NASA Technical Reports Server (NTRS)

    Kapovits, I.; Nagyvary, J.

    1978-01-01

    The two types of thiophosphate reactivities were studied in a system that involves reactions of 5'-substituted adenosine derivatives. In this system, both nucleophilic displacement on carbon and P-S cleavage are possible. The products and possible mechanisms of cyclization experiments involving different leaving groups are reported. The data indicate superior reactivity of the 3'-OH of the ribonucleoside, although in most other systems the 2'-OH is found to show superior reactivity. It is suggested that thiophosphates might play a role in prebiotic activation and phosphorylation reactions.

  16. A Critical Look at Prebiotics Within the Dietary Fiber Concept.

    PubMed

    Verspreet, Joran; Damen, Bram; Broekaert, Willem F; Verbeke, Kristin; Delcour, Jan A; Courtin, Christophe M

    2016-01-01

    This article reviews the current knowledge of the health effects of dietary fiber and prebiotics and establishes the position of prebiotics within the broader context of dietary fiber. Although the positive health effects of specific fibers on defecation, reduction of postprandial glycemic response, and maintenance of normal blood cholesterol levels are generally accepted, other presumed health benefits of dietary fibers are still debated. There is evidence that specific dietary fibers improve the integrity of the epithelial layer of the intestines, increase the resistance against pathogenic colonization, reduce the risk of developing colorectal cancer, increase mineral absorption, and have a positive impact on the immune system, but these effects are neither generally acknowledged nor completely understood. Many of the latter effects are thought to be particularly elicited by prebiotics. Although the prebiotic concept evolved significantly during the past two decades, the line between prebiotics and nonprebiotic dietary fiber remains vague. Nevertheless, scientific evidence demonstrating the health-promoting potential of prebiotics continues to accumulate and suggests that prebiotic fibers have their rightful place in a healthy diet. PMID:26735801

  17. Prebiotics as functional food ingredients preventing diet-related diseases.

    PubMed

    Florowska, A; Krygier, K; Florowski, T; Dłużewska, E

    2016-05-18

    This paper reviews the potential of prebiotic-containing foods in the prevention or postponement of certain diet-related diseases, such as cardiovascular diseases with hypercholesterolemia, osteoporosis, diabetes, gastrointestinal infections and gut inflammation. Also the data on prebiotics as food ingredients and their impact on food product quality are presented. Prebiotics are short chain carbohydrates that are resistant to the digestion process in the upper part of the digestive system, are not absorbed in any segment of the gastrointestinal system, and finally are selectively fermented by specific genera of colonic bacteria. The mechanisms of the beneficial impacts of prebiotics on human health are very difficult to specify directly, because their health-promoting functions are related to fermentation by intestinal microflora. The impact of prebiotics on diet-related diseases in many ways also depends on the products of their fermentation. Prebiotics as functional food ingredients also have an impact on the quality of food products, due to their textural and gelling properties. Prebiotics as food additives can be very valuable in the creation of functional food aimed at preventing or postponing many diet-related diseases. They additionally have beneficial technological properties which improve the quality of food products. PMID:26961814

  18. Which role for prebiotics at weaning?

    PubMed

    Fanaro, Silvia; Vigi, Vittorio

    2008-09-01

    It is now generally recognized that the intestinal microflora plays a key role for human health and well being. In fact, the gut ecosystem is involved in a number of biologic functions, such as direct and indirect antipathogen activity (nutritive competition, reduction of pH, production of short-chain fatty acids, maturation and protection of the mucosal barrier, etc), synthesis of vitamins, detoxification of potentially harmful substances, and maturation and regulation of the immune system. Weaning represents a crucial step in the development of the intestinal flora and, at the same time, corresponds to a very delicate phase of immunologic maturation. A safe and effective way to beneficially influence the intestinal microflora is the administration of prebiotics, which selectively promote the growth and/or activity of beneficial bacteria, such as bifidobacteria. Some of the studies, which investigated the microbiologic and clinical effectiveness of prebiotics have been conducted at weaning, reporting interesting results. Anyway, many of the promising beneficial effects evidenced still need to be confirmed by further large randomized trials. PMID:18685502

  19. How to Manipulate the Microbiota: Prebiotics.

    PubMed

    Louis, Petra; Flint, Harry J; Michel, Catherine

    2016-01-01

    During the last century, human nutrition has evolved from the definition of our nutritional needs and the identification of ways to meet them, to the identification of food components that can optimise our physiological and psychological functions. This development, which aims to ensure the welfare, health and reduced susceptibility to disease during life, gave birth to the concept of "functional foods". In this context, there is an increasing interest in the physiological effects induced by the dense and diverse microbiota which inhabits the human colon and whose development depends on the fermentation of undigested food residues. Thus, much research aims at identifying ways to guide these impacts in order to benefit the health of the host. It is in this context that the concept of "prebiotics" was developed in the 1990s. Since then, prebiotics have stimulated extensive work in order to clarify their definition, their nature and their physiological properties in accordance with the evolution of knowledge on the intestinal microbiota. However many questions remain open about their specificities, their mechanism(s) of action and therefore the relevance of their current categorisation. PMID:27161355

  20. Is formamide a geochemically plausible prebiotic solvent?

    PubMed

    Bada, Jeffrey L; Chalmers, John H; Cleaves, H James

    2016-07-27

    From a geochemical perspective, significant amounts of pure formamide (HCONH2) would have likely been rare on the early Earth. There may have been mixed formamide-water solutions, but even in the presence of catalyst, solutions with >20 weight% water in formamide would not have produced significant amounts of prebiotic compounds. It might be feasible to produce relatively pure formamide by a rare occurrence of freezing formamide/water mixtures at temperatures lower than formamide's freezing point (2.55 °C) but greater than the freezing point of water. Because of the high density of formamide ice it would have sunk and accumulated at the bottom of the solution. If the remaining water froze on the surface of this ice, and was then removed by a sublimation-ablation process, a small amount of pure formamide ice might have been produced. In addition a recent report suggested that ∼85 weight% formamide could be prepared by a geochemical type of fractional distillation process, offering another possible route for prebiotic formamide production. PMID:27253848

  1. Fiber and Prebiotics: Mechanisms and Health Benefits

    PubMed Central

    Slavin, Joanne

    2013-01-01

    The health benefits of dietary fiber have long been appreciated. Higher intakes of dietary fiber are linked to less cardiovascular disease and fiber plays a role in gut health, with many effective laxatives actually isolated fiber sources. Higher intakes of fiber are linked to lower body weights. Only polysaccharides were included in dietary fiber originally, but more recent definitions have included oligosaccharides as dietary fiber, not based on their chemical measurement as dietary fiber by the accepted total dietary fiber (TDF) method, but on their physiological effects. Inulin, fructo-oligosaccharides, and other oligosaccharides are included as fiber in food labels in the US. Additionally, oligosaccharides are the best known “prebiotics”, “a selectively fermented ingredient that allows specific changes, both in the composition and/or activity in the gastrointestinal microflora that confers benefits upon host well-bring and health.” To date, all known and suspected prebiotics are carbohydrate compounds, primarily oligosaccharides, known to resist digestion in the human small intestine and reach the colon where they are fermented by the gut microflora. Studies have provided evidence that inulin and oligofructose (OF), lactulose, and resistant starch (RS) meet all aspects of the definition, including the stimulation of Bifidobacterium, a beneficial bacterial genus. Other isolated carbohydrates and carbohydrate-containing foods, including galactooligosaccharides (GOS), transgalactooligosaccharides (TOS), polydextrose, wheat dextrin, acacia gum, psyllium, banana, whole grain wheat, and whole grain corn also have prebiotic effects. PMID:23609775

  2. Scientific evidence for health effects attributed to the consumption of probiotics and prebiotics: an update for current perspectives and future challenges.

    PubMed

    Martinez, Rafael Chacon Ruiz; Bedani, Raquel; Saad, Susana Marta Isay

    2015-12-28

    Probiotics and prebiotics, mainly commercialised as food ingredients and also as supplements, are considered highly profitable niche markets. However, in recent years, the food industry has suffered from a series of health claim restrictions on probiotics and prebiotics in many parts of the world, including those made by the European Food Safety Authority. Therefore, we reviewed the core benefits of probiotic and prebiotic consumption on health. A number of studies have examined the prevention and/or management of intestinal infections, respiratory tract infections, CVD, osteoporosis, urogenital infections, cavities, periodontal disease and halitosis, allergic reactions, inflammatory bowel disease and irritable bowel syndrome and Helicobacter pylori gastric infections. In fact, a deeper understanding of the mechanisms involved in human microbiota and immune system modulation by probiotics and prebiotics relies on continuous efforts to establish suitable biomarkers of health and diseases risk factors for the design of clinical trials required for health claim approval. In spite of the promising results, the performance of large, long-term, well-planned, well-aligned clinical studies is crucial to provide more reliability and a more solid basis for the outcomes achieved and to support the potential use of probiotics and prebiotics in clinical practice. PMID:26443321

  3. A mixture of prebiotic oligosaccharides reduces the incidence of atopic dermatitis during the first six months of age

    PubMed Central

    Moro, G; Arslanoglu, S; Stahl, B; Jelinek, J; Wahn, U; Boehm, G

    2006-01-01

    Background Oligosaccharides may alter postnatal immune development by influencing the constitution of gastrointestinal bacterial flora. Aims To investigate the effect of a prebiotic mixture of galacto‐ and long chain fructo‐oligosaccharides on the incidence of atopic dermatitis (AD) during the first six months of life in formula fed infants at high risk of atopy. Methods Prospective, double‐blind, randomised, placebo controlled trial; 259 infants at risk for atopy were enrolled. A total of 102 infants in the prebiotic group and 104 infants in the placebo group completed the study. If bottle feeding was started, the infant was randomly assigned to one of two hydrolysed protein formula groups (0.8 g/100 ml prebiotics or maltodextrine as placebo). All infants were examined for clinical evidence of atopic dermatitis. In a subgroup of 98 infants, faecal flora was analysed. Results Ten infants (9.8%; 95 CI 5.4–17.1%) in the intervention group and 24 infants (23.1%; 95 CI 16.0–32.1%) in the control group developed AD. The severity of the dermatitis was not affected by diet. Prebiotic supplements were associated with a significantly higher number of faecal bifidobacteria compared with controls but there was no significant difference in lactobacilli counts. Conclusion Results show for the first time a beneficial effect of prebiotics on the development of atopic dermatitis in a high risk population of infants. Although the mechanism of this effect requires further investigation, it appears likely that oligosaccharides modulate postnatal immune development by altering bowel flora and have a potential role in primary allergy prevention during infancy. PMID:16873437

  4. Prebiotic synthesis of imidazole-4-acetaldehyde and histidine

    NASA Technical Reports Server (NTRS)

    Shen, Chun; Oro, J.; Yang, Lily; Miller, Stanley L.

    1987-01-01

    The prebiotic synthesis of imidazole-4-acetaldehyde and imidazole-4-glycol from erythrose and formamidine has been demonstrated as well as the prebiotic synthesis of imidazole-4-ethanol and imidazole-4-glycol from erythrose, formaldehyde, and ammonia. The maximum yields of imidazole-4-acetaldehyde, imidazole-4-ethanol, and imidazole-4-glycol obtained in these reactions are 1.6, 5.4, and 6.8 percent respectively, based on the erythrose. Imidazole-4-acetaldehyde would have been converted to histidine on the primitive earth by a Strecker synthesis, and several prebiotic reactions would convert imidazole-4-glycol and imidazole-4-ethanol to imidazole-4-acetaldehyde.

  5. Prebiotic and Probiotic Regulation of Bone Health: Role of the Intestine and its Microbiome.

    PubMed

    McCabe, Laura; Britton, Robert A; Parameswaran, Narayanan

    2015-12-01

    Recent advances in our understanding of how the intestinal microbiome contributes to health and disease have generated great interest in developing strategies for modulating the abundance of microbes and/or their activity to improve overall human health and prevent pathologies such as osteoporosis. Bone is an organ that the gut has long been known to regulate through absorption of calcium, the key bone mineral. However, it is clear that modulation of the gut and its microbiome can affect bone density and strength in a variety of animal models (zebrafish, rodents, chicken) and humans. This is demonstrated in studies ablating the microbiome through antibiotic treatment or using germ-free mouse conditions as well as in studies modulating the microbiome activity and composition through prebiotic and/or probiotic treatment. This review will discuss recent developments in this new and exciting area. PMID:26419466

  6. A possible route to prebiotic vesicle reproduction.

    PubMed

    Luisi, Pier Luigi; Rasi, Pasquale Stano Silvia; Mavelli, Fabio

    2004-01-01

    Spherical bounded structures such as those formed by surfactant aggregates (mostly micelles and vesicles), with an inside that is chemically and physically different from the outside medium, can be seen as primitive cell models. As such, they are fundamental structures for the theory of autopoiesis as originally formulated by Varela and Maturana. In particular, since self-reproduction is a very important feature of minimal cellular life, the study of self-reproduction of micelles and vesicles represents a quite challenging bio-mimetic approach. Our laboratory has put much effort in recent years into implementing self-reproduction of vesicles as models for self-reproduction of cellular bounded structures, and this article is a further contribution in this direction. In particular, we deal with the so-called matrix effect of vesicles, related to the fact that when fresh surfactant is added to an aqueous solution containing preformed vesicles of a very narrow size distribution, the newly formed vesicles (instead of being polydisperse, as is usually the case) have dimensions very close to those of the preformed ones. In practice, this corresponds to a mechanism of reproduction of vesicles of the same size. In this article, the matrix effect is re-elaborated in the perspective of the origin of life, and in particular in terms of the prebiotic mechanisms that might permit the growth and reproduction of vesicles. The data are analyzed by dynamic light scattering with a new program that permits the calculation of the number-weighted size distribution. It is shown that, on adding a stoichiometric amount of oleate micelles to preformed oleate vesicles extruded at 50 and 100 nm, the final distribution contains about twice the initial number of particles, centered around 50 and 100 nm. The same holds when oleate is added to preformed phospholipid liposomes. By contrast, when the same amount of oleate is added to an aqueous solution (as a control experiment), a very broad

  7. Stability of Lactobacillus rhamnosus GG in prebiotic edible films

    PubMed Central

    Soukoulis, Christos; Behboudi-Jobbehdar, Solmaz; Yonekura, Lina; Parmenter, Christopher; Fisk, Ian D.

    2014-01-01

    The concept of prebiotic edible films as effective vehicles for encapsulating probiotic living cells is presented. Four soluble fibres (inulin, polydextrose, glucose-oligosaccharides and wheat dextrin) were selected as prebiotic co-components of gelatine based matrices plasticised with glycerol and used for the immobilisation of Lactobacillusrhamnosus GG. The addition of prebiotics was associated with a more compact and uniform film structure, with no detectable interspaces or micropores; probiotic inclusion did not significantly change the structure of the films. Glucose-oligosaccharides and polydextrose significantly enhanced L. rhamnosus GG viability during air drying (by 300% and 75%, respectively), whilst a 33% and 80% reduction in viable counts was observed for inulin and wheat dextrin. Contrarily, inulin was the most effective at controlling the sub-lethal effects on L. rhamnosus GG during storage. However, in all cases the supplementation of edible films with prebiotics ameliorated the storage stability of L. rhamnosus GG. PMID:24767059

  8. Stability of Lactobacillus rhamnosus GG in prebiotic edible films.

    PubMed

    Soukoulis, Christos; Behboudi-Jobbehdar, Solmaz; Yonekura, Lina; Parmenter, Christopher; Fisk, Ian D

    2014-09-15

    The concept of prebiotic edible films as effective vehicles for encapsulating probiotic living cells is presented. Four soluble fibres (inulin, polydextrose, glucose-oligosaccharides and wheat dextrin) were selected as prebiotic co-components of gelatine based matrices plasticised with glycerol and used for the immobilisation of Lactobacillus rhamnosus GG. The addition of prebiotics was associated with a more compact and uniform film structure, with no detectable interspaces or micropores; probiotic inclusion did not significantly change the structure of the films. Glucose-oligosaccharides and polydextrose significantly enhanced L. rhamnosus GG viability during air drying (by 300% and 75%, respectively), whilst a 33% and 80% reduction in viable counts was observed for inulin and wheat dextrin. Contrarily, inulin was the most effective at controlling the sub-lethal effects on L. rhamnosus GG during storage. However, in all cases the supplementation of edible films with prebiotics ameliorated the storage stability of L. rhamnosus GG. PMID:24767059

  9. Prebiotics from Marine Macroalgae for Human and Animal Health Applications

    PubMed Central

    O’Sullivan, Laurie; Murphy, Brian; McLoughlin, Peter; Duggan, Patrick; Lawlor, Peadar G.; Hughes, Helen; Gardiner, Gillian E.

    2010-01-01

    The marine environment is an untapped source of bioactive compounds. Specifically, marine macroalgae (seaweeds) are rich in polysaccharides that could potentially be exploited as prebiotic functional ingredients for both human and animal health applications. Prebiotics are non-digestible, selectively fermented compounds that stimulate the growth and/or activity of beneficial gut microbiota which, in turn, confer health benefits on the host. This review will introduce the concept and potential applications of prebiotics, followed by an outline of the chemistry of seaweed polysaccharides. Their potential for use as prebiotics for both humans and animals will be highlighted by reviewing data from both in vitro and in vivo studies conducted to date. PMID:20714423

  10. The cometary contribution to prebiotic chemistry

    NASA Technical Reports Server (NTRS)

    Oro, J.; Mills, T.; Lazcano, A.

    1992-01-01

    The chemical composition of cometary nuclei is examined to estimate the potential contribution of volatiles to the prebiotic earth from cometary collisions. Observations of cometary nuclei are reviewed to describe the chemical evolution of the objects and their theoretical potential for affecting the terrestrial environment. Specific attention is given to the plausibility of the single-impact formation of the earth-moon system, and experiments are proposed for testing the present theories. It is proposed that significant contributions of biogenic elements such as C, H, N, O, P, and S resulted from these nuclei colliding with the earth. Observations of the solar atmosphere and of the circumstellar shells of C-rich stars indicate that compounds such as CO, C2, and H2O were not pyrolyzed as a result of collision events. The compounds are theorized to have established the foundation for the abiotic synthesis of key biochemical molecules.

  11. Clays and other minerals in prebiotic processes

    NASA Technical Reports Server (NTRS)

    Paecht-Horowitz, M.

    1984-01-01

    Clays and other minerals have been investigated in context with prebiotic processes, mainly in polymerization of amino acids. It was found that peptides adsorbed on the clay, prior to polymerization, influence the reaction. The ratio between the amount of the peptides adsorbed and that of the clay is important for the yield as well as for the degrees of polymerization obtained. Adsorption prior to reaction produces a certain order in the aggregates of the clay particles which might induce better reaction results. Excess of added peptides disturbs this order and causes lesser degrees of polymerization. In addition to adsorption, clays are also able to occlude between their layers substances out of the environment, up to very high concentrations.

  12. Atmospheric aerosols as prebiotic chemical reactors

    PubMed Central

    Dobson, Christopher M.; Ellison, G. Barney; Tuck, Adrian F.; Vaida, Veronica

    2000-01-01

    Aerosol particles in the atmosphere have recently been found to contain a large number of chemical elements and a high content of organic material. The latter property is explicable by an inverted micelle model. The aerosol sizes with significant atmospheric lifetimes are the same as those of single-celled organisms, and they are predicted by the interplay of aerodynamic drag, surface tension, and gravity. We propose that large populations of such aerosols could have afforded an environment, by means of their ability to concentrate molecules in a wide variety of physical conditions, for key chemical transformations in the prebiotic world. We also suggest that aerosols could have been precursors to life, since it is generally agreed that the common ancestor of terrestrial life was a single-celled organism. The early steps in some of these initial transformations should be accessible to experimental investigation. PMID:11035775

  13. The evolution of the prebiotic atmosphere

    NASA Technical Reports Server (NTRS)

    Kasting, J. F.

    1984-01-01

    One-dimensional radiative-convective and photochemical models are used to estimate the vertical temperature structure and composition of the earth's prebiotic atmosphere. Greatly enhanced CO2 levels (100-1000 times present) are required to keep the mean surface temperature above freezing in the face of decreased solar luminosity during the earth's early history. Such high CO2 partial pressures would have affected the atmospheric oxidation state by facilitating the photochemical production of soluble species including H2O2 and H2CO. Oxidation of ferrous iron in the oceans by H2O2 dissolved in rainwater should have kept the atmospheric H2 mixing ratio above 0.0002, and the ground-level O2 mixing ratio below 10 to the -11th, regardless of the magnitude of the rate of volcanic release of reduced gases.

  14. Prebiotic syntheses of purines and pyrimidines

    NASA Technical Reports Server (NTRS)

    Basile, B.; Oro, J.; Lazcano, A.

    1984-01-01

    The results of experimental and theoretical investigations of the prebiotic synthesis of purines and pyramidines are surveyed. Topics examined include the synthesis of purines from HCN via 4,5-disubstituted imidazole derivatives in aqueous solutions or liquid NH3, simultaneous formation of amino acids and purines by electron irradiation of CH4-NH3-H2O mixtures, synthesis of pyrimadines from cynoacetylene, energetics, formation of bases under anhydrous or concentrated conditions, formation of bases under dilute conditions, Fischer-Tropsch-type reactions, and the role of activated intermediates. It is pointed out that the precursor compounds have been detected in the interstellar medium, on Titan, and in other solar-system bodies, and that solar-nebula HCN concentrations of the order of 1-10 mM have been estimated on the basis of meteorite measurements.

  15. Metabolism and motility in prebiotic structures

    PubMed Central

    Hanczyc, Martin M.

    2011-01-01

    Easily accessible, primitive chemical structures produced by self-assembly of hydrophobic substances into oil droplets may result in self-moving agents able to sense their environment and move to avoid equilibrium. These structures would constitute very primitive examples of life on the Earth, even more primitive than simple bilayer vesicle structures. A few examples of simple chemical systems are presented that self-organize to produce oil droplets capable of movement, environment remodelling and primitive chemotaxis. These chemical agents are powered by an internal chemical reaction based on the hydrolysis of an oleic anhydride precursor or on the hydrolysis of hydrogen cyanide (HCN) polymer, a plausible prebiotic chemistry. Results are presented on both the behaviour of such droplets and the surface-active properties of HCN polymer products. Such motile agents would be capable of finding resources while escaping equilibrium and sustaining themselves through an internal metabolism, thus providing a working chemical model for a possible origin of life. PMID:21930579

  16. Prebiotic phosphorylation of nucleosides in formamide

    NASA Technical Reports Server (NTRS)

    Schoffstall, A. M.

    1976-01-01

    Results are presented for an experimental study intended to assess phosphorylation under neither aqueous nor dry thermal conditions. Instead, phosphorylations were attempted in possible nonaqueous prebiotic solvents. Formamide appeared to be the most obvious candidate for phosphorylation studies. Three main classes of phosphorylated products were formed in formamide solution: adenosine monophosphates, cyclic adenosine phosphate, and adenosine diphosphates. Experiments were designed to investigate the extent of phosphorylation of nucleosides in formamide, the relative amounts of nucleoside monophosphate, diphosphates and cyclic phosphate formed and the relative effectiveness of different sources of phosphate as phosphorylating agents in formamide. Reaction variables were temperature, nature of the phosphate or condensed phosphate, nucleoside, concentration of reactants and possible effects of additives. Product identification was based on qualitative and quantitative thin layer chromatography.

  17. Recent advances on prebiotic lactulose production.

    PubMed

    Sitanggang, Azis Boing; Drews, Anja; Kraume, Matthias

    2016-09-01

    Lactulose, a synthetic disaccharide, has received increasing interest due to its role as a prebiotic. The production of lactulose is important in the dairy industry, as it is regarded as a high value-added derivative of whey or lactose. The industrial production of lactulose is still mainly done by chemical isomerization. Due to concerns on the environmental and tedious separation processes, the enzymatic-based lactulose synthesis has been regarded as an interesting alternative. This work aims at comparing chemical and enzyme-catalyzed lactulose synthesis. With an emphasis on the latter one, this review discusses the influences of the critical operating conditions and the suited operation mode on the transgalactosylation of lactulose using microbial enzymes. As an update and supplement to other previous reviews, this work also summarizes the recent reports that highlighted the enzymatic isomerization of lactose using cellobiose 2-epimerase to produce lactulose at elevated yields. PMID:27465854

  18. Prebiotic-like chemistry on Titan.

    PubMed

    Raulin, François; Brassé, Coralie; Poch, Olivier; Coll, Patrice

    2012-08-21

    Titan, the largest satellite of Saturn, is the only one in the solar system with a dense atmosphere. Mainly composed of dinitrogen with several % of methane, this atmosphere experiences complex organic processes, both in the gas and aerosol phases, which are of prebiotic interest and within an environment of astrobiological interest. This tutorial review presents the different approaches which can be followed to study such an exotic place and its chemistry: observation, theoretical modeling and experimental simulation. It describes the Cassini-Huygens mission, as an example of observational tools, and gives the new astrobiologically oriented vision of Titan which is now available by coupling the three approaches. This includes the many analogies between Titan and the Earth, in spite of the much lower temperature in the Saturn system, the complex organic chemistry in the atmosphere, from the gas to the aerosol phases, but also the potential organic chemistry on Titan's surface, and in its possible internal water ocean. PMID:22481630

  19. Atmospheric Prebiotic Chemistry and Organic Hazes.

    PubMed

    Trainer, Melissa G

    2013-08-01

    Earth's atmospheric composition at the time of the origin of life is not known, but it has often been suggested that chemical transformation of reactive species in the atmosphere was a significant source of prebiotic organic molecules. Experimental and theoretical studies over the past half century have shown that atmospheric synthesis can yield molecules such as amino acids and nucleobases, but these processes are very sensitive to gas composition and energy source. Abiotic synthesis of organic molecules is more productive in reduced atmospheres, yet the primitive Earth may not have been as reducing as earlier workers assumed, and recent research has reflected this shift in thinking. This work provides a survey of the range of chemical products that can be produced given a set of atmospheric conditions, with a particular focus on recent reports. Intertwined with the discussion of atmospheric synthesis is the consideration of an organic haze layer, which has been suggested as a possible ultraviolet shield on the anoxic early Earth. Since such a haze layer - if formed - would serve as a reservoir for organic molecules, the chemical composition of the aerosol should be closely examined. The results highlighted here show that a variety of products can be formed in mildly reducing or even neutral atmospheres, demonstrating that contributions of atmospheric synthesis to the organic inventory on early Earth should not be discounted. This review intends to bridge current knowledge of the range of possible atmospheric conditions in the prebiotic environment and pathways for synthesis under such conditions by examining the possible products of organic chemistry in the early atmosphere. PMID:24143126

  20. Atmospheric Prebiotic Chemistry and Organic Hazes

    PubMed Central

    Trainer, Melissa G.

    2013-01-01

    Earth’s atmospheric composition at the time of the origin of life is not known, but it has often been suggested that chemical transformation of reactive species in the atmosphere was a significant source of prebiotic organic molecules. Experimental and theoretical studies over the past half century have shown that atmospheric synthesis can yield molecules such as amino acids and nucleobases, but these processes are very sensitive to gas composition and energy source. Abiotic synthesis of organic molecules is more productive in reduced atmospheres, yet the primitive Earth may not have been as reducing as earlier workers assumed, and recent research has reflected this shift in thinking. This work provides a survey of the range of chemical products that can be produced given a set of atmospheric conditions, with a particular focus on recent reports. Intertwined with the discussion of atmospheric synthesis is the consideration of an organic haze layer, which has been suggested as a possible ultraviolet shield on the anoxic early Earth. Since such a haze layer – if formed – would serve as a reservoir for organic molecules, the chemical composition of the aerosol should be closely examined. The results highlighted here show that a variety of products can be formed in mildly reducing or even neutral atmospheres, demonstrating that contributions of atmospheric synthesis to the organic inventory on early Earth should not be discounted. This review intends to bridge current knowledge of the range of possible atmospheric conditions in the prebiotic environment and pathways for synthesis under such conditions by examining the possible products of organic chemistry in the early atmosphere. PMID:24143126

  1. Endogenous Synthesis of Prebiotic Organic Molecules

    NASA Technical Reports Server (NTRS)

    Miller, Stanley L.

    1996-01-01

    The necessary condition for the synthesis of organic compounds on the primitive earth is the presence of reducing conditions. This means an atmosphere of CH4, CO, or CO2 + H2. The atmospheric nitrogen can be N2 with a trace of NH3, but NH4(+) is needed in the ocean at least for amino acid synthesis. Many attempts have been made to use CO2 + H2O atmospheres for prebiotic synthesis, but these give at best extremely low yields of organic compounds, except in the presence of H2. Even strong reducing agents such as FeS + H2S or the mineral assemblages of the submarine vents fail to give significant yields of organic compounds with CO2. There appears to be a high kinetic barrier to the non-biological reduction of CO2 at low temperatures using geological reducing agents. The most abundant source of energy for prebiotic synthesis is ultraviolet light followed by electric discharges, with electric discharges being more efficient, although it is not clear which was the important energy source. Photochemical process would also make significant contributions. In an atmosphere Of CO2, N2, and H2O with no H2, the production rates of HCN and H2CO would be very low, 0.001 or less than that of a relatively reducing atmosphere. The concentration of organic compounds under these non-reducing conditions would be so low that there is doubt whether the concentration mechanism would be adequate for further steps toward the origin of life. A number of workers have calculated the influx of comets and meteorites on the primitive earth as a source of organic compounds. We conclude that while some organic material was added to the earth from comets and meteorites the amount available from these sources at a given time was at best only a few percent of that from earth bases syntheses under reducing conditions.

  2. Drivers of liking for yogurt drinks with prebiotics and probiotics.

    PubMed

    Allgeyer, L C; Miller, M J; Lee, S-Y

    2010-05-01

    Several studies have addressed the sensory properties of yogurt. However, as the market for yogurt continues to expand and new varieties of yogurt with novel ingredients emerge, additional sensory tests are needed to ensure the quality of the products. Three selected prebiotics, soluble corn fiber, polydextrose, and chicory inulin, were each added at an excellent source of fiber (5 g fiber/serving) or a good fiber source (2.5 g fiber/serving) levels into a yogurt drink base. Three additional yogurt drinks contained 5 g of each of the separate prebiotics along with a mixture of probiotics (Bifidobacterium lactis Bb-12 and Lactobacillus acidophilus LA-5). A control sample with no prebiotics or probiotics was also included in the experimental design. Yogurt drinks were evaluated by 110 consumers for overall acceptance, acceptance of aroma, appearance, taste, and texture, and purchase intent. Demographic information pertaining to consumer knowledge of prebiotics and probiotics was collected. Consumer data were correlated with previously obtained descriptive analysis data to identify drivers of liking. Data were analyzed by analysis of variance (ANOVA), Fisher's least significant difference (LSD), cluster analysis, internal preference mapping, and external preference mapping. Total variance explained by the internal and external preference maps were 32.2% and 64.6%, respectively, which showed higher levels of the prebiotics with probiotics drove consumer liking compared to lower levels without probiotics. In terms of ingredients added, chicory inulin and polydextrose were preferred over soluble corn fiber. Yogurt drinks with these prebiotics included and probiotics were characterized by a medium level of sweetness and high viscosity. Development of new prebiotic and probiotic containing drinkable yogurts should strive for a medium level of sweetness and high viscosity for maximum consumer acceptance. PMID:20546424

  3. Dissolution enhancement of curcumin via curcumin-prebiotic inulin nanoparticles.

    PubMed

    Fares, Mohammad M; Salem, Mu'taz Sheikh

    2015-01-01

    Dissolution enhancement of curcumin via prebiotic inulin designed to orally deliver poorly water-soluble curcumin at duodenum low acidity (pH 5.5) was investigated. Different prebiotic inulin-curcumin nanoparticles were synthesized in ethanol-water binary system at different pre-adjusted pH values. Characterization via FTIR, XRD and TGA revealed the formation of curcumin-inulin conjugates, whereas surface morphology via SEM and TEM techniques implied the formation of nanoparticle beads and nanoclusters. Prebiotic inulin-curcumin nanoparticles prepared at pH 7.0 demonstrated a maximum curcumin dissolution enhancement of ≈90% with respect to 30% for curcumin alone at pH 5.5. Power law constant values were in accordance with dissolution enhancement investigations. All samples show Fickian diffusion mechanism. XRD investigations confirm that inulin maintain its crystalline structure in curcumin-inulin conjugate structure, which confirms that it can exert successfully its prebiotic role in the gastrointestinal (GI) tract. Therefore, the use of curcumin-inulin nanoparticles can perform dual-mission in the GI tract at the duodenum environment; release of 90% of curcumin followed by prebiotic activity of inulin, which will probably play a significant role in cancer therapeutics for the coming generations. PMID:25632979

  4. A prebiotic fiber increases the formation and subsequent absorption of compound K following oral administration of ginseng in rats

    PubMed Central

    Kim, Kyung-Ah; Yoo, Hye Hyun; Gu, Wan; Yu, Dae-Hyung; Jin, Ming Ji; Choi, Hae-Lim; Yuan, Kathy; Guerin-Deremaux, Laetitia; Kim, Dong-Hyun

    2014-01-01

    Background Gut microflora play a crucial role in the biotransformation of ginsenosides to compound K (CK), which may affect the pharmacological effects of ginseng. Prebiotics, such as NUTRIOSE, could enhance the formation and consequent absorption of CK through the modulation of gut microbial metabolic activities. In this study, the effect of a prebiotic fiber (NUTRIOSE) on the pharmacokinetics of ginsenoside CK, a bioactive metabolite of ginsenosides, and its mechanism of action were investigated. Methods Male Sprague–Dawley rats were given control or NUTRIOSE-containing diets (control diet + NUTRIOSE) for 2 wk, and ginseng extract or vehicle was then orally administered. Blood samples were collected to investigate the pharmacokinetics of CK using liquid chromatography–tandem mass spectrometry. Fecal activities that metabolize ginsenoside Rb1 to CK were assayed with fecal specimens or bacteria cultures. Results When ginseng extract was orally administered to rats fed with 2.5%, 5%, or 10% NUTRIOSE containing diets, the maximum plasma concentration (Cmax) and area under the plasma concentration–time curve values of CK significantly increased in a NUTRIOSE content-dependent manner. NUTRIOSE intake increased glycosidase activity and CK formation in rat intestinal contents. The CK-forming activities of intestinal microbiota cultured in vitro were significantly induced by NUTRIOSE. Conclusion These results show that prebiotic diets, such as NUTRIOSE, may promote the metabolic conversion of ginsenosides to CK and the subsequent absorption of CK in the gastrointestinal tract and may potentiate the pharmacological effects of ginseng. PMID:26045693

  5. Prebiotic syntheses of purines and pyrimidines

    NASA Astrophysics Data System (ADS)

    Basile, B.; Lazcano, A.; Oró, J.

    The work done in many laboratories during the last two decades has confirmed that hydrogen cyanide and cyanoacetylene are the two major precursors for the prebiotic synthesis of purines and pyrimidines, respectively. Although several different pathways for the synthesis of purines have been described, they are all variations of the initial mechanism proposed by Oró and Kimball, where hydrogen cyanide leads first to the formation of a 4,5-disubstituted imidazole derivative, and then to the closing of the purine ring with a C1 compound. A number of experiments have shown that purines and pyrimidines can also be obtained from methane, ammonia (nitrogen), and water mixtures, provided an activating source of energy (radiation, electric discharges, etc.) is available. However, in this case the yields are lower by about two orders of magnitude because of the intermediate formation of hydrogen cyanide and cyanoacetylene. The latter two compounds have been found in interstellar space, Titan and other bodies of the solar system. They were probably present in the primordial parent bodies from the solar nebula in concentrations of 10-2 to 10-3 M as inferred from recent calculations by Miller and coworkers obtained for the Murchison meteorite. These concentrations should have been sufficient to generate relatively large amounts of purine and pyrimidine bases on the primitive Earth.

  6. Probiotics, Prebiotics, and Synbiotics: Gut and Beyond

    PubMed Central

    Vyas, Usha; Ranganathan, Natarajan

    2012-01-01

    The human intestinal tract has been colonized by thousands of species of bacteria during the coevolution of man and microbes. Gut-borne microbes outnumber the total number of body tissue cells by a factor of ten. Recent metagenomic analysis of the human gut microbiota has revealed the presence of some 3.3 million genes, as compared to the mere 23 thousand genes present in the cells of the tissues in the entire human body. Evidence for various beneficial roles of the intestinal microbiota in human health and disease is expanding rapidly. Perturbation of the intestinal microbiota may lead to chronic diseases such as autoimmune diseases, colon cancers, gastric ulcers, cardiovascular disease, functional bowel diseases, and obesity. Restoration of the gut microbiota may be difficult to accomplish, but the use of probiotics has led to promising results in a large number of well-designed (clinical) studies. Microbiomics has spurred a dramatic increase in scientific, industrial, and public interest in probiotics and prebiotics as possible agents for gut microbiota management and control. Genomics and bioinformatics tools may allow us to establish mechanistic relationships among gut microbiota, health status, and the effects of drugs in the individual. This will hopefully provide perspectives for personalized gut microbiota management. PMID:23049548

  7. Intrinsic immunomodulatory effects of low-digestible carbohydrates selectively extend their anti-inflammatory prebiotic potentials.

    PubMed

    Breton, Jérôme; Plé, Coline; Guerin-Deremaux, Laetitia; Pot, Bruno; Lefranc-Millot, Catherine; Wils, Daniel; Foligné, Benoit

    2015-01-01

    The beneficial effects of carbohydrate-derived fibers are mainly attributed to modulation of the microbiota, increased colonic fermentation, and the production of short-chain fatty acids. We studied the direct immune responses to alimentary fibers in in vitro and in vivo models. Firstly, we evaluated the immunomodulation induced by nine different types of low-digestible fibers on human peripheral blood mononuclear cells. None of the fibers tested induced cytokine production in baseline conditions. However, only one from all fibers almost completely inhibited the production of anti- and proinflammatory cytokines induced by bacteria. Secondly, the impact of short- (five days) and long-term (three weeks) oral treatments with selected fibers was assessed in the trinitrobenzene-sulfonic acid colitis model in mice. The immunosuppressive fiber significantly reduced levels of inflammatory markers over both treatment periods, whereas a nonimmunomodulatory fiber had no effect. The two fibers did not differ in terms of the observed fermentation products and colonic microbiota after three weeks of treatment, suggesting that the anti-inflammatory action was not related to prebiotic properties. Hence, we observed a direct effect of a specific fiber on the murine immune system. This intrinsic, fiber-dependent immunomodulatory potential may extend prebiotic-mediated protection in inflammatory bowel disease. PMID:25977916

  8. In vitro evaluation method for screening of candidate prebiotic foods.

    PubMed

    Date, Yasuhiro; Nakanishi, Yumiko; Fukuda, Shinji; Nuijima, Yumi; Kato, Tamotsu; Umehara, Mikihisa; Ohno, Hiroshi; Kikuchi, Jun

    2014-01-01

    The aim of this work was to develop a simple and rapid in vitro evaluation method for screening and discovery of uncharacterised and untapped prebiotic foods. Using a NMR-based metabolomic approach coupled with multivariate statistical analysis, the metabolic profiles generated by intestinal microbiota after in vitro incubation with feces were examined. The viscous substances of Japanese bunching onion (JBOVS) were identified as one of the candidate prebiotic foods by this in vitro screening method. The JBOVS were primarily composed of sugar components, especially fructose-based carbohydrates. Our results suggested that ingestion of JBOVS contributed to lactate and acetate production by the intestinal microbiota, and were accompanied by an increase in the Lactobacillus murinus and Bacteroidetes sp. populations in the intestine and fluctuation of the host-microbial co-metabolic process. Therefore, our approach should be useful as a rapid and simple screening tool for potential prebiotic foods. PMID:24444934

  9. Synthesis of long Prebiotic Oligomers on Mineral Surfaces

    NASA Technical Reports Server (NTRS)

    Ferris, James P.; Hill, Aubrey R., Jr.; Liu, Rihe; Orgel, Leslie E.

    1996-01-01

    Most theories of the origin of biological organization assume that polymers with lengths in the range of 30-60 monomers are needed to make a genetic system viable. But it has not proved possible to synthesize plausibly prebiotic polymers this long by condensation in aqueous solution, because hydrolysis competes with polymerization. The potential of mineral surfaces to facilitate prebiotic polymerization was pointed out long ago. Here we describe a system that models prebiotic polymerization by the oligomerization of activated monomers -both nucleotides and amino acids. We find that whereas the reactions in solution produce only short oligomers (the longest typically being a 10-mer), the presence of mineral surfaces (montmorillonite for nucleotides, illite and hydroxylapatite for amino adds) induces the formation of oligomers up to 55 monomers long. These are formed by successive "feedings" with the monomers; polymerization takes place on the mineral surfaces in a manner akin to solid-phase synthesis of biopolymers.

  10. The prebiotic synthesis of amino acids - interstellar vs. atmospheric mechanisms

    NASA Astrophysics Data System (ADS)

    Meierhenrich, U. J.; Muñoz Caro, G. M.; Schutte, W. A.; Barbier, B.; Arcones Segovia, A.; Rosenbauer, H.; Thiemann, W. H.-P.; Brack, A.

    2002-11-01

    Until very recently, prebiotic amino acids were believed to have been generated in the atmosphere of the early Earth, as successfully simulated by the Urey-Miller experiments. Two independent studies now identified ice photochemistry in the interstellar medium as a possible source of prebiotic amino acids. Ultraviolet irradiation of ice mixtures containing identified interstellar molecules (such as H2O, CO2, CO, CH3OH, and NH3) in the conditions of vacuum and low temperature found in the interstellar medium generated amino acid structures including glycine, alanine, serine, valine, proline, and aspartic acid. After warmup, hydrolysis and derivatization, our team was able to identify 16 amino acids as well as furans and pyrroles. Enantioselective analyses of the amino acids showed racemic mixtures. A prebiotic interstellar origin of amino acid structures is now discussed to be a plausible alternative to the Urey-Miller mechanism.

  11. Novel probiotics and prebiotics: road to the market.

    PubMed

    Kumar, Himanshu; Salminen, Seppo; Verhagen, Hans; Rowland, Ian; Heimbach, Jim; Bañares, Silvia; Young, Tony; Nomoto, Koji; Lalonde, Mélanie

    2015-04-01

    Novel probiotics and prebiotics designed to manipulate the gut microbiota for improving health outcomes are in demand as the importance of the gut microbiota in human health is revealed. The regulations governing introduction of novel probiotics and prebiotics vary by geographical region. Novel foods and foods with health claims fall under specific regulations in several countries. The paper reviews the main requirements of the regulations in the EU, USA, Canada and Japan. We propose a number of areas that need to be addressed in any safety assessment of novel probiotics and prebiotics. These include publication of the genomic sequence, antibiotic resistance profiling, selection of appropriate in vivo model, toxicological studies (including toxin production) and definition of target population. PMID:25499742

  12. Prebiotic effects of a novel combination of galactooligosaccharides and maltodextrins.

    PubMed

    Musilova, Sarka; Rada, Vojtech; Marounek, Milan; Nevoral, Jiri; Dušková, Dagmar; Bunesova, Vera; Vlkova, Eva; Zelenka, Richard

    2015-06-01

    Prebiotics are used for stimulating the growth of beneficial microorganisms in the gut. However, it is very difficult to find a suitable prebiotic mixture that exclusively supports the growth of beneficial microbes such as bifidobacteria and lactobacilli. We tested the effects of a prebiotic mixture in vitro by incubating it with fecal samples and in vivo by administration of the prebiotic supplement to healthy adult volunteers, followed by analysis of their fecal microbiota. The effect of the oligosaccharides on bacterial metabolism was studied by analyzing short-chain fatty acid (SCFA) production in vitro and the SCFA pattern for the stool samples of volunteers. In the in vitro test, a higher proportion of bifidobacteria (25.77%) was seen in the total bacterial population after cultivation on a prebiotic mixture than on the control medium (7.94%). The gram-negative anaerobe count significantly decreased from 8.70 to 6.40 log CFU/g (from 35.21% to 0.60%) and the Escherichia coli count decreased from 7.41 to 6.27 log CFU/g (from 1.78% to 0.44%). Administration of a prebiotic mixture in vivo (9 g of galactooligosaccharides [GOS]+1 g of maltodextrins; daily for 5 days) significantly increased the fecal bifidobacterial count from 9.45 to 9.83 log CFU/g (from 40.80% to 53.85% of total bacteria) and reduced the E. coli count from 7.23 to 6.28 log CFU/g (from 55.35% to 45.06% of total bacteria). The mixture comprising GOS and maltodextrins thus exhibited bifidogenic properties, promoting the performance of bifidobacteria by boosting their growth and inhibiting the growth of undesirable bacteria. PMID:25525835

  13. Plant Cell Wall Polysaccharides as Potential Resources for the Development of Novel Prebiotics

    PubMed Central

    Kim, Dojung; Paek, Seung-Ho

    2012-01-01

    Prebiotic oligosaccharides, with a degree of polymerization (DP) of mostly less than 10, exhibit diverse biological activities that contribute to human health. Currently available prebiotics are mostly derived from disaccharides and simple polysaccharides found in plants. Subtle differences in the structures of oligosaccharides can cause significant differences in their prebiotic proper-ties. Therefore, alternative substances supplying polysaccharides that have more diverse and complex structures are necessary for the development of novel oligosaccharides that have actions not present in existing prebiotics. In this review, we show that structural polysaccharides found in plant cell walls, such as xylans and pectins, are particularly potential resources supplying broadly diverse polysaccharides to produce new prebiotics. PMID:24009823

  14. Oceanic protection of prebiotic organic compounds from UV radiation

    NASA Technical Reports Server (NTRS)

    Cleaves, H. J.; Miller, S. L.; Bada, J. L. (Principal Investigator)

    1998-01-01

    It is frequently stated that UV light would cause massive destruction of prebiotic organic compounds because of the absence of an ozone layer. The elevated UV flux of the early sun compounds this problem. This applies to organic compounds of both terrestrial and extraterrestrial origin. Attempts to deal with this problem generally involve atmospheric absorbers. We show here that prebiotic organic polymers as well as several inorganic compounds are sufficient to protect oceanic organic molecules from UV degradation. This aqueous protection is in addition to any atmospheric UV absorbers and should be a ubiquitous planetary phenomenon serving to increase the size of planetary habitable zones.

  15. The prebiotic synthesis of pyrimidines in frozen solution

    NASA Astrophysics Data System (ADS)

    Cleaves, H. James, II; Nelson, Kevin E.; Miller, Stanley L.

    2006-05-01

    Most prebiotic syntheses depend on the reaction of concentrated precursor compounds to produce bio-organic molecules. It is now believed that the early Earth’s atmosphere was not reducing enough to have permitted copious synthesis of precursor molecules. Freezing allows reaction to occur even from dilute solution. This reaction has been demonstrated for the purines but not for the pyrimidines. It is shown here that dilute solutions of simple prebiotic molecules produce the biological pyrimidines cytosine and uracil upon freezing. Cold environments may have allowed synthesis of all of the RNA bases even from low organic yielding atmospheres, such as those of the early Earth, Mars, Titan and Europa.

  16. Prebiotic Chemical Evolution in the Astrophysical Context

    NASA Astrophysics Data System (ADS)

    Ziurys, L. M.; Adande, G. R.; Edwards, J. L.; Schmidt, D. R.; Halfen, D. T.; Woolf, N. J.

    2015-06-01

    An ever increasing amount of molecular material is being discovered in the interstellar medium, associated with the birth and death of stars and planetary systems. Radio and millimeter-wave astronomical observations, made possible by high-resolution laboratory spectroscopy, uniquely trace the history of gas-phase molecules with biogenic elements. Using a combination of both disciplines, the full extent of the cycling of molecular matter, from circumstellar ejecta of dying stars - objects which expel large amounts of carbon - to nascent solar systems, has been investigated. Such stellar ejecta have been found to exhibit a rich and varied chemical content. Observations demonstrate that this molecular material is passed onto planetary nebulae, the final phase of stellar evolution. Here the star sheds almost its entire original mass, becoming an ultraviolet-emitting white dwarf. Molecules such as H2CO, HCN, HCO+, and CCH are present in significant concentrations across the entire age span of such nebulae. These data suggest that gas-phase polyatomic, carbon-containing molecules survive the planetary nebula phase and subsequently are transported into the interstellar medium, seeding the chemistry of diffuse and then dense clouds. The extent of the chemical complexity in dense clouds is unknown, hindered by the high spectral line density. Organic species such as acetamide and methyl amine are present in such objects, and NH2CHO has a wide Galactic distribution. However, organophosphorus compounds have not yet been detected in dense clouds. Based on carbon and nitrogen isotope ratios, molecular material from the ISM appears to become incorporated into solar system planetesimals. It is therefore likely that interstellar synthesis influences prebiotic chemistry on planet surfaces.

  17. Prebiotic chemical evolution in the astrophysical context.

    PubMed

    Ziurys, L M; Adande, G R; Edwards, J L; Schmidt, D R; Halfen, D T; Woolf, N J

    2015-06-01

    An ever increasing amount of molecular material is being discovered in the interstellar medium, associated with the birth and death of stars and planetary systems. Radio and millimeter-wave astronomical observations, made possible by high-resolution laboratory spectroscopy, uniquely trace the history of gas-phase molecules with biogenic elements. Using a combination of both disciplines, the full extent of the cycling of molecular matter, from circumstellar ejecta of dying stars - objects which expel large amounts of carbon - to nascent solar systems, has been investigated. Such stellar ejecta have been found to exhibit a rich and varied chemical content. Observations demonstrate that this molecular material is passed onto planetary nebulae, the final phase of stellar evolution. Here the star sheds almost its entire original mass, becoming an ultraviolet-emitting white dwarf. Molecules such as H2CO, HCN, HCO(+), and CCH are present in significant concentrations across the entire age span of such nebulae. These data suggest that gas-phase polyatomic, carbon-containing molecules survive the planetary nebula phase and subsequently are transported into the interstellar medium, seeding the chemistry of diffuse and then dense clouds. The extent of the chemical complexity in dense clouds is unknown, hindered by the high spectral line density. Organic species such as acetamide and methyl amine are present in such objects, and NH2CHO has a wide Galactic distribution. However, organophosphorus compounds have not yet been detected in dense clouds. Based on carbon and nitrogen isotope ratios, molecular material from the ISM appears to become incorporated into solar system planetesimals. It is therefore likely that interstellar synthesis influences prebiotic chemistry on planet surfaces. PMID:25894971

  18. Atmospheric Prebiotic Chemistry and Organic Hazes

    NASA Technical Reports Server (NTRS)

    Trainer, Melissa G.

    2012-01-01

    Earth's atmospheric composition at the time of the origin of life is not known, but it has often been suggested that chemical transformation of reactive species in the atmosphere was a significant source of pre biotic organic molecules. Experimental and theoretical studies over the past half century have shown that atmospheric synthesis can yield molecules such as amino acids and nucleobases, but these processes are very sensitive to gas composition and energy source. Abiotic synthesis of organic molecules is more productive in reduced atmospheres, yet the primitive Earth may not have been as reducing as earlier workers assumed, and recent research has reflected this shift in thinking. This work provides a survey of the range of chemical products that can be produced given a set of atmospheric conditions, with a particular focus on recent reports. Intertwined with the discussion of atmospheric synthesis is the consideration of an organic haze layer, which has been suggested as a possible ultraviolet shield on the anoxic early Earth. Since such a haze layer - if formed - would serve as a reservoir for organic molecules, the chemical composition of the aerosol should be closely examined. The results highlighted here show that a variety of products can be formed in mildly reducing or even neutral atmospheres, demonstrating that contributions of atmospheric synthesis to the organic inventory on early Earth should not be discounted. This review intends to bridge current knowledge of the range of possible atmospheric conditions in the prebiotic environment and pathways for synthesis under such conditions by examining the possible products of organic chemistry in the early atmosphere.

  19. Prebiotic Organic Matter from the Center of the Galaxy

    NASA Astrophysics Data System (ADS)

    Halfen, DeWayne; Ziurys, Lucy M.

    2016-06-01

    The origins of life on Earth must have begun with simple organic compounds. A plausible source of such prebiotic molecules was the interstellar medium (ISM). Of the over 160 molecules that have been identified in interstellar gas, about half have been discovered in one source, Sagittarius B2(N), located in the Galactic Center. This giant molecular cloud is also home to many large organic species observed in the ISM. How complex these species can become is unknown. In order to accurately establish an inventory of potentially, prebiotic organic molecules, we completed a continuous spectral-line survey of Sgr B2(N) at the confusion limit using the Arizona Radio Observatory facilities: the Kitt Peak 12 m and the Submillimeter Telescope. The survey covers the 1, 2, and 3 mm atmospheric windows in the range 68 - 280 GHz, and about 15,000 individual spectral lines have been observed. Seventy-four molecules have been identified in the data, including several potential prebiotic species, such as glycolaldehyde, acetamide, and methyl isocyanate. These molecules are relatively abundant in Sgr B2(N), with fractional abundances of f ~ 10-10 - 10-12 relative to H2. Current results of this survey will be presented, along with its implications for interstellar organic chemistry and prebiotic synthesis. A comparison with organics found in comets and meteorites will also be discussed.

  20. Prebiotically plausible oligoribonucleotide ligation facilitated by chemoselective acetylation

    NASA Astrophysics Data System (ADS)

    Bowler, Frank R.; Chan, Christopher K. W.; Duffy, Colm D.; Gerland, Béatrice; Islam, Saidul; Powner, Matthew W.; Sutherland, John D.; Xu, Jianfeng

    2013-05-01

    The recent synthesis of pyrimidine ribonucleoside-2‧,3‧-cyclic phosphates under prebiotically plausible conditions has strengthened the case for the involvement of ribonucleic acid (RNA) at an early stage in the origin of life. However, a prebiotic conversion of these weakly activated monomers, and their purine counterparts, to the 3‧,5‧-linked RNA polymers of extant biochemistry has been lacking (previous attempts led only to short oligomers with mixed linkages). Here we show that the 2‧-hydroxyl group of oligoribonucleotide-3‧-phosphates can be chemoselectively acetylated in water under prebiotically credible conditions, which allows rapid and efficient template-directed ligation. The 2‧-O-acetyl group at the ligation junction of the product RNA strand can be removed under conditions that leave the internucleotide bonds intact. Remarkably, acetylation of mixed oligomers that possess either 2‧- or 3‧-terminal phosphates is selective for the 2‧-hydroxyl group of the latter. This newly discovered chemistry thus suggests a prebiotic route from ribonucleoside-2‧,3‧-cyclic phosphates to predominantly 3‧,5‧-linked RNA via partially 2‧-O-acetylated RNA.

  1. Structural and functional aspects of prebiotics used in infant nutrition.

    PubMed

    Boehm, Günther; Moro, Guido

    2008-09-01

    Breast-feeding is associated with several benefits. Among them, the balanced postnatal development of the immune system is 1 of the key functions of breast-feeding. Although this effect is of multifactorial origin, it is widely accepted that the entire intestinal microbiota of breast-fed infants represents an important stimulating factor of the postnatal development of the immune system. The effect of breast-feeding on the intestinal microbiota can not be attributed to a single compound, but there is accumulating evidence that human milk oligosaccharides play a crucial role. Because there is a broad consensus that the intestinal microbiota plays an important physiological role for the host, many attempts have been made to influence the intestinal flora by dietary interventions. This article summarizes results of intervention studies in which nonmilk oligosaccharides have been used to mimic the prebiotic effect of breast-feeding. A second focus has been related to the question of whether the prebiotic activity has beneficial effects on the postnatal development of the immune system. The data clearly demonstrate that prebiotics of nonmilk origin can mimic the prebiotic effect of breast-feeding, and this has positive consequences for the postnatal development of the immune system. PMID:18716193

  2. The potential for prebiotic synthesis in hydrothermal systems. [Abstract only

    NASA Technical Reports Server (NTRS)

    Ferris, James P.

    1994-01-01

    Contemporary hydrothermal systems provide a reducing environment where organic compounds are formed and may react to generate the molecules used in the first living systems. The organic compounds percolate through mineral assemblages at a variety of temperatures so the proposed synthetic reactions are driven by heat and catalyzed by minerals (Ferris, 1992). Some examples of potential prebiotic reactions are discussed.

  3. Proton-Induced Collisions on Potential Prebiotic Species

    NASA Astrophysics Data System (ADS)

    Bacchus-Montabonel, Marie-Christine

    2016-03-01

    With regard to the fascinating question of the origin of life, special interest has been devoted to potential prebiotic molecules which could drive the emergence of life. In the widely discussed hypothesis of a possible exogen apparition of life, the transport of those prebiotic species and their survival under spatial conditions is of strong interest. In particular their stability under solar radiation or in collisions with bare nucleus has to be considered. In that sense, taking account of the abundance of protons in ionized clouds of the interstellar medium, we have developed a detailed theoretical study of the charge transfer collision dynamics induced by impact of protons on a series of possible prebiotic compounds. Three main types of molecules have been considered: first of all the DNA and RNA building blocks with on a one hand the nucleobases uracil and thymine, and on the other hand the 2-deoxy-D-ribose sugar skeleton in its furanose and pyranose forms. The study has been extended to the 2-aminooxazole suggested to be a possible precursor of RNA nucleotides. The theoretical treatment involves ab-initio quantum chemistry molecular calculations followed by a semiclassical collision dynamics. Some qualitative trends may be suggested for the proton-induced damage of such prebiotic species.

  4. The potential of resistant starch as a prebiotic.

    PubMed

    Zaman, Siti A; Sarbini, Shahrul R

    2016-06-01

    Resistant starch is defined as the total amount of starch and the products of starch degradation that resists digestion in the small intestine. Starches that were able to resist the digestion will arrive at the colon where they will be fermented by the gut microbiota, producing a variety of products which include short chain fatty acids that can provide a range of physiological benefits. There are several factors that could affect the resistant starch content of a carbohydrate which includes the starch granule morphology, the amylose-amylopectin ratio and its association with other food component. One of the current interests on resistant starch is their potential to be used as a prebiotic, which is a non-digestible food ingredient that benefits the host by stimulating the growth or activity of one or a limited number of beneficial bacteria in the colon. A resistant starch must fulfill three criterions to be classified as a prebiotic; resistance to the upper gastrointestinal environment, fermentation by the intestinal microbiota and selective stimulation of the growth and/or activity of the beneficial bacteria. The market of prebiotic is expected to reach USD 198 million in 2014 led by the export of oligosaccharides. Realizing this, novel carbohydrates such as resistant starch from various starch sources can contribute to the advancement of the prebiotic industry. PMID:25582732

  5. Effects of prebiotics on mineral absorption: mechanisms of action

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is extensive evidence in experimental animals that prebiotics, such as inulin-type fructans, can increase the absorption of a variety of minerals, including calcium, magnesium, iron, and zinc, and that they may act through several possible mechanisms. The purpose of this review is to discuss t...

  6. Can prebiotics and probiotics improve therapeutic outcomes for undernourished individuals?

    PubMed Central

    Sheridan, Paul O; Bindels, Laure B; Saulnier, Delphine M; Reid, Gregor; Nova, Esther; Holmgren, Kerstin; O'Toole, Paul W; Bunn, James; Delzenne, Nathalie; Scott, Karen P

    2014-01-01

    It has become clear in recent years that the human intestinal microbiota plays an important role in maintaining health and thus is an attractive target for clinical interventions. Scientists and clinicians have become increasingly interested in assessing the ability of probiotics and prebiotics to enhance the nutritional status of malnourished children, pregnant women, the elderly, and individuals with non-communicable disease-associated malnutrition. A workshop was held by the International Scientific Association for Probiotics and Prebiotics (ISAPP), drawing on the knowledge of experts from industry, medicine, and academia, with the objective to assess the status of our understanding of the link between the microbiome and under-nutrition, specifically in relation to probiotic and prebiotic treatments for under-nourished individuals. These discussions led to four recommendations:   (1) The categories of malnourished individuals need to be differentiated To improve treatment outcomes, subjects should first be categorized based on the cause of malnutrition, additional health-concerns, differences in the gut microbiota, and sociological considerations. (2) Define a baseline “healthy” gut microbiota for each category Altered nutrient requirement (for example, in pregnancy and old age) and individual variation may change what constitutes a healthy gut microbiota for the individual. (3) Perform studies using model systems to test the effectiveness of potential probiotics and prebiotics against these specific categories These should illustrate how certain microbiota profiles can be altered, as members of different categories may respond differently to the same treatment. (4) Perform robust well-designed human studies with probiotics and/or prebiotics, with appropriate, defined primary outcomes and sample size These are critical to show efficacy and understand responder and non-responder outcomes. It is hoped that these recommendations will lead to new approaches

  7. Simulating the UV Environment For the Synthesis of Prebiotic Molecules

    NASA Astrophysics Data System (ADS)

    Ranjan, S.; Sasselov, D.

    2014-03-01

    UV radiation plays a key role in the era of biogenesis. The young Sun was more UV-active than the modern Sun (Ribas et al. 2010), and the Earth lacked an ozone layer, implying a larger UV flux both on Earth, as well as on asteroids/comets. Ultraviolet radiation can help drive prebiotic molecule synthesis (e.g., Chyba et al. 1992; Powner et al. 2009) or destroy biologically important molecules (e.g., Johns et al. 1967). These effects are wavelength dependent: they are sensitive to ionzation, bond, and ro-vibrational transition energies of biologically relevant molecules and their precursors. When simulating the environment at biogenesis it is therefore important to ensure realistic levels of UV input, in both magnitude and spectral shape. Many laboratory simulations of biomolecule synthesis under prebiotic conditions to date have been done with atomic lamps (e.g., Powner et al. 2007). These lamps are safe, stable, and affordable UV sources, well-suited for initial studies. However, their emission spectra are a poor match to prebiotic conditions: low-pressure lamps are characterized by line emission, while higher-pressure lamps do not well-reproduce the spectrum of the young Sun. In this paper, we present spectra that are more realistic approximations to prebiotic conditions. Using published opacity lists and atmospheric models, we compute the attenuation of the flux from a young Sunanalog due to water, and from the present-day Sun due to a planetary atmosphere. We compare these spectra to those emitted by lamps used in studies today, and explore the potential biological implications of the differences. We conclude by discussing possibilities for better simulating the prebiotic UV environment in lab setups.

  8. Prebiotic administration normalizes lipopolysaccharide (LPS)-induced anxiety and cortical 5-HT2A receptor and IL1-β levels in male mice.

    PubMed

    Savignac, Helene M; Couch, Yvonne; Stratford, Michael; Bannerman, David M; Tzortzis, George; Anthony, Daniel C; Burnet, Philip W J

    2016-02-01

    The manipulation of the enteric microbiota with specific prebiotics and probiotics, has been shown to reduce the host's inflammatory response, alter brain chemistry, and modulate anxiety behaviour in both rodents and humans. However, the neuro-immune and behavioural effects of prebiotics on sickness behaviour have not been explored. Here, adult male CD1 mice were fed with a specific mix of non-digestible galacto-oligosaccharides (Bimuno®, BGOS) for 3 weeks, before receiving a single injection of lipopolysaccharide (LPS), which induces sickness behaviour and anxiety. Locomotor and marble burying activities were assessed 4h after LPS injection, and after 24h, anxiety in the light-dark box was assessed. Cytokine expression, and key components of the serotonergic (5-Hydroxytryptamine, 5-HT) and glutamatergic system were evaluated in the frontal cortex to determine the impact of BGOS administration at a molecular level. BGOS-fed mice were less anxious in the light-dark box compared to controls 24h after the LPS injection. Elevated cortical IL-1β concentrations in control mice 28 h after LPS were not observed in BGOS-fed animals. This significant BGOS×LPS interaction was also observed for 5HT2A receptors, but not for 5HT1A receptors, 5HT, 5HIAA, NMDA receptor subunits, or other cytokines. The intake of BGOS did not influence LPS-mediated reductions in marble burying behaviour, and its effect on locomotor activity was equivocal. Together, our data show that the prebiotic BGOS has an anxiolytic effect, which may be related to the modulation of cortical IL-1β and 5-HT2A receptor expression. Our data suggest a potential role for prebiotics in the treatment of neuropsychiatric disorders where anxiety and neuroinflammation are prominent clinical features. PMID:26476141

  9. New Approaches for Bacteriotherapy: Prebiotics, New-Generation Probiotics, and Synbiotics

    PubMed Central

    Patel, Rachna; DuPont, Herbert L.

    2015-01-01

    The gut microbiota has a significant role in human health and disease. Dysbiosis of the intestinal ecosystem contributes to the development of certain illnesses that can be reversed by favorable alterations by probiotics. The published literature was reviewed to identify scientific data showing a relationship between imbalance of gut bacteria and development of diseases that can be improved by biologic products. The medical conditions vary from infectious and antibiotic-associated diarrhea to obesity to chronic neurologic disorders. A number of controlled clinical trials have been performed to show important biologic effects in a number of these conditions through administration of prebiotics, probiotics, and synbiotics. Controlled clinical trials have identified a limited number of prebiotics, probiotic strains, and synbiotics that favorably prevent or improve the symptoms of various disorders including inflammatory bowel disease, irritable bowel syndrome, infectious and antibiotic-associated diarrhea, diabetes, nonalcoholic fatty liver disease, necrotizing enterocolitis in very low birth weight infants, and hepatic encephalopathy. Studies have shown that probiotics alter gut flora and lead to elaboration of flora metabolites that influence health through 1 of 3 general mechanisms: direct antimicrobial effects, enhancement of mucosal barrier integrity, and immune modulation. Restoring the balance of intestinal flora by introducing probiotics for disease prevention and treatment could be beneficial to human health. It is also clear that significant differences exist between different probiotic species. Metagenomics and metatranscriptomics together with bioinformatics have allowed us to study the cross-talk between the gut microbiota and the host, furthering insight into the next generation of biologic products. PMID:25922396

  10. New approaches for bacteriotherapy: prebiotics, new-generation probiotics, and synbiotics.

    PubMed

    Patel, Rachna; DuPont, Herbert L

    2015-05-15

    The gut microbiota has a significant role in human health and disease. Dysbiosis of the intestinal ecosystem contributes to the development of certain illnesses that can be reversed by favorable alterations by probiotics. The published literature was reviewed to identify scientific data showing a relationship between imbalance of gut bacteria and development of diseases that can be improved by biologic products. The medical conditions vary from infectious and antibiotic-associated diarrhea to obesity to chronic neurologic disorders. A number of controlled clinical trials have been performed to show important biologic effects in a number of these conditions through administration of prebiotics, probiotics, and synbiotics. Controlled clinical trials have identified a limited number of prebiotics, probiotic strains, and synbiotics that favorably prevent or improve the symptoms of various disorders including inflammatory bowel disease, irritable bowel syndrome, infectious and antibiotic-associated diarrhea, diabetes, nonalcoholic fatty liver disease, necrotizing enterocolitis in very low birth weight infants, and hepatic encephalopathy. Studies have shown that probiotics alter gut flora and lead to elaboration of flora metabolites that influence health through 1 of 3 general mechanisms: direct antimicrobial effects, enhancement of mucosal barrier integrity, and immune modulation. Restoring the balance of intestinal flora by introducing probiotics for disease prevention and treatment could be beneficial to human health. It is also clear that significant differences exist between different probiotic species. Metagenomics and metatranscriptomics together with bioinformatics have allowed us to study the cross-talk between the gut microbiota and the host, furthering insight into the next generation of biologic products. PMID:25922396

  11. Prebiotics and the health benefits of fiber: current regulatory status, future research, and goals.

    PubMed

    Brownawell, Amy M; Caers, Wim; Gibson, Glenn R; Kendall, Cyril W C; Lewis, Kara D; Ringel, Yehuda; Slavin, Joanne L

    2012-05-01

    First defined in the mid-1990s, prebiotics, which alter the composition and activity of gastrointestinal (GI) microbiota to improve health and well-being, have generated scientific and consumer interest and regulatory debate. The Life Sciences Research Organization, Inc. (LSRO) held a workshop, Prebiotics and the Health Benefits of Fiber: Future Research and Goals, in February 2011 to assess the current state of the science and the international regulatory environment for prebiotics, identify research gaps, and create a strategy for future research. A developing body of evidence supports a role for prebiotics in reducing the risk and severity of GI infection and inflammation, including diarrhea, inflammatory bowel disease, and ulcerative colitis as well as bowel function disorders, including irritable bowel syndrome. Prebiotics also increase the bioavailability and uptake of minerals and data suggest that they reduce the risk of obesity by promoting satiety and weight loss. Additional research is needed to define the relationship between the consumption of different prebiotics and improvement of human health. New information derived from the characterization of the composition and function of different prebiotics as well as the interactions among and between gut microbiota and the human host would improve our understanding of the effects of prebiotics on health and disease and could assist in surmounting regulatory issues related to prebiotic use. PMID:22457389

  12. Recent developments in prebiotics to selectively impact beneficial microbes and promote intestinal health.

    PubMed

    Rastall, Robert A; Gibson, Glenn R

    2015-04-01

    Prebiotics are non-digestible food ingredients that have a specific stimulatory effect upon selected populations of gut bacteria. The usual target microorganisms for prebiotic approaches are bifidobacteria. Numerous human feeding studies have shown the prebiotic influences that galactans and fructans can exert. Other candidate prebiotics are under investigation. The field is now moving towards identifying the health aspect associated with their use. Many avenues of gut related health are being researched, including reduction of diarrhoea, immune stimulation, and improved mineral bioavailability. Most current emphasis appears to be towards various parameters associated with metabolic syndrome. These include markers of insulin resistance, appetite, satiety, blood lipids and inflammatory status. PMID:25448231

  13. Spectroscopic Studies of Pre-Biotic Carbon Chemistry

    NASA Technical Reports Server (NTRS)

    Blake, Geoffrey A.

    2003-01-01

    As described in the original proposal and in our progress reports, research in the Blake group supported by the Exobiology program seeks to understand the pre-biotic chemistry of carbon along with that of other first- and second-row elements from the earliest stages of star formation through the development of planetary systems. The major tool used is spectroscopy, and the program has observational, laboratory, and theoretical components. The observational and theoretical programs are concerned primarily with a quantitative assessment of the chemical budgets of the biogenic elements in the circumstellar environment of forming stars and planetary systems, while the laboratory work is focused on the complex species that characterize the pre-biotic chemistry of carbon. We outline below our results over the past year acquired, in part, with Exobiology support.

  14. Prebiotic organic syntheses and the origin of life

    NASA Technical Reports Server (NTRS)

    Chang, S.; Desmarais, D.; Mack, R.; Miller, S. L.; Strathearn, G. E.

    1983-01-01

    The outline of a modern paradigm for the origins of life on earth was first formulated by Oparin (1924). According to the considered hypothesis, living organisms arose naturally on the primitive earth through a lengthy process of chemical evolution of organic matter which began in the atmosphere and culminated in the primordial seas. Details regarding the chemical evolution paradigm are discussed, and chemical evolutionary processes formulated by principal contributors are reviewed in a historical context. Attention is given to the Oparin model of the prebiotic earth, the Urey model, the Rubey model, a multistage model for early atmospheric evolution, and other variations on the theme of prebiotic atmospheres. Evidence in support of the chemical evolution paradigm is considered along with modern models regarding the accretion of earth and the formation of its core, and problems and prospects for future studies.

  15. Application of the organic on water reactions to prebiotic chemistry

    NASA Astrophysics Data System (ADS)

    Kolb, Vera M.

    2012-10-01

    The old view that prebiotic reactions in water are hampered by the low solubility of the organic compounds in water is now being revised due to the discoveries of the reactions "on water". These reactions occur in the heterogeneous system comprising of the organic compounds and water. Unexpectedly, such reactions are extremely efficient; they often give quantitative yields, and are accelerated in the presence of water as compared to the organic solvents. These "on water" reactions are not the same as the "in water" reactions, which occur in solution, and are thus homogenous. Examples of the "on water" reactions include Diels-Alder, Claisen, Passerini and Ugi reactions, among many others. Some of these reactions are multicomponent, but give a single product. We survey a selected number of the "on water" reactions, which have a potential prebiotic applications.

  16. Shock-Synthesis of Prebiotic Compounds in Impacting Simple Ices

    NASA Astrophysics Data System (ADS)

    Goldman, N.

    2013-12-01

    How and when prebiotic organic material such as amino acids appeared on the primitive planet has been debated without resolution in the open literature for close to 60 years. Earlier studies have shown that the synthesis of life-building molecules such as amino acids, polypeptides, and DNA and RNA nucleobases is much more likely in a reducing environment, e.g., rich in H2 and CH4. However, the current viewpoint is that the composition of early Earth's atmosphere was more oxidizing, consisting mainly of CO2, with significantly lesser amounts of N2, H2S, HCl, and water vapor. The possibility exists that both prebiotic raw materials and the requisite energy for their synthesis may have been delivered to the Earth simultaneously by a comet impact. Cometary ices are predominantly water, containing many small molecules important to prebiotic aqueous chemistry, e.g., NH3, CH3OH, and an impact can provide an abundant supply of energy to drive chemical reactivity. The flux of organic matter to Earth via comets and asteroids during periods of heavy bombardment may have been as high as 1013 kg/yr, delivering up to several orders of magnitude greater mass of organics than what likely pre-existed on the planet. We have conducted simulations of the chemical reactivity within impacting icy materials to close to equilibrium using quantum molecular dynamics (MD) simulations. Here, we have simulated the thermodynamic conditions of the entire impacting event, including shock compression due to impact with the planetary surface, followed by expansion due to the rarefaction wave passing through the material, and cooling and equilibration to conditions extant on the planet. Our simulations show that shock compression induces the formation of extended C-C and C-N bonded networks, which break apart to form prebiotic material upon expansion and cooling. Impacts with peak thermodynamic conditions of 36 GPa (1 GPa = 10 kbar) and 2800 K yielded functionalized aromatic hydrocarbons upon

  17. Production of functional probiotic, prebiotic, and synbiotic ice creams.

    PubMed

    Di Criscio, T; Fratianni, A; Mignogna, R; Cinquanta, L; Coppola, R; Sorrentino, E; Panfili, G

    2010-10-01

    In this work, 3 types of ice cream were produced: a probiotic ice cream produced by adding potentially probiotic microorganisms such as Lactobacillus casei and Lactobacillus rhamnosus; a prebiotic ice cream produced by adding inulin, a prebiotic substrate; and a synbiotic ice cream produced by adding probiotic microorganisms and inulin in combination. In addition to microbial counts, pH, acidity, and physical and functional properties of the ice creams were evaluated. The experimental ice creams preserved the probiotic bacteria and had counts of viable lactic acid bacteria after frozen storage that met the minimum required to achieve probiotic effects. Moreover, most of the ice creams showed good nutritional and sensory properties, with the best results obtained with Lb. casei and 2.5% inulin. PMID:20854989

  18. Spectroscopic Studies of Pre-Biotic Carbon Chemistry

    NASA Technical Reports Server (NTRS)

    Blake, Geoffrey A.

    2002-01-01

    As described in the original proposal and in our progress reports, research in the Blake group supported by the Exobiology program seeks to understand the pre-biotic chemistry of carbon along with that of other first- and second-row elements from the earliest stages of star formation through the development of planetary systems. The major tool used is spectroscopy, and the program has observational, laboratory, and theoretical components. The observational and theoretical programs are concerned primarily with a quantitative assessment of the chemical budgets of the biogenic elements in star-forming molecular cloud cores, while the laboratory work is focused on the complex species that characterize the prebiotic chemistry of carbon. We outline below our results over the past two years acquired, in part, with Exobiology support.

  19. Beta structures of alternating polypeptides and their possible prebiotic significance

    NASA Technical Reports Server (NTRS)

    Brack, A.; Orgel, L. E.

    1975-01-01

    A survey of the commonest amino acids formed in prebiotic conditions suggests that the earliest form of genetic coding may have specified polypeptides with a strong tendency to form stable beta-sheet structures. Poly(Val-Lys), like other polypeptides in which hydrophobic and hydrophilic residues alternate, tends to form beta structures. It is shown that bilayers with a hydrophobic interior and a hydrophilic exterior may be present in aqueous solution.

  20. Evolutionary routes from a prebiotic ANA-world.

    PubMed

    Braun, Sebastian; Humphreys, Christine; Dale, Trevor C

    2012-03-01

    Recent experimental support has been generated for a model of prebiotic development that postulates a role for Amyloid-Nucleic Acid (ANA)-fibers as the earliest replicating entities capable of undergoing Darwinian evolution. Here, this new model is compared with existing RNA-world models with a particular focus on trajectories that lead to evolutionary-beneficial interactions between nucleic acid, protein and lipid components. This analysis suggests a number of new areas for fruitful experimental studies. PMID:22808333

  1. Evaluating experimental artifacts in hydrothermal prebiotic synthesis experiments

    NASA Technical Reports Server (NTRS)

    Smirnov, Alexander; Schoonen, Martin A A.

    2003-01-01

    Control experiments with ultra pure deionized water were conducted to evaluate the organic contamination in hydrothermal prebiotic experiments. Different combinations of reaction vessel material, sampling tubing and stirring were tested and the amounts of organic contaminants determined. All tested types of polymer tubing were proven to introduce organic contaminants (formate, acetate and propionate ions) into the reacting solution. Stainless steel has a catalytic effect on the decomposition of formate, consistent with earlier work at high temperatures and pressures.

  2. Exploring the Fate of Nitrogen Heterocycles in Complex Prebiotic Mixtures

    NASA Technical Reports Server (NTRS)

    Smith, Karen E.; Callahan, Michael P.; Cleaves, Henderson J.; Dworkin, Jason P.; House, Christopher H.

    2011-01-01

    A long standing question in the field of prebiotic chemistry is the origin of the genetic macromolecules DNA and RNA. DNA and RNA have very complex structures with repeating subunits of nucleotides, which are composed of nucleobases (nitrogen heterocycles) connected to sugar-phosphate. Due to the instability of some nucleobases (e.g. cytosine), difficulty of synthesis and instability of D-ribose, and the likely scarcity of polyphosphates necessary for the modern nucleotides, alternative nucleotides have been proposed for constructing the first genetic material. Thus, we have begun to investigate the chemistry of nitrogen heterocycles in plausible, complex prebiotic mixtures in an effort to identify robust reactions and potential alternative nucleotides. We have taken a complex prebiotic mixture produced by a spark discharge acting on a gas mixture of N2, CO2, CH4, and H2, and reacted it with four nitrogen heterocycles: uracil, 5-hydroxymethyluracil, guanine, and isoxanthopterin (2-amino-4,7-dihydroxypteridine). The products of the reaction between the spark mixture and each nitrogen heterocycle were characterized by liquid chromatography coupled to UV spectroscopy and Orbitrap mass spectrometry. We found that the reaction between the spark mixtUl'e and isoxanthopterin formed one major product, which was a cyanide adduct. 5-hydroxymethyluracil also reacted with the spark mixture to form a cyanide adduct, uracil-5-acetonitrile, which has been synthesized previously by reacting HCN with S-hydroxymethyluracil. Unlike isoxanthopterin, the chromatogram of the 5-hydroxymethyluracil reaction was much more complex with multiple products including spark-modified dimers. Additionally, we observed that HMU readily self-polymerizes in solution to a variety of oligomers consistent with those suggested by Cleaves. Guanine and uracil, the biological nucleobases, did not react with the spark mixture, even at high temperature (100 C). This suggests that there are alternative

  3. Evaluating Experimental Artifacts in Hydrothermal Prebiotic Synthesis Experiments

    NASA Astrophysics Data System (ADS)

    Smirnov, Alexander; Schoonen, Martin A. A.

    2003-04-01

    Control experiments with ultra pure deionized water were conducted to evaluate the organic contamination in hydrothermal prebiotic experiments. Different combinations of reaction vessel material, sampling tubing and stirring were tested and the amounts of organic contaminants determined. All tested types of polymer tubing were proven to introduce organic contaminants (formate, acetate and propionate ions) into the reacting solution. Stainless steel has a catalytic effect on the decomposition of formate, consistent with earlier work at high temperatures and pressures.

  4. Intestinal microbiota, probiotics and prebiotics in inflammatory bowel disease.

    PubMed

    Orel, Rok; Kamhi Trop, Tina

    2014-09-01

    It has been presumed that aberrant immune response to intestinal microorganisms in genetically predisposed individuals may play a major role in the pathogenesis of the inflammatory bowel disease, and there is a good deal of evidence supporting this hypothesis. Commensal enteric bacteria probably play a central role in pathogenesis, providing continuous antigenic stimulation that causes chronic intestinal injury. A strong biologic rationale supports the use of probiotics and prebiotics for inflammatory bowel disease therapy. Many probiotic strains exhibit anti-inflammatory properties through their effects on different immune cells, pro-inflammatory cytokine secretion depression, and the induction of anti-inflammatory cytokines. There is very strong evidence supporting the use of multispecies probiotic VSL#3 for the prevention or recurrence of postoperative pouchitis in patients. For treatment of active ulcerative colitis, as well as for maintenance therapy, the clinical evidence of efficacy is strongest for VSL#3 and Escherichia coli Nissle 1917. Moreover, some prebiotics, such as germinated barley foodstuff, Psyllium or oligofructose-enriched inulin, might provide some benefit in patients with active ulcerative colitis or ulcerative colitis in remission. The results of clinical trials in the treatment of active Crohn's disease or the maintenance of its remission with probiotics and prebiotics are disappointing and do not support their use in this disease. The only exception is weak evidence of advantageous use of Saccharomyces boulardii concomitantly with medical therapy in maintenance treatment. PMID:25206258

  5. Chili Peppers, Curcumins, and Prebiotics in Gastrointestinal Health and Disease.

    PubMed

    Patcharatrakul, Tanisa; Gonlachanvit, Sutep

    2016-04-01

    There is growing evidence for the role of several natural products as either useful agents or adjuncts in the management of functional GI disorders (FGIDs). In this review, we examine the medical evidence for three such compounds: chili, a culinary spice; curcumin, another spice and active derivative of a root bark; and prebiotics, which are nondigestible food products. Chili may affect the pathogenesis of abdominal pain especially in functional dyspepsia and cause other symptoms. It may have a therapeutic role in FGIDs through desensitization of transient receptor potential vanilloid-1 receptor. Curcumin, the active ingredient of turmeric rhizome, has been shown in several preclinical studies and uncontrolled clinical trials as having effects on gut inflammation, gut permeability and the brain-gut axis, especially in FGIDs. Prebiotics, the non-digestible food ingredients in dietary fiber, may serve as nutrients and selectively stimulate the growth and/or activity of certain colonic bacteria. The net effect of this change on colonic microbiota may lead to the production of acidic metabolites and other compounds that help to reduce the production of toxins and suppress the growth of harmful or disease-causing enteric pathogens. Although some clinical benefit in IBS has been shown, high dose intake of prebiotics may cause more bloating from bacterial fermentation. PMID:26973345

  6. Probiotics, prebiotics, and the host microbiome: the science of translation

    PubMed Central

    Petschow, Bryon; Doré, Joël; Hibberd, Patricia; Dinan, Timothy; Reid, Gregor; Blaser, Martin; Cani, Patrice D; Degnan, Fred H; Foster, Jane; Gibson, Glenn; Hutton, John; Klaenhammer, Todd R; Ley, Ruth; Nieuwdorp, Max; Pot, Bruno; Relman, David; Serazin, Andrew; Sanders, Mary Ellen

    2013-01-01

    Recent advances in our understanding of the community structure and function of the human microbiome have implications for the potential role of probiotics and prebiotics in promoting human health. A group of experts recently met to review the latest advances in microbiota/microbiome research and discuss the implications for development of probiotics and prebiotics, primarily as they relate to effects mediated via the intestine. The goals of the meeting were to share recent advances in research on the microbiota, microbiome, probiotics, and prebiotics, and to discuss these findings in the contexts of regulatory barriers, evolving healthcare environments, and potential effects on a variety of health topics, including the development of obesity and diabetes; the long-term consequences of exposure to antibiotics early in life to the gastrointestinal (GI) microbiota; lactose intolerance; and the relationship between the GI microbiota and the central nervous system, with implications for depression, cognition, satiety, and mental health for people living in developed and developing countries. This report provides an overview of these discussions. PMID:24266656

  7. Probiotics, prebiotics, and the host microbiome: the science of translation.

    PubMed

    Petschow, Bryon; Doré, Joël; Hibberd, Patricia; Dinan, Timothy; Reid, Gregor; Blaser, Martin; Cani, Patrice D; Degnan, Fred H; Foster, Jane; Gibson, Glenn; Hutton, John; Klaenhammer, Todd R; Ley, Ruth; Nieuwdorp, Max; Pot, Bruno; Relman, David; Serazin, Andrew; Sanders, Mary Ellen

    2013-12-01

    Recent advances in our understanding of the community structure and function of the human microbiome have implications for the potential role of probiotics and prebiotics in promoting human health. A group of experts recently met to review the latest advances in microbiota/microbiome research and discuss the implications for development of probiotics and prebiotics, primarily as they relate to effects mediated via the intestine. The goals of the meeting were to share recent advances in research on the microbiota, microbiome, probiotics, and prebiotics, and to discuss these findings in the contexts of regulatory barriers, evolving healthcare environments, and potential effects on a variety of health topics, including the development of obesity and diabetes; the long-term consequences of exposure to antibiotics early in life to the gastrointestinal (GI) microbiota; lactose intolerance; and the relationship between the GI microbiota and the central nervous system, with implications for depression, cognition, satiety, and mental health for people living in developed and developing countries. This report provides an overview of these discussions. PMID:24266656

  8. Intestinal microbiota, probiotics and prebiotics in inflammatory bowel disease

    PubMed Central

    Orel, Rok; Kamhi Trop, Tina

    2014-01-01

    It has been presumed that aberrant immune response to intestinal microorganisms in genetically predisposed individuals may play a major role in the pathogenesis of the inflammatory bowel disease, and there is a good deal of evidence supporting this hypothesis. Commensal enteric bacteria probably play a central role in pathogenesis, providing continuous antigenic stimulation that causes chronic intestinal injury. A strong biologic rationale supports the use of probiotics and prebiotics for inflammatory bowel disease therapy. Many probiotic strains exhibit anti-inflammatory properties through their effects on different immune cells, pro-inflammatory cytokine secretion depression, and the induction of anti-inflammatory cytokines. There is very strong evidence supporting the use of multispecies probiotic VSL#3 for the prevention or recurrence of postoperative pouchitis in patients. For treatment of active ulcerative colitis, as well as for maintenance therapy, the clinical evidence of efficacy is strongest for VSL#3 and Escherichia coli Nissle 1917. Moreover, some prebiotics, such as germinated barley foodstuff, Psyllium or oligofructose-enriched inulin, might provide some benefit in patients with active ulcerative colitis or ulcerative colitis in remission. The results of clinical trials in the treatment of active Crohn’s disease or the maintenance of its remission with probiotics and prebiotics are disappointing and do not support their use in this disease. The only exception is weak evidence of advantageous use of Saccharomyces boulardii concomitantly with medical therapy in maintenance treatment. PMID:25206258

  9. Intestinal Sucrase as a Novel Target Contributing to the Regulation of Glycemia by Prebiotics

    PubMed Central

    Neyrinck, Audrey M.; Pachikian, Barbara; Taminiau, Bernard; Daube, Georges; Frédérick, Raphaël; Cani, Patrice D.; Bindels, Laure B.; Delzenne, Nathalie M.

    2016-01-01

    Inulin-type fructans (ITF) are known for their capacity to modulate gut microbiota, energy metabolism and to improve glycemia in several animal models of obesity, and in humans. The potential contribution of ITF as modulators of sugar digestion by host enzymes has not been evaluated yet. A sucrose challenge has been performed on naive mice fed a standard diet supplemented with or without native chicory inulin (Fibruline 5%) for 3 weeks. The area under the curve of glycemia as well as sucrase activity in the small intestine were lowered after inulin treatment. Pyrosequencing of the 16S rRNA gene confirmed important changes in gut microbiota (mostly in favor of Blautia genus) due to inulin extract supplementation. Interestingly, the suppressive effect of inulin extract on postprandial glycemia also occurred when inulin was directly added to the sucrose solution, suggesting that the effect on sucrose digestion did not require chronic inulin administration. In vitro tests confirmed a direct inhibition of sucrase enzyme by the inulin extract, thereby suggesting that native chicory inulin, in addition to its well-known prebiotic effect, is also able to decrease the digestibility of carbohydrates, a phenomenon that can contribute in the control of post prandial glycemia. We may not exclude that the sucrose escaping the digestion could also contribute to the changes in the gut microbiota after a chronic treatment with inulin. PMID:27532866

  10. Prebiotic carbohydrate-related research within the USDA Agricultural Research Service

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Agricultural Research Service of the U.S. Department of Agriculture is interested in the development of prebiotic carbohydrates for a number of reasons. Many of the novel carbohydrates used or proposed for use as prebiotics are made from agricultural commodities such as milk, cornstarch, sugar,...

  11. Effects of dietary Aspergillus meal prebiotic on turkey poults production parameters and bone qualities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to evaluate the effects of dietary Aspergillus meal (AM), a prebiotic on performance and bone parameters of neonatal turkey poults. Prebiotics are nondigestible food ingredients that beneficially affect the host and have been shown to stimulate calcium and magnesium a...

  12. Effect of prebiotic supplementation and calcium intake on body mass index

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our objective was to assess the effects of a prebiotic supplement and usual calcium intake on body composition changes during pubertal growth. We measured anthropometry and body fat with dual-energy X-ray absorptionmetry in 97 young adolescents who were randomized to receive either a daily prebiotic...

  13. Fermentation properties and potential prebiotic activity of Bimuno® galacto-oligosaccharide (65 % galacto-oligosaccharide content) on in vitro gut microbiota parameters.

    PubMed

    Grimaldi, Roberta; Swann, Jonathan R; Vulevic, Jelena; Gibson, Glenn R; Costabile, Adele

    2016-08-01

    Prebiotic oligosaccharides have the ability to generate important changes in the gut microbiota composition that may confer health benefits to the host. Reducing the impurities in prebiotic mixtures could expand their applications in food industries and improve their selectivity and prebiotic effect on the potential beneficial bacteria such as bifidobacteria and lactobacilli. This study aimed to determine the in vitro potential fermentation properties of a 65 % galacto-oligosaccharide (GOS) content Bimuno® GOS (B-GOS) on gut microbiota composition and their metabolites. Fermentation of 65 % B-GOS was compared with 52 % B-GOS in pH- and volume-controlled dose-response anaerobic batch culture experiments. In total, three different doses (1, 0·5 and 0·33 g equivalent to 0·1, 0·05 and 0·033 g/l) were tested. Changes in the gut microbiota during a time course were identified by fluorescence in situ hybridisation, whereas small molecular weight metabolomics profiles and SCFA were determined by 1H-NMR analysis and GC, respectively. The 65 % B-GOS showed positive modulation of the microbiota composition during the first 8 h of fermentation with all doses. Administration of the specific doses of B-GOS induced a significant increase in acetate as the major SCFA synthesised compared with propionate and butyrate concentrations, but there were no significant differences between substrates. The 65 % B-GOS in syrup format seems to have, in all the analysis, an efficient prebiotic effect. However, the applicability of such changes remains to be shown in an in vivo trial. PMID:27267934

  14. Prebiotic fibres dose-dependently increase satiety hormones and alter Bacteroidetes and Firmicutes in lean and obese JCR:LA-cp rats.

    PubMed

    Parnell, Jill A; Reimer, Raylene A

    2012-02-01

    There is a growing interest in modulating gut microbiota with diet in the context of obesity. The purpose of the present study was to evaluate the dose-dependent effects of prebiotics (inulin and oligofructose) on gut satiety hormones, energy expenditure, gastric emptying and gut microbiota. Male lean and obese JCR:LA-cp rats were randomised to either of the following: lean 0 % fibre (LC), lean 10 % fibre (LF), lean 20 % fibre (LHF), obese 0 % fibre (OC), obese 10 % fibre (OF) or obese 20 % fibre (OHF). Body composition, gastric emptying, energy expenditure, plasma satiety hormone concentrations and gut microbiota (using quantitative PCR) were measured. Caecal proglucagon and peptide YY mRNA levels were up-regulated 2-fold in the LF, OF and OHF groups and 3-fold in the LHF group. Ghrelin O-acyltransferase mRNA levels were higher in obese v. lean rats and decreased in the OHF group. Plasma ghrelin response was attenuated in the LHF group. Microbial species measured in the Bacteroidetes division decreased, whereas those in the Firmicutes increased in obese v. lean rats and improved with prebiotic intake. Bifidobacterium and Lactobacillus increased in the OHF v. OC group. Bacteroides and total bacteria negatively correlated with percentage of body fat and body weight. Enterobacteriaceae increased in conjunction with glucose area under the curve (AUC) and glucagon-like peptide-1 AUC. Bacteroides and total bacteria correlated positively with ghrelin AUC yet negatively with insulin AUC and energy intake (P < 0·05). Several of the mechanisms through which prebiotics act (food intake, satiety hormones and alterations in gut microbiota) are regulated in a dose-dependent manner. The combined effects of prebiotics may have therapeutic potential for obesity. PMID:21767445

  15. Hypocholesterolemic Properties and Prebiotic Effects of Mexican Ganoderma lucidum in C57BL/6 Mice.

    PubMed

    Meneses, María E; Martínez-Carrera, Daniel; Torres, Nimbe; Sánchez-Tapia, Mónica; Aguilar-López, Miriam; Morales, Porfirio; Sobal, Mercedes; Bernabé, Teodoro; Escudero, Helios; Granados-Portillo, Omar; Tovar, Armando R

    2016-01-01

    Edible and medicinal mushrooms contain bioactive compounds with promising effects on several cardiovascular risk biomarkers. However, strains of Ganoderma lucidum of Mexican origin have not yet been studied. Standardized extracts of G. lucidum (Gl) were given to C57BL/6 mice fed a high-cholesterol diet compared with the drug simvastatin. The effects of the extracts on serum biochemical parameters, liver lipid content, cholesterol metabolism, and the composition of gut microbiota were assessed. Acetylsalicylic acid (10 mM) added to the cultivation substrate modulated properties of Gl extracts obtained from mature basidiomata. Compared to the high-cholesterol diet group, the consumption of Gl extracts significantly reduced total serum cholesterol (by 19.2% to 27.1%), LDL-C (by 4.5% to 35.1%), triglyceride concentration (by 16.3% to 46.6%), hepatic cholesterol (by 28.7% to 52%) and hepatic triglycerides (by 43.8% to 56.6%). These effects were associated with a significant reduction in the expression of lipogenic genes (Hmgcr, Srebp1c, Fasn, and Acaca) and genes involved in reverse cholesterol transport (Abcg5 and Abcg8), as well as an increase in Ldlr gene expression in the liver. No significant changes were observed in the gene expression of Srebp2, Abca1 or Cyp7a1. In several cases, Gl-1 or Gl-2 extracts showed better effects on lipid metabolism than the drug simvastatin. A proposed mechanism of action for the reduction in cholesterol levels is mediated by α-glucans and β-glucans from Gl, which promoted decreased absorption of cholesterol in the gut, as well as greater excretion of fecal bile acids and cholesterol. The prebiotic effects of Gl-1 and Gl-2 extracts modulated the composition of gut microbiota and produced an increase in the Lactobacillaceae family and Lactobacillus genus level compared to the control group, high-cholesterol diet group and group supplemented with simvastatin. Mexican genetic resources of Gl represent a new source of bioactive compounds

  16. Hypocholesterolemic Properties and Prebiotic Effects of Mexican Ganoderma lucidum in C57BL/6 Mice

    PubMed Central

    Meneses, María E.; Martínez-Carrera, Daniel; Torres, Nimbe; Sánchez-Tapia, Mónica; Aguilar-López, Miriam; Morales, Porfirio; Sobal, Mercedes; Bernabé, Teodoro; Escudero, Helios; Granados-Portillo, Omar; Tovar, Armando R.

    2016-01-01

    Edible and medicinal mushrooms contain bioactive compounds with promising effects on several cardiovascular risk biomarkers. However, strains of Ganoderma lucidum of Mexican origin have not yet been studied. Standardized extracts of G. lucidum (Gl) were given to C57BL/6 mice fed a high-cholesterol diet compared with the drug simvastatin. The effects of the extracts on serum biochemical parameters, liver lipid content, cholesterol metabolism, and the composition of gut microbiota were assessed. Acetylsalicylic acid (10 mM) added to the cultivation substrate modulated properties of Gl extracts obtained from mature basidiomata. Compared to the high-cholesterol diet group, the consumption of Gl extracts significantly reduced total serum cholesterol (by 19.2% to 27.1%), LDL-C (by 4.5% to 35.1%), triglyceride concentration (by 16.3% to 46.6%), hepatic cholesterol (by 28.7% to 52%) and hepatic triglycerides (by 43.8% to 56.6%). These effects were associated with a significant reduction in the expression of lipogenic genes (Hmgcr, Srebp1c, Fasn, and Acaca) and genes involved in reverse cholesterol transport (Abcg5 and Abcg8), as well as an increase in Ldlr gene expression in the liver. No significant changes were observed in the gene expression of Srebp2, Abca1 or Cyp7a1. In several cases, Gl-1 or Gl-2 extracts showed better effects on lipid metabolism than the drug simvastatin. A proposed mechanism of action for the reduction in cholesterol levels is mediated by α-glucans and β-glucans from Gl, which promoted decreased absorption of cholesterol in the gut, as well as greater excretion of fecal bile acids and cholesterol. The prebiotic effects of Gl-1 and Gl-2 extracts modulated the composition of gut microbiota and produced an increase in the Lactobacillaceae family and Lactobacillus genus level compared to the control group, high-cholesterol diet group and group supplemented with simvastatin. Mexican genetic resources of Gl represent a new source of bioactive compounds

  17. The Role of Probiotics and Prebiotics in Inducing Gut Immunity

    PubMed Central

    Vieira, Angélica T.; Teixeira, Mauro M.; Martins, Flaviano S.

    2013-01-01

    The gut immune system is influenced by many factors, including dietary components and commensal bacteria. Nutrients that affect gut immunity and strategies that restore a healthy gut microbial community by affecting the microbial composition are being developed as new therapeutic approaches to treat several inflammatory diseases. Although probiotics (live microorganisms) and prebiotics (food components) have shown promise as treatments for several diseases in both clinical and animal studies, an understanding of the molecular mechanisms behind the direct and indirect effects on the gut immune response will facilitate better and possibly more efficient therapy for diseases. In this review, we will first describe the concept of prebiotics, probiotics, and symbiotics and cover the most recently well-established scientific findings regarding the direct and indirect mechanisms by which these dietary approaches can influence gut immunity. Emphasis will be placed on the relationship of diet, the microbiota, and the gut immune system. Second, we will highlight recent results from our group, which suggest a new dietary manipulation that includes the use of nutrient products (organic selenium and Lithothamnium muelleri) and probiotics (Saccharomyces boulardii UFMG 905 and Bifidobacterium sp.) that can stimulate and manipulate the gut immune response, inducing intestinal homeostasis. Furthermore, the purpose of this review is to discuss and translate all of this knowledge into therapeutic strategies and into treatment for extra-intestinal compartment pathologies. We will conclude by discussing perspectives and molecular advances regarding the use of prebiotics or probiotics as new therapeutic strategies that manipulate the microbial composition and the gut immune responses of the host. PMID:24376446

  18. Prebiotic effect of Agave fourcroydes fructans: an animal model.

    PubMed

    García-Curbelo, Yanelys; Bocourt, Ramón; Savón, Lourdes L; García-Vieyra, Maria Isabel; López, Mercedes G

    2015-09-01

    The use of prebiotics such as fructans has increased in human and animal nutrition because of their productive performance and health benefits. Agave fourcroydes has shown high concentrations of fructans in their stems; however, there is no information on new products derived from this plant that might enhance its added value. Therefore, we evaluated the prebiotic effect of Agave fourcroydes fructans in an animal model. Male mice (C57BL/6J) were fed on parallel form with a standard diet or diets supplemented with 10% of fructans from Cichorium intybus (Raftilose P95) and Agave fourcroydes from Cuba for 35 days. The body weight, food intake, blood glucose, triglycerides and cholesterol, gastrointestinal organ weights, fermentation indicators in cecal and colon contents and mineral content in femurs were determined. The body weight and food intake of mice were not significantly modified by any treatment. However, serum glucose, cholesterol and triglycerides decreased (P < 0.01) in the fructans groups with respect to the standard diet group; this decrement was higher in the A. fourcroydes group with respect to the Raftilose P95 group. Mice groups supplemented with fructans exhibited increased (P < 0.01) total and wall cecal and colon weights. The fermentation indicators, short-chain fatty acids (SCFAs) and pH decreased (P < 0.001) in the groups that consumed fructans in their diets with respect to the standard diet. The diets supplemented with fructans also increased the mineral concentrations of calcium (P < 0.01) and magnesium (P < 0.05) in the right femurs. In conclusion, the inclusion of fructans from Agave fourcroydes in the mice diet induced a prebiotic response, similar to or greater than the commercial product (Raftilose P95) and this constitutes a promising alternative with potential use not only in animal but also in human diets. PMID:26237650

  19. The role of probiotics and prebiotics in inducing gut immunity.

    PubMed

    Vieira, Angélica T; Teixeira, Mauro M; Martins, Flaviano S

    2013-01-01

    The gut immune system is influenced by many factors, including dietary components and commensal bacteria. Nutrients that affect gut immunity and strategies that restore a healthy gut microbial community by affecting the microbial composition are being developed as new therapeutic approaches to treat several inflammatory diseases. Although probiotics (live microorganisms) and prebiotics (food components) have shown promise as treatments for several diseases in both clinical and animal studies, an understanding of the molecular mechanisms behind the direct and indirect effects on the gut immune response will facilitate better and possibly more efficient therapy for diseases. In this review, we will first describe the concept of prebiotics, probiotics, and symbiotics and cover the most recently well-established scientific findings regarding the direct and indirect mechanisms by which these dietary approaches can influence gut immunity. Emphasis will be placed on the relationship of diet, the microbiota, and the gut immune system. Second, we will highlight recent results from our group, which suggest a new dietary manipulation that includes the use of nutrient products (organic selenium and Lithothamnium muelleri) and probiotics (Saccharomyces boulardii UFMG 905 and Bifidobacterium sp.) that can stimulate and manipulate the gut immune response, inducing intestinal homeostasis. Furthermore, the purpose of this review is to discuss and translate all of this knowledge into therapeutic strategies and into treatment for extra-intestinal compartment pathologies. We will conclude by discussing perspectives and molecular advances regarding the use of prebiotics or probiotics as new therapeutic strategies that manipulate the microbial composition and the gut immune responses of the host. PMID:24376446

  20. Prebiotic phosphate ester syntheses in a deep eutectic solvent.

    PubMed

    Gull, Maheen; Zhou, Manshui; Fernández, Facundo M; Pasek, Matthew A

    2014-02-01

    We report a route to synthesize a wide range of organophosphates of biological significance in a deep eutectic solvent (2:1 urea and choline chloride), utilizing various orthophosphate sources. Heating an organic alcohol in the solvent along with a soluble phosphorus source yields phosphorus esters of choline as well as that of the added organic in yields between 15 to 99 %. In addition, phosphite analogs of biological phosphates and peptides were also formed by the simple mixing of reagents and heating at 60-70 °C in the deep eutectic solvent. The presented dehydration reactions are relevant to prebiotic and green chemistry in alternative solvents. PMID:24368625

  1. Cyanogen induced phosphorylation of D-fructose. [prebiotic modeling

    NASA Technical Reports Server (NTRS)

    Degani, CH.; Kawatsuji, M.; Halmann, M.

    1975-01-01

    It has been demonstrated that a phosphorylated sugar, identified as alpha-D-fructopyranose, can be formed as the result of cyanogen-induced phosphorylation of D-fructose at pH 8.8. The product was isolated from barium and cyclohexylammonium salts and identified on the basis of its chromatographic and electrophoretic properties, its lability to hydrolysis by alkaline phosphatase, the rate of its acid-catalyzed hydrolysis, and the results of periodate oxidation and optical rotatory measurements. These results support the suggestion that the cyanogen-induced phosphorylation of free sugars could be a possible process for formation of sugar phosphates under prebiotic conditions (Halman et al., 1969).

  2. Formation of the imidazolides of dinucleotides under potentially prebiotic conditions

    NASA Technical Reports Server (NTRS)

    Sleeper, H. L.; Lohrmann, R.; Orgel, L. E.

    1978-01-01

    Imidazolides of dinucleotides such as ImpApA can be formed from the corresponding dinucleotides in a two-stage process, which gives up to 15% yields under potentially prebiotic conditions. First a solution of the dinucleotide and sodium trimetaphosphate is dried out at constant temperature and humidity. This produces polyphosphates such as p(n)ApA in excellent yield (greater than or equal to 80%). The products are dissolved in water, imidazole is added, and the solution is dried out again. This yields the 5'-phosphorimidazolides.

  3. Rotational spectroscopy and observational astronomy of prebiotic molecules

    NASA Astrophysics Data System (ADS)

    Widicus Weaver, Susanna Leigh

    It is now widely believed that prebiotic molecules were delivered to the early Earth by planetesimals and their associated interplanetary dust particles. Yet the formation pathways for these molecules are not clear. Amino acids and sugars have been found in carbonaceous chondrites, but only much simpler species have been detected in the interstellar medium (ISM). Prebiotic organics could have formed in the ISM and been directly incorporated into planetesimals, or simpler species could have: formed in the ISM and then been incorporated into planetesimals, undergone further processing, and been delivered to Earth. Limits on interstellar chemistry must therefore be established through observational astronomy before potential prebiotic formation pathways can be assessed. These observations require laboratory spectroscopic investigation of the species of interest. This thesis is an interdisciplinary study involving laboratory rotational spectroscopy and astronomical observations of several key prebiotic molecules. The laboratory work has focused on obtaining the rotational spectra of the simplest three-carbon ketose sugar, 1,3-dihydroxyacetone, and its structural isomers methyl glycolate and dimethyl carbonate, as well as aminoethanol, the predicted interstellar precursor to alanine. The pure rotational spectral analysis of the low-lying torsional states of the simplest a-hydroxy aldehyde, glycolaldehyde, has also been completed. The original Balle-Flygare Fourier transform microwave spectrometer was used to obtain the microwave spectra, while both the Jet Propulsion Laboratory and Caltech direct absorption flow cell spectrometers were used for additional direct absorption millimeter and submillimeter studies. The results of these laboratory experiments were used to guide observational searches with the Caltech Submillimeter Observatory, the Owens Valley Millimeter Array; and the Green Bank Telascope toward the hot core sources Sgr B2(N-LMH), Orion Hot Core

  4. Current status of the prebiotic synthesis of small molecules

    NASA Technical Reports Server (NTRS)

    Miller, Stanley L.

    1986-01-01

    Experiments designed to simulate conditions on the primitive earth and to demonstrate how the organic compounds that made up the first living organisms were synthesized are described. Simulated atmospheres with CH4, N2, NH3, and H2O were found to be most effective for synthesis of small prebiotic molecules, although atmospheres with H2, CO, N2, and H2O, and with H2, CO2, N2, and H2O also give good yields of organic compounds provided the H2/CO and H2/CO2 ratios are above 1 and 2, respectively. The spark discharge (which is a good source of HCN) and UV light are also important. Reasonable prebiotic syntheses were worked out for the amino acids that occur in proteins (with the exception of lysine, arginine, and histidine), and for purines, pyrimidines, sugars, and nicotinic acid. Many of the molecules that have been produced in these simulated primitive-earth experiments are found in carbonaceous chondrites.

  5. Radioactivity as a significant energy source in prebiotic synthesis.

    PubMed

    Garzón, L; Garzón, M L

    2001-01-01

    Radioactivity in the continental crust (due mainly to the isotopes 238U, 235U, 232Th and 40K), as a energy source for chemical evolution in the early Archean (between 3.5 and approximately 4 Ga bp), is reviewed. The most important radioactive source in the continental crust is due to the production and accumulation of radioactive gases within the crust voids (porosity). The study of such mechanism has allowed us to reach a deeper understanding about the nature of the radioactive source and to describe its behavior, particularly with regard to prebiotic chemical evolution. An effective total energy of 3 x 10(18) Ja-1 has been obtained for a depth of 1 km, 4 Ga ago. If a depth of 30 km is taken, the obtained value is almost equal to the UV solar energy radiation (lambda < 150 nm). Within the voids the radioactive source of the continental crust played a relevant role in prebiotic synthesis. In uranium deposits of the same age, the role of radioactivity must have been even more relevant in favoring chemical evolution. PMID:11296523

  6. Prebiotically plausible mechanisms increase compositional diversity of nucleic acid sequences

    PubMed Central

    Derr, Julien; Manapat, Michael L.; Rajamani, Sudha; Leu, Kevin; Xulvi-Brunet, Ramon; Joseph, Isaac; Nowak, Martin A.; Chen, Irene A.

    2012-01-01

    During the origin of life, the biological information of nucleic acid polymers must have increased to encode functional molecules (the RNA world). Ribozymes tend to be compositionally unbiased, as is the vast majority of possible sequence space. However, ribonucleotides vary greatly in synthetic yield, reactivity and degradation rate, and their non-enzymatic polymerization results in compositionally biased sequences. While natural selection could lead to complex sequences, molecules with some activity are required to begin this process. Was the emergence of compositionally diverse sequences a matter of chance, or could prebiotically plausible reactions counter chemical biases to increase the probability of finding a ribozyme? Our in silico simulations using a two-letter alphabet show that template-directed ligation and high concatenation rates counter compositional bias and shift the pool toward longer sequences, permitting greater exploration of sequence space and stable folding. We verified experimentally that unbiased DNA sequences are more efficient templates for ligation, thus increasing the compositional diversity of the pool. Our work suggests that prebiotically plausible chemical mechanisms of nucleic acid polymerization and ligation could predispose toward a diverse pool of longer, potentially structured molecules. Such mechanisms could have set the stage for the appearance of functional activity very early in the emergence of life. PMID:22319215

  7. Prebiotic hydrocarbon synthesis in impacting reduced astrophysical icy mixtures

    DOE PAGESBeta

    Koziol, Lucas; Goldman, Nir

    2015-04-21

    We present results of prebiotic organic synthesis in shock-compressed reducing mixtures of simple ices from quantum molecular dynamics simulations extended to close to chemical equilibrium timescales. Given the relative abundance of carbon in reduced forms in astrophysical ices as well as the tendency of these mixtures to form complex hydrocarbons under the presence of external stimuli, it is possible that cometary impacts on a planetary surface could have yielded a larger array of prebiotic organic compounds than previously investigated. We find that the high pressures and temperatures due to shock compression yield a large assortment of carbon- and nitrogen-bonded extendedmore » structures that are highly reactive with short molecular lifetimes. Expansion and cooling causes these materials to break apart and form a wide variety of stable, potentially life-building compounds, including long-chain linear and branched hydrocarbons, large heterocyclic compounds, and a variety of different amines and exotic amino acids. Lastly, our results help provide a bottom-up understanding of hydrocarbon impact synthesis on the early Earth and its role in producing life-building molecules from simple starting materials.« less

  8. Sunlight-Driven, Water-Mediated Generation of Prebiotic Complexity

    NASA Astrophysics Data System (ADS)

    Rapf, R.; Griffith, E. C.; Perkins, R. J.; Vaida, V.

    2014-12-01

    Formation of chemically complex biomolecules from simple, organic molecules under prebiotic conditions is both a thermodynamic and kinetic challenge. Synthesis of such molecules and their subsequent self-assembly into ordered structures requires a favorable source of energy as well as a favorable entropic environment. Our approach couples two such auspicious conditions, using sunlight as the energetic driver and air-water interfaces as the reaction medium. The Sun provides a large, prebiotically relevant source of energy to fuel synthetic photochemistry. Air-water interfaces are widely prevalent on oceans, lakes, and atmospheric aerosols and provide unique reaction environments that ameliorate some of the thermodynamic challenges of the aqueous bulk. Using these experimental principles, we demonstrate the ability to generate chemical complexity via in situ observation of non-enzymatic peptide bond synthesis at the surface of water. Additionally, we will discuss the photochemical formation of a double-tailed membrane component in aqueous solution, which subsequently self-assembles into ordered, three-dimensional structures.

  9. Selective derivatization and sequestration of ribose from a prebiotic mix.

    PubMed

    Springsteen, Greg; Joyce, Gerald F

    2004-08-11

    Observations regarding the catalytic potential of RNA and the role of RNA in biology have formed the basis for the "RNA world" hypothesis, which suggests that a genetic system based on self-replicating polyribonucleotides preceded modern biology. However, attempts to devise a realistic prebiotic synthesis of nucleic acids from simple starting materials have been plagued by problems of poor chemical selectivity, lack of stereo- and regiospecificity, and similar rates of formation and degradation of some of the key intermediates. For example, ribose would have been only a small component of a highly complex mix of sugars resulting from the condensation of formaldehyde in a prebiotic world. In addition, ribose is more reactive and degrades more rapidly compared with most other monosaccharides. This study demonstrates an approach for the preferential sequestration of ribose relative to other sugars that takes advantage of its greater reactivity. Cyanamide reacts especially rapidly with ribose to form a stable bicyclic adduct. This product crystallizes spontaneously in aqueous solution, whereas the corresponding products derived from threose, galactose, glucose, mannose, and each of the other pentoses do not. Furthermore, when employing a racemic mixture of d- and l-ribose, enantiomerically twinned crystals are formed that contain discrete homochiral domains. PMID:15291561

  10. Understanding Organics in Meteorites and the Pre-Biotic Environment

    NASA Technical Reports Server (NTRS)

    Zare, Richard N.

    2003-01-01

    (1) Refinement of the analytic capabilities of our experiment via characterization of molecule-specific response and the effects upon analysis of the type of sample under investigation; (2) Measurement of polycyclic aromatic hydrocarbons (PAHs) with high sensitivity and spatial resolution within extraterrestrial samples; (3) Investigation of the interstellar reactions of PAHs via the analysis of species formed in systems modeling dust grains and ices; (4) Investigations into the potential role of PAHs in prebiotic and early biotic chemistry via photoreactions of PAHs under simulated prebiotic Earth conditions. To meet these objectives, we use microprobe laser-desorption, laser-ionization mass spectrometry (MuL(exp 2)MS), which is a sensitive, selective, and spatially resolved technique for detection of aromatic compounds. Appendix A presents a description of the MuL(exp 2)MS technique. The initial grant proposal was for a three-year funding period, while the award was given for a one-year interim period. Because of this change in time period, emphasis was shifted from the first research goal, which was more development-oriented, in order to focus more on the other analysis-oriented goals. The progress made on each of the four research areas is given below.

  11. Spatial Models of Prebiotic Evolution: Soup Before Pizza?

    NASA Astrophysics Data System (ADS)

    Scheuring, István; Czárán, Tamás; Szabó, Péter; Károlyi, György; Toroczkai, Zoltán

    2003-10-01

    The problem of information integration and resistance to the invasion of parasitic mutants in prebiotic replicator systems is a notorious issue of research on the origin of life. Almost all theoretical studies published so far have demonstrated that some kind of spatial structure is indispensable for the persistence and/or the parasite resistance of any feasible replicator system. Based on a detailed critical survey of spatial models on prebiotic information integration, we suggest a possible scenario for replicator system evolution leading to the emergence of the first protocells capable of independent life. We show that even the spatial versions of the hypercycle model are vulnerable to selfish parasites in heterogeneous habitats. Contrary, the metabolic system remains persistent and coexistent with its parasites both on heterogeneous surfaces and in chaotically mixing flowing media. Persistent metabolic parasites can be converted to metabolic cooperators, or they can gradually obtain replicase activity. Our simulations show that, once replicase activity emerged, a gradual and simultaneous evolutionary improvement of replicase functionality (speed and fidelity) and template efficiency is possible only on a surface that constrains the mobility of macromolecule replicators. Based on the results of the models reviewed, we suggest that open chaotic flows (`soup') and surface dynamics (`pizza') both played key roles in the sequence of evolutionary events ultimately concluding in the appearance of the first living cell on Earth.

  12. Prebiotic synthesis of protobiopolymers under alkaline ocean conditions.

    PubMed

    Ruiz-Bermejo, Marta; Rivas, Luis A; Palacín, Arantxa; Menor-Salván, César; Osuna-Esteban, Susana

    2011-08-01

    Clasically, prebiotic chemistry has focused on the production and identification of simple organic molecules, many of them forming part of "intractable polymers" named tholins. In a previous work, we demonstrated that in experiments using an external energy source and inorganic carbon the aqueous aerosols improved the formation of hydrophilic tholins. Herein, we elucidate the role of pH (from 4 to 12) in prebiotic experiments using saline aqueous aerosols, spark discharges and an atmosphere containing CH(4). At all values of pH, the saline aqueous aerosols increased the production of a significant variety of carboxylic acids that could have been present in a primitive Krebs cycle. Moreover, the study for the first time of hydrophilic tholins by 2-D electrophoresis revealed that these are formed by a set of unexpected heavy polymeric species. The initial alkaline conditions significantly increased both the apparent molecular weight of polymeric species up to 80 kDa and their diversity. We propose the term of protobiopolymers to denote those polymeric species fractionated by 2-D electrophoresis since these are formed by biomolecules present in living systems and show diversity in length as well as in functional groups. Thus, aerosols formed in simulated alkaline ocean conditions could provide an optimal medium for the formation of the primeval materials that could be precursors to the emergence of life. PMID:21161385

  13. Prebiotic hydrocarbon synthesis in impacting reduced astrophysical icy mixtures

    SciTech Connect

    Koziol, Lucas; Goldman, Nir

    2015-04-21

    We present results of prebiotic organic synthesis in shock-compressed reducing mixtures of simple ices from quantum molecular dynamics simulations extended to close to chemical equilibrium timescales. Given the relative abundance of carbon in reduced forms in astrophysical ices as well as the tendency of these mixtures to form complex hydrocarbons under the presence of external stimuli, it is possible that cometary impacts on a planetary surface could have yielded a larger array of prebiotic organic compounds than previously investigated. We find that the high pressures and temperatures due to shock compression yield a large assortment of carbon- and nitrogen-bonded extended structures that are highly reactive with short molecular lifetimes. Expansion and cooling causes these materials to break apart and form a wide variety of stable, potentially life-building compounds, including long-chain linear and branched hydrocarbons, large heterocyclic compounds, and a variety of different amines and exotic amino acids. Lastly, our results help provide a bottom-up understanding of hydrocarbon impact synthesis on the early Earth and its role in producing life-building molecules from simple starting materials.

  14. Atmospheric production of glycolaldehyde under hazy prebiotic conditions.

    PubMed

    Harman, Chester E; Kasting, James F; Wolf, Eric T

    2013-04-01

    The early Earth's atmosphere, with extremely low levels of molecular oxygen and an appreciable abiotic flux of methane, could have been a source of organic compounds necessary for prebiotic chemistry. Here, we investigate the formation of a key RNA precursor, glycolaldehyde (2-hydroxyacetaldehyde, or GA) using a 1-dimensional photochemical model. Maximum atmospheric production of GA occurs when the CH4:CO2 ratio is close to 0.02. The total atmospheric production rate of GA remains small, only 1 × 10(7) mol yr(-1). Somewhat greater amounts of GA production, up to 2 × 10(8) mol yr(-1), could have been provided by the formose reaction or by direct delivery from space. Even with these additional production mechanisms, open ocean GA concentrations would have remained at or below ~1 μM, much smaller than the 1-2 M concentrations required for prebiotic synthesis routes like those proposed by Powner et al. (Nature 459:239-242, 2009). Additional production or concentration mechanisms for GA, or alternative formation mechanisms for RNA, are needed, if this was indeed how life originated on the early Earth. PMID:23695543

  15. Prebiotic hydrocarbon synthesis in impacting reduced astrophysical icy mixtures

    NASA Astrophysics Data System (ADS)

    Goldman, Nir; Koziol, Lucas

    2015-06-01

    We present results of prebiotic organic synthesis in shock compressed reducing mixtures of simple ices from quantum molecular dynamics simulations extended to close to chemical equilibrium time-scales. Given the relative abundance of carbon in reduced forms in astrophysical ices as well as the tendency of these mixtures to form complex hydrocarbons under the presence of external stimuli, it is possible that cometary impact on a planetary surface could have yielded a larger array of prebiotic organic compounds than previously investigated. We find that the high pressures and temperatures due to shock compression yield a large assortment of carbon and nitrogen bonded extended structures that are highly reactive with short molecular lifetimes. Expansion and cooling causes these materials to break apart and form a wide variety of stable, potentially life-building compounds, including long-chain linear and branched hydrocarbons, large heterocyclic compounds, and a variety of different amines and exotic amino acids. Our results help provide a bottom-up understanding for hydrocarbon impact synthesis on early Earth and its role in producing life building molecules from simple starting materials. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  16. Comets as a possible source of prebiotic molecules

    NASA Technical Reports Server (NTRS)

    Huebner, W. F.; Boice, D. C.

    1992-01-01

    Prebiotic molecules derive from abiotic organic molecules, radicals, and ions that pervade the universe at temperatures as high as several 1000 K. Here we review the role of organic molecules that condensed at low temperatures before or during comet formation in the early history of the Solar System. Recent spacecraft encounters and ground-based observations of carbon-rich volatile and dust components of comet comae provide a broad database for the investigation of these organic molecules. New laboratory data for some potential cometary organics are presented. Probable icy organic constituents of the nucleus and CHON particles as likely candidates for the distributed sources of gas-phase organic species in the coma are discussed. There is broad agreement that many organic molecules observed in the coma originate from the dust that must have existed in the solar nebula at the time and place of comet formation. We conclude that complex organic molecules found in comets may be a source of prebiotic molecules that led to the origins of life.

  17. Prebiotic Hydrocarbon Synthesis in Impacting Reduced Astrophysical Icy Mixtures

    NASA Astrophysics Data System (ADS)

    Koziol, Lucas; Goldman, Nir

    2015-04-01

    We present results of prebiotic organic synthesis in shock-compressed reducing mixtures of simple ices from quantum molecular dynamics simulations extended to close to chemical equilibrium timescales. Given the relative abundance of carbon in reduced forms in astrophysical ices as well as the tendency of these mixtures to form complex hydrocarbons under the presence of external stimuli, it is possible that cometary impacts on a planetary surface could have yielded a larger array of prebiotic organic compounds than previously investigated. We find that the high pressures and temperatures due to shock compression yield a large assortment of carbon- and nitrogen-bonded extended structures that are highly reactive with short molecular lifetimes. Expansion and cooling causes these materials to break apart and form a wide variety of stable, potentially life-building compounds, including long-chain linear and branched hydrocarbons, large heterocyclic compounds, and a variety of different amines and exotic amino acids. Our results help provide a bottom-up understanding of hydrocarbon impact synthesis on the early Earth and its role in producing life-building molecules from simple starting materials.

  18. A comparative study of prebiotic and present day translational models

    NASA Technical Reports Server (NTRS)

    Rein, R.; Raghunathan, G.; Mcdonald, J.; Shibata, M.; Srinivasan, S.

    1986-01-01

    It is generally recognized that the understanding of the molecular basis of primitive translation is a fundamental step in developing a theory of the origin of life. However, even in modern molecular biology, the mechanism for the decoding of messenger RNA triplet codons into an amino acid sequence of a protein on the ribosome is understood incompletely. Most of the proposed models for prebiotic translation lack, not only experimental support, but also a careful theoretical scrutiny of their compatibility with well understood stereochemical and energetic principles of nucleic acid structure, molecular recognition principles, and the chemistry of peptide bond formation. Present studies are concerned with comparative structural modelling and mechanistic simulation of the decoding apparatus ranging from those proposed for prebiotic conditions to the ones involved in modern biology. Any primitive decoding machinery based on nucleic acids and proteins, and most likely the modern day system, has to satisfy certain geometrical constraints. The charged amino acyl and the peptidyl termini of successive adaptors have to be adjacent in space in order to satisfy the stereochemical requirements for amide bond formation. Simultaneously, the same adaptors have to recognize successive codons on the messenger. This translational complex has to be realized by components that obey nucleic acid conformational principles, stabilities, and specificities. This generalized condition greatly restricts the number of acceptable adaptor structures.

  19. Enantioselective autocatalysis. Spontaneous resolution and the prebiotic generation of chirality

    NASA Astrophysics Data System (ADS)

    Bonner, William A.

    1994-02-01

    Theoretical and experimental models for autocatalytic systems leading to the prebiotic origin of chiralityvia the spontaneous symmetry breaking (resolution) of racemic substrates are reviewed. Of the experimental models so far studied, only 2nd order assymetric transformations during crystallization of optically labile enantiometers, leading to their spontaneous resolution under racemizing conditions (SRURC) have been successful. Our objective was to investigate in further detail the most promising of these systems from the point of view of its overall efficiency and its potential viability as a mechanism for the spontaneous generation of molecular chirality on the prebiotic Earth. To this end the 1,4-benzo-diazepinooxazole derivative XI, having a single asymmetric carbon atom, has been synthesized. We here confirm a report in the literature that (±)-XI undergoes SRURC in methanol, both on crystallization and as a slurry. The ‘total spontaneous resolution’ of (±)-XI has been achieved in a yield of 99%, of which 80% had an optical purity ofca. 93%. Arguments are presented that SRURC of racemic substrates, while thus demonstrably effective in laboratory experiments, was probably not of major importance for the origin or amplification of molecular chirality on the primitive earth.

  20. Prebiotic Synthesis of Protobiopolymers Under Alkaline Ocean Conditions

    NASA Astrophysics Data System (ADS)

    Ruiz-Bermejo, Marta; Rivas, Luis A.; Palacín, Arantxa; Menor-Salván, César; Osuna-Esteban, Susana

    2011-08-01

    Clasically, prebiotic chemistry has focused on the production and identification of simple organic molecules, many of them forming part of "intractable polymers" named tholins. In a previous work, we demonstrated that in experiments using an external energy source and inorganic carbon the aqueous aerosols improved the formation of hydrophilic tholins. Herein, we elucidate the role of pH (from 4 to 12) in prebiotic experiments using saline aqueous aerosols, spark discharges and an atmosphere containing CH4. At all values of pH, the saline aqueous aerosols increased the production of a significant variety of carboxylic acids that could have been present in a primitive Krebs cycle. Moreover, the study for the first time of hydrophilic tholins by 2-D electrophoresis revealed that these are formed by a set of unexpected heavy polymeric species. The initial alkaline conditions significantly increased both the apparent molecular weight of polymeric species up to 80 kDa and their diversity. We propose the term of protobiopolymers to denote those polymeric species fractionated by 2-D electrophoresis since these are formed by biomolecules present in living systems and show diversity in length as well as in functional groups. Thus, aerosols formed in simulated alkaline ocean conditions could provide an optimal medium for the formation of the primeval materials that could be precursors to the emergence of life.

  1. Influence of prebiotics, probiotics and protein ingredients on mycotoxin bioaccessibility.

    PubMed

    Ferrer, M; Manyes, L; Mañes, J; Meca, G

    2015-03-01

    The aim of this study was to investigate the influence of prebiotic compounds (cellulose and inulin), food ingredients (milk whey, β-lactoglobulin and calcium caseinate) and several probiotic microorganisms on the bioaccessibility of beauvericin (BEA), enniatins (ENs A, A1, B, B1), deoxynivalenol (DON) and zearalenone (ZEA) present in wheat crispy bread produced with wheat flour previously fermented with F. tricinctum, F. culmorum and G. zeae. The bioaccessibility of mycotoxins was determined by a dynamic simulated gastrointestinal digestion system, imitating the human digestive physiological conditions of the gastrointestinal tract. Mycotoxins were determined in the simulated intestinal fluids by liquid chromatography-tandem mass spectrometry (LC-MS/MS). EN bioaccessibility ranged from 15.1 to 30.6%, whereas the values evidenced for BEA ranged from 12 to 19%. DON showed bioaccessibility data ranging from 0.8 to 5.6% whereas for ZEA the data evidenced ranged from 26 to 44%. The bioaccessibility reduction evidenced using probiotic microorganisms for the mycotoxins studied ranged from 21 to 27.1% for ENs, from 29 to 39.7% for DON, from 41 to 57% for ZEA and from 6.6 to 10.5% for BEA. The addition of prebiotic and bioactive microorganisms decreased the bioaccessibility of mycotoxins, with a concentration-dependent behavior, thus being a potential strategy for reducing human exposure to these minor mycotoxins. PMID:25673154

  2. Electrostatic activation of prebiotic chemistry in substellar atmospheres

    NASA Astrophysics Data System (ADS)

    Stark, C. R.; Helling, Ch.; Diver, D. A.; Rimmer, P. B.

    2014-04-01

    Charged dust grains in the atmospheres of exoplanets may play a key role in the formation of prebiotic molecules, necessary to the origin of life. Dust grains submerged in an atmospheric plasma become negatively charged and attract a flux of ions that are accelerated from the plasma. The energy of the ions upon reaching the grain surface may be sufficient to overcome the activation energy of particular chemical reactions that would be unattainable via ion and neutral bombardment from classical, thermal excitation. As a result, prebiotic molecules or their precursors could be synthesized on the surface of dust grains that form clouds in exoplanetary atmospheres. This paper investigates the energization of the plasma ions, and the dependence on the plasma electron temperature, in the atmospheres of substellar objects such as gas giant planets. Calculations show that modest electron temperatures of ~1 eV (~104 K) are enough to accelerate ions to sufficient energies that exceed the activation energies required for the formation of formaldehyde, ammonia, hydrogen cyanide and the amino acid glycine.

  3. Multiple omics uncovers host-gut microbial mutualism during prebiotic fructooligosaccharide supplementation.

    PubMed

    Kato, Tamotsu; Fukuda, Shinji; Fujiwara, Akemi; Suda, Wataru; Hattori, Masahira; Kikuchi, Jun; Ohno, Hiroshi

    2014-10-01

    Fructooligosaccharide (FOS), a prebiotic well known for its health-promoting properties, can improve the human gut ecosystem most likely through changes in its microbial composition. However, the detailed mechanism(s) of action of FOS in the modulation of the gut ecosystem remain(s) obscure. Traditional methods of profiling microbes and metabolites could barely show any significant features due to the existence of large interindividual differences, but our novel microbe-metabolite correlation approach, combined with faecal immunoglobulin A (IgA) measurements, has revealed that the induction of mucosal IgA by FOS supplementation correlated with the presence of specific bacteria. Furthermore, the metabolic dynamics of butyrate, L-phenylalanine, L-lysine and tyramine were positively correlated with that of these bacteria and IgA production, whereas p-cresol was negatively correlated. Taken together, our focused intraindividual analysis with omics approaches is a powerful strategy for uncovering the gut molecular network and could provide a new vista for understanding the human gut ecosystem. PMID:24848698

  4. Practical prebiotics, probiotics and synbiotics for allergists: how useful are they?

    PubMed

    Johannsen, H; Prescott, S L

    2009-12-01

    With the advent of the hygiene hypothesis, probiotics have provided an avenue of hope in curbing the allergic epidemic. The initial enthusiasm has been tempered by recognition of the inherent complexities of this approach. This review examines the current clinical evidence and practical issues in using probiotics and related products, for the prevention and treatment of allergic disease. So far, probiotics have shown more promise, albeit limited, in the primary prevention of allergic disease rather than in the treatment of established disease. These effects have largely been limited to the prevention of early childhood conditions such as eczema, with no consistent effects on other allergic outcomes. There is emerging evidence that clinical effects may be strain specific, but again these findings have been inconsistent. While there have been several meta-analyses to examine probiotics in both the prevention and the treatment of allergic disease, these have been hampered by significant heterogeneity between studies, including wide variations in the strains used, the methods and timing of administration and the age and assessment of allergic outcomes. In any case, these have also become outdated by a series of new studies published in the last year. Although it is not yet clear exactly how the growing number of new studies will modify the results of meta-analyses, it is likely that these will add yet further heterogeneity that will continue to make interpretation of pooled data difficult. At this stage, the effects of prebiotics, synbiotics and postbiotics are even less clear. Thus, while there is little doubt that microbiota modulate immune development and can prevent the allergic phenotype, the optimal way of achieving this is far from clear. Given the current level of evidence, it is not appropriate to recommend prebiotics/probiotics/synbiotics or postbiotics as a part of standard therapy or for the prevention of any allergic conditions. Further studies are needed

  5. An In Vitro Approach to Study Effects of Prebiotics and Probiotics on the Faecal Microbiota and Selected Immune Parameters Relevant to the Elderly.

    PubMed

    Liu, Yue; Gibson, Glenn R; Walton, Gemma E

    2016-01-01

    The aging process leads to alterations of gut microbiota and modifications to the immune response, such changes may be associated with increased disease risk. Prebiotics and probiotics can modulate microbiome changes induced by aging; however, their effects have not been directly compared. The aim of this study was to use anaerobic batch culture fermenters to assess the impact of various fermentable carbohydrates and microorganisms on the gut microbiota and selected immune markers. Elderly volunteers were used as donors for these experiments to enable relevance to an aging population. The impact of fermentation supernatants on immune markers relevant to the elderly were assessed in vitro. Levels of IL-1β, IL-6, IL-8, IL-10 and TNF-α in peripheral blood mononuclear cell culture supernatants were measured using flow cytometry. Trans-galactooligosaccharides (B-GOS) and inulin both stimulated bifidobacteria compared to other treatments (p<0.05). Fermentation supernatants taken from faecal batch cultures supplemented with B-GOS, inulin, B. bifidum, L. acidophilus and Ba. coagulans inhibited LPS induced TNF-α (p<0.05). IL-10 production, induced by LPS, was enhanced by fermentation supernatants from faecal batch cultures supplemented with B-GOS, inulin, B. bifidum, L. acidophilus, Ba. coagulans and Bac. thetaiotaomicron (p<0.05). To conclude, prebiotics and probiotics could lead to potentially beneficial effects to host health by targeting specific bacterial groups, increasing saccharolytic fermentation and decreasing inflammation associated with aging. Compared to probiotics, prebiotics led to greater microbiota modulation at the genus level within the fermenters. PMID:27612304

  6. Prebiotic Polymer Synthesis and the Origin of Glycolytic Metabolism

    NASA Technical Reports Server (NTRS)

    Weber, Arthur L.

    1998-01-01

    Our research resulted in several discoveries which contributed to understanding the origin and operation of life. (1) Most importantly, we discovered a new pathway of prebiotic amino acid synthesis in which formaldehyde and glycolaldehyde (formose reaction substrates) react with ammonia to give alanine and homoserine in the presence of thiol catalysts. The thiol-dependent synthesis of amino acids undoubtedly occurs via amino acid thioester intermediates capable of forming peptides. This 'one-pot' reaction system operates under mild aqueous conditions, and like modern amino acid biosynthesis, uses sugar intermediates which are converted to amino acids by energy-yielding redox disproportionation. Preliminary evidence suggests that this type of process can be "evolved" by a serial transfer methods that lead to enrichment of autocatalytic molecules. (2) We established that prebiotic peptide polymers can be made by condensation of amino acid thioesters (homocysteine thiolactone and S-(N-beta-orotidyl- diaminopropionic acid) ethanethiol), and that prebiotic polydisulfide polymers can be generated by oxidation of dithiols with iron(III) in minerals. (3) In our analysis of metabolism we discovered the primary energy source of biosynthesis -- chemical energy made available by the redox disproportionation of substrate carbon groups. We concluded that the energy and reactivity of sugars make them the optimal substrate for the origin and operation of terrestrial (or extraterrestrial) life. (4) Since it is likely that the use of optimal sugar substrates in biosynthesis sets the average oxidation number of functional biocarbon throughout the Universe near 0.0 (the reduction level of formaldehyde), we proposed that a line(s) in the microwave spectrum of formaldehyde could be rationally selected as a frequency for interstellar communication that symbolizes life. (5) Finally, in preparation for the analysis of Martian meteorite samples, we upgraded our HPLC system to one femtomole

  7. Isolation and prebiotic activity of inulin-type fructan extracted from Pfaffia glomerata (Spreng) Pedersen roots.

    PubMed

    Caleffi, Edilainy Rizzieri; Krausová, Gabriela; Hyršlová, Ivana; Paredes, Larry Ladislao Ramos; dos Santos, Marcelo Müller; Sassaki, Guilherme Lanzi; Gonçalves, Regina Aparecida Correia; de Oliveira, Arildo José Braz

    2015-09-01

    Pfaffia glomerata (Amaranthaceae) is popularly known as "Brazilian ginseng." Previous studies have shown that fructose is the major carbohydrate component present in its roots. Inulin-type fructans, polymers of fructose, are the most widespread and researched prebiotics. Here, we isolated and chemically characterized inulin extracted from P. glomerata roots and investigated its potential prebiotic effect. Fructans were isolated and their structures were determined using colorimetric, chromatography, polarimetry, and spectroscopic analysis. The degree of polymerization (DP) was determined, and an in vitro prebiotic test was performed. The structure of inulin was confirmed by chromatography and spectroscopic analysis and through comparison with existing data. Representatives from the genera Lactobacillus and Bifidobacterium utilized inulin from P. glomerata, because growth was significantly stimulated, while this ability is strain specific. The results indicated that inulin extracted from P. glomerata roots represents a promising new source of inulin-type prebiotics. PMID:26126944

  8. Induction of regulatory T cells: A role for probiotics and prebiotics to suppress autoimmunity.

    PubMed

    Dwivedi, Mitesh; Kumar, Prasant; Laddha, Naresh C; Kemp, E Helen

    2016-04-01

    Regulatory T cells (Tregs) are comprised of a heterogeneous population of cells that play a vital role in suppressing inflammation and maintaining immune tolerance. Given the crucial role of Tregs in maintaining immune homeostasis, it is probably not surprising that many microbial species and their metabolites have the potential to induce Tregs. There is now great interest in the therapeutic potential of probiotics and prebiotics based strategies for a range of autoimmune disorders. This review will summarise recent findings concerning the role of probiotics and prebiotics in induction of Tregs to ameliorate the autoimmune conditions. In addition, the article is focused to explain the different mechanisms of Treg induction and function by these probiotics and prebiotics, based on the available studies till date. The article further proposes that induction of Tregs by probiotics and prebiotics could lead to the development of new therapeutic approach towards curbing the autoimmune response and as an alternative to detrimental immunosuppressive drugs. PMID:26774011

  9. A high-yielding, strictly regioselective prebiotic purine nucleoside formation pathway.

    PubMed

    Becker, Sidney; Thoma, Ines; Deutsch, Amrei; Gehrke, Tim; Mayer, Peter; Zipse, Hendrik; Carell, Thomas

    2016-05-13

    The origin of life is believed to have started with prebiotic molecules reacting along unidentified pathways to produce key molecules such as nucleosides. To date, a single prebiotic pathway to purine nucleosides had been proposed. It is considered to be inefficient due to missing regioselectivity and low yields. We report that the condensation of formamidopyrimidines (FaPys) with sugars provides the natural N-9 nucleosides with extreme regioselectivity and in good yields (60%). The FaPys are available from formic acid and aminopyrimidines, which are in turn available from prebiotic molecules that were also detected during the Rosetta comet mission. This nucleoside formation pathway can be fused to sugar-forming reactions to produce pentosides, providing a plausible scenario of how purine nucleosides may have formed under prebiotic conditions. PMID:27174989

  10. Synbiotic effect of various prebiotics on in vitro activities of probiotic lactobacilli.

    PubMed

    Nagpal, Ravinder; Kaur, Anmol

    2011-01-01

    In the present study, five Lactobacillus strains were evaluated for their viability in presence of different prebiotics viz. inulin, oligofructose, lactulose, raftilose, and honey. The viability of lactobacilli was observed before and after 5 weeks of refrigerated storage. The doubling time varied from 5.2 hrs to 9.6 hrs. The lowest doubling time was for Lactobacillus plantarum M5 followed by L. plantarum Ch1 with inulin. Viability of lactobacilli was greatest with inulin. The growth and viability in presence of prebiotics were found to be strain-specific. Hence, it could be concluded that the addition of prebiotics have a significant effect on probiotics, and hence, a combination of suitable Lactobacillus strain(s) with a specific prebiotic could be a viable probiotic-based functional food approach in administering the beneficial bacteria in-vivo. PMID:21888588

  11. Prebiotic syntheses of vitamin coenzymes: I. Cysteamine and 2-mercaptoethanesulfonic acid (coenzyme M)

    NASA Technical Reports Server (NTRS)

    Miller, S. L.; Schlesinger, G.

    1993-01-01

    The reaction of NH3 and SO3(2-) with ethylene sulfide is shown to be a prebiotic synthesis of cysteamine and 2-mercaptoethanesulfonic acid (coenzyme M). A similar reaction with ethylene imine would give cysteamine and taurine. Ethylene oxide would react with NH3 and N(CH3)3 to give the phospholipid components ethanolamine and choline. The prebiotic sources of ethylene sulfide, ethylene imine and ethylene oxide are discussed. Cysteamine itself is not a suitable thioester for metabolic processes because of acyl transfer to the amino group, but this can be prevented by using an amide of cysteamine. The use of cysteamine in coenzyme A may have been due to its prebiotic abundance. The facile prebiotic synthesis of both cysteamine and coenzyme M suggests that they were involved in very early metabolic pathways.

  12. Influence of different prebiotics and mode of their administration on broiler chicken performance.

    PubMed

    Bednarczyk, M; Stadnicka, K; Kozłowska, I; Abiuso, C; Tavaniello, S; Dankowiakowska, A; Sławińska, A; Maiorano, G

    2016-08-01

    In the post-antibiotics era, prebiotics are proposed as alternatives to antibiotic growth promoters in poultry production. The goal of this study was to compare in ovo method of prebiotic delivery with in-water supplementation and with both methods combined (in ovo+in-water) in broiler chickens. Two trials were conducted. Trial 1 was carried out to optimize the doses of two prebiotics, DN (DiNovo®, extract of beta-glucans) and BI (Bi2tos, trans-galactooligosaccharides), for in ovo delivery. The estimated parameters were hatchability and bacteriological status of the newly hatched chicks. Prebiotics were dissolved in 0.2 ml of physiological saline, at the doses: 0.18, 0.88, 3.5 and 7.0 mg/embryo; control group (C) was injected in ovo with 0.2 ml of physiological saline. Trial 2 was conducted to evaluate effects of different prebiotics (DN, BI and raffinose family oligosaccharides (RFO)) delivered in ovo, in-water and in a combined way (in ovo+in-water) on broiler chickens performance. The results of the Trial 1 indicated that the optimal dose of DN and BI prebiotics delivered in ovo, that did not reduce chicks' hatchability, was 0.88 mg/embryo (DN) and 3.5 mg/embryo (BI). Both prebiotics numerically increased number of lactobacilli and bifidobacteria in chicken feces (P>0.05). In Trial 2, all prebiotics (DN, BI and RFO) significantly increased BW gain compared with the C group (P<0.05), especially during the first 21 days of life. However, feed intake and feed conversion ratio were increased upon prebiotics delivery irrespective of method used. Injection of prebiotics in ovo combined with in-water supplementation did not express synergistic effects on broilers performance compared with in ovo injection only. Taken together, those results confirm that single in ovo prebiotics injection into the chicken embryo can successfully replace prolonged in-water supplementation post hatching. PMID:26936310

  13. Use of probiotics and prebiotics in infant feeding.

    PubMed

    Bertelsen, Randi J; Jensen, Elizabeth T; Ringel-Kulka, Tamar

    2016-02-01

    Gut colonization by beneficial bacteria in early life is necessary for establishing the gut mucosal barrier, maturation of the immune system and preventing infections with enteric pathogens. Mode of delivery, prematurity, breastfeeding, and use of antibiotics are some of many factors that have been described to influence early life colonization. Dysbiosis, the absence of normal colonization, is associated with many disease conditions. Pre- and probiotics are commonly used as supplementation in infant formula, such as prebiotic oligosaccharides for stimulation of Bifidobacterium growth aiming to mimic the high levels of these commensal bacteria in the gut of breastfed infants. Studies suggest that probiotic supplementation may be beneficial in prevention and management of disease (e.g., reducing the risk of necrotizing enterocolitis in preterm infants and treatment of acute gastroenteritis in children). Although these studies show promising beneficial effects, the long-term risks or health benefits of pre- and probiotic supplementation are not clear. PMID:27048895

  14. Amyloid Aggregates Arise from Amino Acid Condensations under Prebiotic Conditions.

    PubMed

    Greenwald, Jason; Friedmann, Michael P; Riek, Roland

    2016-09-12

    Current theories on the origin of life reveal significant gaps in our understanding of the mechanisms that allowed simple chemical precursors to coalesce into the complex polymers that are needed to sustain life. The volcanic gas carbonyl sulfide (COS) is known to catalyze the condensation of amino acids under aqueous conditions, but the reported di-, tri-, and tetra-peptides are too short to support a regular tertiary structure. Here, we demonstrate that alanine and valine, two of the proteinogenic amino acids believed to have been among the most abundant on a prebiotic earth, can polymerize into peptides and subsequently assemble into ordered amyloid fibers comprising a cross-β-sheet quaternary structure following COS-activated continuous polymerization of as little as 1 mm amino acid. Furthermore, this spontaneous assembly is not limited to pure amino acids, since mixtures of glycine, alanine, aspartate, and valine yield similar structures. PMID:27511635

  15. Prebiotic synthesis of simple sugars by photoredox systems chemistry

    NASA Astrophysics Data System (ADS)

    Ritson, Dougal; Sutherland, John D.

    2012-11-01

    A recent synthesis of activated pyrimidine ribonucleotides under prebiotically plausible conditions relied on mixed oxygenous and nitrogenous systems chemistry. As it stands, this synthesis provides support for the involvement of RNA in the origin of life, but such support would be considerably strengthened if the sugar building blocks for the synthesis—glycolaldehyde and glyceraldehyde—could be shown to derive from one carbon feedstock molecules using similarly mixed oxygenous and nitrogenous systems chemistry. Here, we show that these sugars can be formed from hydrogen cyanide by ultraviolet irradiation in the presence of cyanometallates in a remarkable systems chemistry process. Using copper cyanide complexes, the process operates catalytically to disproportionate hydrogen cyanide, first generating the sugars and then sequestering them as simple derivatives.

  16. Stereoselective Syntheses of Pentose Sugars Under Realistic Prebiotic Conditions

    NASA Astrophysics Data System (ADS)

    Pizzarello, Sandra; Weber, Arthur L.

    2010-02-01

    Glycolaldehyde and dl-glyceraldehyde reacted in a water-buffered solution under mildly acidic conditions and in the presence of chiral dipeptide catalysts produced pentose sugars whose configuration is affected by the chirality of the catalyst. The chiral effect was found to vary between catalysts and to be largest for di-valine. Lyxose, arabinose, ribose and xylose are formed in different amounts, whose relative proportions do not change significantly with the varying of conditions. With LL-peptide catalysts, ribose was the only pentose sugar to have a significant D-enantiomeric excess ( ee) (≤44%), lyxose displayed an L- ee of ≤66%, arabinose a smaller L- ee of ≤8%, and xylose was about racemic. These data expand our previous findings for tetrose sugars and further substantiate the suggestion that interactions between simple molecules of prebiotic relevance on the early Earth might have included the transfer of chiral asymmetry and advanced molecular evolution.

  17. Prebiotic materials from on and off the early Earth

    NASA Technical Reports Server (NTRS)

    Bernstein, Max

    2006-01-01

    One of the great puzzles of all time is how did life arise? It has been universally presumed that life arose in a soup rich in compounds made mostly of carbon, the kind of which we are currently composed. Where did these organic molecules come from? In this talk I will review proposed contributions to pre-biotic organic chemistry from both terrestrial processes (i.e., hydrothermal vents, Miller-Urey syntheses) and also from space. While the former is perhaps better known and more commonly taught in school, we now know that comet and asteroid dust deliver tons of organics to the Earth every day, and there is a growing consensus among scientists that molecules from space played an important role in making the Earth habitable, and perhaps even provided specific compounds that were directly related to the origin of life.

  18. Health benefits of probiotics and prebiotics in women.

    PubMed

    de Vrese, Michael

    2009-03-01

    Among the numerous positive effects of probiotic microorganisms and prebiotic carbohydrates observed in clinical studies--the majority of which, however, does not fulfil the criteria of pharmaceutical verification--some are of specific relevance to female health. The present review addresses--besides some notes concerning the potential microbiota-hormone interactions--the first line with preventive and/or therapeutic applications of probiotic bacteria in order to maintain a balanced intestinal and urogenital flora, as well as in the case of irritable bowel syndrome, constipation (idiopathic slow-transit) and urogenital tract infections. Further aspects are the promotion of bone health and osteoporosis prevention brought about by inulin, oligofructose and galactooligosaccharides. Some further conditions, namely anorexia nervosa, the premenstrual syndrome as well as prevention or alleviation of climacteric and menopausal disorders, for which the use of probiotics is rather hypothetical or is largely studied by alternative medicine practising physicians, are addressed briefly. PMID:19237621

  19. Prebiotic synthesis and reactions of nucleosides and nucleotides

    NASA Technical Reports Server (NTRS)

    Ferris, J. P.; Yanagawa, H.; Hagan, W. J., Jr.

    1983-01-01

    The potential of diiminosuccinonitrile (DISN) as a prebiotic phosphorylating agent is studied. This compound is formed readily by the oxidation of diaminomaleonitrile, a tetramer of HCN. DISN is shown to produce the cyclization of 3'-adenosine monophosphate to adenosine 2',3'-cyclic phosphate in up to 40 percent yield. The DISN-mediated phosphorylation of uridine to uridine monophosphate is determined not to proceed efficiently in aqueous solution. The reaction of DISN and BrCN with uridine-5'-phosphate and uridine is found to result in the formation of 2,2'-anhydronucleotides and 2,2'-anhydronucleosides, respectively, and other reaction products resulting from an initial reaction at the 2' and 3'-hydroxyl groups. Homoionic montmorillonites were employed to study the clay mineral catalysis of the cyclization of adenosine-3'-phosphate.

  20. Structural studies on HCN oligomers. [catalysts for prebiotic processes

    NASA Technical Reports Server (NTRS)

    Ferris, J. P.; Edelson, E. H.; Auyeung, J. M.; Joshi, P. C.

    1981-01-01

    NMR spectral studies on the HCN oligomers suggest the presence of carboxamide and urea groupings. The release of CO2, H2O, HCN, CH3CN, HCONH2 and pyridine on pyrolysis is consistent with the presence of these groupings as well as carboxylic acid groups. No basic primary amine groupings could be detected with fluorescamine. Hydrazinolysis of the HCN oligomers releases 10% of the amino acids normally released by acid hydrolysis. The oligomers give a positive biuret test but this is not due to the presence of peptide bonds. There is no conclusive evidence for the presence of peptide bonds in the HCN oligomers. No diglycine was detected on partial hydrolysis of the HCN oligomers at pH 8.5 suggesting that HCN oligomers were not a source of prebiotic peptides.

  1. Infrared laser photolysis - A new tool for the study of prebiotic chemistry

    NASA Technical Reports Server (NTRS)

    Davis, D. D.; Smith, G. R.; Guillory, W. A.

    1980-01-01

    Infrared laser induced dielectric breakdown and multiphoton absorption experiments on CH4/NH3 'atmospheres' are described. It is found that HCN, a central intermediate in prebiotic chemistry, is a principal product. This, combined with the fact that dielectric breakdown appears to have much in common with ordinary electric sparks, suggests that the laser could be a useful tool in studies of prebiotic chemistry. Several possible experiments in this vein are suggested.

  2. Probiotics, prebiotics and the gastrointestinal tract in health and disease.

    PubMed

    Vitetta, Luis; Briskey, David; Alford, Hollie; Hall, Sean; Coulson, Samantha

    2014-06-01

    The microbiome located in the human gastrointestinal tract (GIT) comprises the largest community (diverse and dense) of bacteria, and in conjunction with a conducive internal milieu, promotes the development of regulated pro- and anti-inflammatory signals within the GIT that promotes immunological and metabolic tolerance. In addition, host-microbial interactions govern GIT inflammation and provide cues for upholding metabolic regulation in both the host and microbes. Failure to regulate inflammatory responses can increase the risk of developing inflammatory conditions in the GIT. Here, we review clinical studies regarding the efficacy of probiotics/prebiotics and the role they may have in restoring host metabolic homeostasis by rescuing the inflammatory response. The clinical studies reviewed included functional constipation, antibiotic-associated diarrhoea, Clostridium difficile diarrhoea, infectious diarrhoea/gastroenteritis, irritable bowel syndrome, inflammatory bowel diseases and necrotizing enterocolitis. We have demonstrated that there was an overall reduction in risk when probiotics were administered over placebo in the majority of GIT inflammatory conditions. The effect size of a cumulative reduction in relative risk for the GIT conditions/diseases investigated was 0.65 (0.61-0.70) (z = 13.3); p < 0.0001 that is an average reduction in risk of 35 % in favour of probiotics. We also progress a hypothesis that the GIT comprises numerous micro-axes (e.g. mucus secretion, Th1/Th2 balance) that are in operational homeostasis; hence probiotics and prebiotics may have a significant pharmacobiotic regulatory role in maintaining host GIT homeostasis in disease states partially through reactive oxygen species signalling. PMID:24633989

  3. Hydrothermal Systems of Kamchatka are Models of the Prebiotic Environment

    NASA Astrophysics Data System (ADS)

    Kompanichenko, V. N.; Poturay, V. A.; Shlufman, K. V.

    2015-06-01

    The composition of organic matter and fluctuations of thermodynamic parameters were investigated in the hydrothermal systems of the Kamchatka peninsula in the context of the origin of life. Organics were analyzed by gas-chromatography/mass spectrometry, and 111 organic compounds belonging to 14 homologous series (aromatic hydrocarbons, alkanes and isoalkanes, halogenated aromatic hydrocarbons, carboxylic acids, esters, etc.) were found in hot springs inhabited by Archaeal and Bacterial thermophiles. The organics detected in the sterile condensate of water-steam mixture taken from deep boreholes (temperature 108-175 °C) consisted of 69 compounds of 11 homologous series, with aromatic hydrocarbons and alkanes being prevalent. The organic material included important prebiotic components such as nitrogen-containing compounds and lipid precursors. A separate organic phase (oil) was discovered in the Uzon Caldera. A biogenic origin is supported by the presence of sterane and hopane biomarkers and the δ13C value of the bulk oil; its age determined by 14C measurements was 1030 ± 40 years. Multilevel fluctuations of thermodynamic parameters proposed to be required for the origin of life were determined in the Mutnovsky and Pauzhetsky hydrothermal systems. The low-frequency component of the hydrothermal fluid pressure varied by up to 2 bars over periods of hours to days, while mid-frequency variations had regular micro-oscillations with periods of about 20 min; the high-frequency component displayed sharp changes of pressure and microfluctuations with periods less than 5 min. The correlation coefficient between pressure and temperature ranges from 0.89 to 0.99 (average 0.96). The natural regimes of pressure and temperature fluctuations in Kamchatka hydrothermal systems can guide future experiments on prebiotic chemistry under oscillating conditions.

  4. Prebiotic organic synthesis under hydrothermal conditions: an overview

    NASA Astrophysics Data System (ADS)

    Simoneit, Bernd R. T.

    Organic compounds which are obviously synthesized from inorganic precursors (e.g., CO) by hydrothermal activity are currently a research topic in prebiotic chemistry leading to the origin of life. However, such de novo products would be overwhelmed in present Earth environments, by an excess of thermal alteration (pyrolysis) products formed from contemporary life (e.g., hydrocarbons, alkanoic acids, etc.). Thus, organic syntheses must be demonstrated and distinguished from organic matter alteration initially in the laboratory and then in the field. Organic synthesis under hydrothermal conditions is theoretically possible and various established industrial processes are used to synthesize organic compounds from inorganic substrates with the aid of catalysts. A set of Strecker-type synthesis experiments has been carried out under hydrothermal conditions (150 °C), producing various amino acids. The formation of lipid compounds during an aqueous organic synthesis (Fischer-Tropsch-type) reaction was reported, using solutions of oxalic acid (also formic acid) as the carbon and hydrogen sources, and heating at discrete temperatures (50° intervals) from 100 to 400 °C. The maximum lipid yield, especially for oxygenated compounds was in the window of 150-250 °C. The compounds range from C6 to >C33, including n-alkanols, n-alkanoic acids, n-alkyl formates, n-alkanones, and n-alkanes, all with no carbon number preferences. These lipid compounds, especially the acids, can form lipid bilayers or micelles, potential precursors for membranes. Reductive condensation (i.e., dehydration) reactions also occur under simulated hydrothermal conditions and form amide, nitrile and ester bonds. The chemistry and kinetics of the condensation reactions are under further study and have the potential for oligomerization of acid-amides in aqueous medium. Abiotic organic compounds are not biomarkers per se because they do not originate from biosynthesis. Thus, they should be regarded as a

  5. Hydrothermal Systems of Kamchatka are Models of the Prebiotic Environment.

    PubMed

    Kompanichenko, V N; Poturay, V A; Shlufman, K V

    2015-06-01

    The composition of organic matter and fluctuations of thermodynamic parameters were investigated in the hydrothermal systems of the Kamchatka peninsula in the context of the origin of life. Organics were analyzed by gas-chromatography/mass spectrometry, and 111 organic compounds belonging to 14 homologous series (aromatic hydrocarbons, alkanes and isoalkanes, halogenated aromatic hydrocarbons, carboxylic acids, esters, etc.) were found in hot springs inhabited by Archaeal and Bacterial thermophiles. The organics detected in the sterile condensate of water-steam mixture taken from deep boreholes (temperature 108-175 °C) consisted of 69 compounds of 11 homologous series, with aromatic hydrocarbons and alkanes being prevalent. The organic material included important prebiotic components such as nitrogen-containing compounds and lipid precursors. A separate organic phase (oil) was discovered in the Uzon Caldera. A biogenic origin is supported by the presence of sterane and hopane biomarkers and the δ(13)C value of the bulk oil; its age determined by (14)C measurements was 1030 ± 40 years. Multilevel fluctuations of thermodynamic parameters proposed to be required for the origin of life were determined in the Mutnovsky and Pauzhetsky hydrothermal systems. The low-frequency component of the hydrothermal fluid pressure varied by up to 2 bars over periods of hours to days, while mid-frequency variations had regular micro-oscillations with periods of about 20 min; the high-frequency component displayed sharp changes of pressure and microfluctuations with periods less than 5 min. The correlation coefficient between pressure and temperature ranges from 0.89 to 0.99 (average 0.96). The natural regimes of pressure and temperature fluctuations in Kamchatka hydrothermal systems can guide future experiments on prebiotic chemistry under oscillating conditions. PMID:25796393

  6. Prebiotic Lipidic Amphiphiles and Condensing Agents on the Early Earth

    PubMed Central

    Fiore, Michele; Strazewski, Peter

    2016-01-01

    It is still uncertain how the first minimal cellular systems evolved to the complexity required for life to begin, but it is obvious that the role of amphiphilic compounds in the origin of life is one of huge relevance. Over the last four decades a number of studies have demonstrated how amphiphilic molecules can be synthesized under plausibly prebiotic conditions. The majority of these experiments also gave evidence for the ability of so formed amphiphiles to assemble in closed membranes of vesicles that, in principle, could have compartmented first biological processes on early Earth, including the emergence of self-replicating systems. For a competitive selection of the best performing molecular replicators to become operative, some kind of bounded units capable of harboring them are indispensable. Without the competition between dynamic populations of different compartments, life itself could not be distinguished from an otherwise disparate array or network of molecular interactions. In this review, we describe experiments that demonstrate how different prebiotically-available building blocks can become precursors of phospholipids that form vesicles. We discuss the experimental conditions that resemble plausibly those of the early Earth (or elsewhere) and consider the analytical methods that were used to characterize synthetic products. Two brief sections focus on phosphorylating agents, catalysts and coupling agents with particular attention given to their geochemical context. In Section 5, we describe how condensing agents such as cyanamide and urea can promote the abiotic synthesis of phospholipids. We conclude the review by reflecting on future studies of phospholipid compartments, particularly, on evolvable chemical systems that include giant vesicles composed of different lipidic amphiphiles. PMID:27043635

  7. Prebiotic Lipidic Amphiphiles and Condensing Agents on the Early Earth.

    PubMed

    Fiore, Michele; Strazewski, Peter

    2016-01-01

    It is still uncertain how the first minimal cellular systems evolved to the complexity required for life to begin, but it is obvious that the role of amphiphilic compounds in the origin of life is one of huge relevance. Over the last four decades a number of studies have demonstrated how amphiphilic molecules can be synthesized under plausibly prebiotic conditions. The majority of these experiments also gave evidence for the ability of so formed amphiphiles to assemble in closed membranes of vesicles that, in principle, could have compartmented first biological processes on early Earth, including the emergence of self-replicating systems. For a competitive selection of the best performing molecular replicators to become operative, some kind of bounded units capable of harboring them are indispensable. Without the competition between dynamic populations of different compartments, life itself could not be distinguished from an otherwise disparate array or network of molecular interactions. In this review, we describe experiments that demonstrate how different prebiotically-available building blocks can become precursors of phospholipids that form vesicles. We discuss the experimental conditions that resemble plausibly those of the early Earth (or elsewhere) and consider the analytical methods that were used to characterize synthetic products. Two brief sections focus on phosphorylating agents, catalysts and coupling agents with particular attention given to their geochemical context. In Section 5, we describe how condensing agents such as cyanamide and urea can promote the abiotic synthesis of phospholipids. We conclude the review by reflecting on future studies of phospholipid compartments, particularly, on evolvable chemical systems that include giant vesicles composed of different lipidic amphiphiles. PMID:27043635

  8. The use of prebiotics during the first year of life for atopy prevention and treatment

    PubMed Central

    de Moura, Priscilla Negrão; Rosário Filho, Nelson Augusto

    2013-01-01

    The incidence of allergic diseases has increased in recent decades. Therefore, the aim of this systematic review was to assess the efficacy of prebiotics for the prevention and treatment of allergic manifestations in children. We sought to conduct a systematic review of the effectiveness of prebiotics in the prevention and treatment of allergic diseases in children. We searched the MEDLINE, EMBASE, Cochrane Library, LILACS, SciELO, IBECS, Web of Science and Clinical Trials databases as well as Google Scholar and the references of the articles identified. Randomised clinical trials, in which one of the treatments was performed with prebiotics and the control group was treated with placebo, were included in the review. The data selection were performed by two reviewers, and the study quality was evaluated according to the Consolidated Standards of Reporting Trials (CONSORT) items, according to the recommendations for improving the quality of reports of randomised clinical trials. The selected studies showed heterogeneity with regard to the participants, albeit with similar outcomes. The treatment group size ranged from 134 to 259 children, and the studies compared prebiotic to placebo treatment in each group. In general, these articles showed a trend toward less allergic reactions in the groups receiving active therapy with prebiotics. Although there was a trend for reduced allergic symptoms following the administration of prebiotics, there was not sufficient evidence to establish that such treatment is effective for the prevention of allergies in children. PMID:25400918

  9. Efficacy of a novel prebiotic and a commercial probiotic in reducing mortality and production losses due to cold stress and Escherichia coli challenge of broiler chicks 1.

    PubMed

    Huff, G R; Huff, W E; Rath, N C; El-Gohary, F A; Zhou, Z Y; Shini, S

    2015-05-01

    Prebiotics consisting of resistant starch may alter intestinal ecology, thus modulating inflammation and increasing intestinal health through increased cecal production of short-chain fatty acids (SCFA). Probiotics may directly alter the intestinal microbiome, resulting in the same effects. We hypothesize that adding prebiotics and probiotics to feed may protect the gut of young chicks under stress. Studies 1, 2, and 3 evaluated treatments in a cold stress (CS) and Escherichia coli (EC) oral challenge to 430 day-old broiler chicks for 3 wk. In study 1, prebiotics were administered as 15% of the diet during the first week only and consisted of the following: Hi-Maize resistant starch (HM), potato starch (PS), or raw potato (RP). In studies 2 and 3, the PS treatment was identical to study 1, and an additional probiotic treatment (PRO) was administered in feed and water. In study 1, PS protected BW during the first week and decreased the mortality of CS/EC-challenged birds during the first week and wk 3, while RP decreased the mortality of warm-brooded birds challenged with EC during the first week. In study 2, PS decreased and PRO increased the main effect mean (MEM) of the first week BW. PS and PRO numerically decreased the feed conversion ratio (FCR) by 23 and 29 points, respectively, in CS/EC-challenged birds with no effects on mortality. In study 3, PS decreased and PRO increased the first week and wk 3 MEM BW. PS numerically increased FCR by 16 points, while PRO decreased FCR by 2 points. Both PS and PRO tended to increase overall mortality, and PRO significantly increased mortality in the CS/EC challenge. These results suggest that the effects of PS may be too variable in this challenge model for further study; however, the PRO treatment improved production values and may have potential as an alternative to antibiotics during the first weeks after hatch. PMID:25743418

  10. Influence of the UV Environment on the Synthesis of Prebiotic Molecules.

    PubMed

    Ranjan, Sukrit; Sasselov, Dimitar D

    2016-01-01

    Ultraviolet radiation is common to most planetary environments and could play a key role in the chemistry of molecules relevant to abiogenesis (prebiotic chemistry). In this work, we explore the impact of UV light on prebiotic chemistry that might occur in liquid water on the surface of a planet with an atmosphere. We consider effects including atmospheric absorption, attenuation by water, and stellar variability to constrain the UV input as a function of wavelength. We conclude that the UV environment would be characterized by broadband input, and wavelengths below 204 nm and 168 nm would be shielded out by atmospheric CO2 and water, respectively. We compare this broadband prebiotic UV input to the narrowband UV sources (e.g., mercury lamps) often used in laboratory studies of prebiotic chemistry and explore the implications for the conclusions drawn from these experiments. We consider as case studies the ribonucleotide synthesis pathway of Powner et al. (2009) and the sugar synthesis pathway of Ritson and Sutherland (2012). Irradiation by narrowband UV light from a mercury lamp formed an integral component of these studies; we quantitatively explore the impact of more realistic UV input on the conclusions that can be drawn from these experiments. Finally, we explore the constraints solar UV input places on the buildup of prebiotically important feedstock gasses like CH4 and HCN. Our results demonstrate the importance of characterizing the wavelength dependence (action spectra) of prebiotic synthesis pathways to determine how pathways derived under laboratory irradiation conditions will function under planetary prebiotic conditions. PMID:26789356

  11. Effect of prebiotic on gut development and ascites incidence of broilers reared in a hypoxic environment.

    PubMed

    Solis de los Santos, F; Farnell, M B; Téllez, G; Balog, J M; Anthony, N B; Torres-Rodriguez, A; Higgins, S; Hargis, B M; Donoghue, A M

    2005-07-01

    Modern broilers have been genetically selected for an increased growth rate and improved feed conversion, but they are also more susceptible to ascites. Ascites occurs when there is an imbalance between available oxygen and the oxygen demand of the broiler. We hypothesized that promoting neonatal gut development with a prebiotic, such as Aspergillus meal (Prebiotic-AM), would enhance gut efficiency, decrease the oxygen demand of the gut, and reduce ascites incidence. In this study, we compared the effect of Prebiotic-AM on ascites incidence and gut development in commercial broilers reared at a local altitude (390 m above sea level) and a simulated high altitude (2,900 m above sea level). Half of the birds received a National Research Council recommended corn-soybean ration, and the other half received the same ration supplemented with 0.2% Prebiotic-AM. These 2 groups were further divided into a local altitude group and a simulated high altitude group for a total of 4 treatment combinations. Tissues were collected on d 1, 3, 7, 14, and 21 from the duodenum and lower ileum and placed in 10% buffered formalin for morphometric analysis. At a simulated high altitude, ascites incidence was 68% for birds fed the Prebiotic-AM supplement compared with 92% ascites incidence in birds given the control feed. The simulated high altitude decreased (P < 0.05) gut development, but prebiotic-treated birds reared in hypoxic conditions had similar gut development to control birds reared at local altitude. These data suggest that a feed ration supplemented with Prebiotic-AM may reduce the effect of hypoxia on broiler gut development and ascites incidence. PMID:16050126

  12. New Insights into Prebiotic Chemistry from Old Archived Miller Extracts

    NASA Technical Reports Server (NTRS)

    Parker, Eric T.; Cleaves, H. James; Dworkin, Jason P.; Glavin, Daniel P.; Callahan, Michael P.; Aubrey, Andrew D.; Lazcano, Antonio; Bada, Jeffrey L.

    2011-01-01

    Following the discovery of an archived set of samples from Stanley Miller's early experiments, analyses were undertaken to better understand the diversity of compounds produced from electric discharges acting on reducing gas mixtures. The paper chromatography methods that Miller used in the 1950s were only capable of detecting a few amino acids and were unable to provide substantial quantitative data relative to today's techniques. Current analytical techniques are much more sensitive and selective, and are capable of precisely quantifying a much larger range of amino acids and their enantiomeric abundances. In one study, preserved dried samples produced by Miller using a lesser-known volcanic apparatus which differed from Miller's classic apparatus in that it utilized an aspirator that injected steam into the electric discharge chamber, simulating a volcanic eruption. The volcanic apparatus produced a wider variety of amino acids than the classic configuration. Prebiotic compounds synthesized in these environments may have locally accumulated where they could have undergone further processing. An additional preserved set of samples from an experiment conducted in 1958 were also found in Miller's archived collection. These samples which had been generated using a mixture of CH4, NH3, H2S and CO2 were collected, catalogued, and stored by Miller, but for unknown reasons were never studied. In our analyses a total of 23 amino acids and 4 amines, including 7 organosulfur compounds, were detected in these samples. The major amino acids with chiral centers are racemic within the accuracy of the measurements, indicating that they are not contaminants introduced during sample storage. This experiment marks the first synthesis of sulfur amino acids from spark discharge experiments designed to imitate primordial environments. The relative yield of some amino acids, in particular the isomers of amino butyric acid, are the highest ever found in a spark discharge experiment

  13. The Gastrointestinal Microbiome and Musculoskeletal Diseases: A Beneficial Role for Probiotics and Prebiotics

    PubMed Central

    Vitetta, Luis; Coulson, Samantha; Linnane, Anthony W.; Butt, Henry

    2013-01-01

    Natural medicines are an attractive option for patients diagnosed with common and debilitating musculoskeletal diseases such as Osteoarthritis (OA) or Rheumatoid Arthritis (RA). The high rate of self-medication with natural products is due to (1) lack of an available cure and (2) serious adverse events associated with chronic use of pharmaceutical medications in particular non-steroidal anti-inflammatory drugs (NSAIDs) and high dose paracetamol. Pharmaceuticals to treat pain may disrupt gastrointestinal (GIT) barrier integrity inducing GIT inflammation and a state of and hyper-permeability. Probiotics and prebiotics may comprise plausible therapeutic options that can restore GIT barrier functionality and down regulate pro-inflammatory mediators by modulating the activity of, for example, Clostridia species known to induce pro-inflammatory mediators. The effect may comprise the rescue of gut barrier physiological function. A postulated requirement has been the abrogation of free radical formation by numerous natural antioxidant molecules in order to improve musculoskeletal health outcomes, this notion in our view, is in error. The production of reactive oxygen species (ROS) in different anatomical environments including the GIT by the epithelial lining and the commensal microbe cohort is a regulated process, leading to the formation of hydrogen peroxide which is now well recognized as an essential second messenger required for normal cellular homeostasis and physiological function. The GIT commensal profile that tolerates the host does so by regulating pro-inflammatory and anti-inflammatory GIT mucosal actions through the activity of ROS signaling thereby controlling the activity of pathogenic bacterial species. PMID:25437335

  14. Effects of Orange Juice Formulation on Prebiotic Functionality Using an In Vitro Colonic Model System

    PubMed Central

    Costabile, Adele; Walton, Gemma E.; Tzortzis, George; Vulevic, Jelena; Charalampopoulos, Dimitris; Gibson, Glenn R.

    2015-01-01

    A three-stage continuous fermentative colonic model system was used to monitor in vitro the effect of different orange juice formulations on prebiotic activity. Three different juices with and without Bimuno, a GOS mixture containing galactooligosaccharides (B-GOS) were assessed in terms of their ability to induce a bifidogenic microbiota. The recipe development was based on incorporating 2.75g B-GOS into a 250 ml serving of juice (65°Brix of concentrate juice). Alongside the production of B-GOS juice, a control juice – orange juice without any additional Bimuno and a positive control juice, containing all the components of Bimuno (glucose, galactose and lactose) in the same relative proportions with the exception of B-GOS were developed. Ion Exchange Chromotography analysis was used to test the maintenance of bimuno components after the production process. Data showed that sterilisation had no significant effect on concentration of B-GOS and simple sugars. The three juice formulations were digested under conditions resembling the gastric and small intestinal environments. Main bacterial groups of the faecal microbiota were evaluated throughout the colonic model study using 16S rRNA-based fluorescence in situ hybridization (FISH). Potential effects of supplementation of the juices on microbial metabolism were studied measuring short chain fatty acids (SCFAs) using gas chromatography. Furthermore, B-GOS juices showed positive modulations of the microbiota composition and metabolic activity. In particular, numbers of faecal bifidobacteria and lactobacilli were significantly higher when B-GOS juice was fermented compared to controls. Furthermore, fermentation of B-GOS juice resulted in an increase in Roseburia subcluster and concomitantly increased butyrate production, which is of potential benefit to the host. In conclusion, this study has shown B-GOS within orange juice can have a beneficial effect on the fecal microbiota. PMID:25807417

  15. Effects of orange juice formulation on prebiotic functionality using an in vitro colonic model system.

    PubMed

    Costabile, Adele; Walton, Gemma E; Tzortzis, George; Vulevic, Jelena; Charalampopoulos, Dimitris; Gibson, Glenn R

    2015-01-01

    A three-stage continuous fermentative colonic model system was used to monitor in vitro the effect of different orange juice formulations on prebiotic activity. Three different juices with and without Bimuno, a GOS mixture containing galactooligosaccharides (B-GOS) were assessed in terms of their ability to induce a bifidogenic microbiota. The recipe development was based on incorporating 2.75g B-GOS into a 250 ml serving of juice (65°Brix of concentrate juice). Alongside the production of B-GOS juice, a control juice--orange juice without any additional Bimuno and a positive control juice, containing all the components of Bimuno (glucose, galactose and lactose) in the same relative proportions with the exception of B-GOS were developed. Ion Exchange Chromotography analysis was used to test the maintenance of bimuno components after the production process. Data showed that sterilisation had no significant effect on concentration of B-GOS and simple sugars. The three juice formulations were digested under conditions resembling the gastric and small intestinal environments. Main bacterial groups of the faecal microbiota were evaluated throughout the colonic model study using 16S rRNA-based fluorescence in situ hybridization (FISH). Potential effects of supplementation of the juices on microbial metabolism were studied measuring short chain fatty acids (SCFAs) using gas chromatography. Furthermore, B-GOS juices showed positive modulations of the microbiota composition and metabolic activity. In particular, numbers of faecal bifidobacteria and lactobacilli were significantly higher when B-GOS juice was fermented compared to controls. Furthermore, fermentation of B-GOS juice resulted in an increase in Roseburia subcluster and concomitantly increased butyrate production, which is of potential benefit to the host. In conclusion, this study has shown B-GOS within orange juice can have a beneficial effect on the fecal microbiota. PMID:25807417

  16. Resistant starch for modulation of gut microbiota: Promising adjuvant therapy for chronic kidney disease patients?

    PubMed

    Moraes, Cristiane; Borges, Natália A; Mafra, Denise

    2016-08-01

    The gut microbiota has been extensively studied in all health science fields because its imbalance is linked to many disorders, such as inflammation and oxidative stress, thereby contributing to cardiovascular disease, obesity, diabetes and chronic kidney disease (CKD) complications. Novel therapeutic strategies that aim to reduce the complications caused by this imbalance have increased in recent years. Studies have shown that prebiotic supplementation can beneficially modulate the gut microbiota in CKD patients. Prebiotics consist of non-digestible dietary soluble fiber, which acts as a substrate for the gut microbiota. Resistant starch (RS) is a type of dietary fiber that can reach the large bowel and act as a substrate for microbial fermentation; for these reasons, it has been considered to be a prebiotic. Few studies have analyzed the effects of RS on the gut microbiota in CKD patients. This review discusses recent information about RS and the potential role of the gut microbiota, with a particular emphasis on CKD patients. PMID:26830416

  17. Probiotics, prebiotics infant formula use in preterm or low birth weight infants: a systematic review

    PubMed Central

    2012-01-01

    Background Previous reviews (2005 to 2009) on preterm infants given probiotics or prebiotics with breast milk or mixed feeds focused on prevention of Necrotizing Enterocolitis, sepsis and diarrhea. This review assessed if probiotics, prebiotics led to improved growth and clinical outcomes in formula fed preterm infants. Methods Cochrane methodology was followed using randomized controlled trials (RCTs) which compared preterm formula containing probiotic(s) or prebiotic(s) to conventional preterm formula in preterm infants. The mean difference (MD) and corresponding 95% confidence intervals (CI) were reported for continuous outcomes, risk ratio (RR) and corresponding 95% CI for dichotomous outcomes. Heterogeneity was assessed by visual inspection of forest plots and a chi2 test. An I2 test assessed inconsistencies across studies. I2> 50% represented substantial heterogeneity. Results Four probiotics studies (N=212), 4 prebiotics studies (N=126) were included. Probiotics: There were no significant differences in weight gain (MD 1.96, 95% CI: -2.64 to 6.56, 2 studies, n=34) or in maximal enteral feed (MD 35.20, 95% CI: -7.61 to 78.02, 2 studies, n=34), number of stools per day increased significantly in probiotic group (MD 1.60, 95% CI: 1.20 to 2.00, 1 study, n=20). Prebiotics: Galacto-oligosaccharide / Fructo-oligosaccharide (GOS/FOS) yielded no significant difference in weight gain (MD 0.04, 95% CI: -2.65 to 2.73, 2 studies, n=50), GOS/FOS yielded no significant differences in length gain (MD 0.01, 95% CI: -0.03 to 0.04, 2 studies, n=50). There were no significant differences in head growth (MD −0.01, 95% CI: -0.02 to 0.00, 2 studies, n=76) or age at full enteral feed (MD −0.79, 95% CI: -2.20 to 0.61, 2 studies, n=86). Stool frequency increased significantly in prebiotic group (MD 0.80, 95% CI: 0.48 to 1.1, 2 studies, n=86). GOS/FOS and FOS yielded higher bifidobacteria counts in prebiotics group (MD 2.10, 95% CI: 0.96 to 3.24, n=27) and (MD 0.48, 95% CI: 0

  18. Self-Assembly of Phosphate Amphiphiles in Mixtures of Prebiotically Plausible Surfactants

    PubMed Central

    Albertsen, A.N.; Duffy, C.D.; Sutherland, J.D.

    2014-01-01

    Abstract The spontaneous formation of closed bilayer structures from prebiotically plausible amphiphiles is an essential requirement for the emergence of early cells on prebiotic Earth. The sources of amphiphiles could have been both endo- and exogenous (accretion of meteorite carbonaceous material or interstellar dust particles). Among all prebiotic possible amphiphile candidates, those containing phosphate are the least investigated species because their self-assembly occurs in a seemingly too narrow range of conditions. The self-assembly of simple phosphate amphiphiles should, however, be of great interest, as contemporary membranes predominantly contain phospholipids. In contrast to common expectations, we show that these amphiphiles can be easily synthesized under prebiotically plausible environmental conditions and can efficiently form bilayer structures in the presence of various co-surfactants across a large range of pH values. Vesiculation was even observed in crude reaction mixtures that contained 1-decanol as the amphiphile precursor. The two best co-surfactants promoted vesicle formation over the entire pH range in aqueous solutions. Expanding the pH range where bilayer membranes self-assemble and remain intact is a prerequisite for the emergence of early cell-like compartments and their preservation under fluctuating environmental conditions. These mixed bilayers also retained small charged solutes, such as dyes. These results demonstrate that alkyl phosphate amphiphiles might have played a significant role as early compartment building blocks. Key Words: Vesicles—Alkyl phosphate—Prebiotic synthesis—Amphiphile mixtures. Astrobiology 14, 462–472. PMID:24885934

  19. In vitro fermentability and prebiotic potential of soyabean Okara by human faecal microbiota.

    PubMed

    Pérez-López, E; Cela, D; Costabile, A; Mateos-Aparicio, I; Rupérez, P

    2016-09-01

    At present, there is a huge interest in finding new prebiotics from agrofood industrial waste, such as the soyabean by-product Okara, rich in insoluble dietary fibre. A previous treatment of Okara with high hydrostatic pressure assisted by the food-grade enzyme Ultraflo ® L achieved a 58·2 % increment in its soluble dietary fibre (SDF) contents. Therefore, potential prebiotic effect of both treated and native Okara was assayed using 48 h, pH-controlled, anaerobic batch cultures inoculated with human faecal slurries, which simulate the human gut. Changes in faecal microbiota were evaluated using 16S rRNA-based fluorescence in situ hybridisation, whereas release of SCFA and lactic acid was assessed by HPLC. Both Okara samples exhibited potential prebiotic effects but Okara treated to maximise its SDF content showed higher SCFA plus lactic acid, better growth promotion of beneficial bacteria, including bifidobacteria after 4 and 48 h and lactobacilli after 4 h of fermentation, and a greater inhibition of potentially harmful bacterial groups such as clostridia and Bacteroides. Differences found between fructo-oligosaccharides and Okara substrates could be attributed to the great complexity of Okara's cell wall, which would need longer times to be fermented than other easily digested molecules, thus allowing an extended potential prebiotic effect. These results support an in vitro potential prebiotic effect of Okara. PMID:27469454

  20. Prebiotic Alternatives to Proteins: Structure and Function of Hyperbranched Polyesters

    NASA Astrophysics Data System (ADS)

    Mamajanov, Irena; Callahan, Michael P.; Dworkin, Jason P.; Cody, George D.

    2015-06-01

    Proteins are responsible multiple biological functions, such as ligand binding, catalysis, and ion channeling. This functionality is enabled by proteins' three-dimensional structures that require long polypeptides. Since plausibly prebiotic synthesis of functional polypeptides has proven challenging in the laboratory, we propose that these functions may have been initially performed by alternative macromolecular constructs, namely hyperbranched polymers (HBPs), during early stages of chemical evolution. HBPs can be straightforwardly synthesized in one-pot processes, possess globular structures determined by their architecture as opposed to folding in proteins, and have documented ligand binding and catalytic properties. Our initial study focuses on glycerol-citric acid HBPs synthesized via moderate heating in the dry state. The polymerization products consisted of a mixture of isomeric structures of varying molar mass as evidenced by NMR, mass spectrometry and size-exclusion chromatography. Addition of divalent cations during polymerization resulted in increased incorporation of citric acid into the HBPs and the possible formation of cation-oligomer complexes. The chelating properties of citric acid govern the makeup of the resulting polymer, turning the polymerization system into a rudimentary smart material.

  1. Molecular Asymmetry in Prebiotic Chemistry: An Account from Meteorites.

    PubMed

    Pizzarello, Sandra

    2016-01-01

    Carbonaceous Chondrite (CC) meteorites are fragments of asteroids, solar planetesimals that never became large enough to separate matter by their density, like terrestrial planets. CC contains various amounts of organic carbon and carry a record of chemical evolution as it came to be in the Solar System, at the time the Earth was formed and before the origins of life. We review this record as it pertains to the chiral asymmetry determined for several organic compounds in CC, which reaches a broad molecular distribution and enantiomeric excesses of up to 50%-60%. Because homochirality is an indispensable attribute of extant polymers and these meteoritic enantiomeric excesses are still, to date, the only case of chiral asymmetry in organic molecules measured outside the biosphere, the possibility of an exogenous delivery of primed prebiotic compounds to early Earth from meteorites is often proposed. Whether this exogenous delivery held a chiral advantage in molecular evolution remains an open question, as many others regarding the origins of life are. PMID:27089368

  2. Inulin Potential for Enzymatic Obtaining of Prebiotic Oligosaccharides.

    PubMed

    Flores, Adriana C; Morlett, Jesús A; Rodríguez, Raúl

    2016-08-17

    Oligosaccharides have been marketed since the 80s as low-calorie agents and recently have gained interest in the pharmaceutical and food industry as functional sweeteners and prebiotic enriching population of Bifidobacteria. Currently, they have an approximated value of $200 per kg and recently, inulin has been proposed as a feedstock for production of oligosaccharides through selective hydrolysis by action of endoinulinase. High optimum temperature (60°C) and thermostability are two important criteria that determine suitability of this enzyme for industrial applications as well as enzyme cost, a major limiting factor. Significant reduction in cost can be achieved by employing low-value and abundant inulin-rich plants as Jerusalem artichoke, dahlia, yacon, garlic, and onion, among others. In general, the early harvested tubers of these plants contain a greater amount of highly polymerized sugar fractions, which offer more industrial value than late-harvested tubers or those after storage. Also, development of recombinant microorganisms could be useful to reduce the cost of enzyme technology for large-scale production of oligosaccharides. In the case of fungal inulinases, several studies of cloning and modification have been made to achieve greater efficiency. The present paper reviews inulin from vegetable sources as feedstock for oligosaccharides production through the action of inulinases, the impact of polymerization degree of inulin and its availability, and some strategies to increase oligosaccharide production. PMID:25746219

  3. Prebiotic materials from on and off the early Earth

    PubMed Central

    Bernstein, Max

    2006-01-01

    One of the greatest puzzles of all time is how did life arise? It has been universally presumed that life arose in a soup rich in carbon compounds, but from where did these organic molecules come? In this article, I will review proposed terrestrial sources of prebiotic organic molecules, such as Miller–Urey synthesis (including how they would depend on the oxidation state of the atmosphere) and hydrothermal vents and also input from space. While the former is perhaps better known and more commonly taught in school, we now know that comet and asteroid dust deliver tons of organics to the Earth every day, therefore this flux of reduced carbon from space probably also played a role in making the Earth habitable. We will compare and contrast the types and abundances of organics from on and off the Earth given standard assumptions. Perhaps each process provided specific compounds (amino acids, sugars, amphiphiles) that were directly related to the origin or early evolution of life. In any case, whether planetary, nebular or interstellar, we will consider how one might attempt to distinguish between abiotic organic molecules from actual signs of life as part of a robotic search for life in the Solar System. PMID:17008210

  4. An efficient prebiotic synthesis of cytosine and uracil

    NASA Astrophysics Data System (ADS)

    Robertson, Michael P.; Miller, Stanley L.

    1995-06-01

    IN contrast to the purines1 3, the routes that have been proposed for the prebiotic synthesis of pyrimidines from simple precursors give only low yields. Cytosine can be synthesized from cyano-acetylene and cyanate4,5; the former precursor is produced from a spark discharge in a CH4/N2 mixture4,5 and is an abundant interstellar molecule6. But this reaction requires relatively high concentrations of cyanate (>0.1 M), which are unlikely to occur in aqueous media as cyanate is hydrolysed rapidly to CO2 and NH3. An alternative route that has been explored7 is the reaction of cyanoacetaldehyde (formed by hydrolysis of cyanoacetylene8) with urea. But at low concentrations of urea, this reaction produces no detectable quantities of cytosine7. Here we show that in concentrated urea solution-such as might have been found in an evaporating lagoon or in pools on drying beaches on the early Earth-cyanoacetaldehyde reacts to form cytosine in yields of 30-50%, from which uracil can be formed by hydrolysis. These reactions provide a plausible route to the pyrimidine bases required in the RNA world9.

  5. Out of fuzzy chemistry: from prebiotic chemistry to metabolic networks.

    PubMed

    Peretó, Juli

    2012-08-21

    The origin of life on Earth was a chemical affair. So how did primitive biochemical systems originate from geochemical and cosmochemical processes on the young planet? Contemporary research into the origins of life subscribes to the Darwinian principle of material causes operating in an evolutionary context, as advocated by A. I. Oparin and J. B. S. Haldane in the 1920s. In its simplest form (e.g., a bacterial cell) extant biological complexity relies on the functional integration of metabolic networks and replicative genomes inside a lipid boundary. Different research programmes have explored the prebiotic plausibility of each of these autocatalytic subsystems and combinations thereof: self-maintained networks of small molecules, template chemistry, and self-reproductive vesicles. This tutorial review focuses on the debates surrounding the origin of metabolism and offers a brief overview of current studies on the evolution of metabolic networks. I suggest that a leitmotif in the origin and evolution of metabolism is the role played by catalysers' substrate ambiguity and multifunctionality. PMID:22508108

  6. Probiotics, prebiotics and competitive exclusion for prophylaxis against bacterial disease.

    PubMed

    Callaway, T R; Edrington, T S; Anderson, R C; Harvey, R B; Genovese, K J; Kennedy, C N; Venn, D W; Nisbet, D J

    2008-12-01

    The microbial population of the intestinal tract is a complex natural resource that can be utilized in an effort to reduce the impact of pathogenic bacteria that affect animal production and efficiency, as well as the safety of food products. Strategies have been devised to reduce the populations of food-borne pathogenic bacteria in animals at the on-farm stage. Many of these techniques rely on harnessing the natural competitive nature of bacteria to eliminate pathogens that negatively impact animal production or food safety. Thus feed products that are classified as probiotics, prebiotics and competitive exclusion cultures have been utilized as pathogen reduction strategies in food animals with varying degrees of success. The efficacy of these products is often due to specific microbial ecological factors that alter the competitive pressures experienced by the microbial population of the gut. A few products have been shown to be effective under field conditions and many have shown indications of effectiveness under experimental conditions and as a result probiotic products are widely used in all animal species and nearly all production systems. This review explores the ecology behind the efficacy of these products against pathogens found in food animals, including those that enter the food chain and impact human consumers. PMID:19102792

  7. Molecular Asymmetry in Prebiotic Chemistry: An Account from Meteorites

    PubMed Central

    Pizzarello, Sandra

    2016-01-01

    Carbonaceous Chondrite (CC) meteorites are fragments of asteroids, solar planetesimals that never became large enough to separate matter by their density, like terrestrial planets. CC contains various amounts of organic carbon and carry a record of chemical evolution as it came to be in the Solar System, at the time the Earth was formed and before the origins of life. We review this record as it pertains to the chiral asymmetry determined for several organic compounds in CC, which reaches a broad molecular distribution and enantiomeric excesses of up to 50%–60%. Because homochirality is an indispensable attribute of extant polymers and these meteoritic enantiomeric excesses are still, to date, the only case of chiral asymmetry in organic molecules measured outside the biosphere, the possibility of an exogenous delivery of primed prebiotic compounds to early Earth from meteorites is often proposed. Whether this exogenous delivery held a chiral advantage in molecular evolution remains an open question, as many others regarding the origins of life are. PMID:27089368

  8. [Use of probiotics and prebiotics in primary care].

    PubMed

    Álvarez Calatayud, Guillermo; Azpiroz, Fernando

    2015-01-01

    Probiotics are used in a great number of both paediatric and adult diseases, mainly in gastrointestinal disorders, like diarrhoea. Nevertheless, their beneficial effect on immune alterations, such as atopic dermatitis and, more recently, in women related diseases such as vulvovaginitis and mastitis have also been observed. However, the use of probiotics is not completely implemented into the routine clinical practice for primary care physicians. There is still a great controversy with scarce scientific evidence, due to the diversity in the designs thereof which justifies the variability in the efficacy results. This outcome leads to difficulties in developing definitive treatment guidelines although there are exceptions, for example, WGO. The aim of this workshop, held at the VI Congress of the Spanish Society of Probiotics and Prebiotics is the training of primary care physicians, both paediatricians and general practitioners in the clinical applications of these nutritional preparations in different diseases: acute diarrhoea; antibiotic associated diarrhoea, necrotizing enterocolitis, employment in infant milk formulas, infant colic, irritable bowel syndrome and inflammatory bowel disease, as well as vulvovaginitis and mastitis. PMID:25659055

  9. Cool Stars May Have Different Prebiotic Chemical Mix

    NASA Technical Reports Server (NTRS)

    2009-01-01

    NASA's Spitzer Space Telescope detected a prebiotic, or potentially life-forming, molecule called hydrogen cyanide (HCN) in the planet-forming disks around yellow stars like our sun, but not in the disks around cooler, reddish stars.

    The observations are plotted in this graph, called a spectrum, in which light from the gas in the disks around the stars has been split up into its basic components, or wavelengths. Data from stars like our sun are yellow, and data from cool stars are orange. Light wavelengths are shown on the X-axis, and the relative brightness of disk emission is shown on the Y-axis. The signature of a baseline molecule, called acetylene (C2H2), was seen for both types of stars, but hydrogen cyanide was seen only around stars like our sun.

    Hydrogen cyanide is an organic, nitrogen-containing molecule. Five hydrogen cyanide molecules can link up to form adenine, one of the four chemical bases of DNA.

  10. Dynamical Study of Prebiotic Processing by Comet Impact

    NASA Technical Reports Server (NTRS)

    Huo, Winifred M.; Dateo, Christopher E.; McKay, Christopher P.; Borucki, William J.

    2003-01-01

    Comets and meteoroids that bombarded the Earth, other planets and moons are considered possible deliverers of prebiotic materials manufactured in space. Simultaneously, chemical processing can be initiated by the large kinetic energy imparted to the planetary atmosphere during comet/meteoroid entry. The efficiency of organic synthesis and the diversity of products by impact shock are known to decrease as the reducing power of the atmosphere decreases. It is generally accepted that rich organic products are produced in a methane atmosphere whereas a carbon dioxide atmosphere is reported to yield a dearth of products In order to understand the details of impact chemistry and how it depends on the atmospheric composition, we carried out simulations of the chemistry initiated by comet/meteoroid impact upon a planetary atmosphere using different atmospheric compositions. The simulations were done by solving the set of coupled equations for mass, momentum, and energy conservations, chemical kinetics, and transport, that describe a high-energy impact shock, subsequent expansion and cooling of the hot shocked gas by mixing with the ambient gas, and the eventual steady state composition.

  11. Isotopic characterisation of prebiotic synthesis of organic material

    NASA Technical Reports Server (NTRS)

    Kerridge, J. F.; Chang, S.

    1986-01-01

    Many primitive meteorites contain an insoluble organic material, much like terrestrial kerogen, whose mode of origin is currently unknown. When sujbected to stepwise decomposition, this material, unlike its terrestrial counterpart, reveals characteristic release patterns for the stable isotopes of carbon, hydrogen and nitrogen as a function of fractional release of each element. The purpose of this study is to try to match those release patterns using organic matter synthesised in the laboratory under controlled conditions. If successful, such a study would shed light on the origin of kerogen-like organic matter in the early solar system and, by extension, on prebiotic organic synthesis in general. The range of possible syntheses, starting materials and reaction conditions to be investigated is considerable. Samples analysed to date include: a heavy oil produced by Fischer-Tropsch-type catalysis of CO + H2; a solid residue generated by a plasma discharge in CO + H2 + N2; a solid deposited on the electrodes of a Miller-Urey synthesis operating on CH4 + H2O + N2; and a solid residue formed by polymerization of light hydrocarbons procured by a Miller-Urey discharge acting on CH4. Significant structure is observed in the release patterns for the carbon and hydrogen isotopes from the synthetic samples, though there is little evidence for isotopic fractionation during the analysis itself.

  12. Functional food concept and its application to prebiotics.

    PubMed

    Roberfroid, M

    2002-09-01

    A food can be regarded as functional if it is satisfactorily demonstrated to affect beneficially one or more target functions in the body, beyond adequate nutritional effects, in a way which is relevant to either the state of wellbeing and health or the reduction of the risk of a disease. A food can be made functional by increasing the concentration, adding or improving the bioavailability of a particular component. Functional food science will serve to establish claims based either on enhanced function or disease risk reduction. Inulin and oligofructose are functional food ingredients present in miscellaneous edible plants. They are non-digestible oligosaccharides classified as dietary fibres. The target for their functional effects is the colonic microflora that ferment them and for which they serve as selective "fertilizers"; the gastrointestinal physiology; the immune functions; the bioavailability of minerals; the metabolism of lipids; and colonic carcinogenesis. The scientific data available on the nutritional effects of inulin and oligofructose provide strong evidence for a prebiotic effect (i.e., selective stimulation of growth of bifidobacteria in colonic microbiota), improvement of bowel habit (both stool frequency and stool weight) and improved calcium bioavailability. PMID:12408452

  13. Sugar-Driven Prebiotic Synthesis of Ammonia from Nitrite

    NASA Astrophysics Data System (ADS)

    Weber, Arthur L.

    2010-03-01

    Reaction of 3-5 carbon sugars, glycolaldehyde, and α-ketoaldehydes with nitrite under mild anaerobic aqueous conditions yielded ammonia, an essential substrate for the synthesis of nitrogen-containing molecules during abiogenesis. Under the same conditions, ammonia synthesis was not driven by formaldehyde, glyoxylate, 2-deoxyribose, and glucose, a result indicating that the reduction process requires an organic reductant containing either an accessible α-hydroxycarbonyl group or an α-dicarbonyl group. Small amounts of aqueous Fe+3 catalyzed the sugar-driven synthesis of ammonia. The glyceraldehyde concentration dependence of ammonia synthesis, and control studies of ammonia’s reaction with glyceraldehyde, indicated that ammonia formation is accompanied by incorporation of part of the synthesized ammonia into sugar-derived organic products. The ability of sugars to drive the synthesis of ammonia is considered important to abiogenesis because it provides a way to generate photochemically unstable ammonia at sites of sugar-based origin-of-life processes from nitrite, a plausible prebiotic nitrogen species.

  14. Sugar-driven prebiotic synthesis of ammonia from nitrite.

    PubMed

    Weber, Arthur L

    2010-06-01

    Reaction of 3-5 carbon sugars, glycolaldehyde, and alpha-ketoaldehydes with nitrite under mild anaerobic aqueous conditions yielded ammonia, an essential substrate for the synthesis of nitrogen-containing molecules during abiogenesis. Under the same conditions, ammonia synthesis was not driven by formaldehyde, glyoxylate, 2-deoxyribose, and glucose, a result indicating that the reduction process requires an organic reductant containing either an accessible alpha-hydroxycarbonyl group or an alpha-dicarbonyl group. Small amounts of aqueous Fe(+3) catalyzed the sugar-driven synthesis of ammonia. The glyceraldehyde concentration dependence of ammonia synthesis, and control studies of ammonia's reaction with glyceraldehyde, indicated that ammonia formation is accompanied by incorporation of part of the synthesized ammonia into sugar-derived organic products. The ability of sugars to drive the synthesis of ammonia is considered important to abiogenesis because it provides a way to generate photochemically unstable ammonia at sites of sugar-based origin-of-life processes from nitrite, a plausible prebiotic nitrogen species. PMID:20213158

  15. Nonequilibrium Steady States in Models of Prebiotic Evolution

    NASA Astrophysics Data System (ADS)

    Halley, J. W.; Wynveen, A.

    2014-12-01

    We report computational results from a model for prebiotic evolution.The model is schematic, but contains a correct description of thebasic statistical problem associated with understanding how the initiation of life can occur given the strong entropic barriers (sometimesknown as 'Eigen's paradox' and appearing in experiments as the 'tar problem'). The model is similar to one of the modelsintroduced years ago by Kauffman and coworkers. The important innovationwhich we introduce is imposition of the requirement that, to qualifyas a lifelike dynamical chemical system, the system must not be inchemical equilibrium. That constraint turns out to have major qualitativeeffects on the conclusions. In particular, very sparse chemical networksturn out to be the most favorable ones for generating autocatalyticnonequilibrium states. This suggests qualitatively that deserts might bebetter than ponds for initiating life. Some details of the models andsimulations will be described, including recent results in which weintroduce spatial diffusion and a proxy for temperature into the description ofthe model chemistry. Results on growth rates, convergence and theoverall probability of generation of lifelike states as a function ofparameters of the chemical network model will be presented.

  16. An efficient prebiotic synthesis of cytosine and uracil

    NASA Technical Reports Server (NTRS)

    Robertson, M. P.; Miller, S. L.

    1995-01-01

    In contrast to the purines, the routes that have been proposed for the prebiotic synthesis of pyrimidines from simple precursors give only low yields. Cytosine can be synthesized from cyanoacetylene and cyanate; the former precursor is produced from a spark discharge in a CH4/N2 mixture and is an abundant interstellar molecule. But this reaction requires relatively high concentrations of cyanate (> 0.1 M), which are unlikely to occur in aqueous media as cyanate is hydrolysed rapidly to CO2 and NH3. An alternative route that has been explored is the reaction of cyanoacetaldehyde (formed by hydrolysis of cyanoacetylene) with urea. But at low concentrations of urea, this reaction produces no detectable quantities of cytosine. Here we show that in concentrated urea solution--such as might have been found in an evaporating lagoon or in pools on drying beaches on the early Earth--cyanoacetaldehyde reacts to form cytosine in yields of 30-50%, from which uracil can be formed by hydrolysis. These reactions provide a plausible route to the pyrimidine bases required in the RNA world.

  17. Accumulation of formamide in hydrothermal pores to form prebiotic nucleobases.

    PubMed

    Niether, Doreen; Afanasenkau, Dzmitry; Dhont, Jan K G; Wiegand, Simone

    2016-04-19

    Formamide is one of the important compounds from which prebiotic molecules can be synthesized, provided that its concentration is sufficiently high. For nucleotides and short DNA strands, it has been shown that a high degree of accumulation in hydrothermal pores occurs, so that temperature gradients might play a role in the origin of life [Baaske P, et al. (2007)Proc Natl Acad Sci USA104(22):9346-9351]. We show that the same combination of thermophoresis and convection in hydrothermal pores leads to accumulation of formamide up to concentrations where nucleobases are formed. The thermophoretic properties of aqueous formamide solutions are studied by means of Infrared Thermal Diffusion Forced Rayleigh Scattering. These data are used in numerical finite element calculations in hydrothermal pores for various initial concentrations, ambient temperatures, and pore sizes. The high degree of formamide accumulation is due to an unusual temperature and concentration dependence of the thermophoretic behavior of formamide. The accumulation fold in part of the pores increases strongly with increasing aspect ratio of the pores, and saturates to highly concentrated aqueous formamide solutions of ∼85 wt% at large aspect ratios. Time-dependent studies show that these high concentrations are reached after 45-90 d, starting with an initial formamide weight fraction of[Formula: see text]wt % that is typical for concentrations in shallow lakes on early Earth. PMID:27044100

  18. Recent developments in manufacturing oligosaccharides with prebiotic functions.

    PubMed

    Kovács, Zoltán; Benjamins, Eric; Grau, Konrad; Ur Rehman, Amad; Ebrahimi, Mehrdad; Czermak, Peter

    2014-01-01

    The market for prebiotics is steadily growing. To satisfy this increasing worldwide demand, the introduction of effective bioprocessing methods and implementation strategies is required. In this chapter, we review recent developments in the manufacture of galactooligosaccharides (GOS) and fructooligosaccharides (FOS). These well-established oligosaccharides (OS) provide several health benefits and have excellent technological properties that make their use as food ingredients especially attractive. The biosyntheses of lactose-based GOS and sucrose-based FOS show similarities in terms of reaction mechanisms and product formation. Both GOS and FOS can be synthesized using whole cells or (partially) purified enzymes in immobilized or free forms. The biocatalysis results in a final product that consists of OS, unreacted disaccharides, and monosaccharides. This incomplete conversion poses a challenge to manufacturers because an enrichment of OS in this mixture adds value to the product. For removing digestible carbohydrates from OS, a variety of bioengineering techniques have been investigated, including downstream separation technologies, additional bioconversion steps applying enzymes, and selective fermentation strategies. This chapter summarizes the state-of-the-art manufacturing strategies and recent advances in bioprocessing technologies that can lead to new possibilities for manufacturing and purifying sucrose-based FOS and lactose-based GOS. PMID:23942834

  19. Examining Prebiotic Chemistry Using O(^1D) Insertion Reactions

    NASA Astrophysics Data System (ADS)

    Hays, Brian M.; Laas, Jacob C.; Weaver, Susanna L. Widicus

    2013-06-01

    Aminomethanol, methanediol, and methoxymethanol are all prebiotic molecules expected to form via photo-driven grain surface chemistry in the interstellar medium (ISM). These molecules are expected to be precursors for larger, biologically-relevant molecules in the ISM such as sugars and amino acids. These three molecules have not yet been detected in the ISM because of the lack of available rotational spectra. A high resolution (sub)millimeter spectrometer coupled to a molecular source is being used to study these molecules using O(^1D) insertion reactions. The O(^1D) chemistry is initiated using an excimer laser, and the products of the insertion reactions are adiabatically cooled using a supersonic expansion. Experimental parameters are being optimized by examination of methanol formed from O(^1D) insertion into methane. Theoretical studies of the structure and reaction energies for aminomethanol, methanediol, and methoxymethanol have been conducted to guide the laboratory studies once the methanol experiment has been optimized. The results of the calculations and initial experimental results will be presented.

  20. Prebiotic materials from on and off the early Earth.

    PubMed

    Bernstein, Max

    2006-10-29

    One of the greatest puzzles of all time is how did life arise? It has been universally presumed that life arose in a soup rich in carbon compounds, but from where did these organic molecules come? In this article, I will review proposed terrestrial sources of prebiotic organic molecules, such as Miller-Urey synthesis (including how they would depend on the oxidation state of the atmosphere) and hydrothermal vents and also input from space. While the former is perhaps better known and more commonly taught in school, we now know that comet and asteroid dust deliver tons of organics to the Earth every day, therefore this flux of reduced carbon from space probably also played a role in making the Earth habitable. We will compare and contrast the types and abundances of organics from on and off the Earth given standard assumptions. Perhaps each process provided specific compounds (amino acids, sugars, amphiphiles) that were directly related to the origin or early evolution of life. In any case, whether planetary, nebular or interstellar, we will consider how one might attempt to distinguish between abiotic organic molecules from actual signs of life as part of a robotic search for life in the Solar System. PMID:17008210

  1. Intrinsic selectivity in some prebiotic reactions of urazole with sugars

    NASA Astrophysics Data System (ADS)

    Kolb, Vera M.; Colloton, Patricia A.

    2004-02-01

    Urazole (1,2,4-triazolidine-3,5-dione) (1), 4-methylurazole (12), and its carbon analog, 4,4-dimethylpyrazolidine-3,5-dione (18), react with 2-deoxy-D-ribose (2-deoxy-D-erythro-pentose; 6) in an aqueous solution at room temperature in a regioselective manner (a single substitution on a hydrazidic nitrogen, no reaction on the imide nitrogen) to give a mixture of four nucleosides. These are α and β pyranosides (p) and α and β furanosides (f). The α p forms in a stereoselective manner. A crystalline precipitate is formed in each of the above reactions, which is an exclusive enantiospecific product, 1R, 2R α p. 1 with 2-deoxy-L-ribose (10) gives a precipitate with the exclusive 1S, 2S α p stereochemistry. With 2-deoxy-D-glucose (2-deoxy-D-arabino-hexose; 7) the reaction with 1 is stereospecific, since only one isomer, β p, forms in the solution. Causes of enhanced reactivity of 1 with sugars were also studied. It was found that cyclic hydrazide analogs of 1, such as 12 and 18, are reactive, but open-chain analogs, 1,2,-diacetylhydrazine (21) and 1,2-dicarbethoxyhydrazine (22), are not. Although this reactivity assessment was done qualitatively and under restrictive reaction conditions, it still may be valuable for understanding α -effect of hydrazide nucleophiles. The prebiotic significance of our results is discussed.

  2. Prebiotic supplementation and adequate calcium intake have beneficial effects on body mass index changes during early adolescence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Prebiotics have been shown to enhance bone and gastrointestinal health. Recent data suggest a benefit to weight maintenance as well. However, few data are available in children or adolescents. The interactive effects of prebiotic intake and calcium intake on weight maintenance are unknown. Our objec...

  3. Effects of the prebiotics GroBiotic-A and inulin on the intestinal microbiota of red drum, Sciaenops ocellatus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two separate feeding trials examined the effects of dietary supplementation of the prebiotics GroBiotic®-A and inulin on growth performance and gastrointestinal tract microbiota of the red drum Sciaenops ocellatus. In the first feeding trial, fishmeal-based diets without prebiotics or supplemented ...

  4. 'The way to a man's heart is through his gut microbiota'--dietary pro- and prebiotics for the management of cardiovascular risk.

    PubMed

    Tuohy, Kieran M; Fava, Francesca; Viola, Roberto

    2014-05-01

    The human gut microbiota has been identified as a possible novel CVD risk factor. This review aims to summarise recent insights connecting human gut microbiome activities with CVD and how such activities may be modulated by diet. Aberrant gut microbiota profiles have been associated with obesity, type 1 and type 2 diabetes and non-alcoholic fatty liver disease. Transfer of microbiota from obese animals induces metabolic disease and obesity in germ-free animals. Conversely, transfer of pathogen-free microbiota from lean healthy human donors to patients with metabolic disease can increase insulin sensitivity. Not only are aberrant microbiota profiles associated with metabolic disease, but the flux of metabolites derived from gut microbial metabolism of choline, phosphatidylcholine and l-carnitine has been shown to contribute directly to CVD pathology, providing one explanation for increased disease risk of eating too much red meat. Diet, especially high intake of fermentable fibres and plant polyphenols, appears to regulate microbial activities within the gut, supporting regulatory guidelines encouraging increased consumption of whole-plant foods (fruit, vegetables and whole-grain cereals), and providing the scientific rationale for the design of efficacious prebiotics. Similarly, recent human studies with carefully selected probiotic strains show that ingestion of viable microorganisms with the ability to hydrolyse bile salts can lower blood cholesterol, a recognised risk factor in CVD. Taken together such observations raise the intriguing possibility that gut microbiome modulation by whole-plant foods, probiotics and prebiotics may be at the base of healthy eating pyramids advised by regulatory agencies across the globe. In conclusion, dietary strategies which modulate the gut microbiota or their metabolic activities are emerging as efficacious tools for reducing CVD risk and indicate that indeed, the way to a healthy heart may be through a healthy gut microbiota

  5. Characterization and prebiotic activity of aqueous extract and indigestible polysaccharide from Anoectochilus formosanus.

    PubMed

    Yang, Li-Chan; Lin, Wen-Chuan; Lu, Ting-Jang

    2012-09-01

    Anoectochilus formosanus (Orchidaceae) is a folk medicine in Asia. This study investigated the in vivo and in vitro prebiotic effects of an aqueous extract of A. formosanus (SAEAF) and of an indigestible polysaccharide (AFP) isolated from SAEAF. Chemical analyses showed AFP was mainly composed of arabinogalactan type II (AG-II), with an average molecular weight of 29 kDa. Following 4 weeks of oral administration to rats, SAEAF exhibited prebiotic effects including a decrease in cecum pH and increases of calcium absorption and fecal bifidobacteria. Furthermore, through a bioactivity-guided separation strategy, AFP was proven to be a bifidogenic component in vitro fecal strains fermentation and in vivo administration to mice. In RT-PCR analysis of Bifidobacterium , AFP increased the expression of ABC transporter related to nutrient uptake. Thus, AFP, a polysaccharide from A. formosanus, was demonstrated to be a prebiotic that has a positive health effect on gut microbiota. PMID:22793881

  6. Spontaneous formation and base pairing of plausible prebiotic nucleotides in water.

    PubMed

    Cafferty, Brian J; Fialho, David M; Khanam, Jaheda; Krishnamurthy, Ramanarayanan; Hud, Nicholas V

    2016-01-01

    The RNA World hypothesis presupposes that abiotic reactions originally produced nucleotides, the monomers of RNA and universal constituents of metabolism. However, compatible prebiotic reactions for the synthesis of complementary (that is, base pairing) nucleotides and mechanisms for their mutual selection within a complex chemical environment have not been reported. Here we show that two plausible prebiotic heterocycles, melamine and barbituric acid, form glycosidic linkages with ribose and ribose-5-phosphate in water to produce nucleosides and nucleotides in good yields. Even without purification, these nucleotides base pair in aqueous solution to create linear supramolecular assemblies containing thousands of ordered nucleotides. Nucleotide anomerization and supramolecular assemblies favour the biologically relevant β-anomer form of these ribonucleotides, revealing abiotic mechanisms by which nucleotide structure and configuration could have been originally favoured. These findings indicate that nucleotide formation and selection may have been robust processes on the prebiotic Earth, if other nucleobases preceded those of extant life. PMID:27108699

  7. Interactions between prebiotics, probiotics, polyunsaturated fatty acids and polyphenols: diet or supplementation for metabolic syndrome prevention?

    PubMed

    Peluso, Ilaria; Romanelli, Luca; Palmery, Maura

    2014-05-01

    The metabolic syndrome can be prevented by the Mediterranean diet, characterized by fiber, omega-3 polyunsaturated fatty acids and polyphenols. However, the composition of the Mediterranean diet, which can be viewed as a natural multiple supplement, is poorly controlled, and its beneficial effects poorly predictable. The metabolic syndrome is associated with intestinal dysbiosis and the gut microbioma seems to be the main target and player in the interactions occurring between probiotics, prebiotics, omega 3 polyunsaturated fatty acids, and polyphenols. From the reviewed evidence, it is reasonable to manage growth and metabolism of gut microflora with specific prebiotics and polyphenols. Even though the healthy properties of functional foods and nutraceuticals still need to be fully elucidated, available data suggest that well-designed supplements, containing the better ratio of omega-3 polyunsaturated fatty acids and antioxidants, specific probiotic strains, and selected polyphenols and prebiotics, could be useful in metabolic syndrome prevention and treatment. PMID:24467635

  8. High dietary intake of prebiotic inulin-type fructans in the prehistoric Chihuahuan Desert.

    PubMed

    Leach, Jeff D; Sobolik, Kristin D

    2010-06-01

    Archaeological evidence from dry cave deposits in the northern Chihuahuan Desert reveal intensive utilisation of desert plants that store prebiotic inulin-type fructans as the primary carbohydrate. In this semi-arid region limited rainfall and poor soil conditions prevented the adoption of agriculture and thus provides a unique glimpse into a pure hunter-forager economy spanning over 10 000 years. Ancient cooking features, stable carbon isotope analysis of human skeletons, and well-preserved coprolites and macrobotanical remains reveal a plant-based diet that included a dietary intake of about 135 g prebiotic inulin-type fructans per d by the average adult male hunter-forager. These data reveal that man is well adapted to daily intakes of prebiotics well above those currently consumed in the modern diet. PMID:20416127

  9. Spontaneous formation and base pairing of plausible prebiotic nucleotides in water

    PubMed Central

    Cafferty, Brian J.; Fialho, David M.; Khanam, Jaheda; Krishnamurthy, Ramanarayanan; Hud, Nicholas V.

    2016-01-01

    The RNA World hypothesis presupposes that abiotic reactions originally produced nucleotides, the monomers of RNA and universal constituents of metabolism. However, compatible prebiotic reactions for the synthesis of complementary (that is, base pairing) nucleotides and mechanisms for their mutual selection within a complex chemical environment have not been reported. Here we show that two plausible prebiotic heterocycles, melamine and barbituric acid, form glycosidic linkages with ribose and ribose-5-phosphate in water to produce nucleosides and nucleotides in good yields. Even without purification, these nucleotides base pair in aqueous solution to create linear supramolecular assemblies containing thousands of ordered nucleotides. Nucleotide anomerization and supramolecular assemblies favour the biologically relevant β-anomer form of these ribonucleotides, revealing abiotic mechanisms by which nucleotide structure and configuration could have been originally favoured. These findings indicate that nucleotide formation and selection may have been robust processes on the prebiotic Earth, if other nucleobases preceded those of extant life. PMID:27108699

  10. Application of inulin in cheese as prebiotic, fat replacer and texturizer: a review.

    PubMed

    Karimi, Reza; Azizi, Mohammad Hossein; Ghasemlou, Mehran; Vaziri, Moharam

    2015-03-30

    Inulin is a food ingredient that belongs to a class of carbohydrates known as fructans. Nutritionally it has functional properties and health-promoting effects that include reduced calorie value, dietary fiber and prebiotic effects. Inulin is increasingly used in industrially processed dairy and non-dairy products because it is a bulking agent for use in fat replacement, textural modification and organoleptic improvement. Addition of inulin to different kinds of cheese can be beneficial in the manufacture of a reduced- or low-fat, texturized, symbiotic product. This paper gives an overview of some aspects of the microstructural, textural, rheological, prebiotic and sensorial effects of inulin incorporated in cheese as fat replacer, prebiotic and texture modifier. PMID:25563948

  11. Prebiotic organic matter - Possible pathways for synthesis in a geological context

    NASA Technical Reports Server (NTRS)

    Chang, S.

    1982-01-01

    Models for the accretion of the earth, core formation, differentiation of the planet into core, mantle, crust, and atmosphere, and prebiotic synthesis of organic materials are reviewed. The development of the Haldane-Oparin and Urey models is traced, and the effect of accretion time on the outgassing process and the composition of the consequent atmosphere is examined. Model prebiotic atmospheres are calculated, the extent of equilibration of the primitive atmosphere is studied and the evolution of the atmosphere prior to organic chemical evolution is reviewed. Finally, experimental progress in synthesis of biological monomers and polymers under presumed early earth conditions is covered.

  12. Micronutrients, N-Acetyl Cysteine, Probiotics and Prebiotics, a Review of Effectiveness in Reducing HIV Progression

    PubMed Central

    Hummelen, Ruben; Hemsworth, Jaimie; Reid, Gregor

    2010-01-01

    Low serum concentrations of micronutrients, intestinal abnormalities, and an inflammatory state have been associated with HIV progression. These may be ameliorated by micronutrients, N-acetyl cysteine, probiotics, and prebiotics. This review aims to integrate the evidence from clinical trials of these interventions on the progression of HIV. Vitamin B, C, E, and folic acid have been shown to delay the progression of HIV. Supplementation with selenium, N-acetyl cysteine, probiotics, and prebiotics has considerable potential, but the evidence needs to be further substantiated. Vitamin A, iron, and zinc have been associated with adverse effects and caution is warranted for their use. PMID:22254046

  13. Polycyclic Aromatic Hydrocarbons as Plausible Prebiotic Membrane Components

    NASA Astrophysics Data System (ADS)

    Groen, Joost; Deamer, David W.; Kros, Alexander; Ehrenfreund, Pascale

    2012-08-01

    Aromatic molecules delivered to the young Earth during the heavy bombardment phase in the early history of our solar system were likely to be among the most abundant and stable organic compounds available. The Aromatic World hypothesis suggests that aromatic molecules might function as container elements, energy transduction elements and templating genetic components for early life forms. To investigate the possible role of aromatic molecules as container elements, we incorporated different polycyclic aromatic hydrocarbons (PAH) in the membranes of fatty acid vesicles. The goal was to determine whether PAH could function as a stabilizing agent, similar to the role that cholesterol plays in membranes today. We studied vesicle size distribution, critical vesicle concentration and permeability of the bilayers using C6-C10 fatty acids mixed with amphiphilic PAH derivatives such as 1-hydroxypyrene, 9-anthracene carboxylic acid and 1,4 chrysene quinone. Dynamic Light Scattering (DLS) spectroscopy was used to measure the size distribution of vesicles and incorporation of PAH species was established by phase-contrast and epifluorescence microscopy. We employed conductimetric titration to determine the minimal concentration at which fatty acids could form stable vesicles in the presence of PAHs. We found that oxidized PAH derivatives can be incorporated into decanoic acid (DA) vesicle bilayers in mole ratios up to 1:10 (PAH:DA). Vesicle size distribution and critical vesicle concentration were largely unaffected by PAH incorporation, but 1-hydroxypyrene and 9-anthracene carboxylic acid lowered the permeability of fatty acid bilayers to small solutes up to 4-fold. These data represent the first indication of a cholesterol-like stabilizing effect of oxidized PAH derivatives in a simulated prebiotic membrane.

  14. Polycyclic aromatic hydrocarbons as plausible prebiotic membrane components.

    PubMed

    Groen, Joost; Deamer, David W; Kros, Alexander; Ehrenfreund, Pascale

    2012-08-01

    Aromatic molecules delivered to the young Earth during the heavy bombardment phase in the early history of our solar system were likely to be among the most abundant and stable organic compounds available. The Aromatic World hypothesis suggests that aromatic molecules might function as container elements, energy transduction elements and templating genetic components for early life forms. To investigate the possible role of aromatic molecules as container elements, we incorporated different polycyclic aromatic hydrocarbons (PAH) in the membranes of fatty acid vesicles. The goal was to determine whether PAH could function as a stabilizing agent, similar to the role that cholesterol plays in membranes today. We studied vesicle size distribution, critical vesicle concentration and permeability of the bilayers using C(6)-C(10) fatty acids mixed with amphiphilic PAH derivatives such as 1-hydroxypyrene, 9-anthracene carboxylic acid and 1,4 chrysene quinone. Dynamic Light Scattering (DLS) spectroscopy was used to measure the size distribution of vesicles and incorporation of PAH species was established by phase-contrast and epifluorescence microscopy. We employed conductimetric titration to determine the minimal concentration at which fatty acids could form stable vesicles in the presence of PAHs. We found that oxidized PAH derivatives can be incorporated into decanoic acid (DA) vesicle bilayers in mole ratios up to 1:10 (PAH:DA). Vesicle size distribution and critical vesicle concentration were largely unaffected by PAH incorporation, but 1-hydroxypyrene and 9-anthracene carboxylic acid lowered the permeability of fatty acid bilayers to small solutes up to 4-fold. These data represent the first indication of a cholesterol-like stabilizing effect of oxidized PAH derivatives in a simulated prebiotic membrane. PMID:22798228

  15. The Porphobilinogen Conundrum in Prebiotic Routes to Tetrapyrrole Macrocycles

    NASA Astrophysics Data System (ADS)

    Taniguchi, Masahiko; Ptaszek, Marcin; Chandrashaker, Vanampally; Lindsey, Jonathan S.

    2016-05-01

    Attempts to develop a credible prebiotic route to tetrapyrroles have relied on enzyme-free recapitulation of the extant biosynthesis, but this process has foundered from the inability to form the pyrrole porphobilinogen (PBG) in good yield by self-condensation of the precursor δ-aminolevulinic acid (ALA). PBG undergoes robust oligomerization in aqueous solution to give uroporphyrinogen (4 isomers) in good yield. ALA, PBG, and uroporphyrinogen III are universal precursors to all known tetrapyrrole macrocycles. The enzymic formation of PBG entails carbon-carbon bond formation between the less stable enolate/enamine of one ALA molecule (3-position) and the carbonyl/imine (4-position) of the second ALA molecule; without enzymes, the first ALA reacts at the more stable enolate/enamine (5-position) and gives the pyrrole pseudo-PBG. pseudo-PBG cannot self-condense, yet has one open α-pyrrole position and is proposed to be a terminator of oligopyrromethane chain-growth from PBG. Here, 23 analogues of ALA have been subjected to density functional theoretical (DFT) calculations, but no motif has been identified that directs reaction at the 3-position. Deuteriation experiments suggested 5-(phosphonooxy)levulinic acid would react preferentially at the 3- versus 5-position, but a hybrid condensation with ALA gave no observable uroporphyrin. The results suggest efforts toward a biomimetic, enzyme-free route to tetrapyrroles from ALA should turn away from structure-directed reactions and focus on catalysts that orient the two aminoketones to form PBG in a kinetically controlled process, thereby avoiding formation of pseudo-PBG.

  16. Accumulation of formamide in hydrothermal pores to form prebiotic nucleobases

    NASA Astrophysics Data System (ADS)

    Niether, Doreen; Afanasenkau, Dzmitry; Dhont, Jan K. G.

    2016-04-01

    Formamide is one of the important compounds from which prebiotic molecules can be synthesized, provided that its concentration is sufficiently high. For nucleotides and short DNA strands, it has been shown that a high degree of accumulation in hydrothermal pores occurs, so that temperature gradients might play a role in the origin of life [Baaske P, et al. (2007) Proc Natl Acad Sci USA 104(22):9346-9351]. We show that the same combination of thermophoresis and convection in hydrothermal pores leads to accumulation of formamide up to concentrations where nucleobases are formed. The thermophoretic properties of aqueous formamide solutions are studied by means of Infrared Thermal Diffusion Forced Rayleigh Scattering. These data are used in numerical finite element calculations in hydrothermal pores for various initial concentrations, ambient temperatures, and pore sizes. The high degree of formamide accumulation is due to an unusual temperature and concentration dependence of the thermophoretic behavior of formamide. The accumulation fold in part of the pores increases strongly with increasing aspect ratio of the pores, and saturates to highly concentrated aqueous formamide solutions of ˜85 wt% at large aspect ratios. Time-dependent studies show that these high concentrations are reached after 45-90 d, starting with an initial formamide weight fraction of 10-310-3 wt % that is typical for concentrations in shallow lakes on early Earth.

  17. The enhancement activities of histidyl-histidine in some prebiotic reactions

    NASA Technical Reports Server (NTRS)

    Shen, C.; Lazcano, A.; Oro, J.

    1990-01-01

    The prebiotic synthesis of His and its dimer has led us to study the possible catalytic properties of His-His. The enhancing effect of His-His has been tested in the dephosphorylation of dAMP, the hydrolysis of oligo(A)12, and the oligomerization of 2'3'-cAMP.

  18. Gut Microbiota: Impact of probiotics, prebiotics, synbiotics, pharmabiotics and postbiotics on human health

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Multidisciplinary approaches enabled a better understanding of the connection between human gut microbes and health. This knowledge is rapidly changing how we think about probiotics and related –biotics (prebiotics, synbiotics, pharmabiotics and postbiotics). Functional –omics approaches are very im...

  19. Self-assembly of phosphate amphiphiles in mixtures of prebiotically plausible surfactants.

    PubMed

    Albertsen, A N; Duffy, C D; Sutherland, J D; Monnard, P-A

    2014-06-01

    The spontaneous formation of closed bilayer structures from prebiotically plausible amphiphiles is an essential requirement for the emergence of early cells on prebiotic Earth. The sources of amphiphiles could have been both endo- and exogenous (accretion of meteorite carbonaceous material or interstellar dust particles). Among all prebiotic possible amphiphile candidates, those containing phosphate are the least investigated species because their self-assembly occurs in a seemingly too narrow range of conditions. The self-assembly of simple phosphate amphiphiles should, however, be of great interest, as contemporary membranes predominantly contain phospholipids. In contrast to common expectations, we show that these amphiphiles can be easily synthesized under prebiotically plausible environmental conditions and can efficiently form bilayer structures in the presence of various co-surfactants across a large range of pH values. Vesiculation was even observed in crude reaction mixtures that contained 1-decanol as the amphiphile precursor. The two best co-surfactants promoted vesicle formation over the entire pH range in aqueous solutions. Expanding the pH range where bilayer membranes self-assemble and remain intact is a prerequisite for the emergence of early cell-like compartments and their preservation under fluctuating environmental conditions. These mixed bilayers also retained small charged solutes, such as dyes. These results demonstrate that alkyl phosphate amphiphiles might have played a significant role as early compartment building blocks. PMID:24885934

  20. The prebiotic synthesis of deoxythymidine oligonucleotides. II - Comparison of condensing agents

    NASA Technical Reports Server (NTRS)

    Odom, D. G.; Brady, J. T.

    1975-01-01

    A reaction which oligomerizes nucleotides under possible prebiotic conditions has been characterized. Nucleoside monophosphate in the presence of cyanamide at acid pH condenses to form dithymidine pyrophosphate and phosphodiester bonded compounds. Imidazole compounds and activated precursors such as nucleoside triphosphate are not necessary for this oligomerization reaction which produces primarily cyclic oligonucleotides.

  1. Isolation of prebiotic carbohydrates by supercritical fluid extraction. Scaling-up and economical feasibility.

    PubMed

    Montañés, F; Fornari, T; Olano, A; Ibáñez, E

    2012-08-10

    Production of prebiotic carbohydrates at competitive prices is a challenge nowadays since the well-established production processes involve many purification steps which are labour intensive and require important amounts of reagents and products thus increasing prebiotic's price. Several processes have been studied in our laboratory involving the use of Supercritical Fluid Technology to fractionate and purify carbohydrate solid mixtures. Research carried out at laboratory scale using theoretical mixtures (lactose/lactulose and galactose/tagatose), commercially available carbohydrate mixtures and carbohydrate mixtures produced by enzymatic transglycosylation and isomerized with complexating reagents demonstrated that purification of prebiotic carbohydrates was technically possible by supercritical fluid extraction. In the present work, the process optimized at laboratory scale to fractionate carbohydrate mixtures produced by enzymatic transglycosylation has been scaled-up to an industrial level and its economic feasibility has been simulated employing AspenONE(®) V7.3 software to obtain consistent data supporting the interest of a potential investment for prebiotics production at large scale using supercritical fluids. PMID:22560345

  2. Simplified protein design biased for prebiotic amino acids yields a foldable, halophilic protein.

    PubMed

    Longo, Liam M; Lee, Jihun; Blaber, Michael

    2013-02-01

    A compendium of different types of abiotic chemical syntheses identifies a consensus set of 10 "prebiotic" α-amino acids. Before the emergence of biosynthetic pathways, this set is the most plausible resource for protein formation (i.e., proteogenesis) within the overall process of abiogenesis. An essential unsolved question regarding this prebiotic set is whether it defines a "foldable set"--that is, does it contain sufficient chemical information to permit cooperatively folding polypeptides? If so, what (if any) characteristic properties might such polypeptides exhibit? To investigate these questions, two "primitive" versions of an extant protein fold (the β-trefoil) were produced by top-down symmetric deconstruction, resulting in a reduced alphabet size of 12 or 13 amino acids and a percentage of prebiotic amino acids approaching 80%. These proteins show a substantial acidification of pI and require high salt concentrations for cooperative folding. The results suggest that the prebiotic amino acids do comprise a foldable set within the halophile environment. PMID:23341608

  3. Processing, cooking, and cooling affect prebiotic concentrations in lentil (Lens culinaris Medikus)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lentil is an important staple food crop in many regions world-wide and is a good source of protein (20-30%) and various micronutrients. Lentil contains raffinose-family oligosaccharides (RFO), resistant starch (RS), and other prebiotic compounds essential for maintenance of healthy gastrointestinal ...

  4. A simple model of the thermal prebiotic oligomerization of amino acids.

    PubMed

    Mosqueira, F G; Ramos-Bernal, S; Negrón-Mendoza, A

    2000-07-01

    We construct a probabilistic model with the aid of the Markov chain formalism to describe and give a physico-chemical justification to an oligomerization process of a set of amino acids under certain prebiotic conditions. Such chemical process shows a remarkable bias in the polymer products that our model can explain. Some predictions and limitations are also discussed. PMID:11004386

  5. Effect of Lactose as a Prebiotic on Turkey Body Weight Under Commercial Conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of a commercially available lactic acid bacteria (LAB) probiotic alone and supplemented with lactose as prebiotic, was evaluated for effects on turkey body weight during the brooding and grow out phases under commercial conditions in two experiments. Turkey poults were given the probioti...

  6. Similar calcium status is present in infants fed formula with and without prebiotics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Prebiotic oligosaccharides can increase calcium absorption in adolescents and adults. Whether they affect calcium absorption in infants has not been assessed. Few data are available to compare the calcium status of infants fed modern infant formulas to that of breast fed infants. To evaluate calcium...

  7. The Prebiotic Synthesis of Ethylenediamine Monoacetic Acid, The Repeating Unit of Peptide Nucleic Acids

    NASA Technical Reports Server (NTRS)

    Nelson, Kevin E.; Miller, Stanley L.

    1992-01-01

    The polymerization of ribonucleic acids or their precursors constitutes an important event in prebiotic chemistry. The various problems using ribonucleotides to make RNA suggest that there may have been a precursor. An attractive possibility are the peptide nucleic acids (PNA). PNAs are nucleotide analogs that make use of a polymer of ethylenediamine monoacetic acid (EDMA or 2-amninoethyl glycine) with the bases attached by an acetic acid. EDMA is an especially attractive alternative to the ribose phosphate or deoxyribose phosphate backbone because it contains no chiral centers and is potentially prebiotic, but there is no reported prebiotic synthesis. We have synthesized both EDMA and ethylenediamine diacetic acid (EDDA) from the prebiotic compounds ethylenediamine, formaldehyde, and hydrogen cyanide. The yields of EDMA range from 11 to 79% along with some sEDDA and uEDDA. These reactions work with concentrations of 10(exp -1)M and as low as 10(exp -4)M, and the reaction is likely to be effective at even lower concentrations. Ethylenediamine is a likely prebiotic compound, but it has not yet been demonstrated, although compounds such as ethanolamine and cysteamine have been proven to be prebiotic. Under neutral pH and heating at l00 C, EDMA is converted to the lactam, monoketopiperazine (MKP). The cyclization occurs and has an approximate ratio of MKP/EDMA = 3 at equilibrium. We have measured the solubilities of EDMA center dot H20 as 6.4 m, EDMA center dot HCl center dot H20 as 13.7 m, and EDMA center dot 2HCl center dot H20 as 3.4 m. These syntheses together with the high solubility of EDMA suggest that EDMA would concentrate in drying lagoons and might efficiently form polymers. Given the instability of ribose and the poor polymerizability of nucleotides, the prebiotic presence of EDMA and the possibility of its polymerization raises the possibility that PNAs are the progenitors of present day nucleic acids. A pre-RNA world may have existed in which PNAs or

  8. Polycyclic aromatic hydrocarbons: primitive pigment systems in the prebiotic environment.

    PubMed

    Deamer, D W

    1992-01-01

    Polycyclic aromatic hydrocarbons (PAH) in the form of polymerized derivatives represent over 90% of the organic material of carbonaceous chondrites. It now appears likely that there was substantial survival of the organic content of meteoritic and cometary infall during late accretion, so that PAH would presumably be major components of the organic inventory present on the prebiotic Earth. An important question relative to chemical evolution and energy transduction is the nature of pigments which could be available to make light energy available to the earliest cellular forms of life. PAH and their derivatives all absorb light in the near UV and blue wavelengths, and are candidates for primitive pigments. We have explored this possibility in a model system consisting of mixtures of pyrene, fluoranthene and pyrene derivatives with hexadecane, dispersed in dilute salt solutions. Upon illumination, photochemical oxidation of the hexadecane occurs, with long-chain amphiphiles such as 2-hexadecanone and 2-hexadecanol as products. Because the reaction proceeds under strictly anaerobic conditions, the source of oxygen is apparently water. We also observed acid pH shifts during illumination. Photochemical production of hydrogen ion is significant, in that chemiosmotic proton gradients across membranes are used by all contemporary cells as a source of energy for ATP synthesis and nutrient transport. To test whether the protons could be used to transduce light energy into a useful form, PAH derivatives were included in lipid bilayer membranes (liposomes). Upon illumination, protons (or acidic products) were produced and accumulated inside the vesicles, so that substantial pH gradients were established across the membranes, acid inside. We conclude that PAH dissolved in aliphatic hydrocarbons absorb light energy and use it to oxidize the hydrocarbon to long-chain amphiphilic molecules. The oxidation is accompanied by release of protons. If PAH derivatives are included in the

  9. Optimum conditions for prebiotic evolution in extraterrestrial environments

    NASA Astrophysics Data System (ADS)

    Abbas, Ousama H.

    The overall goal of the dissertation was to devise synthetic pathways leading to the production of peptides and amino acids from smaller organic precursors. To this end, eight different zeolites were tested in order to determine their catalytic potential in the conversion of amino acids to peptides. The zeolites tested were either synthetic or naturally occurring. Acidic solutions of amino acids were prepared with or without zeolites and their reactivity was monitored over a four-week time interval. The kinetics and feasibility of peptide synthesis from selected amino acid combinations was investigated via the paper chromatography technique. Nine different amino acids were tested. The nature and extent of product were measured at constant time intervals. It was found that two ZSM-5 synthetic zeolites as well as the Fisher Scientific zeolite mix without alumina salts may have a catalytic potential in the conversion of amino acids to peptides. The conversion was verified by matching the paper chromatogram of the experimental product with that of a known peptide. The experimental results demonstrate that the optimum solvent system for paper chromatographic analysis of the zeolite-catalyzed self-assembly of the amino acids L-aspartic acid, L- asparagine, L-histidine, and L-serine is a 50:50 mixture of 1-butanol and acetone by volume. For the amino acids L-alanine, L-glycine, and L-valine, the optimum solvent was found to be a 30:70 mixture of ammonia and propanol by volume. A mathematical model describing the distance traveled (spot position) versus reaction time was constructed for the zeolite-catalyzed conversion of L- leucine and L-tyrosine and was found to approximately follow the function f(t) = 25 ln t. Two case studies for prebiotic synthesis leading to the production of amino acids or peptides in extraterrestrial environments were discussed: one involving Saturn's moon Titan, and the other involving Jupiter's moon Europa. In the Titan study, it was determined

  10. Impact Delivery of Prebiotic Organic Matter to Planetary Surfaces

    NASA Astrophysics Data System (ADS)

    Pierazzo, E.; Chyba, C. F.

    Organic compounds, liquid water, and a source of energy are necessary requirements for life as we know it. Few places in the solar system appear to satisfy these requirements. Besides Earth, Mars and Europa may have provided at some point during their history the most promising environments for the origin of life. Here we address the role of impacts as a mechanism for the delivery of organic compounds to Earth, Mars, Europa, and the Moon through high-resolution hydrocode simulations. The results suggest that on the Earth some amino acids (such as aspartic acid and glutamic acid) could survive large cometary impacts at the percent level, enough to equal or exceed concentrations due to Miller-Urey synthesis in a CO2-rich atmosphere. In particular, a grazing impact could have delivered to early Earth amounts of certain amino acids comparable to the background steady-state production. Substantial survival of some amino acids occurs in cometary impacts for Mars as well. Analogous to the situation on Earth, asteroid impacts on Mars do not seem to result in signi.cant survival, even if lower impact velocities increase the survival of amino acids. In cometary impacts, however, the increased amino acid survival in part counteracts the e.ect of the lower Martian escape velocity (5 km/s for Mars versus 11.2 km/s for the Earth) that causes some projectile material to escape Mars gravity and be lost to space. Projectile escape becomes dominant in grazing impacts, which are thus not a signi.cant source of organics on Mars. Projectile escape is dominant on Europa (escape velocity of 2 km/s); as a result, cometary impacts provide a negligible contribution to Europa's prebiotic organic inventory. However, as models of the circum-Jovian nebula suggest that Europa might have formed largely bereft of some biogenic elements, cometary impacts could be the primary source of some of Europa's biogenic elements. Finally, although subject to an impact history similar to that of the Earth and

  11. Innate immune response of pullets fed diets supplemented with prebiotics and synbiotics.

    PubMed

    Yitbarek, A; Echeverry, H; Munyaka, P; Rodriguez-Lecompte, J C

    2015-08-01

    Prebiotics and synbiotics are considered to be among the most promising replacements for in-feed antibiotic growth promoters (AGP) in poultry feed. The current study was designed to study the effect of Bacitracin methylene disalicylate (BMD) (Control), yeast-derived carbohydrates (YDC), and a blend of YDC and probiotics [Lactobacillus acidophilus, Lactobacillus casei, Streptococcus faecium, Bacillus subtilis, and YDC] (SNB) in the performance and innate immune response of pullets. Feed intake and BW were measured on a weekly basis. At the end of the study (d 21), 10 birds/treatment were sacrificed by cervical dislocation and ileum, cecal tonsil, and spleen samples were collected for gene expression analysis. No significant difference (P > 0.05) in feed intake and G:F was observed among treatments. In the second and third wk age, higher BW gain was observed in SNB treatment compared to control and both control and YDC treatments, respectively. Expression of TLR2b was upregulated in YDC and SNB in the ileum, and in SNB in the spleen (P < 0.05). Expression of TLR4 was downregulated in SNB in the cecal tonsil. Expression of TLR21 was downregulated in YDC in the ileum, while it was upregulated in SNB in the spleen (P < 0.05). In the ileum, YDC resulted in downregulated IL-12p35, CxCLi2, and IL-13, and SNB resulted in upregulated IL-6, interferon (IFN)-γ, and IL-4 (P < 0.05). In the cecal tonsil, YDC resulted in upregulated IL-12p35, IL-2, IL-13 and IL-10, and SNB resulted in downregulated IL-2 and upregulated IL-13 and IL-10 (P < 0.05). In the spleen, YDC resulted in dowregulated IL-2 and CxCLi2, and SNB resulted in upregulated IL-6, IFN-γ, IL-4, and IL-10 (P < 0.05). In conclusion, no change in performance was observed. Innate immune response analysis showed SNB with a more potent effect compared to YDC where the former showed a balanced T-helper (Th)-1/Th-2 response locally and a more Th-2-dependent response systemically; SNB might provide a more beneficial immune

  12. Effect of a Prebiotic Formulation on Frailty Syndrome: A Randomized, Double-Blind Clinical Trial

    PubMed Central

    Buigues, Cristina; Fernández-Garrido, Julio; Pruimboom, Leo; Hoogland, Aldert J.; Navarro-Martínez, Rut; Martínez-Martínez, Mary; Verdejo, Yolanda; Mascarós, Mari Carmen; Peris, Carlos; Cauli, Omar

    2016-01-01

    Aging can result in major changes in the composition and metabolic activities of bacterial populations in the gastrointestinal system and result in impaired function of the immune system. We assessed the efficacy of prebiotic Darmocare Pre® (Bonusan Besloten Vennootschap (BV), Numansdorp, The Netherlands) to evaluate whether the regular intake of this product can improve frailty criteria, functional status and response of the immune system in elderly people affected by the frailty syndrome. The study was a placebo-controlled, randomized, double blind design in sixty older participants aged 65 and over. The prebiotic product was composed of a mixture of inulin plus fructooligosaccharides and was compared with placebo (maltodextrin). Participants were randomized to a parallel group intervention of 13 weeks’ duration with a daily intake of Darmocare Pre® or placebo. Either prebiotic or placebo were administered after breakfast (between 9–10 a.m.) dissolved in a glass of water carefully stirred just before drinking. The primary outcome was to study the effect on frailty syndrome. The secondary outcomes were effect on functional and cognitive behavior and sleep quality. Moreover, we evaluated whether prebiotic administration alters blood parameters (haemogram and biochemical analysis). The overall rate of frailty was not significantly modified by Darmocare Pre® administration. Nevertheless, prebiotic administration compared with placebo significantly improved two frailty criteria, e.g., exhaustion and handgrip strength (p < 0.01 and p < 0.05, respectively). No significant effects were observed in functional and cognitive behavior or sleep quality. The use of novel therapeutic approaches influencing the gut microbiota–muscle–brain axis could be considered for treatment of the frailty syndrome. PMID:27314331

  13. Effect of a Prebiotic Formulation on Frailty Syndrome: A Randomized, Double-Blind Clinical Trial.

    PubMed

    Buigues, Cristina; Fernández-Garrido, Julio; Pruimboom, Leo; Hoogland, Aldert J; Navarro-Martínez, Rut; Martínez-Martínez, Mary; Verdejo, Yolanda; Mascarós, Mari Carmen; Peris, Carlos; Cauli, Omar

    2016-01-01

    Aging can result in major changes in the composition and metabolic activities of bacterial populations in the gastrointestinal system and result in impaired function of the immune system. We assessed the efficacy of prebiotic Darmocare Pre(®) (Bonusan Besloten Vennootschap (BV), Numansdorp, The Netherlands) to evaluate whether the regular intake of this product can improve frailty criteria, functional status and response of the immune system in elderly people affected by the frailty syndrome. The study was a placebo-controlled, randomized, double blind design in sixty older participants aged 65 and over. The prebiotic product was composed of a mixture of inulin plus fructooligosaccharides and was compared with placebo (maltodextrin). Participants were randomized to a parallel group intervention of 13 weeks' duration with a daily intake of Darmocare Pre(®) or placebo. Either prebiotic or placebo were administered after breakfast (between 9-10 a.m.) dissolved in a glass of water carefully stirred just before drinking. The primary outcome was to study the effect on frailty syndrome. The secondary outcomes were effect on functional and cognitive behavior and sleep quality. Moreover, we evaluated whether prebiotic administration alters blood parameters (haemogram and biochemical analysis). The overall rate of frailty was not significantly modified by Darmocare Pre(®) administration. Nevertheless, prebiotic administration compared with placebo significantly improved two frailty criteria, e.g., exhaustion and handgrip strength (p < 0.01 and p < 0.05, respectively). No significant effects were observed in functional and cognitive behavior or sleep quality. The use of novel therapeutic approaches influencing the gut microbiota-muscle-brain axis could be considered for treatment of the frailty syndrome. PMID:27314331

  14. De novo synthesis and functional study of primitive polypeptides in the prebiotic protein world

    NASA Astrophysics Data System (ADS)

    Fujishima, Kosuke; Wang, Kendrick; Ferreira, Raphael; Rothschild, Lynn

    DNA, RNA and proteins within a lipid-bound membrane are the core components of life, but the order of their appearance during the origin and evolution of life is still under debate. The widely accepted “RNA World” hypothesis states that RNA likely emerged prior to proteins and DNA since RNA can serve both replicative and catalytic roles. While biochemists have reproduced the synthesis, polymerization, and replication of nucleotides/RNA under controlled prebiotic conditions, such complex organic molecules were not present in significant amounts on the prebiotic Earth. In contrast, amino acids are naturally abundant in various prebiotic contexts such as carbonaceous chondrites and Urey-Miller type experiments, and many studies have demonstrated plausible prebiotic conditions that could condense/polymerize amino acids to give rise to short peptides. These findings support the basis of a “Protein World” hypothesis for life, however little has been done to study the functions of such primitive peptides. Here, we present a novel synthetic biology-based approach to the de novo synthesis of over billions of primitive peptides/proteins derived from a limited set of naturally abundant proteinogenic amino acids. Of these peptides, ones with divalent metal-binding capability are of particular interest and will be screened and identified. Certain divalent metals are likely present in prebiotic environments and both coordinate well with amino acids and catalyze reactions, which are difficult to achieve in organic chemistry. Furthermore, since D-chiral and non-proteinogenic amino acids are also abundant in the universe and may provide insight into the pathway by which life developed, the methods to analyze primitive peptides consisting of these amino acids will be discussed. By understanding this natural pathway, we will be able to better understand how life developed here on Earth and the probability of life arising elsewhere.

  15. The Microbiota and Transgenomic Networks: Potential Implications for Maternal-Fetal Medicine.

    PubMed

    Santolaya-Forgas, Joaquin; Townsend, Ryan; Santolaya, Jacobo L; Patel, Priya; Herrera-Garcia, Guadalupe; Castracane, V Daniel

    2016-01-01

    The maternal microbiota has long been considered a potential cause for adverse perinatal outcomes. Gene expression regulators in prokaryotic and eukaryotic cells are influenced by changes in their microenvironments. We propose the novel idea that during in utero development, an adaptive and dynamic gene-regulatory cross talk might exist between the host genome and the maternal microbiota. Understanding these cross talks could increase the appreciation for the discovery of new diagnostics and therapeutics in maternal-fetal medicine. PMID:26544907

  16. An in vitro study of the effect of probiotics, prebiotics and synbiotics on the elderly faecal microbiota.

    PubMed

    Likotrafiti, Eleni; Tuohy, Kieran M; Gibson, Glenn R; Rastall, Robert A

    2014-06-01

    The use of dietary intervention in the elderly in order to beneficially modulate their gut microbiota has not been extensively studied. The influence of two probiotics (Bifidobacterium longum and Lactobacillus fermentum) and two prebiotics [isomaltooligosaccharides (IMO) and short-chain fructooligosaccharides (FOS)], individually and in synbiotic combinations (B. longum with IMO, L. fermentum with FOS) on the gut microbiota of elderly individuals was investigated using faecal batch cultures and three-stage continuous culture systems. Population changes of major bacterial groups were enumerated using fluorescent in situ hybridisation (FISH). B. longum and IMO alone significantly increased the Bifidobacterium count after 5 and 10 h of fermentation and their synbiotic combination significantly decreased the Bacteroides count after 5 h of fermentation. L. fermentum and FOS alone significantly increased the Bifidobacterium count after 10 h and 5, 10 and 24 h of fermentation respectively. B. longum with IMO as well as B. longum and IMO alone significantly increased acetic acid concentration during the fermentation in batch cultures. In the three-stage continuous culture systems, both synbiotic combinations increased the Bifidobacterium and Lactobacillus count in the third vessel representing the distal colon. In addition, the synbiotic combination of L. fermentum with scFOS resulted in a significant increase in the concentration of acetic acid. The results show that the elderly gut microbiota can be modulated in vitro with the appropriate pro-, pre- and synbiotics. PMID:24685554

  17. Expanding the evaluation of probiotics and prebiotics for aquafeeds: perspectives on the limitations and needs for surrogate measures of effectiveness

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Probiotics (live or inactivated beneficial microorganisms) and prebiotics (indigestible nutrients for beneficial microorganisms) have been used as additives to aquafeeds as a means to improve production (immunity and growth) in intensively-reared finfish species. The research literature has document...

  18. Growth promoting effects of prebiotic yeast cell wall products in starter broilers under an immune stress and Clostridium perfringens challenge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was designed to investigate the growth promoting effects of supplementing different sources and concentrations of prebiotic yeast cell wall (YCW) products containing mannanoligosaccharides in starter broilers under an immune stress and Clostridium perfringens challenge. Through a series ...

  19. Importance of prebiotics in aquaculture as immunostimulants. Effects on immune system of Sparus aurata and Dicentrarchus labrax.

    PubMed

    Carbone, Donatella; Faggio, Caterina

    2016-07-01

    Infectious diseases in fish represent a major problem for the aquaculture field as they produce extensive damages and loss. Over the last few years, with increased development of the aquaculture industry, different methods have been used to contrast these pathologies. Common interest has led to the use of components (as additives in diets) that could contrast diseases without causing any negative impact on the environment. These components are represented by prebiotics, probiotics, and plant extracts. In this review, the effects of prebiotics are described. Prebiotics are indigestible fibres fermented by gut enzymes and commensal bacteria, whose beneficial effects are due to the by-products generated from fermentation. The influence of pre-biotics on the immune system of fish is called immunosaccharides. Mannanoligosaccharides (MOS), Fructooligosaccharides (FOS) and Inulin act at different levels in the innate immune response. For example, through phagocytosis, lysozyme activity, and the complement system activity, an increase in fish growth and an amelioration of their health status is brought about. In this review, the use of prebiotics in aquaculture, such as immunostimulants, has been highlighted: particularly in two teleost fish species, Sparus aurata and Dicentrarchus labrax. The results demonstrate that the road is still long and further studies are required, but the use of prebiotics, individually or coupled together, can open the doors to pioneering a new model of alternative components to antimicrobial agents. PMID:27074444

  20. Chilled milk-based desserts as emerging probiotic and prebiotic products.

    PubMed

    Buriti, Flávia C A; Saad, Susana M I

    2014-01-01

    Nowadays, food companies are endeavoring to differentiate their products through creative segmentation and positioning strategies based on superior functionality and quality. Some kinds of dairy desserts have shown a great market potential, as a function of consumers interested in healthier and functional products with fine taste and mouthfeel. In this context, chilled dairy desserts are emerging as attractive options for the incorporation of probiotic cultures and prebiotic ingredients, as seen in the previous launches from the food industry, as well as in the growing number of scientific studies dealing with this subject published in the last years. The main aspects involved in the development of probiotic and/or prebiotic dairy desserts for storage under refrigerated conditions are presented in this review. PMID:24188264

  1. Prebiotic effect of diosgenin, an immunoactive steroidal sapogenin of the Chinese yam.

    PubMed

    Huang, Chung-Hsiung; Cheng, Jin-Yi; Deng, Ming-Chung; Chou, Chung-Hsi; Jan, Tong-Rong

    2012-05-01

    This study investigated the effect of diosgenin, a yam-derived phytochemical, on the growth of enteric lactic acid bacteria (LAB). The in vivo effect of diosgenin on the density of intestinal flora was examined in a murine model of food allergy. Oral administration with diosgenin markedly restored the diminished density of faecal LAB associated with allergic reactions. The direct effect of diosgenin and several structure-related steroidal compounds on the growth of faecal anaerobes isolated from diosgenin-administered mice was also investigated. The presence of diosgenin significantly enhanced the growth of Lactobacillus murinus and Lactobacillus reuteri, but not enterococci. Structure-activity relationship analysis showed that the prebiotic activity of steroidal sapogenins might require structural elements of the C5-C6 double bond and intact E- and F-rings. Collectively, these results indicate that steroidal sapogenins may be a novel class of prebiotics to LAB. PMID:26434311

  2. Microbiota Manipulation With Prebiotics and Probiotics in Patients Undergoing Stem Cell Transplantation

    PubMed Central

    Andermann, Tessa M.; Rezvani, Andrew; Bhatt, Ami S.

    2016-01-01

    Hematopoietic stem cell transplantation (HSCT) is a potentially life-saving therapy that often comes at the cost of complications such as graft-versus-host disease and post-transplant infections. With improved technology to under-stand the ecosystem of microorganisms (viruses, bacteria, fungi, and microeukaryotes) that make up the gut microbiota, there is increasing evidence of the microbiota’s contribution to the development of post-transplant complications. Antibiotics have traditionally been the mainstay of microbiota-altering therapies available to physicians. Recently, interest is increasing in the use of prebiotics and probiotics to support the development and sustainability of a healthier microbiota. In this review, we will describe the evidence for the use of prebiotics and probiotics in combating microbiota dysbiosis and explore the ways in which they may be used in future research to potentially improve clinical outcomes and decrease rates of graft-versus-host disease (GVHD) and post-transplant infection. PMID:26780719

  3. Synthesis of Glycine and Other Prebiotic Compounds in the Interstellar Medium - An Example of Radiation Chemistry.

    NASA Astrophysics Data System (ADS)

    Mason, N. J.; Sivaraman, B.; Jeetha, S.; Dawes, A.; Hunniford, A.; McCullough, R. W.

    2007-08-01

    To understand how life can begin on a habitable planet such as the Earth, it is essential to know what organic compounds were likely to have been available, and how they interacted with the planetary environment. Therefore an understanding of the mechanisms by which organic chemical compounds are formed (so called /prebiotic chemistry/) is essential. Recent data from space based telescopes are revealing the interstellar medium as a rich 'chemical factory' in which many hydrocarbon speices are present (e.g. formic and acetic acid, alcohols and esters). Whether larger more complex species such as amino acids can form remains unknown since they can not, at present, be detected. However laboratory experiments that recreate the conditions of the ISM and the conditions under which stars and planets evolve have recently shown that such 'prebiotic compounds' may be formed through radiation induced chemistry. Details of these experiments will be discussed with the example of glycine formation used as an exemplar for such molecular synthesis.

  4. Rapeseed polysaccharides as prebiotics on growth and acidifying activity of probiotics in vitro.

    PubMed

    Wang, Xiao; Huang, Meiying; Yang, Fan; Sun, Hanju; Zhou, Xianxuan; Guo, Ying; Wang, Xiaoli; Zhang, Manli

    2015-07-10

    In vitro digestibility, prebiotic activity and chemical composition of polysaccharides from rapeseed were deliberately studied in this paper. After preliminary treatments, two fractions of polysaccharides (RP1 and RP2) were obtained after purification by DEAE-cellulose and Sephadex G-100. Their primary structural feature and molecule weights were characterized. Furthermore, their digestibility was also evaluated by artificial gastric juice and α-amylase. Finally, their proliferative effect on bifidobacteria and lactobacilli and acid production of the resulting probiotics in vitro were investigated. The results showed that RP1 and RP2 were homogeneously protein-bound polysaccharides with molecular weights of 28.51 and 6.55 kDa, respectively. They were resistant to hydrolysis by artificial gastric juice and α-amylase. Moreover, they could also significantly stimulate the tested probiotics to proliferate and produce organic acids. These findings clearly suggest the polysaccharides from rapeseed are potential to be exploited as novel prebiotics. PMID:25857979

  5. Microbiota Manipulation With Prebiotics and Probiotics in Patients Undergoing Stem Cell Transplantation.

    PubMed

    Andermann, Tessa M; Rezvani, Andrew; Bhatt, Ami S

    2016-02-01

    Hematopoietic stem cell transplantation (HSCT) is a potentially life-saving therapy that often comes at the cost of complications such as graft-versus-host disease and post-transplant infections. With improved technology to understand the ecosystem of microorganisms (viruses, bacteria, fungi, and microeukaryotes) that make up the gut microbiota, there is increasing evidence of the microbiota's contribution to the development of post-transplant complications. Antibiotics have traditionally been the mainstay of microbiota-altering therapies available to physicians. Recently, interest is increasing in the use of prebiotics and probiotics to support the development and sustainability of a healthier microbiota. In this review, we will describe the evidence for the use of prebiotics and probiotics in combating microbiota dysbiosis and explore the ways in which they may be used in future research to potentially improve clinical outcomes and decrease rates of graft-versus-host disease (GVHD) and post-transplant infection. PMID:26780719

  6. Probiotics and Prebiotics for Prevention of Food Allergy: Indications and Recommendations by Societies and Institutions.

    PubMed

    Koletzko, Sibylle

    2016-07-01

    Probiotics are defined as "live microorganisms that, when administered in adequate amounts, confer a health benefit on the host". Unfortunately, misuse of the term probiotic is very common. According to the regulation of the European food safety authority (EFSA) health claims on pre- and probiotics are not judged as favorable. Scientific societies should give guidance to the consumers and health care professionals on the use of probiotics and prebiotics for prevention and disease management. There is currently no positive recommendation from international scientific medical societies to use prebiotics or probiotics for treatment of food allergy or other allergic manifestations and for prevention of food allergy, allergic rhinitis, and asthma. Discrepant recommendations exist for probiotics for prevention of eczema in high risk infants. PMID:27380601

  7. Therapeutic Use of Prebiotics, Probiotics, and Postbiotics to Prevent Necrotizing Enterocolitis: What is the Current Evidence?

    PubMed Central

    Patel, Ravi Mangal; Denning, Patricia Wei

    2013-01-01

    Synopsis Necrotizing enterocolitis (NEC) is a leading cause of neonatal morbidity and mortality and preventative therapies that are both effective and safe are urgently needed. Current evidence from therapeutic trials suggests that probiotics are effective in decreasing NEC in preterm infants and probiotics are currently the most promising therapy on the horizon for this devastating disease. However, concerns regarding safety and optimal dosing have limited the widespread adoption of routine clinical use of probiotics in preterm infants. In addition, prebiotics and postbiotics may be potential alternatives or adjunctive therapies to the administration of live microorganisms, although studies demonstrating their clinical efficacy in preventing NEC are lacking. This review summarizes the current evidence regarding the use of probiotics, prebiotics and postbiotics in the preterm infant, including its therapeutic role in preventing NEC. PMID:23415261

  8. Meteorite-catalyzed syntheses of nucleosides and of other prebiotic compounds from formamide under proton irradiation

    PubMed Central

    Saladino, Raffaele; Carota, Eleonora; Botta, Giorgia; Kapralov, Mikhail; Timoshenko, Gennady N.; Rozanov, Alexei Y.; Krasavin, Eugene; Di Mauro, Ernesto

    2015-01-01

    Liquid formamide has been irradiated by high-energy proton beams in the presence of powdered meteorites, and the products of the catalyzed resulting syntheses were analyzed by mass spectrometry. Relative to the controls (no radiation, or no formamide, or no catalyst), an extremely rich, variegate, and prebiotically relevant panel of compounds was observed. The meteorites tested were representative of the four major classes: iron, stony iron, chondrites, and achondrites. The products obtained were amino acids, carboxylic acids, nucleobases, sugars, and, most notably, four nucleosides: cytidine, uridine, adenosine, and thymidine. In accordance with theoretical studies, the detection of HCN oligomers suggests the occurrence of mechanisms based on the generation of radical cyanide species (CN·) for the synthesis of nucleobases. Given that many of the compounds obtained are key components of extant organisms, these observations contribute to outline plausible exogenous high-energy–based prebiotic scenarios and their possible boundary conditions, as discussed. PMID:25870268

  9. Is There an Optimal Level of Open-Endedness in Prebiotic Evolution?

    NASA Astrophysics Data System (ADS)

    Markovitch, Omer; Sorek, Daniel; Lui, Leong Ting; Lancet, Doron; Krasnogor, Natalio

    2012-10-01

    In this paper we explore the question of whether there is an optimal set up for a putative prebiotic system leading to open-ended evolution (OEE) of the events unfolding within this system. We do so by proposing two key innovations. First, we introduce a new index that measures OEE as a function of the likelihood of events unfolding within a universe given its initial conditions. Next, we apply this index to a variant of the graded autocatalysis replication domain (GARD) model, Segre et al. (P Natl Acad Sci USA 97(8):4112-4117, 2000; Markovitch and Lancet Artif Life 18(3), 2012), and use it to study - under a unified and concise prebiotic evolutionary framework - both a variety of initial conditions of the universe and the OEE of species that evolve from them.

  10. Is there an optimal level of open-endedness in prebiotic evolution?

    PubMed

    Markovitch, Omer; Sorek, Daniel; Lui, Leong Ting; Lancet, Doron; Krasnogor, Natalio

    2012-10-01

    In this paper we explore the question of whether there is an optimal set up for a putative prebiotic system leading to open-ended evolution (OEE) of the events unfolding within this system. We do so by proposing two key innovations. First, we introduce a new index that measures OEE as a function of the likelihood of events unfolding within a universe given its initial conditions. Next, we apply this index to a variant of the graded autocatalysis replication domain (GARD) model, Segre et al. (P Natl Acad Sci USA 97(8):4112-4117, 2000; Markovitch and Lancet Artif Life 18(3), 2012), and use it to study--under a unified and concise prebiotic evolutionary framework--both a variety of initial conditions of the universe and the OEE of species that evolve from them. PMID:23114973

  11. Nucleobases and Other Prebiotic Species from the UV Irradiation of Pyrimidine in Astrophysical Ices

    NASA Technical Reports Server (NTRS)

    Sandford, Scott; Materese, Christopher; Nuevo, Michel

    2012-01-01

    Nucleobases are aromatic N-heterocycles that constitute the informational subunits of DNA and RNA and are divided into two families: pyrimidine bases (uracil, cytosine, and thymine) and purine bases (adenine and guanine). Nucleobases have been detected in meteorites and their extraterrestrial origin confirmed by isotope measurement. Although no N-heterocycles have been individually identified in the ISM, the 6.2-micron interstellar emission feature seen towards many astronomical objects suggests a population of such molecules is likely present. We report on a study of the formation of pyrimidine-based molecules, including nucleobases and other species of prebiotic interest, from the ultraviolet (UV) irradiation of pyrimidine in low temperature ices containing H2O, NH3, C3OH, and CH4, to simulate the astrophysical conditions under which prebiotic species may be formed in the Solar System.

  12. Prebiotics Do Not Influence the Severity of Atopic Dermatitis in Infants: A Randomised Controlled Trial

    PubMed Central

    Hill, Martin; Skýba, Tomáš

    2015-01-01

    The objective was to evaluate the effects of a hypoallergenic (HA) formula supplemented with prebiotic galacto-oligosaccharides on the severity of atopic manifestations. A randomised clinical trial was conducted. The control group was infants, fed with hypoallergenic formula and without supplementation. The duration of the study was six months. The primary outcome of the study was a difference in the severity of atopic dermatitis measured using SCORAD (Scoring Atopic Dermatitis) criteria. Secondary outcomes were anthropometry (length, weight, and head circumference), together with the tolerance and incidence of infections. Both groups showed a decrease of average SCORAD values, but no statistically significant difference between the evaluated groups was observed. There were no statistically significant differences in anthropometry, or the tolerance or incidence of infections. Although there is no evidence, that consumption of a hypoallergenic infant formula enriched with prebiotic galacto-oligosaccharides had any effect on SCORAD, it was safe and well tolerated. Trial Registration www.clinicaltrials.gov NCT 02077088 PMID:26571488

  13. Meteorite-catalyzed syntheses of nucleosides and of other prebiotic compounds from formamide under proton irradiation.

    PubMed

    Saladino, Raffaele; Carota, Eleonora; Botta, Giorgia; Kapralov, Mikhail; Timoshenko, Gennady N; Rozanov, Alexei Y; Krasavin, Eugene; Di Mauro, Ernesto

    2015-05-26

    Liquid formamide has been irradiated by high-energy proton beams in the presence of powdered meteorites, and the products of the catalyzed resulting syntheses were analyzed by mass spectrometry. Relative to the controls (no radiation, or no formamide, or no catalyst), an extremely rich, variegate, and prebiotically relevant panel of compounds was observed. The meteorites tested were representative of the four major classes: iron, stony iron, chondrites, and achondrites. The products obtained were amino acids, carboxylic acids, nucleobases, sugars, and, most notably, four nucleosides: cytidine, uridine, adenosine, and thymidine. In accordance with theoretical studies, the detection of HCN oligomers suggests the occurrence of mechanisms based on the generation of radical cyanide species (CN·) for the synthesis of nucleobases. Given that many of the compounds obtained are key components of extant organisms, these observations contribute to outline plausible exogenous high-energy-based prebiotic scenarios and their possible boundary conditions, as discussed. PMID:25870268

  14. Prebiotic Synthesis of Adenine and Amino Acids Under Europa-like Conditions

    NASA Technical Reports Server (NTRS)

    Levy, Matthew; Miller, Stanley L.; Brinton, Karen; Bada, Jeffrey L.

    2003-01-01

    In order to simulate prebiotic synthetic processes on Europa and other ice-covered planets and satellites. we have investigated the prebiotic synthesis of organic compounds from dilute solutions of NH4CN frozen for 25 year at -20 and -78 C. In addition the aqueous products of spark discharge reactions from a reducing atmosphere were frozen for 5 years at -20%. We find that both adenine and guanine, as well as a simple set of amino acids dominated by glycine, are produced in substantial yields under these conditions. These results indicate that some of the key components necessary for the origin of life may have been available on Europa throughout its history and suggest that the circumstellar zone where life might arise may be m der than previously thought.

  15. Prebiotic synthesis of adenine and amino acids under Europa-like conditions

    NASA Technical Reports Server (NTRS)

    Levy, M.; Miller, S. L.; Brinton, K.; Bada, J. L.

    2000-01-01

    In order to simulate prebiotic synthetic processes on Europa and other ice-covered planets and satellites, we have investigated the prebiotic synthesis of organic compounds from dilute solutions of NH4CN frozen for 25 years at -20 and -78 degrees C. In addition, the aqueous products of spark discharge reactions from a reducing atmosphere were frozen for 5 years at -20 degrees C. We find that both adenine and guanine, as well as a simple set of amino acids dominated by glycine, are produced in substantial yields under these conditions. These results indicate that some of the key components necessary for the origin of life may have been available on Europa throughout its history and suggest that the circumstellar zone where life might arise may be wider than previously thought.

  16. The possible roles of water in the prebiotic chemical evolution of DNA.

    PubMed

    Cui, Shuxun

    2010-09-21

    There is no doubt that water is pivotal to life. Yet, as the emergence of life is still a big challenge in science, the detailed involvement of water in that process is not well recognized. Following the clues provided by recent single-molecule studies on DNA, we attempt to elucidate the possible roles of water in the prebiotic chemical evolution. Water has long been recognized as an important reactant in the Miller-Urey experiment and then as the only solvent of the primitive soup. Besides that, water also played a vital role in the prebiotic chemical evolution: water is the important criterion in the combinatorial library screening for self-assembling macromolecules. With this notion, the uniformity of biochemistry for all terrestrial life may be explained. A possible roadmap from the inorganic world to the origin of life is also discussed. PMID:20577681

  17. The catalysis of nucleotide polymerization by compounds of divalent lead. [prebiotic synthesis

    NASA Technical Reports Server (NTRS)

    Sleeper, H. L.; Orgel, L. E.

    1979-01-01

    The nonenzymatic, nontemplate catalysis of nucleotide polymerization by Pb(2+) ions, a possible prebiotic catalyst, is reported. Adenosine and uridine phosphoimidazoles were reacted in buffered solutions of lead salts and products were analyzed by means of paper chromatography and electrophoresis. In the presence of Pb(2+) ion at pH 8.0 and 7.0 the reaction is found to progress rapidly with excellent yields of oligomers, with optimal yields observed at pH 8.0. Little temperature dependence in the range 0 to 30 C is observed, however hydrolysis of the reaction products is minimal when the reaction is carried out at 0 C. Results show that the yield of oligomers is insensitive to mixing or the source of lead ions, indicating that naturally occurring minerals or precipitates could be a source of Pb(2+) ions under prebiotic conditions.

  18. Catalytic role of Manganese oxides in prebiotic Nucleobases synthesis from Formamide

    NASA Astrophysics Data System (ADS)

    Bhushan, Brij

    2012-07-01

    The evolution of living cell from chemicals is more complicated reaction which could be studied in multistep. A study of prebiotic synthesis of naturally occurring purine and pyrimidine derivatives from formamide under catalytic condition with different oxides of manganese reveals a significant role. Manganese oxides are highly efficient in the conversion of formamide into different nucleobases. Neat formamide is converted to the purine, 9-(hydroxyacetyl) purine, cytosine, 4(3H)-pyrimidinone, thymine and adenine in good yield. Metal oxides have provided their surfaces and catalyzed the reactions from simple molecules to more complex bio-organic molecules. Our results show that probably prebiotic reactions might have occured on the sea floor where the existence of manganese oxide is second to iron transition metal minerals.

  19. The prebiotic synthesis of modified purines and their potential role in the RNA world

    NASA Technical Reports Server (NTRS)

    Levy, M.; Miller, S. L.; Bada, J. L. (Principal Investigator)

    1999-01-01

    Modified purines are found in all organisms in the tRNA, rRNA, and even DNA, raising the possibility of an early role for these compounds in the evolution of life. These include N6-methyladenine, 1-methyladenine, N6,N6-dimethyladenine, 1-methylhypoxanthine, 1-methylguanine, and N2-methylguanine. We find that these bases as well as a number of nonbiological modified purines can be synthesized from adenine and guanine by the simple reaction of an amine or an amino group with adenine and guanine under the concentrated conditions of the drying-lagoon or drying-beach model of prebiotic synthesis with yields as high as 50%. These compounds are therefore as prebiotic as adenine and guanine and could have played an important role in the RNA world by providing additional functional groups in ribozymes, especially for the construction of hydrophobic binding pockets.

  20. The applications of polysaccharides from various mushroom wastes as prebiotics in different systems.

    PubMed

    Chou, Wei-Ting; Sheih, I-Chuan; Fang, Tony J

    2013-07-01

    The bases or stipes of mushrooms are normally discarded as low-economic value animal feed and compost. There are no known reports on deriving polysaccharides from these mushroom wastes for use as prebiotics. This study showed that the relatively low concentration (0.1% to 0.5%) of polysaccharides from Lentinula edodes stipe, Pleurotus eryngii base, and Flammulina velutipes base can enhance the survival rate of Lactobacillus acidophilus, Lactobacillus casei, and Bifidobacterium longum subsp. longum during cold storage. The polysaccharides had synergistic effects with the peptides and amino acids from a yogurt culture to maintain probiotics above 10(7) CFU/mL during cold storage, and they also had significant protective effects on these probiotics in simulated gastric and bile juice conditions to achieve beneficial effects in the host. These results showed that mushroom wastes, which are cheaper than other sources, could be an important, new, alternative source of prebiotics. PMID:23701736

  1. Are commercial probiotics and prebiotics effective in the treatment and prevention of honeybee nosemosis C?

    PubMed

    Ptaszyńska, Aneta A; Borsuk, Grzegorz; Zdybicka-Barabas, Agnieszka; Cytryńska, Małgorzata; Małek, Wanda

    2016-01-01

    The study was conducted to investigate the effect of Lactobacillus rhamnosus (a commercial probiotic) and inulin (a prebiotic) on the survival rates of honeybees infected and uninfected with Nosema ceranae, the level of phenoloxidase (PO) activity, the course of nosemosis, and the effect on the prevention of nosemosis development in bees. The cells of L. rhamnosus exhibited a high rate of survival in 56.56 % sugar syrup, which was used to feed the honeybees. Surprisingly, honeybees fed with sugar syrup supplemented with a commercial probiotic and a probiotic + prebiotic were more susceptible to N. ceranae infection, and their lifespan was much shorter. The number of microsporidian spores in the honeybees fed for 9 days prior to N. ceranae infection with a sugar syrup supplemented with a commercial probiotic was 25 times higher (970 million spores per one honeybee) than in a control group fed with pure sucrose syrup (38 million spores per one honeybee). PO activity reached its highest level in the hemolymph of this honeybee control group uninfected with N. ceranae. The addition of probiotics or both probiotics and prebiotics to the food of uninfected bees led to the ~2-fold decrease in the PO activity. The infection of honeybees with N. ceranae accompanied an almost 20-fold decrease in the PO level. The inulin supplemented solely at a concentration of 2 μg/mL was the only administrated factor which did not significantly affect honeybees' survival, the PO activity, or the nosemosis infection level. In conclusion, the supplementation of honeybees' diet with improperly selected probiotics or both probiotics and prebiotics does not prevent nosemosis development, can de-regulate insect immune systems, and may significantly increase bee mortality. PMID:26437644

  2. Peptide formation in the prebiotic era - Thermal condensation of glycine in fluctuating clay environments

    NASA Technical Reports Server (NTRS)

    Lahav, N.; White, D.; Chang, S.

    1978-01-01

    As geologically relevant models of prebiotic environments, systems consisting of clay, water, and amino acids were subjected to cyclic variations in temperature and water content. Fluctuations of both variables produced longer oligopeptides in higher yields than were produced by temperature fluctuations alone. The results suggest that fluctuating environments provided a favorable geological setting in which the rate and extent of chemical evolution would have been determined by the number and frequency of cycles.

  3. Effects of prebiotic, protein level, and stocking density on performance, immunity, and stress indicators of broilers.

    PubMed

    Houshmand, M; Azhar, K; Zulkifli, I; Bejo, M H; Kamyab, A

    2012-02-01

    An experiment was conducted to determine the effects of period on the performance, immunity, and some stress indicators of broilers fed 2 levels of protein and stocked at a normal or high stocking density. Experimental treatments consisted of a 2 × 2 × 2 factorial arrangement with 2 levels of prebiotic (with or without prebiotic), 2 levels of dietary CP [NRC-recommended or low CP level (85% of NRC-recommended level)], and 2 levels of stocking density (10 birds/m(2) as the normal density or 16 birds/m(2) as the high density), for a total of 8 treatments. Each treatment had 5 replicates (cages). Birds were reared in 3-tiered battery cages with wire floors in an open-sided housing system under natural tropical conditions. Housing and general management practices were similar for all treatment groups. Starter and finisher diets in mash form were fed from 1 to 21 d and 22 to 42 d of age, respectively. Supplementation with a prebiotic had no significant effect on performance, immunity, and stress indicators (blood glucose, cholesterol, corticosterone, and heterophil:lymphocyte ratio). Protein level significantly influenced broiler performance but did not affect immunity or stress indicators (except for cholesterol level). The normal stocking density resulted in better FCR and also higher antibody titer against Newcastle disease compared with the high stocking density. However, density had no significant effect on blood levels of glucose, cholesterol, corticosterone, and the heterophil:lymphocyte ratio. Significant interactions between protein level and stocking density were observed for BW gain and final BW. The results indicated that, under the conditions of this experiment, dietary addition of a prebiotic had no significant effect on the performance, immunity, and stress indicators of broilers. PMID:22252353

  4. From the Primitive Atmosphere to the Prebiotic Soup to the Pre-RNA World

    NASA Technical Reports Server (NTRS)

    Miller, Stanley L.

    1996-01-01

    Organic compounds would have been produced in an earth's atmosphere that was reducing. The soup would contain amino and hydroxy acids, together with smaller amounts of purines and pyrimidines. The presence' of sugars is less likely, although they can be produced by the formose reaction from formaldehyde. However, the prebiotic synthesis of RNA has not been demonstrated. One problem is that ribose is not produced selectively over other pentoses and hexoses, except under special conditions. The second problem is that ribose is unstable, with a half-life at pH7 and 100 C of 73 minutes (44 years at 0 C). Other sugars are similarly unstable. Another problem is that there is no efficient prebiotic synthesis of polyphosphates, nor the glycosidic bond of nucleosides. This suggests that there may have been an informational macromolecule that preceded RNA. The RNA world refers to the time when RNA carried both the genetic information and the catalytic activity, and was subsequently converted to the DNA/protein world when protein synthesis began. Preceeding the RNA world was the Pre-RNA world, where a backbone different from ribose phosphate was used, and the bases may have been different from adenine, uracil, guanine and cytosine. We have shown recently that cytosine and uracil can be synthesized efficiently under prebiotic conditions using a dried lagoon model instead of the usual dilute ocean hypothesis. In addition, we have shown that uracil adds formaldehyde efficiently to give 5- hydroxymethyl uracil, which in turn adds various nucleophiles to give uracil analogs of most of the amino acids that occur in proteins. For example, the ammonia, guanidine and imidazole adducts from the analogs of lysine, arginine and histidine. This suggests that the catalytic potential of RNA may have been much more extensive than previously assumed. The major problem is finding out what was the precursor to the ribose phosphate backbone. This will be the key to developing prebiotic self

  5. Spatial Autocatalytic Dynamics: An Approach to Modeling Prebiotic Evolution. Chapter 1

    NASA Technical Reports Server (NTRS)

    Stassinopoulos, Dimitris; Colombano, Silvano P.; Lohn , Jason D.; Haith, Gary L.; Scargle, Jeffrey; Liang, Shoudan; Lee, T. K.

    1999-01-01

    This paper addresses the origin of robust and evolvable metabolic functions, and the conditions under which it took place. We propose that spatial considerations, traditionally ignored, are essential to answering these important questions in prebiotic evolution. Our probabilistic cellular automaton model, based on work on autocatalytic metabolisms by Eigen, Kauffman, and others, has biologically interesting dynamical behavior that is missed if spatial extension is ignored.

  6. Are Probiotics or Prebiotics Useful in Pediatric Irritable Bowel Syndrome or Inflammatory Bowel Disease?

    PubMed Central

    Guandalini, Stefano

    2014-01-01

    Treatment options for irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) are notoriously either inadequate (IBS) or loaded with potentially serious side effects and risks (IBD). In recent years, a growing interest in effective and safer alternatives has focused on the potential role of probiotics and their metabolic substrates, prebiotics. It is in fact conceivable that the microbiome might be targeted by providing the metabolic fuel needed for the growth and expansion of beneficial microorganisms (prebiotics) or by administering to the host such microorganisms (probiotics). This review presents a concise update on currently available data, with a special emphasis on children. Data for prebiotics in IBS are scarce. Low doses have shown a beneficial effect, while high doses are counterproductive. On the contrary, several controlled trials of probiotics have yielded encouraging results. A meta-analysis including nine randomized clinical trials in children showed an improvement in abdominal pain for Lactobacillus GG, Lactobacillus reuteri DSM 17938, and the probiotic mixture VSL#3. The patients most benefiting from probiotics were those with predominant diarrhea or with a post-infectious IBS. In IBD, the use of prebiotics has been tested only rarely and in small scale clinical trials, with mixed results. As for probiotics, data in humans from about three dozens clinical trials offer mixed outcomes. So far, none of the tested probiotics has proven successful in Crohn’s disease, while in ulcerative colitis a recent meta-analysis on 12 clinical trials (1 of them in children) showed efficacy for the probiotic mixture VSL#3 in contributing to induce and to maintain remission. It is evident that this is a rapidly evolving and promising field; more data are very likely to yield a better understanding on what strains should be used in different specific clinical settings and in what doses. PMID:25593899

  7. On the possible role of organic melanoidin polymers as matrices for prebiotic activity.

    PubMed

    Nissenbaum, A; Kenyon, D H; Oro, J

    1975-12-29

    One of the major diagenetic pathways of organic matter in recent sediments involves the condensation of cellular constituents, particularly amino acids and sugars, into insoluble melanoidin-type polymers. These polymers consist mainly of humic and fulvic acids and make up the major part of the organic carbon reservoir in recent sediments. We suggest that a similar set of reactions between abiotically formed amino acids and sugars, and more generally between aldehydes and amines, occurred on a large scale in the prebiotic hydrosphere. The rapid formation of this insoluble polymeric material would have removed the bulk of the dissolved organic carbon from the primitive oceans and would thus have prevented the formation of an "organic soup". Melanoidin polymers have several properties which make them attractive hypothetical precursors of contemporary oxidation-reduction coenzymes: 1. they contain heterocyclic nitrogen compounds similar to the nitrogenous bases; 2. they contain a high concentration of stable free radicals; and 3. they tend to concentrate those heavy metals which play prominent roles in contemporary enzymic redox processes. The prebiotic formation of similar polymers could, therefore, have provided the starting point for a basic class of biochemical reactions. We suggest that the prebiotic scenario involved chemical and protoenzymic reactions at the sediment-ocean interface in relatively shallow waters and under conditions not much different from those of the recent environment. PMID:1542

  8. Alternative bases in the RNA world: the prebiotic synthesis of urazole and its ribosides

    NASA Technical Reports Server (NTRS)

    Kolb, V. M.; Dworkin, J. P.; Miller, S. L.

    1994-01-01

    Urazole is a five-membered heterocyclic compound which is isosteric with uracil's hydrogen-bonding segment. Urazole reacts spontaneoulsy with ribose (and other aldoses) to give a mixture of four ribosides: alpha and beta pyranosides and furanosides. This reaction occurs in aqueous solution at mild temperatures. Thermodynamic and kinetic parameters for the reaction of urazole with ribose were determined. In contrast, uracil is completely unreactive with ribose under these conditions. Urazole's unusual reactivity is ascribed to the hydrazine portion of the molecule. Urazole can be synthesized from biuret and hydrazine under prebiotic conditions. The prebiotic synthesis of guanazole, which is isosteric in part to diaminopyrimidine and cytosine, is accomplished from dicyandiamide and hydrazine. Kinetic parameters for both prebiotic reactions were measured. Urazole and guanazole are transparent in the UV, which would be a favorable property in the absence of an ozone layer on the early Earth. Urazole makes hydrogen bonds with adenine in DMSO similar to those of uracil, as established by H NMR. All of these properties make urazole an attractive potential precursor to uracil and guanazole a potential precursor to cytosine in the RNA or pre-RNA world.

  9. Prebiotic and Synbiotic Treatment before Colorectal Surgery--Randomised Double Blind Trial.

    PubMed

    Krebs, Bojan

    2016-04-01

    The aim of our study was to demonstrate higher concentrations of lactic acid bacteria (LAB) on the colonic mucosa in operated colorectal cancer patients treated with oral intake of synbiotics or prebiotics preoperatively. We also tried to prove that the systemic inflammatory response after surgery is not so severe in patients who took synbiotics or prebiotics, furthermore these patients have less postoperative complications and a favorable postoperative course. 73 patients with preceding colorectal operations were recruited. They were randomized into three groups. One group received preoperatively prebiotics, the second synbiotics in and third was preoperatively cleansed. We have defined the number of four different probiotic bacteria on colonic mucosa with polymerase chain reaction (PCR). Serum levels of interleukin-6, CRP, fibrinogen, white cell count and differential blood count were measured pre- and postoperatively to determine systemic inflammatory response. We succeed in confirming that in the synbiotic group there were considerably more LAB presented on the mucosa. They did pass the upper gastrointestinal tract and were isolated in colonic mucosa. On the other hand, we did not find any statistical differences in systemic inflammatory response measured by upper factors and no differences in postoperative course and complications rate between all three groups. PMID:27301235

  10. Phosphorus: a Case for Mineral-Organic Reactions in Prebiotic Chemistry

    NASA Astrophysics Data System (ADS)

    Pasek, Matthew; Herschy, Barry; Kee, Terence P.

    2015-06-01

    The ubiquity of phosphorus (P) in modern biochemistry suggests that P may have participated in prebiotic chemistry prior to the emergence of life. Of the major biogenic elements, phosphorus alone lacks a substantial volatile phase and its ultimate source therefore had to have been a mineral. However, as most native P minerals are chemically un-reactive within the temperature-pressure-pH regimes of contemporary life, it begs the question as to whether the most primitive early living systems on earth had access to a more chemically reactive P-mineral inventory. The meteoritic mineral schreibersite has been proposed as an important source of reactive P on the early earth. The chemistry of schreibersite as a P source is summarized and reviewed here. Recent work has also shown that reduced oxidation state P compounds were present on the early earth; these compounds lend credence to the relevance of schreibersite as a prebiotic mineral. Ultimately, schreibersite will oxidize to phosphate, but several high-energy P intermediates may have provided the reactive material necessary for incorporating P into prebiotic molecules.

  11. Prebiotic chemistry in icy grain mantles in space. An experimental and observational approach.

    PubMed

    Muñoz Caro, Guillermo M; Dartois, Emmanuel

    2013-03-01

    A compendium of different solid carbonaceous materials detected in space is presented, focussing on the search for organic matter of prebiotic interest. This journey takes us from the carbon grains likely formed in the atmospheres of evolved stars to organic grain mantles made from ice processing thought to be present in dense interstellar clouds and circumstellar regions, making a stop in solar system objects that could have delivered organic species to the early Earth. The most abundant carbon materials detected to date in space appear to be of little biological relevance. On the other hand, organic refractory residues, made in the laboratory from UV-photoprocessing followed by warm-up of interstellar ice analogs, are a hydrocarbon material rich in O and N containing chemical compounds that could act as initiators of prebiotic chemistry. A similar material might be present in dust grains inside dense clouds or circumstellar regions, some comets, and as a minor component in carbonaceous chondrites. We use infrared spectroscopy as a tool to spot organic refractory matter in various space environments. The delivery of organic materials via comets, (micro-) meteorites, and interplanetary dust particles to the primitive Earth might have contributed as a starting material for prebiotic chemistry. To test this hypothesis, it is first essential to characterize the composition of exogenous organic matter. PMID:23340705

  12. Influence of cabbage processing methods and prebiotic manipulation of colonic microflora on glucosinolate breakdown in man.

    PubMed

    Fuller, Zoë; Louis, Petra; Mihajlovski, Agnès; Rungapamestry, Vanessa; Ratcliffe, Brian; Duncan, Alan J

    2007-08-01

    Glucosinolate consumption from brassica vegetables has been implicated in reduction of cancer risk. The isothiocyanate breakdown products of glucosinolates appear to be particularly important as chemoprotective agents. Before consumption, brassica vegetables are generally cooked, causing the plant enzyme, myrosinase, to be denatured, influencing the profile of glucosinolate breakdown products produced. Some human intestinal microflora species show myrosinase-like activity (e.g. bifidobacteria). We aimed to increase bifidobacteria by offering a prebiotic (inulin) in a randomised crossover study. Six volunteers consumed inulin (10 g/d) for 21 d followed by a 21 d control period (no inulin). Treatment periods were reversed for the remaining six volunteers. During the last 5 d of each period two cabbage-containing meals were consumed. Total urine output was collected for 24 h following each meal. Cabbage was microwaved for 2 min (lightly cooked) or 5.5 min (fully cooked). Faecal samples were collected at the start and after the inulin and control treatments. Bifidobacteria were enumerated by real-time PCR. Allyl isothiocyanate production was quantified by measuring urinary excretion of allyl mercapturic acid (AMA). Bifidobacteria increased following prebiotic supplementation (P < 0.001) but there was no impact of this increase on AMA excretion. AMA excretion was greater following consumption of lightly cooked cabbage irrespective of prebiotic treatment (P < 0.001). In conclusion, the most effective way to increase isothiocyanate production may be to limit the length of time that brassica vegetables are cooked prior to consumption. PMID:17403273

  13. Potential of probiotics, prebiotics and synbiotics for management of colorectal cancer

    PubMed Central

    Raman, Maya; Ambalam, Padma; Kondepudi, Kanthi Kiran; Pithva, Sheetal; Kothari, Charmy; Patel, Arti T.; Purama, Ravi Kiran; Dave, J.M.; Vyas, B.R.M.

    2013-01-01

    Colorectal Cancer (CRC) is the second leading cause of cancer-related mortality and is the fourth most common malignant neoplasm in USA. Escaping apoptosis and cell mutation are the prime hallmarks of cancer. It is apparent that balancing the network between DNA damage and DNA repair is critical in preventing carcinogenesis. One-third of cancers might be prevented by nutritious healthy diet, maintaining healthy weight and physical activity. In this review, an attempt is made to abridge the role of carcinogen in colorectal cancer establishment and prognosis, where special attention has been paid to food-borne mutagens and functional role of beneficial human gut microbiome in evading cancer. Further the significance of tailor-made prebiotics, probiotics and synbiotics in cancer management by bio-antimutagenic and desmutagenic activity has been elaborated. Probiotic bacteria are live microorganisms that, when administered in adequate amounts, confer a healthy benefit on the host. Prebiotics are a selectively fermentable non-digestible oligosaccharide or ingredient that brings specific changes, both in the composition and/or activity of the gastrointestinal microflora, conferring health benefits. Synbiotics are a combination of probiotic bacteria and the growth promoting prebiotic ingredients that purport “synergism.” PMID:23511582

  14. Phosphorus: a case for mineral-organic reactions in prebiotic chemistry.

    PubMed

    Pasek, Matthew; Herschy, Barry; Kee, Terence P

    2015-06-01

    The ubiquity of phosphorus (P) in modern biochemistry suggests that P may have participated in prebiotic chemistry prior to the emergence of life. Of the major biogenic elements, phosphorus alone lacks a substantial volatile phase and its ultimate source therefore had to have been a mineral. However, as most native P minerals are chemically un-reactive within the temperature-pressure-pH regimes of contemporary life, it begs the question as to whether the most primitive early living systems on earth had access to a more chemically reactive P-mineral inventory. The meteoritic mineral schreibersite has been proposed as an important source of reactive P on the early earth. The chemistry of schreibersite as a P source is summarized and reviewed here. Recent work has also shown that reduced oxidation state P compounds were present on the early earth; these compounds lend credence to the relevance of schreibersite as a prebiotic mineral. Ultimately, schreibersite will oxidize to phosphate, but several high-energy P intermediates may have provided the reactive material necessary for incorporating P into prebiotic molecules. PMID:25773584

  15. Influence of dietary supplementation of prebiotics (mannanoligosaccharide) on the performance of crossbred calves.

    PubMed

    Ghosh, Sudipta; Mehla, Ram Kumar

    2012-03-01

    Thirty-six Holstein cross calves 5 days of age in their preruminant stage were used to study the effect of feeding prebiotic (mannanoligosaccharide) on their performance up to the age of 2 months. Treatment and control groups consisted of 18 calves each. Treatment group was supplemented with 4 g prebiotic (mannanoligosaccharide)/calf/day. Performance was evaluated by measuring average body weight (BW) gain, feed intake [dry matter (DM), total digestible nutrient (TDN) and crude protein(CP)], feed conversion efficiency (DM, TDN, and CP), fecal score, fecal coliform count and feeding cost. Body weight measured weekly, feed intake measured twice daily, proximate analysis of feeds and fodders analyzed weekly, fecal score monitored daily and fecal coliform count done weekly. There was a significant increase in average body weight gain, feed intake and feed conversion efficiency; and a significant decrease in severity of scours as measured by fecal score and fecal coliform count in the treatment group compared with control group (P < 0.01). Feed cost/kg BW gain was significantly lower in the treatment group compared to control group (P < 0.01). The results suggest that prebiotic (mannanoligosaccharide) can be supplemented to the calves for better performance. PMID:21805307

  16. Prebiotic potential of Agave angustifolia Haw fructans with different degrees of polymerization.

    PubMed

    Velázquez-Martínez, José Rodolfo; González-Cervantes, Rina M; Hernández-Gallegos, Minerva Aurora; Mendiola, Roberto Campos; Aparicio, Antonio R Jiménez; Ocampo, Martha L Arenas

    2014-01-01

    Inulin-type fructans are the most studied prebiotic compounds because of their broad range of health benefits. In particular, plants of the Agave genus are rich in fructans. Agave-derived fructans have a branched structure with both β-(2→1) and β-(2→6) linked fructosyl chains attached to the sucrose start unit with a degree of polymerization (DP) of up to 80 fructose units. The objective of this work was to assess the prebiotic potential of three Agave angustifolia Haw fructan fractions (AFF) with different degrees of polymerization. The three fructan fractions were extracted from the agave stem by lixiviation and then purified by ultrafiltration and ion exchange chromatography: AFF1, AFF2 and AFF3 with high (3-60 fructose units), medium (2-40) and low (2-22) DP, respectively. The fructan profile was determined with high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD), which confirmed a branched fructan structure. Structural elucidation was performed by Fourier Transform Infra-Red Spectroscopy. The AFF spectrum shows characteristic fructan bands. The prebiotic effect of these fractions was assessed in vitro through fermentation by Bifidobacterium and Lactobacillus strains. Four growth patterns were observed. Some bacteria did not grow with any of the AFF, while other strains grew with only AFF3. Some bacteria grew according to the molecular weight of the AFF and some grew indistinctly with the three fructan fractions. PMID:25153877

  17. Potential of probiotics, prebiotics and synbiotics for management of colorectal cancer.

    PubMed

    Raman, Maya; Ambalam, Padma; Kondepudi, Kanthi Kiran; Pithva, Sheetal; Kothari, Charmy; Patel, Arti T; Purama, Ravi Kiran; Dave, J M; Vyas, B R M

    2013-01-01

    Colorectal Cancer (CRC) is the second leading cause of cancer-related mortality and is the fourth most common malignant neoplasm in USA. Escaping apoptosis and cell mutation are the prime hallmarks of cancer. It is apparent that balancing the network between DNA damage and DNA repair is critical in preventing carcinogenesis. One-third of cancers might be prevented by nutritious healthy diet, maintaining healthy weight and physical activity. In this review, an attempt is made to abridge the role of carcinogen in colorectal cancer establishment and prognosis, where special attention has been paid to food-borne mutagens and functional role of beneficial human gut microbiome in evading cancer. Further the significance of tailor-made prebiotics, probiotics and synbiotics in cancer management by bio-antimutagenic and desmutagenic activity has been elaborated. Probiotic bacteria are live microorganisms that, when administered in adequate amounts, confer a healthy benefit on the host. Prebiotics are a selectively fermentable non-digestible oligosaccharide or ingredient that brings specific changes, both in the composition and/or activity of the gastrointestinal microflora, conferring health benefits. Synbiotics are a combination of probiotic bacteria and the growth promoting prebiotic ingredients that purport "synergism." PMID:23511582

  18. On the lack of evolutionary continuity between prebiotic peptides and extant enzymes.

    PubMed

    Raggi, Luciana; Bada, Jeffrey L; Lazcano, Antonio

    2016-07-27

    The significance of experiments that claim to simulate the properties of prebiotic small peptides and polypeptides as models of the polymers that may have preceded proteins is critically addressed. As discussed here, most of these experiments are based only on a small number of a larger set of amino acids that may have been present in the prebiotic environment, supported by both experimental simulations and the repertoire of organic compounds reported in carbonaceous chondrites. Model experiments with small peptides may offer some insights into the processes that contributed to generate the chemical environment leading to the emergence of informational oligomers, but not to the origin of proteins. The large body of circumstantial evidence indicating that catalytic RNA played a key role in the origin of protein synthesis during the early stages of cellular evolution implies that the emergence of the genetic code and of protein biosynthesis are no longer synonymous with the origin of life. Hence, reports on the abiotic synthesis of small catalytic peptides under potential prebiotic conditions do not provide information on the origin of triplet encoded protein biosynthesis, but in some cases may serve as models to understand the properties of the earliest proteins. PMID:27121024

  19. Simplified protein design biased for prebiotic amino acids yields a foldable, halophilic protein

    PubMed Central

    Longo, Liam M.; Lee, Jihun; Blaber, Michael

    2013-01-01

    A compendium of different types of abiotic chemical syntheses identifies a consensus set of 10 “prebiotic” α-amino acids. Before the emergence of biosynthetic pathways, this set is the most plausible resource for protein formation (i.e., proteogenesis) within the overall process of abiogenesis. An essential unsolved question regarding this prebiotic set is whether it defines a “foldable set”—that is, does it contain sufficient chemical information to permit cooperatively folding polypeptides? If so, what (if any) characteristic properties might such polypeptides exhibit? To investigate these questions, two “primitive” versions of an extant protein fold (the β-trefoil) were produced by top-down symmetric deconstruction, resulting in a reduced alphabet size of 12 or 13 amino acids and a percentage of prebiotic amino acids approaching 80%. These proteins show a substantial acidification of pI and require high salt concentrations for cooperative folding. The results suggest that the prebiotic amino acids do comprise a foldable set within the halophile environment. PMID:23341608

  20. Prebiotic syntheses of vitamin coenzymes: II. Pantoic acid, pantothenic acid, and the composition of coenzyme A

    NASA Technical Reports Server (NTRS)

    Miller, S. L.; Schlesinger, G.

    1993-01-01

    Pantoic acid can by synthesized in good prebiotic yield from isobutyraldehyde or alpha-ketoisovaleric acid + H2CO + HCN. Isobutyraldehyde is the Strecker precursor to valine and alpha-ketoisovaleric acid is the valine transamination product. Mg2+ and Ca2+ as well as several transition metals are catalysts for the alpha-ketoisovaleric acid reaction. Pantothenic acid is produced from pantoyl lactone (easily formed from pantoic acid) and the relatively high concentrations of beta-alanine that would be formed on drying prebiotic amino acid mixtures. There is no selectivity for this reaction over glycine, alanine, or gamma-amino butyric acid. The components of coenzyme A are discussed in terms of ease of prebiotic formation and stability and are shown to be plausible choices, but many other compounds are possible. The gamma-OH of pantoic acid needs to be capped to prevent decomposition of pantothenic acid. These results suggest that coenzyme A function was important in the earliest metabolic pathways and that the coenzyme A precursor contained most of the components of the present coenzyme.

  1. Prebiotic stimulation of human colonic butyrate-producing bacteria and bifidobacteria, in vitro.

    PubMed

    Scott, Karen P; Martin, Jennifer C; Duncan, Sylvia H; Flint, Harry J

    2014-01-01

    Dietary macronutrients affect the composition of the gut microbiota, and prebiotics are used to improve and maintain a healthy gut. The impact of prebiotics on dominant gut bacteria other than bifidobacteria, however, is under-researched. Here, we report carbohydrate utilisation patterns for representative butyrate-producing anaerobes, belonging to the Gram-positive Firmicutes families Lachnospiraceae and Ruminococcaceae, by comparison with selected Bacteroides and Bifidobacterium species. Growth assessments using anaerobic Hungate tubes and a new rapid microtitre plate assay were generally in good agreement. The Bacteroides strains tested showed some growth on basal medium with no added carbohydrates, utilising peptides in the growth medium. The butyrate-producing strains exhibited different growth profiles on the substrates, which included starch, inulin, fructooligosaccharides (FOS), galactooligosaccharides (GOS) and xylooligosaccharides (XOS). Eleven were able to grow on short-chain FOS, but this number decreased as the chain length of the fructan substrates increased. Long-chain inulin was utilised by Roseburia inulinivorans, but by none of the Bifidobacterium species examined here. XOS was a more selective growth substrate than FOS, with only six of the 11 Firmicutes strains able to use XOS for growth. These results illustrate the selectivity of different prebiotics and help to explain why some are butyrogenic. PMID:23909466

  2. Prebiotic significance of extraterrestrial ice photochemistry: detection of hydantoin in organic residues.

    PubMed

    de Marcellus, Pierre; Bertrand, Marylène; Nuevo, Michel; Westall, Frances; Le Sergeant d'Hendecourt, Louis

    2011-11-01

    The delivery of extraterrestrial organic materials to primitive Earth from meteorites or micrometeorites has long been postulated to be one of the origins of the prebiotic molecules involved in the subsequent apparition of life. Here, we report on experiments in which vacuum UV photo-irradiation of interstellar/circumstellar ice analogues containing H(2)O, CH(3)OH, and NH(3) led to the production of several molecules of prebiotic interest. These were recovered at room temperature in the semi-refractory, water-soluble residues after evaporation of the ice. In particular, we detected small quantities of hydantoin (2,4-imidazolidinedione), a species suspected to play an important role in the formation of poly- and oligopeptides. In addition, hydantoin is known to form under extraterrestrial, abiotic conditions, since it has been detected, along with various other derivatives, in the soluble part of organic matter of primitive carbonaceous meteorites. This result, together with other related experiments reported recently, points to the potential importance of the photochemistry of interstellar "dirty" ices in the formation of organics in Solar System materials. Such molecules could then have been delivered to the surface of primitive Earth, as well as other telluric (exo-) planets, to help trigger first prebiotic reactions with the capacity to lead to some form of primitive biomolecular activity. PMID:22059641

  3. Acarbose, lente carbohydrate, and prebiotics promote metabolic health and longevity by stimulating intestinal production of GLP-1.

    PubMed

    McCarty, Mark F; DiNicolantonio, James J

    2015-01-01

    The α-glucosidase inhibitor acarbose, which slows carbohydrate digestion and blunts postprandial rises in plasma glucose, has long been used to treat patients with type 2 diabetes or glucose intolerance. Like metformin, acarbose tends to aid weight control, postpone onset of diabetes and decrease risk for cardiovascular events. Acarbose treatment can favourably affect blood pressure, serum lipids, platelet aggregation, progression of carotid intima-media thickness and postprandial endothelial dysfunction. In mice, lifetime acarbose feeding can increase median and maximal lifespan-an effect associated with increased plasma levels of fibroblast growth factor 21 (FGF21) and decreased levels of insulin-like growth factor-I (IGF-I). There is growing reason to suspect that an upregulation of fasting and postprandial production of glucagon-like peptide-1 (GLP-1)-stemming from increased delivery of carbohydrate to L cells in the distal intestinal tract-is largely responsible for the versatile health protection conferred by acarbose. Indeed, GLP-1 exerts protective effects on vascular endothelium, the liver, the heart, pancreatic β cells, and the brain which can rationalise many of the benefits reported with acarbose. And GLP-1 may act on the liver to modulate its production of FGF21 and IGF-I, thereby promoting longevity. The benefits of acarbose are likely mimicked by diets featuring slowly-digested 'lente' carbohydrate, and by certain nutraceuticals which can slow carbohydrate absorption. Prebiotics that promote colonic generation of short-chain fatty acids represent an alternative strategy for boosting intestinal GLP-1 production. The health benefits of all these measures presumably would be potentiated by concurrent use of dipeptidyl peptidase 4 inhibitors, which slow the proteolysis of GLP-1 in the blood. PMID:25685364

  4. Altered gastrointestinal microbiota in irritable bowel syndrome and its modification by diet: probiotics, prebiotics and the low FODMAP diet.

    PubMed

    Staudacher, Heidi M; Whelan, Kevin

    2016-08-01

    Irritable bowel syndrome (IBS) is a functional bowel disorder characterised by abdominal pain or discomfort with disordered defecation. This review describes the role of the gastrointestinal (GI) microbiota in the pathogenesis of IBS and how dietary strategies to manage symptoms impact on the microbial community. Evidence suggests a dysbiosis of the luminal and mucosal colonic microbiota in IBS, frequently characterised by a reduction in species of Bifidobacteria which has been associated with worse symptom profile. Probiotic supplementation trials suggest intentional modulation of the GI microbiota may be effective in treating IBS. A smaller number of prebiotic supplementation studies have also demonstrated effectiveness in IBS whilst increasing Bifidobacteria. In contrast, a novel method of managing IBS symptoms is the restriction of short-chain fermentable carbohydrates (low fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) diet). Studies consistently demonstrate clinical effectiveness of the low FODMAP diet in patients with IBS. However, one unintentional consequence of this dietary intervention is its impact on the microbiota. This leads to an interesting paradox; namely, increasing luminal Bifidobacteria through probiotic supplementation is associated with a reduction in IBS symptoms while in direct conflict to this, the low FODMAP diet has clinical efficacy but markedly reduces luminal Bifidobacteria concentration. Given the multifactorial aetiology of IBS, the heterogeneity of symptoms and the complex and diverse nature of the microbiome, it is probable that both interventions are effective in patient subgroups. However combination treatment has never been explored and as such, presents an exciting opportunity for optimising clinical management, whilst preventing potentially deleterious effects on the GI microbiota. PMID:26908093

  5. Development of chocolate dairy dessert with addition of prebiotics and replacement of sucrose with different high-intensity sweeteners.

    PubMed

    Morais, E C; Morais, A R; Cruz, A G; Bolini, H M A

    2014-05-01

    The aims of this study were (1) to optimize the formulation of a prebiotic chocolate dairy dessert and assess the extent to which sensory properties were affected by adding different concentrations of prebiotics (inulin and fructooligosaccharides) combined with different levels of xanthan and guar gums, and (2) to analyze the ideal and relative sweetness of prebiotic chocolate milk dessert sweetened with different artificial and natural sweeteners. Acceptability was evaluated by 100 consumers using a 9-cm hedonic scale, and the level of sample creaminess was evaluated using a 9-point just-about-right (JAR) scale. Data were subjected to a multivariate regression analysis and fitted to a model provided by response surface methodology. The optimal concentrations were 7.5% (wt/wt) prebiotic and 0.20% (wt/wt) gum (guar and xanthan, in a 2:1 ratio). The ideal sweetness analysis revealed that the ideal concentration of sucrose was 8.13%. The relative sweetness analysis showed that Neotame (NutraSweet Corp., Chicago, IL) had the highest sweetening power compared with the prebiotic chocolate dairy dessert containing 8% sucrose, followed by sucralose, aspartame, and stevia. The study of sweetness in this product is important because consumers desire healthier functional products with no added sugar. PMID:24612793

  6. Total calcium absorption is similar from infant formulas with and without prebiotics and exceeds that in human milk-fed infants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our goal was to evaluate calcium absorption in infants fed a formula containing prebiotics (PF) and one without prebiotics (CF), and to compare calcium absorption from these formulas with a group of human milk-fed (HM) infants. A dual tracer stable isotope method was used to assess calcium absorptio...

  7. Effects of prebiotic oligosaccharides consumption on the growth and expression profile of cell surface-associated proteins of a potential probiotic Lactobacillus rhamnosus FSMM15

    PubMed Central

    MURTINI, Devi; ARYANTINI, Ni Putu Desy; SUJAYA, I Nengah; URASHIMA, Tadasu; FUKUDA, Kenji

    2015-01-01

    To investigate carbohydrate preference of a potential probiotic, Lactobacillus rhamnosus FSMM15, six prebiotics, including two milk-derived prebiotics, galactooligosaccharides and lacto-N-biose I, and four plant-origin prebiotics, beet oligosaccharide syrup, difructose anhydride III, fructooligosaccharides, and raffinose, were examined. The strain utilized the milk-derived prebiotics at similar levels to glucose but did not utilize the plant-origin ones in the same manner, reflecting their genetic background, which allows them to adapt to dairy ecological niches. These prebiotics had little influence on the expression pattern of cell surface-associated proteins in the strain; however, an ATP-binding cassette transporter substrate-binding protein and a glyceraldehyde-3-phosphate dehydrogenase were suggested to be upregulated in response to carbon starvation stress. PMID:26858929

  8. Simulation of Prebiotic Processing by Comet and Meteoroid Impact: Implications for Life on Early Earth and Other Planets

    NASA Technical Reports Server (NTRS)

    Dateo, Christopher E.

    2003-01-01

    We develop a reacting flow model to simulate the shock induced chemistry of comets and meteoroids entering planetary atmospheres. Various atmospheric compositions comprising of simpler molecules (i.e., CH4, CO2, H2O, etc.) are investigated to determine the production efficiency of more complex prebiotic molecules as a function of composition, pressure, and entry velocity. The possible role of comets and meteoroids in creating the inventory of prebiotic material necessary for life on Early Earth is considered. Comets and meteoroids can also introduce new materials from the Interstellar Medium (ISM) to planetary atmospheres. The ablation of water from comets, introducing the element oxygen into Titan's atmosphere will also be considered and its implications for the formation of organic and prebiotic material.

  9. Levansucrases of a Pseudomonas syringae pathovar as catalysts for the synthesis of potentially prebiotic oligo- and polysaccharides.

    PubMed

    Visnapuu, Triinu; Mardo, Karin; Alamäe, Tiina

    2015-12-25

    Gut microbiota influences more physiological and developmental processes of humans and animals than earlier expected. Therefore, the possibility to shape the composition and activity of this bacterial population by prebiotics becomes especially important. Inulin, a β-2,1 linked fructan polymer, from plants and fructooligosaccharides (FOS) derived from it are recognized and already widely used as prebiotics while β-2,6 linked fructans have received much less attention from scientific community. In this mini-review, we will address β-2,6 linked fructans: levan and levan-type FOS as novel potential prebiotics and summarize the literature data on levansucrases of Pseudomonas bacteria which are producing these fructans. The major attention is drawn to stable and highly efficient levansucrases of Pseudomonas syringae pv. tomato, among which the Lsc3 protein has been most thoroughly studied using biochemical methods as well as extensive mutagenesis of the protein. PMID:25644638

  10. Theoretical Studies on the Photochemistry of Pentose Aminooxazoline, a Hypothetical Intermediate Product in the Prebiotic Synthetic Scenario of RNA Nucleotides.

    PubMed

    Ai, Yuejie; Xia, Shuhua; Liao, Rong-Zhen

    2016-09-01

    2-Aminooxazole is generally considered a prebiotic precursor of ribonucleotides on the early earth. Its pentose compound, pentose aminooxazoline, has been suggested to be a key intermediate in the prebiotic synthetic scenario. In this article, detailed mechanism of the photochemistry of pentose aminooxazoline has been studied by performing density functional theory and multireference complete active space self-consistent field calculations. Parallel to the "ring-puckering" process, which leads to ultrafast nonradiative deactivation, several other photodissociation channels are explored in detail. In addition, the influences of the pentose structure and solvation effects with both implicit and explicit water models have been uncovered for both neutral and protonated forms. The current theoretical results provide very important information not only for the photostability of RNA nucleotides but also for an in-depth understanding of the synthesis of other prebiotic nucleotides. PMID:27525736

  11. In vitro assessment of the prebiotic potential of Aloe vera mucilage and its impact on the human microbiota.

    PubMed

    Gullón, Beatriz; Gullón, Patricia; Tavaria, Freni; Alonso, José Luis; Pintado, Manuela

    2015-02-01

    Aloe vera mucilage is reported to be rich in acemannan that is a polysaccharide with a backbone of β-(1→4)-D-mannose residues acetylated at the C-2 and C-3 positions and contains some side chains of galactose and arabinose attached to the C-6 carbon. The evaluation of the prebiotic potential of Aloe vera mucilage was carried out by in vitro fermentation using intestinal microbiota from six healthy donors as the inoculum. The prebiotic activity was assessed through the quantification of short chain fatty acids (SCFA) and the evaluation of dynamic bacterial population in mixed faecal cultures by fluorescence in situ hybridization (FISH). Our findings support the possible incorporation of the Aloe vera mucilage in the development of a variety of food products known as prebiotics aimed at improving gastrointestinal health. PMID:25504136

  12. Prebiotic feeding elevates central brain derived neurotrophic factor, N-methyl-D-aspartate receptor subunits and D-serine.

    PubMed

    Savignac, Helene M; Corona, Giulia; Mills, Henrietta; Chen, Li; Spencer, Jeremy P E; Tzortzis, George; Burnet, Philip W J

    2013-12-01

    The influence of the gut microbiota on brain chemistry has been convincingly demonstrated in rodents. In the absence of gut bacteria, the central expression of brain derived neurotropic factor, (BDNF), and N-methyl-d-aspartate receptor (NMDAR) subunits are reduced, whereas, oral probiotics increase brain BDNF, and impart significant anxiolytic effects. We tested whether prebiotic compounds, which increase intrinsic enteric microbiota, also affected brain BDNF and NMDARs. In addition, we examined whether plasma from prebiotic treated rats released BDNF from human SH-SY5Y neuroblastoma cells, to provide an initial indication of mechanism of action. Rats were gavaged with fructo-oligosaccharides (FOS), galacto-oligosaccharides (GOS) or water for five weeks, prior to measurements of brain BDNF, NMDAR subunits and amino acids associated with glutamate neurotransmission (glutamate, glutamine, and serine and alanine enantiomers). Prebiotics increased hippocampal BDNF and NR1 subunit expression relative to controls. The intake of GOS also increased hippocampal NR2A subunits, and frontal cortex NR1 and d-serine. Prebiotics did not alter glutamate, glutamine, l-serine, l-alanine or d-alanine concentrations in the brain, though GOSfeeding raised plasma d-alanine. Elevated levels of plasma peptide YY (PYY) after GOS intake was observed. Plasma from GOS rats increased the release of BDNF from SH-SY5Y cells, but not in the presence of PYY antisera. The addition of synthetic PYY to SH-SY5Y cell cultures, also elevated BDNF secretion. We conclude that prebiotic-mediated proliferation of gut microbiota in rats, like probiotics, increases brain BDNF expression, possibly through the involvement of gut hormones. The effect of GOS on components of central NMDAR signalling was greater than FOS, and may reflect the proliferative potency of GOS on microbiota. Our data therefore, provide a sound basis to further investigate the utility of prebiotics in the maintenance of brain health and

  13. Effect of dietary probiotic, prebiotic and synbiotic supplementation on performance, immune responses, intestinal morphology and bacterial populations in broilers.

    PubMed

    Salehimanesh, A; Mohammadi, M; Roostaei-Ali Mehr, M

    2016-08-01

    This study was conducted to investigate the effects of probiotic (Primalac), prebiotic (TechnoMos) and synbiotic (Primalac + TechnoMos) supplementation on performance, immune responses, intestinal morphology and bacterial populations of ileum in broilers. A total of 240 one-day-old broiler chicks were randomly divided into four treatment groups which included 60 birds. Control group did not receive any treatment. The chicks in the second, third and fourth groups were fed probiotic (0.9 g/kg), prebiotic (0.9 g/kg) and probiotic (0.9 g/kg) plus probiotic (0.9 g/kg; synbiotic), respectively, at entire period. Daily feed intake, daily weight gain and feed conversion ratio were evaluated. The birds were immunized by sheep red blood cell (SRBC) on days 12 and 29 of age and serum antibody titres were measured on days 28, 35 and 42. Newcastle vaccines administered on days 9, 18 and 27 to chicks and blood samples were collected on day 42. Intestinal morphometric assessment and enumeration of intestinal bacterial populations were performed on day 42. The results indicated that consumption of probiotic, prebiotic and synbiotic had no significant effect on daily feed intake, daily body weight gain, feed conversion ratio, carcass traits, intestinal morphology and bacterial populations of ileum (p > 0.05). Consumption of prebiotic increased total and IgM anti-SRBC titres on days 28 and 42 and antibody titre against Newcastle virus disease on day 42 (p < 0.05). Synbiotic increased only total anti-SRBC on day 28 (p < 0.05). It is concluded that consumption of prebiotic increased humoral immunity in broilers. Therefore, supplementation of diet with prebiotic for improvement of humoral immune responses is superior to synbiotic supplementation. PMID:26847817

  14. The principal fucosylated oligosaccharides of human milk exhibit prebiotic properties on cultured infant microbiota

    PubMed Central

    Yu, Zhuo-Teng; Chen, Ceng; Kling, David E; Liu, Bo; McCoy, John M; Merighi, Massimo; Heidtman, Matthew; Newburg, David S

    2013-01-01

    Breast-fed infant microbiota is typically rich in bifidobacteria. Herein, major human milk oligosaccharides (HMOS) are assessed for their ability to promote the growth of bifidobacteria and to acidify their environment, key features of prebiotics. During in vitro anaerobic fermentation of infant microbiota, supplementation by HMOS significantly decreased the pH even greater than supplementation by fructooligosaccharide (FOS), a prebiotic positive control. HMOS elevated lactate concentrations, increased the proportion of Bifidobacterium spp. in culture, and through their fermentation into organic acids, decreased the proportion of Escherichia and Clostridium perfringens. Three principal components of HMOS, 2′-fucosyllactose, lactodifucotetraose and 3-fucosyllactose, were consumed in these cultures. These three principal oligosaccharides of human milk were then individually tested as supplements for in vitro growth of four individual representative strains of infant gut microbes. Bifidobacterium longum JCM7007 and B. longum ATCC15697 efficiently consumed oligosaccharides and produced abundant lactate and short-chain fatty acids, resulting in significant pH reduction. The specificity of fermentation differed by microbe species and strain and by oligosaccharide structure. Escherichia coli K12 and C. perfringens did not utilize appreciable fucosylated oligosaccharides, and a typical mixture of organic acid fermentation products inhibited their growth. In summary, 2′-fucosyllactose, lactodifucotetraose, and 3-fucosyllactose, when cultured with B. longum JCM7007 and B. longum ATCC15697, exhibit key characteristics of a prebiotic in vitro. If these bifidobacteria are representative of pioneering or keystone species for human microbiota, fucosylated HMOS could strongly promote colonization and maintenance of a mutualist symbiotic microbiome. Thus, these simple glycans could mediate beneficial effects of human milk on infant health. PMID:23028202

  15. Creating Prebiotic Sanctuary: Self-Assembling Supramolecular Peptide Structures Bind and Stabilize RNA

    NASA Astrophysics Data System (ADS)

    Carny, Ohad; Gazit, Ehud

    2011-04-01

    Any attempt to uncover the origins of life must tackle the known `blind watchmaker problem'. That is to demonstrate the likelihood of the emergence of a prebiotic system simple enough to be formed spontaneously and yet complex enough to allow natural selection that will lead to Darwinistic evolution. Studies of short aromatic peptides revealed their ability to self-assemble into ordered and stable structures. The unique physical and chemical characteristics of these peptide assemblies point out to their possible role in the origins of life. We have explored mechanisms by which self-assembling short peptides and RNA fragments could interact together and go through a molecular co-evolution, using diphenylalanine supramolecular assemblies as a model system. The spontaneous formation of these self-assembling peptides under prebiotic conditions, through the salt-induced peptide formation (SIPF) pathway was demonstrated. These peptide assemblies possess the ability to bind and stabilize ribonucleotides in a sequence-depended manner, thus increase their relative fitness. The formation of these peptide assemblies is dependent on the homochirality of the peptide monomers: while homochiral peptides (L-Phe-L-Phe and D-Phe-D-Phe) self-assemble rapidly in aqueous environment, heterochiral diastereoisomers (L-Phe-D-Phe and D-Phe-L-Phe) do not tend to self-assemble. This characteristic consists with the homochirality of all living matter. Finally, based on these findings, we propose a model for the role of short self-assembling peptides in the prebiotic molecular evolution and the origin of life.

  16. Physicochemical Characterization and Potential Prebiotic Effect of Whey Protein Isolate/Inulin Nano Complex.

    PubMed

    Ha, Ho-Kyung; Jeon, Na-Eun; Kim, Jin Wook; Han, Kyoung-Sik; Yun, Sung Seob; Lee, Mee-Ryung; Lee, Won-Jae

    2016-01-01

    The purposes of this study were to investigate the impacts of concentration levels of whey protein isolate (WPI) and inulin on the formation and physicochemical properties of WPI/inulin nano complexes and to evaluate their potential prebiotic effects. WPI/inulin nano complexes were produced using the internal gelation method. Transmission electron microscopy (TEM) and particle size analyzer were used to assess the morphological and physicochemical characterizations of nano complexes, respectively. The encapsulation efficiency of resveratrol in nano complexes was studied using HPLC while the potential prebiotic effects were investigated by measuring the viability of probiotics. In TEM micrographs, the globular forms of nano complexes in the range of 10 and 100 nm were successfully manufactured. An increase in WPI concentration level from 1 to 3% (w/v) resulted in a significant (p<0.05) decrease in the size of nano complexs while inulin concentration level did not affect the size of nano complexes. The polydispersity index of nano complexes was below 0.3 in all cases while the zeta-potential values in the range of -2 and -12 mV were observed. The encapsulation efficiency of resveratrol was significantly (p<0.05) increased as WPI and inulin concentration levels were increased from 1 to 3% (w/v). During incubation at 37℃ for 24 h, WPI/inulin nano complexes exhibited similar viability of probiotics with free inulin and had significantly (p<0.05) higher viability than negative control. In conclusions, WPI and inulin concentration levels were key factors affecting the physicochemical properties of WPI/inulin nano complexes and had potential prebiotic effect. PMID:27194937

  17. The origin and spread of a cooperative replicase in a prebiotic chemical system.

    PubMed

    Shay, Julie A; Huynh, Christopher; Higgs, Paul G

    2015-01-01

    The origin of life requires the emergence of a system of autocatalytic polymers such as RNA. We consider a trans-acting replicase that catalyses replication of a template (either a copy of itself or another sequence). Our model includes alternating plus/minus strand replication where only the plus strand is a catalyst. Prebiotic chemistry generates random sequences and allows for non-catalysed, template-directed synthesis of new strands. These chemical reactions are insufficient to sustain replication, but they provide a background in which the first replicase can arise. In the well-mixed case, the minimum value of the catalytic rate parameter k for which a stable replicating state survives scales as 1/f, where f is the fraction of random sequences that are catalysts. When catalysts are rare (f→0), the replicating state is not stable in for any finite k because the replicases are overrun by parasitic templates already present in the prebiotic system, and by additional parasites created by mutation of the catalyst. In contrast, in 2d spatial simulations, the replicating state is stable for moderate k with appropriate values of the local diffusion constant. We calculate the probability of spread of the replicating state from a single isolated catalyst. This occurs in a parameter range that is narrower than that in which existing replicators are stable. The 2d model uses 'Two׳s Company' rules, where two molecules on a site may replicate, but crowding occurs when three molecules are on one site. A mean-field theory is presented which predicts the most important results of the spatial model. Our results emphasize that the origin of replication is a spatially-localized stochastic transition between a 'dead' state controlled by prebiotic chemistry and a 'living' state controlled by autocatalytic replication. PMID:25245369

  18. Physicochemical Characterization and Potential Prebiotic Effect of Whey Protein Isolate/Inulin Nano Complex

    PubMed Central

    Han, Kyoung-Sik; Yun, Sung Seob; Lee, Mee-Ryung

    2016-01-01

    The purposes of this study were to investigate the impacts of concentration levels of whey protein isolate (WPI) and inulin on the formation and physicochemical properties of WPI/inulin nano complexes and to evaluate their potential prebiotic effects. WPI/inulin nano complexes were produced using the internal gelation method. Transmission electron microscopy (TEM) and particle size analyzer were used to assess the morphological and physicochemical characterizations of nano complexes, respectively. The encapsulation efficiency of resveratrol in nano complexes was studied using HPLC while the potential prebiotic effects were investigated by measuring the viability of probiotics. In TEM micrographs, the globular forms of nano complexes in the range of 10 and 100 nm were successfully manufactured. An increase in WPI concentration level from 1 to 3% (w/v) resulted in a significant (p<0.05) decrease in the size of nano complexs while inulin concentration level did not affect the size of nano complexes. The polydispersity index of nano complexes was below 0.3 in all cases while the zeta-potential values in the range of -2 and -12 mV were observed. The encapsulation efficiency of resveratrol was significantly (p<0.05) increased as WPI and inulin concentration levels were increased from 1 to 3% (w/v). During incubation at 37℃ for 24 h, WPI/inulin nano complexes exhibited similar viability of probiotics with free inulin and had significantly (p<0.05) higher viability than negative control. In conclusions, WPI and inulin concentration levels were key factors affecting the physicochemical properties of WPI/inulin nano complexes and had potential prebiotic effect. PMID:27194937

  19. Energy yields in the prebiotic synthesis of hydrogen cyanide and formaldehyde

    NASA Technical Reports Server (NTRS)

    Stribling, R.; Miller, S. L.

    1986-01-01

    Prebiotic experiments are usually reported in terms of carbon yields, i.e., the yield of product based on the total carbon in the system. These experiments usually involve a large input of energy and are designed to maximize the yields of product. However, large inputs of energy result in multiple activation of the reactants and products. A more realistic prebiotic experiment is to remove the products of the activation step so they are not exposed a second time to the energy source. This is equivalent to transporting the products synthesized in the primitive atmosphere to the ocean, and thereby protecting them from destruction by atmospheric energy sources. Experiments of this type, using lower inputs of energy, give energy yields (moles of products/joule) which can be used to estimate the relative importance of the different energy sources on the primitive earth. Simulated prebiotic atmospheres containing either CH4, CO or CO2 with N2, H2O and variable amounts of H2 were subjected to a high frequency Tesla coil. Samples of the aqueous phase were taken at various time intervals from 1 hr to 7 days, and the energy yields were obtained by extrapolation to zero time. The samples were analyzed for HCN with the cyanide electrode and for H2CO by chromotropic acid. The spark energy was estimated by calorimetry. The temperature rise in an insulated discharge flask was compared with the temperature rise from a resistance heater in the same flask. These results will be compared with calculated production rates of HCN and H2CO from lightning and a number of photochemical processes on the primitive Earth.

  20. Catalysis of Glyceraldehyde Synthesis by Primary or Secondary Amino Acids Under Prebiotic Conditions as a Function of pH

    NASA Astrophysics Data System (ADS)

    Breslow, Ronald; Ramalingam, Vijayakumar; Appayee, Chandrakumar

    2013-10-01

    The synthesis of an excess of D-glyceraldehyde by coupling glycolaldehyde with formaldehyde under prebiotic conditions is catalyzed by L amino acids having primary amino groups at acidic pH's, but at neutral or higher pH's they preferentially form L-glyceraldehyde. L Amino acids having secondary amino groups, such as proline, have the reverse preferences, affording excess L-glyceraldehyde at low pH but excess D-glyceraldehyde at higher pHs. Detailed mechanistic proposals make these preferences understandable. The relevance of these findings to the origin of D sugars on prebiotic Earth is described.

  1. Miller-Urey and Beyond: What Have We Learned About Prebiotic Organic Synthesis Reactions in the Past 60 Years?

    NASA Astrophysics Data System (ADS)

    McCollom, Thomas M.

    2013-05-01

    The synthesis of amino acids in the Miller-Urey spark-discharge experiments in the early 1950s inspired a strong interest in experimental studies of prebiotic organic chemistry that continues today. Over the years, many of the basic building blocks of life as we know it have been synthesized in the laboratory from simple ingredients, including amino acids, sugars, nucleobases, and membrane-forming lipids. Questions remain, however, concerning whether the conditions that allow synthesis of these compounds in the laboratory accurately simulate those that might have been present on the early Earth, and a closer convergence between plausible prebiotic conditions and laboratory simulations remains a challenge for experimentalists.

  2. Biased versus unbiased randomness in homo-polymers and copolymers of amino acids in the prebiotic world.

    PubMed

    Mosqueira, Fernando G; Negron, Alicia; Ramos, Sergio; Polanco, Carlos

    2012-01-01

    The polymerization of amino acids under anhydrous prebiotic conditions was first studied several decades ago. Here we use a stochastic model stressing the relevant role of the polarity of amino acids in the formation of oligopeptides in a prebiotic milieu. Our goal is to outline the predominance of co-polypeptides over homo-polypeptides, resulting not only from the randomness, but also from polarity properties of amino acids. Our results conclude that there was a higher probability of the formation of co-polypeptides than of homo-polymers. Besides, we may hypothesize that the former would have a more ample spectrum of possible chemical functions than homo-polypeptides. PMID:23128064

  3. Possible prebiotic significance of polyamines in the condensation, protection, encapsulation, and biological properties of DNA

    NASA Technical Reports Server (NTRS)

    Baeza, Isabel; Ibanez, Miguel; Wong, Carlos; Chavez, Pedro; Gariglio, Patricio; Oro, J.

    1992-01-01

    While DNA which has undergone ionic condensation with Co(3+)(NH3)6 is resistant to the action of the endonuclase DNAse I, in much the same way as DNA condensed with spermidine, it was significantly less active in transcription with the E. coli RNA polymerase than DNA-spermidine condensed forms. Although both compacted forms of DNA were more efficiently encapsulated into neutral liposomes, negatively charged liposomes were seldom formed in the presence of the present, positive ion-condensed DNA; spermidine is accordingly proposed as a plausible prebiotic DNA-condensing agent. Attention is given to the relevance of the polyimide-nucleic acids complexes in the evolution of life.

  4. Carbon and energy yields in prebiotic syntheses using atmospheres containing CH4, CO and CO2

    NASA Technical Reports Server (NTRS)

    Miller, S. L.; Schlesinger, G.

    1984-01-01

    Yields based on carbon are usually reported in prebiotic experiments, while energy yields (moles/cal) are more useful in estimating the yields of products that would have been obtained from the primitive atmosphere of the earth. Energy yields for the synthesis of HCN and H2CO from a spark discharge were determined for various mixtures of CH4, CO, CO2, H2, H2O, N2 an NH3. The maximum yields of HCN and H2CO from CH4, CO, and CO2 as carbon sources are about 4 x 10 to the -8th moles/cal.

  5. Possible prebiotic synthesis of monosaccharides from formaldehyde in presence of phosphates

    NASA Astrophysics Data System (ADS)

    Simonov, A. N.; Pestunova, O. P.; Matvienko, L. G.; Snytnikov, V. N.; Snytnikova, O. A.; Tsentalovich, Yu. P.; Parmon, V. N.

    Condensation of formaldehyde and lower carbohydrates (glycolaldehyde, glyceraldehyde, and dihydroxyacetone) is effectively catalyzed by heterogeneous and homogeneous phosphates in neutral aqueous medium. The interaction of formaldehyde and dihydroxyacetone leads to the preferential formation of 3-pentulose and erythrulose with yields of 40% and 45%, respectively. In absence of formaldehyde, the condensation of glycolaldehyde and glyceraldehyde catalyzed by phosphates leads to the formation of ribose and fructose. We demonstrate the possibility of formation of higher monosaccharides from pure formaldehyde in the course of the combined photochemical and phosphate-catalyzed reactions in plausible prebiotic conditions.

  6. Photo-alteration of hydantoins against UV light and its relevance to prebiotic chemistry

    NASA Astrophysics Data System (ADS)

    Sarker, Palash K.; Takahashi, Jun-ichi; Obayashi, Yumiko; Kaneko, Takeo; Kobayashi, Kensei

    2013-06-01

    Aqueous solutions of 5-substituted hydantoins were irradiated with ultraviolet (UV) light, to investigate their structural stability against UV radiation as well as the possible photolysis products. The photolysis products were identified and the degree of photolysis was measured using reversed-phase and ion-exchange high-performance liquid chromatography. Hydantoin (2,4-imidazolidinedione) was dominantly detected as a photolysis product of 5-substituted hydantoins. With hydrolysis of UV-irradiated 5-substituted hydantoins, glycine and alanine were dominantly detected. These experimental results are important for the prebiotic photochemistry of 5-substituted hydantoins in the formation of hydantoin since they have been detected in Solar System materials.

  7. Prebiotic Effects of Agave salmiana Fructans in Lactobacillus acidophilus and Bifidobacterium lactis Cultures.

    PubMed

    Castro-Zavala, Adriana; Juárez-Flores, Bertha I; Pinos-Rodríguez, Juan M; Delgado-Portales, Rosa E; Aguirre-Rivera, Juan R; Alcocer-Gouyonnet, Francisco

    2015-11-01

    Agave salmiana is a fructan rich species that is widely distributed in Mexico. The aim of this investigation was to extract the fructans of A. salmiana and evaluate their prebiotic effect in 48 hours in vitro cultures of Bifidobacterium lactis and Lactobacillus acidophilus and to compare this effect with other available fructan sources. A significant difference in pH, optical density and biomass was found in the cultures depending on the source of fructans and the type of bacteria. It was possible to determine a dose-response effect of the A. salmiana fructans and the growth of the studied strains. PMID:26749843

  8. Synergism of Saturn, Enceladus and Titan and Formation of HCNO Prebiotic Molecules

    NASA Technical Reports Server (NTRS)

    Sittler, Edward C.; Cooper, John F.

    2011-01-01

    Saturn as a system has two very exotic moons Titan and Enceladus. Titan, taking in energy from Saturn's magnetosphere, solar UV irradiation, and cosmic rays, can make HCN based molecules as discussed in earlier paper by Raulin and Owen. Space radiation effects at both moons, and as coupled by the Saturn magnetosphere, could cause an unexpected series of events potentially leading to prebiotic chemical evolution at Titan with HCNO from magnetospheric oxygen as the new ingredient. The "Old Faithful" model suggests that Enceladus, highly irradiated by Saturn magnetospheric electrons and thus having a source of chemical energy from radiolytic gas production, has episodic ejections of water vapor, carbon dioxide, and various hydrocarbons into Saturn's magnetosphere. The hydrocarbons do not survive transport through the plasma environment, but oxygen ions from Enceladus water molecules become the dominant ion species in the outer magnetosphere. At Titan, Cassini discovered that 1) keV oxygen ions, evidently from Enceladus, are bombarding Titan's upper atmosphere and 2) heavy positive and negative ions exist in significant abundances within Titan's upper atmosphere. Initial models of heavy ion formation in Titan's upper atmosphere invoked polymerization of aromatics such as benzenes and their radicals to make polycyclic aromatic hydrocarbons (PAH) , while a more recent model by Sittler et al., has raised the possibility of carbon chains forming from the polymerization of acetylene and its radicals to make fullerenes. Laboratory measurements indicate that fullerenes, which are hollow carbon shells, can trap keV oxygen ions. Clustering of the fullerenes with aerosol mixtures from PAHs and the dominant nitrogen molecules could form larger aerosols enriched in trapped oxygen. Aerosol precipitation could then convey these chemically complex structures deeper into the atmosphere and to the moon surface. Ionizing solar UV, magnetospheric electron, and galactic cosmic ray

  9. A possible role of fluctuating clay-water systems in the production of ordered prebiotic oligomers

    NASA Technical Reports Server (NTRS)

    Lahav, N.; White, D. H.

    1980-01-01

    A model is proposed for the intermediate stages of prebiotic evolution, based on the characteristics of the adsorption and condensation of amino acids and nucleotides on the surface area of clay minerals in a fluctuating environment. Template replication and translation of adsorbed oligonucleotides and catalytic effects by peptide products on further condensation are proposed, due to specific properties of hypohydrous clay surfaces as well as the biomolecules themselves. Experimental evidence supports some of the proposed interactions, and all of them can be tested experimentally.

  10. Free radical pathways for the prebiotic formation of xanthine and isoguanine from formamide

    NASA Astrophysics Data System (ADS)

    Jeilani, Yassin A.; Nguyen, Huyen Thi; Cardelino, Beatriz H.; Nguyen, Minh Tho

    2014-04-01

    Free radical pathways for the synthesis of xanthine and isoguanine from formamide were studied using density functional theory (B3LYP/6-311G(d,p)). The proposed mechanisms are complex and appropriate for the non-aqueous scenario of prebiotic reactions. Formation of the carbonyl bond in the nucleobases proceeds through enol-keto tautomerization since the direct formation of the Cdbnd O bond is a highly endothermic step. The mechanisms show 2-amino-imidazole as a precursor for nucleobases and polyazaporphyrin. The proposed mechanisms contribute to a further understanding of the origin of biomolecules.

  11. Origin and evolution of prebiotic organic matter as inferred from the Tagish Lake meteorite.

    PubMed

    Herd, Christopher D K; Blinova, Alexandra; Simkus, Danielle N; Huang, Yongsong; Tarozo, Rafael; Alexander, Conel M O'D; Gyngard, Frank; Nittler, Larry R; Cody, George D; Fogel, Marilyn L; Kebukawa, Yoko; Kilcoyne, A L David; Hilts, Robert W; Slater, Greg F; Glavin, Daniel P; Dworkin, Jason P; Callahan, Michael P; Elsila, Jamie E; De Gregorio, Bradley T; Stroud, Rhonda M

    2011-06-10

    The complex suite of organic materials in carbonaceous chondrite meteorites probably originally formed in the interstellar medium and/or the solar protoplanetary disk, but was subsequently modified in the meteorites' asteroidal parent bodies. The mechanisms of formation and modification are still very poorly understood. We carried out a systematic study of variations in the mineralogy, petrology, and soluble and insoluble organic matter in distinct fragments of the Tagish Lake meteorite. The variations correlate with indicators of parent body aqueous alteration. At least some molecules of prebiotic importance formed during the alteration. PMID:21659601

  12. Origin and Evolution of Prebiotic Organic Matter As Inferred from the Tagish Lake Meteorite

    NASA Astrophysics Data System (ADS)

    Herd, Christopher D. K.; Blinova, Alexandra; Simkus, Danielle N.; Huang, Yongsong; Tarozo, Rafael; Alexander, Conel M. O.'D.; Gyngard, Frank; Nittler, Larry R.; Cody, George D.; Fogel, Marilyn L.; Kebukawa, Yoko; Kilcoyne, A. L. David; Hilts, Robert W.; Slater, Greg F.; Glavin, Daniel P.; Dworkin, Jason P.; Callahan, Michael P.; Elsila, Jamie E.; De Gregorio, Bradley T.; Stroud, Rhonda M.

    2011-06-01

    The complex suite of organic materials in carbonaceous chondrite meteorites probably originally formed in the interstellar medium and/or the solar protoplanetary disk, but was subsequently modified in the meteorites’ asteroidal parent bodies. The mechanisms of formation and modification are still very poorly understood. We carried out a systematic study of variations in the mineralogy, petrology, and soluble and insoluble organic matter in distinct fragments of the Tagish Lake meteorite. The variations correlate with indicators of parent body aqueous alteration. At least some molecules of prebiotic importance formed during the alteration.

  13. Origin and Evolution of Prebiotic Organic Matter as Inferred from the Tagish Lake Meteorite

    NASA Technical Reports Server (NTRS)

    Herd, Christopher D.; Blinova, Alexandra; Simkus, Danielle N.; Huang, Yongsong; Tarozo, Rafael; Alexander, Conel M.; Gyngard, Frank; Nittler, Larry R.; Cody, George D.; Fogel, Marilyn L.; Kebukawa, Yoko; Kilcoyne, A. L.; Hilts, Robert W.; Slater, Greg F.; Glavin, Daniel P.; Dworkin, Jason P.; Callahan, Michael P.; Elsila, Jamie E.; De Gregorio, Bradley T.; Stroud, Rhonda M.

    2011-01-01

    The complex suite of organic materials in carbonaceous chondrite meteorites probably originally formed in the interstellar medium and/or the solar protoplanetary disk, but was subsequently modified in the meteorites' asteroidal parent bodies. The mechanisms of formation and modification are still very poorly understood. We carried out a systematic study of variations in the mineralogy, petrology, and soluble and insoluble organic matter in distinct fragments of the Tagish Lake meteorite. The variations correlate with indicators of parent body aqueous alteration and at least some molecules of pre-biotic importance formed during the alteration.

  14. Prebiotic thermal polymerization of crystals of amino acids via the diketopiperazine reaction.

    PubMed

    Mosqueira, F G; Ramos-Bernal, S; Negrón-Mendoza, A

    2008-01-01

    In this work, we continue our studies on the thermal prebiotic oligomerization of amino acids. The next step is to consider all four types of electromagnetic interactions that our model may admit. In addition, only the polymerization of amino acids via the formation of diketopiperazine, which arises from the cyclodehydration of two amino acids, will be considered. By assuming that only one residue group of two will predominate in the diketopiperazine molecule, it is possible to reduce the three-body problem to a simpler situation with the two objects that we have already solved. PMID:17980955

  15. A vestige of a prebiotic bonding machine is functioning within the contemporary ribosome.

    PubMed

    Krupkin, Miri; Matzov, Donna; Tang, Hua; Metz, Markus; Kalaora, Rinat; Belousoff, Matthew J; Zimmerman, Ella; Bashan, Anat; Yonath, Ada

    2011-10-27

    Based on the presumed capability of a prebiotic pocket-like entity to accommodate substrates whose stereochemistry enables the creation of chemical bonds, it is suggested that a universal symmetrical region identified within all contemporary ribosomes originated from an entity that we term the 'proto-ribosome'. This 'proto-ribosome' could have evolved from an earlier machine that was capable of performing essential tasks in the RNA world, called here the 'pre-proto-ribosome', which was adapted for producing proteins. PMID:21930590

  16. The 1953 Stanley L. Miller Experiment: Fifty Years of Prebiotic Organic Chemistry

    NASA Technical Reports Server (NTRS)

    Lazcano, Antonio; Bada, Jeffrey L.

    2003-01-01

    The field of prebiotic chemistry effectively began with a publication in Science 50 years ago by Stanley L. Miller on the spark discharge synthesis of amino acids and other compounds using a mixture of reduced gases that were thought to represent the components of the atmosphere on the primitive Earth. On the anniversary of this landmark publication, we provide here an accounting of the events leading to the publication of the paper. We also discuss the historical aspects that lead up to the landmark Miller experiment.

  17. Responses of feeding prebiotics on nutrient digestibility, faecal microbiota composition and short-chain fatty acid concentrations in dogs: a meta-analysis.

    PubMed

    Patra, A K

    2011-09-01

    The effects of prebiotics on digestibility, short-chain fatty acid (SCFA) concentrations and bacterial populations in the faeces and immunity in dogs were evaluated by meta-analyses. Overall, data from 15 published studies containing 65 different treatment means of 418 observations from different breeds of dogs were included in the data set. Feeding of prebiotics to dogs did not affect the nutrient intake (P > 0.10), nor did prebiotics change (P > 0.10) the digestibility of dry matter (DM) and fat. However, crude protein (CP) digestibility tended to decrease quadratically (P = 0.06) with increasing dosages of prebiotics, although the degree of prediction was low (R(2) = 0.33). The concentration of total SCFA (P = 0.08; R(2) = 0.90) tended to increase linearly, whereas concentration of acetate (R(2) = 0.25), propionate (R(2) = 0.88) and butyrate (R(2) = 0.85) increased quadratically with increasing dosage of prebiotics in the faeces of dogs. The numbers of beneficial bifidobacteria (P < 0.01; R(2) = 0.62) increased quadratically, but lactobacilli (P < 0.01; R(2) = 0.66) increased linearly with increasing supplementation of prebiotics. The changes in healthy bacterial numbers were affected by the interaction of initial bacterial numbers and dose of prebiotics; bacterial numbers increased relatively more when initial bacterial numbers were low. Dietary composition did not influence the response of prebiotics on lactobacilli and bifidobacterial numbers in this study. The numbers of pathogenic Clostridium perfringens and Escherichia coli were not affected by prebiotics. Prebiotics did not affect the serum immunoglobulin (Ig) concentrations such as IgG, IgA and IgM in dogs. Although prebiotics may tend to have an adverse effect on CP digestibility, prebiotics at doses up to 1.40% food intake (DM basis) might increase the beneficial bacterial populations and SCFA concentrations in the faeces of dogs. Thus, the feeding of prebiotics has a great prospective to improve the

  18. Targeting the Human Microbiome With Antibiotics, Probiotics, and Prebiotics: Gastroenterology Enters the Metagenomics Era

    PubMed Central

    Preidis, Geoffrey A.; Versalovic, James

    2014-01-01

    Studies of metagenomics and the human microbiome will tremendously expand our knowledge of the composition of microbial communities in the human body. As our understanding of microbial variation and corresponding genetic parameters is refined, this information can be applied to rational remodeling or “tailoring” of human-associated microbial communities and their associated functions. Physiologic features such as the development of innate and adaptive immunity, relative susceptibilities to infections, immune tolerance, bioavailability of nutrients, and intestinal barrier function may be modified by changing the composition and functions of the microbial communities. The specialty of gastroenterology will be affected profoundly by the ability to modify the gastrointestinal microbiota through the rational deployment of antibiotics, probiotics, and prebiotics. Antibiotics might be used to remove or suppress undesirable components of the human microbiome. Probiotics can introduce missing microbial components with known beneficial functions for the human host. Prebiotics can enhance the proliferation of beneficial microbes or probiotics, to maximize sustainable changes in the human microbiome. Combinations of these approaches might provide synergistic and effective therapies for specific disorders. The human microbiome could be manipulated by such “smart” strategies to prevent and treat acute gastroenteritis, antibiotic-associated diarrhea and colitis, inflammatory bowel disease, irritable bowel syndrome, necrotizing enterocolitis, and a variety of other disorders. PMID:19462507

  19. Elucidation of an Iterative Process of Carbon-Carbon Bond Formation of Prebiotic Significance

    NASA Astrophysics Data System (ADS)

    Loison, Aurélie; Dubant, Stéphane; Adam, Pierre; Albrecht, Pierre

    2010-12-01

    Laboratory experiments carried out under plausible prebiotic conditions (under conditions that might have occurred at primitive deep-sea hydrothermal vents) in water and involving constituents that occur in the vicinity of submarine hydrothermal vents (e.g., CO, H2S, NiS) have disclosed an iterative Ni-catalyzed pathway of C-C bond formation. This pathway leads from CO to various organic molecules that comprise, notably, thiols, alkylmono- and disulfides, carboxylic acids, and related thioesters containing up to four carbon atoms. Furthermore, similar experiments with organic compounds containing various functionalities, such as thiols, carboxylic acids, thioesters, and alcohols, gave clues to the mechanisms of this novel synthetic process in which reduced metal species, in particular Ni(0), appear to be the key catalysts. Moreover, the formation of aldehydes (and ketones) as labile intermediates via a hydroformylation-related process proved to be at the core of the chain elongation process. Since this process can potentially lead to organic compounds with any chain length, it could have played a significant role in the prebiotic formation of lipidic amphiphilic molecules such as fatty acids, potential precursors of membrane constituents.

  20. A toy model of prebiotic peptide evolution: the possible role of relative amino acid abundances.

    PubMed

    Polanco, Carlos; Buhse, Thomas; Samaniego, José Lino; Castañón González, Jorge Alberto

    2013-01-01

    This paper presents a mathematical-computational toy model based on the assumed dynamic principles of prebiotic peptide evolution. Starting from a pool of amino acid monomers, the model describes in a generalized manner the generation of peptides and their sequential information. The model integrates the intrinsic and dynamic key elements of the initiation of biopolymerization, such as the relative amino acid abundances and polarities, as well as the oligomer reversibility, i.e. fragmentation and recombination, and peptide self-replication. Our modeling results suggest that the relative amino acid abundances, as indicated by Miller-Urey type electric discharge experiments, played a principal role in the early sequential information of peptide profiles. Moreover, the computed profiles display an astonishing similarity to peptide profiles observed in so-called biological common ancestors found in the following three microorganisms; E. coli, M. jannaschii, and S. cereviasiae. The prebiotic peptide fingerprint was obtained by the so-called polarity index method that was earlier reported as a tool for the identification of cationic amphipathic antibacterial short peptides. PMID:23741717

  1. Probiotics and Prebiotics: Present Status and Future Perspectives on Metabolic Disorders.

    PubMed

    Yoo, Ji Youn; Kim, Sung Soo

    2016-01-01

    Metabolic disorders, including type 2 diabetes (T2DM) and cardiovascular disease (CVD), present an increasing public health concern and can significantly undermine an individual's quality of life. The relative risk of CVD, the primary cause of death in T2DM patients, is two to four times higher in people with T2DM compared with those who are non-diabetic. The prevalence of metabolic disorders has been associated with dynamic changes in dietary macronutrient intake and lifestyle changes over recent decades. Recently, the scientific community has considered alteration in gut microbiota composition to constitute one of the most probable factors in the development of metabolic disorders. The altered gut microbiota composition is strongly conducive to increased adiposity, β-cell dysfunction, metabolic endotoxemia, systemic inflammation, and oxidative stress. Probiotics and prebiotics can ameliorate T2DM and CVD through improvement of gut microbiota, which in turn leads to insulin-signaling stimulation and cholesterol-lowering effects. We analyze the currently available data to ascertain further potential benefits and limitations of probiotics and prebiotics in the treatment of metabolic disorders, including T2DM, CVD, and other disease (obesity). The current paper explores the relevant contemporary scientific literature to assist in the derivation of a general perspective of this broad area. PMID:26999199

  2. Catalytic Role of Manganese Oxides in Prebiotic Nucleobases Synthesis from Formamide.

    PubMed

    Bhushan, Brij; Nayak, Arunima; Kamaluddin

    2016-06-01

    Origin of life processes might have begun with the formation of important biomonomers, such as amino acids and nucleotides, from simple molecules present in the prebiotic environment and their subsequent condensation to biopolymers. While studying the prebiotic synthesis of naturally occurring purine and pyrimidine derivatives from formamide, the manganese oxides demonstrated not only good binding for formamide but demonstrated novel catalytic activity. A novel one pot manganese oxide catalyzed synthesis of pyrimidine nucleobases like thymine is reported along with the formation of other nucleobases like purine, 9-(hydroxyacetyl) purine, cytosine, 4(3 H)-pyrimidinone and adenine in acceptable amounts. The work reported is significant in the sense that the synthesis of thymine has exhibited difficulties especially under one pot conditions and also such has been reported only under the catalytic activity of TiO2. The lower oxides of manganese were reported to show higher potential as catalysts and their existence were favored by the reducing atmospheric conditions prevalent on early Earth; thereby confirming the hypothesis that mineral having metals in reduced form might have been more active during the course of chemical evolution. Our results further confirm the role of formamide as a probable precursor for the formation of purine and pyrimidine bases during the course of chemical evolution and origin of life. PMID:26758444

  3. Formation of Nucleobases and Other Prebiotic Species from the UV Irradiation of Pyrimidine in Astrophysical Ices

    NASA Astrophysics Data System (ADS)

    Nuevo, M.; Sandford, S. A.; Milam, S. N.; Materese, C. K.; Elsila, J. E.; Dworkin, J. P.

    2011-05-01

    Nucleobases are N-heterocycles which are the informational subunits of DNA and RNA. Biological nucleobases are divided in two types: pyrimidine bases (uracil, cytosine, and thymine) and purine bases (adenine and guanine). Nucleobases have been detected in meteorites and their extraterrestrial origin has been confirmed by isotope measurements, but no N-heterocycle has ever been observed in the ISM. Experiments showed that the UV irradiation of pyrimidine mixed in astrophysical ices such as H_2O, NH_3, CH_3OH, or any combination of these at low temperature (20-30 K) leads to the formation of multiple photo-products derived from pyrimidine including the nucleobases uracil and cytosine. Theoretical studies on the formation of uracil confirmed its experimental formation pathway and demonstrated that the H_2O matrix plays a key role in the chemistry [9]. Thymine, however, was not found in any of the samples, though other pyrimidine derivatives, as well as other species of prebiotic interest such as urea and the amino acid glycine, could be identified [8]. We will extend this study to the formation of nucleobases and other prebiotic species from the UV irradiation of pyrimidine in astrophysically relevant ice mixtures containing H_2O, NH_3, CH_3OH, CO, and CO_2.

  4. Prebiotic synthesis in atmospheres containing CH4, CO, and CO2. I - Amino acids

    NASA Technical Reports Server (NTRS)

    Schlesinger, G.; Miller, S. L.

    1983-01-01

    The prebiotic synthesis of amino acids, HCN, H2CO, and NH3 using a spark discharge on various simulated primitive earth atmospheres at 25 C is investigated. Various mixtures of CH4, CO, CO2, N2, NH3, H2O, and H2 were utilized in different experiments. The yields of amino acids (1.2-4.7 percent based on the carbon) are found to be approximately independent of the H2/CH4 ratio and the presence of NH3, and a wide variety of amino acids are obtained. Glycine is found to be almost the only amino acid produced from CO and CO2 model atmospheres, with the maximum yield being about the same for the three carbon sources at high H2/carbon ratios,whereas CH4 is superior at low H2/carbon ratios. In addition, it is found that the directly synthesized NH3 together with the NH3 obtained from the hydrolysis of HCN, nitriles, and urea could have been a major source of ammonia in the atmosphere and oceans of the primitive earth. It is determined that prebiotic syntheses from HCN and H2CO to give products such as purines and sugars and some amino acids could have occurred in primitive atmospheres containing CO and CO2 provided the H2/CO and H2/CO2 ratios were greater than about 1.0.

  5. Supramolecular polymerization of a prebiotic nucleoside provides insights into the creation of sequence-controlled polymers

    DOE PAGESBeta

    Wang, Jun; Bonnesen, Peter V; Rangel, E.; Vallejo, E.; Sanchez-Castillo, Ariadna; Cleaves, II, H. James; Baddorf, Arthur P; Sumpter, Bobby G; Pan, Minghu; Maksymovych, Petro; et al

    2016-01-04

    The self-assembly of a nucleoside on Au(111) was studied to ascertain whether polymerization on well-defined substrates constitutes a promising approach for making sequence-controlled polymers. Scanning tunneling microscopy and density functional theory were used to investigate the self-assembly on Au(111) of (RS)-N9-(2,3-dihydroxypropyl)adenine (DHPA), a plausibly prebiotic nucleoside analog of adenosine. It is found that DHPA molecules self-assemble into a hydrogen-bonded polymer that grows almost exclusively along the herringbone reconstruction pattern, has a two component sequence that is repeated over hundreds of nanometers, and is erasable with electron-induced excitation. Although the sequence is simple, more complicated ones are envisioned if two ormore » more nucleoside types are combined. Because polymerization occurs on a substrate in a dry environment, the success of each combination can be gauged with high-resolution imaging and accurate modeling techniques. The resulting characteristics make nucleoside self-assembly on a substrate an attractive approach for designing sequence-controlled polymers. Moreover, by choosing plausibly prebiotic nucleosides, insights may be provided into how nature created the first sequence-controlled polymers capable of storing information. Such insights, in turn, can inspire new ways of synthesizing sequence-controlled polymers.« less

  6. The evolution of the surface of the mineral schreibersite in prebiotic chemistry.

    PubMed

    La Cruz, Nikita L; Qasim, Danna; Abbott-Lyon, Heather; Pirim, Claire; McKee, Aaron D; Orlando, Thomas; Gull, Maheen; Lindsay, Danny; Pasek, Matthew A

    2016-07-27

    We present a study of the reactions of the meteoritic mineral schreibersite (Fe,Ni)3P, focusing primarily on surface chemistry and prebiotic phosphorylation. In this work, a synthetic analogue of the mineral was synthesized by mixing stoichiometric proportions of elemental iron, nickel and phosphorus and heating in a tube furnace at 820 °C for approximately 235 hours under argon or under vacuum, a modification of the method of Skála and Drábek (2002). Once synthesized, the schreibersite was characterized to confirm the identity of the product as well as to elucidate the oxidation processes affecting the surface. In addition to characterization of the solid product, this schreibersite was reacted with water or with organic solutes in a choline chloride-urea deep eutectic mixture, to constrain potential prebiotic products. Major inorganic solutes produced by reaction of water include orthophosphate, phosphite, pyrophosphate and hypophosphate consistent with prior work on Fe3P corrosion. Additionally, schreibersite corrodes in water and dries down to form a deep eutectic solution, generating phosphorylated products, in this case phosphocholine, using this synthesized schreibersite. PMID:27157087

  7. Aldehydes and sugars from evolved precometary ice analogs: Importance of ices in astrochemical and prebiotic evolution

    PubMed Central

    de Marcellus, Pierre; Meinert, Cornelia; Myrgorodska, Iuliia; Nahon, Laurent; Buhse, Thomas; d’Hendecourt, Louis Le Sergeant; Meierhenrich, Uwe J.

    2015-01-01

    Evolved interstellar ices observed in dense protostellar molecular clouds may arguably be considered as part of precometary materials that will later fall on primitive telluric planets, bringing a wealth of complex organic compounds. In our laboratory, experiments reproducing the photo/thermochemical evolution of these ices are routinely performed. Following previous amino acid identifications in the resulting room temperature organic residues, we have searched for a different family of molecules of potential prebiotic interest. Using multidimensional gas chromatography coupled to time-of-flight mass spectrometry, we have detected 10 aldehydes, including the sugar-related glycolaldehyde and glyceraldehyde—two species considered as key prebiotic intermediates in the first steps toward the synthesis of ribonucleotides in a planetary environment. The presence of ammonia in water and methanol ice mixtures appears essential for the recovery of these aldehydes in the refractory organic residue at room temperature, although these products are free of nitrogen. We finally point out the importance of detecting aldehydes and sugars in extraterrestrial environments, in the gas phase of hot molecular clouds, and, more importantly, in comets and in primitive meteorites that have most probably seeded the Earth with organic material as early as 4.2 billion years ago. PMID:25583475

  8. Prebiotic Synthesis from CO Atmospheres: Implications for the origins of life

    NASA Technical Reports Server (NTRS)

    Meyer, Michael (Technical Monitor); Miyakawa, Shin; Yamanashi, Hiroto; Kobayashi, Kensei; Cleaves, H. James; Miller, Stanley L.

    2002-01-01

    Most models of the primitive atmosphere around the time life originated suggest that the atmosphere was dominated by carbon dioxide, largely based on the notion that the atmosphere was derived via volcanic outgassing, and that those gases were similar to those found in modern volcanic effluent. These models tend to downplay the possibility of a strongly reducing atmosphere, which had been thought to be important for prebiotic synthesis and thus the origin of life. However, there is no definitive geologic evidence for the oxidation state of the early atmosphere and bioorganic compounds are not efficiently synthesized from CO2 atmospheres. In the present study, it was shown that a CO-CO2-N2-H2O atmosphere can give a variety of bioorganic compounds with yields comparable to those obtained from a strongly reducing atmosphere. Atmospheres containing carbon monoxide might therefore have been conducive to prebiotic synthesis and perhaps the origin of life. CO-dominant atmospheres could have existed if the production rate of CO from impacts of extraterrestrial materials were high or if the upper mantle had been more reduced than today.

  9. Pre-biotic stage of life origin under non-photosynthetic conditions

    NASA Technical Reports Server (NTRS)

    Bartsev, S. I.; Mezhevikin, V. V.

    2005-01-01

    Spontaneous assembling of a simplest bacterial cell even if all necessary molecules are present in a solution seems to be extremely rare event and from the scientific standpoint has to be considered as impossible. Therefore, a predecessor of a living cell has to be very simple for providing its self-assembling and at the same time it should be able of progressive increase in complexity. Now phase-separated particles, first of all micelles, are put forward as possible predecessors of living cell. According to the offered working concept only phase-separated particles possessing autocatalytic properties can be considered as predecessors of living cells. The first stage of evolution of these phase-separated autocatalytic systems is the appearance of pre-biotic metabolism providing synthesis of amphiphiles for formation of capsules of these systems. This synthesis is maintained by the energy of a base reaction being a component of a planet-chemical cycle. Catalytic system providing functioning of pre-biotic metabolism is based on multivariate oligomeric autocatalyst, which reproduces itself from monomers, penetrating the particles from the outside. Since the autocatalyst realizes random polymerization then a collection of other oligomers possessing different catalytic functions is produced. In the paper the functioning of multivariate oligomeric autocatalyst in flow reactor is analyzed. c2005 Published by Elsevier Ltd on behalf of COSPAR.

  10. Supramolecular polymerization of a prebiotic nucleoside provides insights into the creation of sequence-controlled polymers

    NASA Astrophysics Data System (ADS)

    Wang, Jun; Bonnesen, Peter V.; Rangel, E.; Vallejo, E.; Sanchez-Castillo, Ariadna; James Cleaves, H., II; Baddorf, Arthur P.; Sumpter, Bobby G.; Pan, Minghu; Maksymovych, Petro; Fuentes-Cabrera, Miguel

    2016-01-01

    Self-assembly of a nucleoside on Au(111) was studied to ascertain whether polymerization on well-defined substrates constitutes a promising approach for making sequence-controlled polymers. Scanning tunneling microscopy and density functional theory were used to investigate the self-assembly on Au(111) of (RS)-N9-(2,3-dihydroxypropyl)adenine (DHPA), a plausibly prebiotic nucleoside analog of adenosine. It is found that DHPA molecules self-assemble into a hydrogen-bonded polymer that grows almost exclusively along the herringbone reconstruction pattern, has a two component sequence that is repeated over hundreds of nanometers, and is erasable with electron-induced excitation. Although the sequence is simple, more complicated ones are envisioned if two or more nucleoside types are combined. Because polymerization occurs on a substrate in a dry environment, the success of each combination can be gauged with high-resolution imaging and accurate modeling techniques. These characteristics make nucleoside self-assembly on a substrate an attractive approach for designing sequence-controlled polymers. Further, by choosing plausibly prebiotic nucleosides, insights may be provided into how nature created the first sequence-controlled polymers capable of storing information. Such insights, in turn, can inspire new ways of synthesizing sequence-controlled polymers.

  11. Supramolecular polymerization of a prebiotic nucleoside provides insights into the creation of sequence-controlled polymers

    PubMed Central

    Wang, Jun; Bonnesen, Peter V.; Rangel, E.; Vallejo, E.; Sanchez-Castillo, Ariadna; James Cleaves II, H.; Baddorf, Arthur P.; Sumpter, Bobby G.; Pan, Minghu; Maksymovych, Petro; Fuentes-Cabrera, Miguel

    2016-01-01

    Self-assembly of a nucleoside on Au(111) was studied to ascertain whether polymerization on well-defined substrates constitutes a promising approach for making sequence-controlled polymers. Scanning tunneling microscopy and density functional theory were used to investigate the self-assembly on Au(111) of (RS)-N9-(2,3-dihydroxypropyl)adenine (DHPA), a plausibly prebiotic nucleoside analog of adenosine. It is found that DHPA molecules self-assemble into a hydrogen-bonded polymer that grows almost exclusively along the herringbone reconstruction pattern, has a two component sequence that is repeated over hundreds of nanometers, and is erasable with electron-induced excitation. Although the sequence is simple, more complicated ones are envisioned if two or more nucleoside types are combined. Because polymerization occurs on a substrate in a dry environment, the success of each combination can be gauged with high-resolution imaging and accurate modeling techniques. These characteristics make nucleoside self-assembly on a substrate an attractive approach for designing sequence-controlled polymers. Further, by choosing plausibly prebiotic nucleosides, insights may be provided into how nature created the first sequence-controlled polymers capable of storing information. Such insights, in turn, can inspire new ways of synthesizing sequence-controlled polymers. PMID:26725380

  12. Prebiotics affect nutrient digestibility but not faecal ammonia in dogs fed increased dietary protein levels.

    PubMed

    Hesta, M; Roosen, W; Janssens, G P J; Millet, S; De Wilde, R

    2003-12-01

    An increased protein content and less digestible protein sources in the diet can induce bad faecal odour. The present study investigated the effect of adding prebiotics to dog diets enriched with animal-derived protein sources on apparent digestibilities and faecal ammonia concentration. In three subsequent periods eight healthy beagle dogs were fed a commercial dog diet that was gradually supplemented by up to 50 % with meat and bone meal (MBM), greaves meal (GM) or poultry meal (PM) respectively. Afterwards, 3 % fructo-oligosaccharides or 3 % isomalto-oligosaccharides were substituted for 3 % of the total diet. Supplementation with animal-derived protein sources did not decrease the apparent N digestibility significantly but oligosaccharides did. On the other hand the bacterial N content (% DM) in the faeces was highest in the oligosaccharide groups followed by the protein-supplemented groups and lowest in the control groups. When the apparent N digestibility was corrected for bacterial N no significant differences were noted anymore except for the GM group where the corrected N digestibility was still lower after oligosaccharide supplementation. The amount of faecal ammonia was significantly increased by supplementing with protein or oligosaccharides in the MBM and GM groups but not in the PM group. When apparent N digestibility is interpreted, a correction for bacterial N should be taken into account, especially when prebiotics are added to the diet. Oligosaccharides did not reduce the faecal ammonia concentrations as expected. PMID:14641959

  13. Prebiotic cytosine synthesis: A critical analysis and implications for the origin of life

    PubMed Central

    Shapiro, Robert

    1999-01-01

    A number of theories propose that RNA, or an RNA-like substance, played a role in the origin of life. Usually, such hypotheses presume that the Watson–Crick bases were readily available on prebiotic Earth, for spontaneous incorporation into a replicator. Cytosine, however, has not been reported in analyses of meteorites nor is it among the products of electric spark discharge experiments. The reported prebiotic syntheses of cytosine involve the reaction of cyanoacetylene (or its hydrolysis product, cyanoacetaldehyde), with cyanate, cyanogen, or urea. These substances undergo side reactions with common nucleophiles that appear to proceed more rapidly than cytosine formation. To favor cytosine formation, reactant concentrations are required that are implausible in a natural setting. Furthermore, cytosine is consumed by deamination (the half-life for deamination at 25°C is ≈340 yr) and other reactions. No reactions have been described thus far that would produce cytosine, even in a specialized local setting, at a rate sufficient to compensate for its decomposition. On the basis of this evidence, it appears quite unlikely that cytosine played a role in the origin of life. Theories that involve replicators that function without the Watson–Crick pairs, or no replicator at all, remain as viable alternatives. PMID:10200273

  14. Prebiotic synthesis from CO atmospheres: Implications for the origins of life

    PubMed Central

    Miyakawa, Shin; Yamanashi, Hiroto; Kobayashi, Kensei; Cleaves, H. James; Miller, Stanley L.

    2002-01-01

    Most models of the primitive atmosphere around the time life originated suggest that the atmosphere was dominated by carbon dioxide, largely based on the notion that the atmosphere was derived via volcanic outgassing, and that those gases were similar to those found in modern volcanic effluent. These models tend to downplay the possibility of a strongly reducing atmosphere, which had been thought to be important for prebiotic synthesis and thus the origin of life. However, there is no definitive geologic evidence for the oxidation state of the early atmosphere and bioorganic compounds are not efficiently synthesized from CO2 atmospheres. In the present study, it was shown that a CO-CO2-N2-H2O atmosphere can give a variety of bioorganic compounds with yields comparable to those obtained from a strongly reducing atmosphere. Atmospheres containing carbon monoxide might therefore have been conducive to prebiotic synthesis and perhaps the origin of life. CO-dominant atmospheres could have existed if the production rate of CO from impacts of extraterrestrial materials were high or if the upper mantle had been more reduced than today. PMID:12409606

  15. The Prebiotic Synthesis and Catalytic Role of Imidazoles and Other Condensing Agents

    NASA Astrophysics Data System (ADS)

    Oró, J.; Basile, B.; Cortes, S.; Shen, C.; Yamrom, T.

    1984-12-01

    In the past decade significant advances have been made in the synthesis of oligonucleotides and other polymers by means of imidazoles and other condensing agents. In spite of the current knowledge of the chemistry of imidazoles and their importance as prebiotic catalysts, their formation under primitive earth conditions has not been properly demonstrated. We have now been able to synthesize imidazole as well as its 2-methyl and 4-methyl derivatives under plausible prebiotic conditions. One method utilizes an aldehyde (formaldehyde or acetaldehyde), glyoxal and ammonia as the starting materials for the formation of imidazole and 2-methylimidazole. The other method uses a carbohydrate and ammonia as the key reagents for the synthesis of 4-methylimidazole. The importance of imidazole and related compounds (e.g., cyanamide) in the synthesis of oligonucleotides has been studied by us as well as others. Apparently the charge relay group (-N-C-N-) present in imidazoles, carbodiimides, cyanamide, or the histidine and arginine of enzyme active centers is essential for the synthesis of phosphodiester and pyrophosphate bonds.

  16. Formation of Amino Acid Thioesters for Prebiotic Peptide Synthesis: Catalysis By Amino Acid Products

    NASA Technical Reports Server (NTRS)

    Weber, Arthur L.; DeVincenzi, Donald L. (Technical Monitor)

    1999-01-01

    The origin of life can be described as a series of events in which a prebiotic chemical process came increasingly under the control of its catalytic products. In our search for this prebiotic process that yielded catalytic takeover products (such as polypeptides), we have been investigating a reaction system that generates peptide-forming amino acid thioesters from formaldehyde, glycolaldehyde, and ammonia in the presence of thiols. As shown below, this model process begins by aldol condensation of formaldehyde and glycolaldehyde to give trioses and releases. These sugars then undergo beta-dehydration yielding their respective alpha-ketoaldehydes. Addition of ammonia to the alpha-ketoaldehydes yields imines which can either: (a) rearrange in the presence of thesis to give amino acid thioesters or (be react with another molecule of aldehyde to give imidazoles. This 'one-pot' reaction system operates under mild aqueous conditions, and like modem amino acid biosynthesis, uses sugar intermediates which are converted to products by energy-yielding redox reactions. Recently, we discovered that amino acids, such as the alanine reaction product, catalyze the first and second steps of the process. In the presence of ammonia the process also generates other synthetically useful products, like the important biochemical -- pyruvic acid.

  17. Probiotics and Prebiotics: Present Status and Future Perspectives on Metabolic Disorders

    PubMed Central

    Yoo, Ji Youn; Kim, Sung Soo

    2016-01-01

    Metabolic disorders, including type 2 diabetes (T2DM) and cardiovascular disease (CVD), present an increasing public health concern and can significantly undermine an individual’s quality of life. The relative risk of CVD, the primary cause of death in T2DM patients, is two to four times higher in people with T2DM compared with those who are non-diabetic. The prevalence of metabolic disorders has been associated with dynamic changes in dietary macronutrient intake and lifestyle changes over recent decades. Recently, the scientific community has considered alteration in gut microbiota composition to constitute one of the most probable factors in the development of metabolic disorders. The altered gut microbiota composition is strongly conducive to increased adiposity, β-cell dysfunction, metabolic endotoxemia, systemic inflammation, and oxidative stress. Probiotics and prebiotics can ameliorate T2DM and CVD through improvement of gut microbiota, which in turn leads to insulin-signaling stimulation and cholesterol-lowering effects. We analyze the currently available data to ascertain further potential benefits and limitations of probiotics and prebiotics in the treatment of metabolic disorders, including T2DM, CVD, and other disease (obesity). The current paper explores the relevant contemporary scientific literature to assist in the derivation of a general perspective of this broad area. PMID:26999199

  18. Catalytic Role of Manganese Oxides in Prebiotic Nucleobases Synthesis from Formamide

    NASA Astrophysics Data System (ADS)

    Bhushan, Brij; Nayak, Arunima; Kamaluddin

    2016-06-01

    Origin of life processes might have begun with the formation of important biomonomers, such as amino acids and nucleotides, from simple molecules present in the prebiotic environment and their subsequent condensation to biopolymers. While studying the prebiotic synthesis of naturally occurring purine and pyrimidine derivatives from formamide, the manganese oxides demonstrated not only good binding for formamide but demonstrated novel catalytic activity. A novel one pot manganese oxide catalyzed synthesis of pyrimidine nucleobases like thymine is reported along with the formation of other nucleobases like purine, 9-(hydroxyacetyl) purine, cytosine, 4(3 H)-pyrimidinone and adenine in acceptable amounts. The work reported is significant in the sense that the synthesis of thymine has exhibited difficulties especially under one pot conditions and also such has been reported only under the catalytic activity of TiO2. The lower oxides of manganese were reported to show higher potential as catalysts and their existence were favored by the reducing atmospheric conditions prevalent on early Earth; thereby confirming the hypothesis that mineral having metals in reduced form might have been more active during the course of chemical evolution. Our results further confirm the role of formamide as a probable precursor for the formation of purine and pyrimidine bases during the course of chemical evolution and origin of life.

  19. Processing and Synthesis of Pre-Biotic Chemicals in Hypervelocity Impacts

    NASA Technical Reports Server (NTRS)

    Brickerhoff, W. B.; Managadze, G. G.; Chumikov, A. E.; Managadze, N. G.

    2005-01-01

    Hypervelocity impacts (HVIs) may have played a significant role in establishing the initial organic inventory for pre-biotic chemistry on the Earth and other planetary bodies. In addition to the delivery of organic compounds intact to planetary surfaces, generally at velocities below approx.20 km/s, HVIs also enable synthesis of new molecules. The cooling post-impact plasma plumes of HVIs in the interstellar medium (ISM), the protosolar nebula (PSN), and the early solar system comprise pervasive conditions for organic synthesis. Such plasma synthesis (PS) can operate over many length scales (from nm-scale dust to planets) and energy scales (from molecular rearrangement to atomization and recondensation). HVI experiments with the flexibility to probe the highest velocities and distinguish synthetic routes are a high priority to understand the relevance of PS to exobiology. We describe here recent studies of PS at small spatial scales and extremely high velocities with pulsed laser ablation (PLA). PLA can simulate the extreme plasma conditions generated in impacts of dust particles at speeds of up to 100 km/s or more. When applied to carbonaceous solids, new and pre-biotically relevant molecular species are formed with high efficiency [1,2].

  20. A possible prebiotic origin on volcanic islands of oligopyrrole-type photopigments and electron transfer cofactors.

    PubMed

    Fox, Stefan; Strasdeit, Henry

    2013-06-01

    Tetrapyrroles are essential to basic biochemical processes such as electron transfer and photosynthesis. However, it is not known whether these evolutionary old molecules have a prebiotic origin. We have serendipitously obtained pyrroles, which are the corresponding monomers, in laboratory experiments that simulated the interaction of amino acid-containing seawater with molten lava. The thermal pyrrole formation from amino acids, which so far has only been reported for special cases, can be explained by the observation that the amino acids become metal bonded, for example in (CaCl2)3(Hala)2·6H2O (Hala=DL-alanine), when the seawater evaporates. At a few hundred degrees Celsius, sea salt crusts also release hydrochloric acid (HCl). On primordial volcanic islands, the volatile pyrroles and HCl must have condensed at cooler locations, for example, in rock pools. There, pyrrole oligomerization may have occurred. To study this possibility, we added formaldehyde and nitrite, two species for which plausible prebiotic sources are known, to 2,4-diethylpyrrole and HCl. We found that even at high dilution conjugated (oxidized) oligomers, including octaethylporphyrin and other cyclic and open-chain tetrapyrroles, were formed. All experiments were conducted under rigorously oxygen-free conditions. Our results suggest that primitive versions of present-day biological cofactors such as chlorophylls, bilins, and heme were spontaneously abiotically synthesized on primordial volcanic islands and thus may have been available to the first protocells. PMID:23742230

  1. In vitro assessment of agave fructans (Agave salmiana) as prebiotics and immune system activators.

    PubMed

    Moreno-Vilet, L; Garcia-Hernandez, M H; Delgado-Portales, R E; Corral-Fernandez, N E; Cortez-Espinosa, N; Ruiz-Cabrera, M A; Portales-Perez, D P

    2014-02-01

    The prebiotic effect of agave fructans (Agave salmiana) was evaluated through the growth of two lactic acid bacterial (LAB) strains (Lactobacillus casei and Bifidobacterium lactis). The immune system was activated through the stimulation of peripheral blood mononuclear cells (PBMC) of healthy subjects testing fructans, LAB or a mixture of these compounds at different concentrations. Immune responses, such as early cell activation (CD69), cell cycle progression, nitric oxide (NO) production and the expression of transcription factors for lymphocyte differentiation, were analyzed. Compared with other fructans, the extracted agave fructans showed the highest prebiotic activity and increased levels of CD69 expression, proliferative activity and NO production when administered with the probiotic L. casei. The Th1 lymphocyte differentiation produced through LAB stimulation was greatly diminished after the incorporation of agave fructans. In conclusion, these types of fructans (A. salmiana) are involved in the activation and selective differentiation of cells of the immune system through interactions with probiotics. Thus, agave fructans represent a novel immunomodulator that might benefit the functional food industry. PMID:24211431

  2. VUV photoionization and dissociative photoionization of the prebiotic molecule acetyl cyanide: Theory and experiment

    NASA Astrophysics Data System (ADS)

    Bellili, A.; Schwell, M.; Bénilan, Y.; Fray, N.; Gazeau, M.-C.; Mogren Al-Mogren, M.; Guillemin, J.-C.; Poisson, L.; Hochlaf, M.

    2014-10-01

    The present combined theoretical and experimental investigation concerns the single photoionization of gas-phase acetyl cyanide and the fragmentation pathways of the resulting cation. Acetyl cyanide (AC) is inspired from both the chemistry of cyanoacetylene and the Strecker reaction which are thought to be at the origin of medium sized prebiotic molecules in the interstellar medium. AC can be formed by reaction from cyanoacetylene and water but also from acetaldehyde and HCN or the corresponding radicals. In view of the interpretation of vacuum ultraviolet (VUV) experimental data obtained using synchrotron radiation, we explored the ground potential energy surface (PES) of acetyl cyanide and of its cation using standard and recently implemented explicitly correlated methodologies. Our PES covers the regions of tautomerism (between keto and enol forms) and of the lowest fragmentation channels. This allowed us to deduce accurate thermochemical data for this astrobiologically relevant molecule. Unimolecular decomposition of the AC cation turns out to be very complex. The implications for the evolution of prebiotic molecules under VUV irradiation are discussed.

  3. Supramolecular polymerization of a prebiotic nucleoside provides insights into the creation of sequence-controlled polymers.

    PubMed

    Wang, Jun; Bonnesen, Peter V; Rangel, E; Vallejo, E; Sanchez-Castillo, Ariadna; James Cleaves Ii, H; Baddorf, Arthur P; Sumpter, Bobby G; Pan, Minghu; Maksymovych, Petro; Fuentes-Cabrera, Miguel

    2016-01-01

    Self-assembly of a nucleoside on Au(111) was studied to ascertain whether polymerization on well-defined substrates constitutes a promising approach for making sequence-controlled polymers. Scanning tunneling microscopy and density functional theory were used to investigate the self-assembly on Au(111) of (RS)-N(9)-(2,3-dihydroxypropyl)adenine (DHPA), a plausibly prebiotic nucleoside analog of adenosine. It is found that DHPA molecules self-assemble into a hydrogen-bonded polymer that grows almost exclusively along the herringbone reconstruction pattern, has a two component sequence that is repeated over hundreds of nanometers, and is erasable with electron-induced excitation. Although the sequence is simple, more complicated ones are envisioned if two or more nucleoside types are combined. Because polymerization occurs on a substrate in a dry environment, the success of each combination can be gauged with high-resolution imaging and accurate modeling techniques. These characteristics make nucleoside self-assembly on a substrate an attractive approach for designing sequence-controlled polymers. Further, by choosing plausibly prebiotic nucleosides, insights may be provided into how nature created the first sequence-controlled polymers capable of storing information. Such insights, in turn, can inspire new ways of synthesizing sequence-controlled polymers. PMID:26725380

  4. VUV photoionization and dissociative photoionization of the prebiotic molecule acetyl cyanide: Theory and experiment

    SciTech Connect

    Bellili, A.; Hochlaf, M. E-mail: martin.schwell@lisa.u-pec.fr; Schwell, M. E-mail: martin.schwell@lisa.u-pec.fr; Bénilan, Y.; Fray, N.; Gazeau, M.-C.; Mogren Al-Mogren, M.; Guillemin, J.-C.; Poisson, L.

    2014-10-07

    The present combined theoretical and experimental investigation concerns the single photoionization of gas-phase acetyl cyanide and the fragmentation pathways of the resulting cation. Acetyl cyanide (AC) is inspired from both the chemistry of cyanoacetylene and the Strecker reaction which are thought to be at the origin of medium sized prebiotic molecules in the interstellar medium. AC can be formed by reaction from cyanoacetylene and water but also from acetaldehyde and HCN or the corresponding radicals. In view of the interpretation of vacuum ultraviolet (VUV) experimental data obtained using synchrotron radiation, we explored the ground potential energy surface (PES) of acetyl cyanide and of its cation using standard and recently implemented explicitly correlated methodologies. Our PES covers the regions of tautomerism (between keto and enol forms) and of the lowest fragmentation channels. This allowed us to deduce accurate thermochemical data for this astrobiologically relevant molecule. Unimolecular decomposition of the AC cation turns out to be very complex. The implications for the evolution of prebiotic molecules under VUV irradiation are discussed.

  5. Production, Purification, and in Vitro Evaluation of the Prebiotic Potential of Arabinoxylooligosaccharides from Brewer's Spent Grain.

    PubMed

    Gómez, Belén; Míguez, Beatriz; Veiga, Adán; Parajó, Juan Carlos; Alonso, José Luís

    2015-09-30

    Brewer's spent grain (BSG) samples were subjected to a two-step aqueous processing (starch extraction and autohydrolysis) in order to assess their potential as a raw material for obtaining a mixture of arabinoxylooligosaccharides (AXOS) suitable to be use as prebiotics for elderly. After hydrothermal treatment, the liquors were refined by a sequence of purification and conditioning steps including membrane filtration, enzymatic hydrolysis, and ion exchange. The presence of both substituted (degree of polimerization (DP) = 2-10) and unsubstituted (DP = 2-16) oligosaccharides made up of xylose and arabinose (AXOS) were confirmed in purified mixtures (in which total OS content = 84% w/w) by using chromatographic techniques and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS). Finally, AXOS were evaluated for their prebiotic activity by in vitro fermentation assays using fecal inocula from elderly people, demonstrating that AXOS were slightly better substrates than FOS, in terms of bacterial population shifts as in the production of SCFA. PMID:26345203

  6. Prebiotic consumption in pregnant and lactating women increases IL-27 expression in human milk.

    PubMed

    Kubota, Takayuki; Shimojo, Naoki; Nonaka, Ken; Yamashita, Masakatsu; Ohara, Osamu; Igoshi, Yuka; Ozawa, Naoko; Nakano, Taiji; Morita, Yoshinori; Inoue, Yuzaburo; Arima, Takayasu; Chiba, Kohki; Nakamura, Yoshitaka; Ikegami, Shuji; Masuda, Kentaro; Suzuki, Shuichi; Kohno, Yoichi

    2014-02-01

    The consumption of probiotics by pregnant and lactating women may prevent the onset of allergic disorders in their children by increasing the concentrations of immunoactive agents such as cytokines in breast milk. Prebiotics such as fructo-oligosaccharides (FOS) increase the number of beneficial organisms such as bifidobacteria. Thus, prebiotics may have an effect similar to that of probiotics. The objective of the present study was to carry out a comprehensive analysis of mRNA expression in human milk cells to identify changes in the concentrations of cytokines in breast milk after the consumption of FOS (4 g × 2 times/d) by pregnant and lactating women. The microarray analysis of human milk cells demonstrated that the expression levels of five genes in colostrum samples and fourteen genes in 1-month breast milk samples differed more than 3-fold between the FOS and control groups (sucrose group). The mRNA expression level of IL-27, a cytokine associated with immunoregulatory function, was significantly higher in 1-month breast milk samples obtained from the FOS group than in those obtained from the control group. In addition, the protein concentrations of IL-27 in colostrum and 1-month breast milk samples were significantly higher in the FOS group than in the control group. In conclusion, the consumption of FOS by pregnant and lactating women increases the production of IL-27 in breast milk. Future studies will address the association of this phenomenon with the onset of allergic disorders in children. PMID:24073873

  7. The atmosphere of the primitive earth and the prebiotic synthesis of organic compounds

    NASA Technical Reports Server (NTRS)

    Miller, S. L.; Schlesinger, G.

    1983-01-01

    The prebiotic synthesis of organic compounds is investigated using a spark discharge on various simulated prebiotic atmospheres at 25 C. It is found that glycine is almost the only amino acid produced from the model atmospheres containing CO and CO2. These results show that the maximum yield is about the same for the three carbon sources (CO, CO2, and CH4) at high H2/carbon ratios, but that CH4 is superior at low H2/carbon ratios. CH4 is found to yield a much greater variety of amino acids than either CO or CO2. If it is assumed that amino acids more complex than glycine were required for the origin of life, then these findings indicate the need for CH4 in the primitive atmosphere. The yields of cyanide and formaldehyde are shown to parallel the amino acid results, with yields of HCN and H2CO as high as 13 percent based on carbon. Ammonia is also found to be produced from N2 in experiments with no added NH3 in yields as high as 4.9 percent. These results indicate that large amounts of NH3 would have been synthesized on the primitive earth by electric discharges.

  8. Isolation and prebiotic activity of water-soluble polysaccharides fractions from the bamboo shoots (Phyllostachys praecox).

    PubMed

    He, Shudong; Wang, Xin; Zhang, Yi; Wang, Jing; Sun, Hanju; Wang, Junhui; Cao, Xiaodong; Ye, Yongkang

    2016-10-20

    The water-soluble polysaccharides from bamboo shoots (Phyllostachys praecox) (WBP) were isolated, and the characterizations as well as prebiotic activities were investigated. The yield of WBP was 7.58±0.31% under optimal hot-water extraction conditions. Two fractions, i.e., WBP-1 and WBP-2 with molecular weight of 83.50kDa and 80.08kDa, respectively, were purified by chromatography. Both the polysaccharides fractions were identified as heteropolysaccharides-protein complexes composed of 15 kinds of common amino acids in protein part and rhamnose, arabinose, xylose, mannose, glucose and galactose in different molar ratios in polysaccharide part. The existence of α- and β-glycosidic linkages between the sugar units was confirmed by FTIR and NMR spectra. Compared with the blank control and the reference of FOS, WBP-1 and WBP-2 significantly increased the numbers of Bifidobacterium adolescentis and Bifidobacterium bifidum (P<0.05), which contributed to the production of organic acids, suggesting that the polysaccharides have potential prebiotic properties. PMID:27474570

  9. Bacterial nanocellulose-pectin bionanocomposites as prebiotics against drying and gastrointestinal condition.

    PubMed

    Khorasani, Alireza Chackoshian; Shojaosadati, Seyed Abbas

    2016-02-01

    Various encapsulating materials have been suggested to protect probiotics, but the potential of nanomaterials is yet to be exploited. This study aimed to improve the survivability of Bacillus coagulans entrapping into bionanocomposites comprising of bacterial nanocellulose (BNC), pectin and Schizophyllum commune extract were investigated as new matrices to protect probiotics. The bionanocomposite design was optimized to obtain the highest prebiotic score and survivability of probiotic under drying process and gastrointestinal condition using the simplex-lattice mixture method. The optimal bionanocomposite formulation was obtained by mixing 20% pectin with 80% BNC. High survival rate of B. coagulans after microwave drying (99.43%) and sequential digestion under stimulated gastrointestinal fluids (94.76%) with optimum prebiotic score for B. coagulans (1.00) and for Escherichia coli (0.99), were obtained. Nanoscale properties of BNC, high crystallinity and available surface area resulted in high probiotic protection. Stability test during storage period at ambient temperature, 4°C and -20°C performed viability reduction, respectively, 1.3, 1.7 and 1.8 log CFU/g, which inferred the optimal bionanocomposite could be candidate as useful probiotics protection system in a variety of temperature during long time. PMID:26627598

  10. Prebiotic chemistry in eutectic solutions at the water-ice matrix.

    PubMed

    Menor-Salván, César; Marín-Yaseli, Margarita R

    2012-08-21

    A crystalline ice matrix at subzero temperatures can maintain a liquid phase where organic solutes and salts concentrate to form eutectic solutions. This concentration effect converts the confined reactant solutions in the ice matrix, sometimes making condensation and polymerisation reactions occur more favourably. These reactions occur at significantly high rates from a prebiotic chemistry standpoint, and the labile products can be protected from degradation. The experimental study of the synthesis of nitrogen heterocycles at the ice-water system showed the efficiency of this scenario and could explain the origin of nucleobases in the inner Solar System bodies, including meteorites and extra-terrestrial ices, and on the early Earth. The same conditions can also favour the condensation of monomers to form ribonucleic acid and peptides. Together with the synthesis of these monomers, the ice world (i.e., the chemical evolution in the range between the freezing point of water and the limit of stability of liquid brines, 273 to 210 K) is an under-explored experimental model in prebiotic chemistry. PMID:22660387

  11. Elementary Reactions and Their Role in Gas-Phase Prebiotic Chemistry

    PubMed Central

    Balucani, Nadia

    2009-01-01

    The formation of complex organic molecules in a reactor filled with gaseous mixtures possibly reproducing the primitive terrestrial atmosphere and ocean demonstrated more than 50 years ago that inorganic synthesis of prebiotic molecules is possible, provided that some form of energy is provided to the system. After that groundbreaking experiment, gas-phase prebiotic molecules have been observed in a wide variety of extraterrestrial objects (including interstellar clouds, comets and planetary atmospheres) where the physical conditions vary widely. A thorough characterization of the chemical evolution of those objects relies on a multi-disciplinary approach: 1) observations allow us to identify the molecules and their number densities as they are nowadays; 2) the chemistry which lies behind their formation starting from atoms and simple molecules is accounted for by complex reaction networks; 3) for a realistic modeling of such networks, a number of experimental parameters are needed and, therefore, the relevant molecular processes should be fully characterized in laboratory experiments. A survey of the available literature reveals, however, that much information is still lacking if it is true that only a small percentage of the elementary reactions considered in the models have been characterized in laboratory experiments. New experimental approaches to characterize the relevant elementary reactions in laboratory are presented and the implications of the results are discussed. PMID:19564951

  12. Abiotic synthesis of RNA in water: a common goal of prebiotic chemistry and bottom-up synthetic biology.

    PubMed

    Cafferty, Brian J; Hud, Nicholas V

    2014-10-01

    For more than half a century chemists have searched for a plausible prebiotic synthesis of RNA. The initial advances of the 1960s and 1970s were followed by decades of measured progress and a growing pessimism about overcoming remaining challenges. Fortunately, the past few years have provided a number of important advances, including new abiotic routes for the synthesis of nucleobases, nucleosides, and nucleotides. Recent discoveries also provide additional support for the hypothesis that RNA is the product of evolution, being preceded by ancestral genetic polymers, or pre-RNAs, that are synthesized more easily than RNA. In some cases, parallel searches for plausible prebiotic routes to RNA and pre-RNAs have provided more than one experimentally verified synthesis of RNA substructures and possible predecessors. Just as the synthesis of a contemporary biological molecule cannot be understood without knowledge of cellular metabolism, it is likely that an integrated approach that takes into account both plausible prebiotic reactions and plausible prebiotic environments will ultimately provide the most satisfactory and unifying chemical scenarios for the origin of nucleic acids. In this context, recent advances towards the abiotic synthesis of RNA and candidates for pre-RNAs are beginning to suggest that some molecules (e.g., urea) were multi-faceted contributors to the origin of nucleic acids, and the origin of life. PMID:25438801

  13. In vitro fermentation response of laying hen cecal bacteria to combinations of fructooligosaccharide (FOS) prebiotic with alfalfa and layer ration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this in vitro study was to evaluate the effects of combining a prebiotic with an alfalfa molting diet on fermentation by laying hen cecal bacteria. Cecal contents from laying hens were diluted to a 1:3000 concentration with an anaerobic dilution solution and added to serum tubes fi...

  14. In ovo injection of prebiotics and synbiotics affects the digestive potency of the pancreas in growing chickens.

    PubMed

    Pruszynska-Oszmalek, E; Kolodziejski, P A; Stadnicka, K; Sassek, M; Chalupka, D; Kuston, B; Nogowski, L; Mackowiak, P; Maiorano, G; Jankowski, J; Bednarczyk, M

    2015-08-01

    The purpose of the study was to examine the effect of 2 prebiotics and 2 synbiotics on the digestive potency of pancreas in 1-, 3-, 7-, 14-, 21-, and 34-day-old cockerels. Prebiotics (inulin and Bi²tos) and synbiotics (inulin + Lactococcus lactis subsp. lactis and Bi²tos + Lactococcus lactis subsp. cremoris) were injected in ovo into the air cell on the 12th d embryonic development. Their application increased the activity of amylase, lipase, and trypsin in the pancreas. The most pronounced changes were observed at the end of the investigated rearing period (d 34). The strongest stimulative effects on amylase were shown by both synbiotics, on lipase synbiotic Bi²tos + Lactococcus lactis subsp. cremoris, and on trypsin all the used prebiotics and synbiotics. Simultaneously, neither the absolute nor the relative mass of the pancreas in comparison to control group were changed. Also, the injected in ovo compounds did not cause a deterioration in the posthatching condition of the chicken liver, as determined by measurement of the activity of marker enzymes in the blood (alanine aminotransferase and aspartate aminotransferase). Treatment with the prebiotics and synbiotics did not change the feed conversion ratio but Bi²tos (galacto-oligosaccharide) and inulin (fructan) + Lactococcus lactis subsp. lactis significantly increased final BW. PMID:26112038

  15. Prebiotic Low Sugar Chocolate Dairy Desserts: Physical and Optical Characteristics and Performance of PARAFAC and PCA Preference Map.

    PubMed

    Morais, E C; Esmerino, E A; Monteiro, R A; Pinheiro, C M; Nunes, C A; Cruz, A G; Bolini, Helena M A

    2016-01-01

    The addition of prebiotic and sweeteners in chocolate dairy desserts opens up new opportunities to develop dairy desserts that besides having a lower calorie intake still has functional properties. In this study, prebiotic low sugar dairy desserts were evaluated by 120 consumers using a 9-point hedonic scale, in relation to the attributes of appearance, aroma, flavor, texture, and overall liking. Internal preference map using parallel factor analysis (PARAFAC) and principal component analysis (PCA) was performed using the consumer data. In addition, physical (texture profile) and optical (instrumental color) analyses were also performed. Prebiotic dairy desserts containing sucrose and sucralose were equally liked by the consumers. These samples were characterized by firmness and gumminess, which can be considered drivers of liking by the consumers. Optimization of the prebiotic low sugar dessert formulation should take in account the choice of ingredients that contribute in a positive manner for these parameters. PARAFAC allowed the extraction of more relevant information in relation to PCA, demonstrating that consumer acceptance analysis can be evaluated by simultaneously considering several attributes. Multiple factor analysis reported Rv value of 0.964, suggesting excellent concordance for both methods. PMID:26613361

  16. Identification of nitrogenous organic species in Titan aerosols analogs: Implication for prebiotic chemistry on Titan and early Earth

    NASA Astrophysics Data System (ADS)

    He, Chao; Smith, Mark A.

    2014-08-01

    Titan has a significant atmosphere composed primarily of nitrogen and methane with a significant organic haze component. Its nitrogen-rich atmosphere, abundant organics, and liquid surface make this moon of interest as a prebiotic laboratory at the planetary scale and one of the best targets for studying prebiotic planetary organic chemistry. In our previous work, we have investigated the chemical composition of Titan aerosol analogs (tholins) and identified a variety of nitrogenous organic molecules. Here we continue our structural investigation and identify four important prebiotic molecules in Titan tholins using NMR, GC-MS and standard sample comparison, including aminoacetonitrile, succinonitrile, acetoguanamine and adenine. On the basis of their structural characteristics, we suggest their formation pathways via simple precursors including methanimine (CH2NH), HCN, NH3, CH3CN and C2H2 in laboratory N2sbnd CH4 plasma or potentially in Titan’s atmosphere. Among these molecules, aminoacetonitrile is a potential precursor of amino acids and peptides, while adenine is a necessary ingredient for DNA and RNA. The identification of these molecules in Titan’s organic aerosol analogs increases our knowledge of Titan’s organic chemistry and its prebiotic implications.

  17. Influence of prebiotics on Lactobacillus reuteri death kinetics under sub-optimal temperatures and pH.

    PubMed

    Altieri, Clelia; Iorio, Maria Clara; Bevilacqua, Antonio; Sinigaglia, Milena

    2016-01-01

    Eaten foodstuffs are usually fortified with prebiotic ingredients, such as inulin and oligofructose (FOS). The main goal of this study was to evaluate the combined effects of inulin and FOS with either suboptimal pH or storage temperature on the viability of Lactobacillus reuteri DSM 20016. Data were modeled through Weibull equation for the evaluation of the microbiological shelf life and the survival time. Prebiotics enhanced the microbiological shelf life and enhanced the survival time of the target bacterium. The use of the factorial ANOVA highlighted that inulin and FOS exerted a different effect as a function of pH and temperature. Inulin prolonged survival time under acidic conditions, while the effect of glucose + FOS was significant at pH 8. Finally, temperature could act by increasing or decreasing the effect of prebiotics, as they could exert a protective effect at 30 °C but not at 44 °C. As the main output of this research, we could suggest that the effect of prebiotics on L. reuteri could be significantly affected by pH and temperature, thus pinpointing that the design of a symbiotic food should also rely on these factors. PMID:26804428

  18. Salinity and pH affect Na+-montmorillonite dissolution and amino acid adsorption: a prebiotic chemistry study

    NASA Astrophysics Data System (ADS)

    Farias, Ana Paula S. F.; Tadayozzi, Yasmin S.; Carneiro, Cristine E. A.; Zaia, Dimas A. M.

    2014-06-01

    The adsorption of amino acids onto minerals in prebiotic seas may have played an important role for their protection against hydrolysis and formation of polymers. In this study, we show that the adsorption of the prebiotic amino acids, glycine (Gly), α-alanine (α-Ala) and β-alanine (β-Ala), onto Na+-montmorillonite was dependent on salinity and pH. Specifically, adsorption decreased from 58.3-88.8 to 0-48.9% when salinity was increased from 10 to 100-150% of modern seawater. This result suggests reduced amino acid adsorption onto minerals in prebiotic seas, which may have been even more saline than the tested conditions. Amino acids also formed complexes with metals in seawater, affecting metal adsorption onto Na+-montmorillonite, and amino acid adsorption was enhanced when added before Na+-montmorillonite was exposed to high saline solutions. Also, the dissolution of Na+-montmorillonite was reduced in the presence of amino acids, with β-Ala being the most effective. Thus, prebiotic chemistry experiments should also consider the integrity of minerals in addition to their adsorption capacity.

  19. Non-digestible oligosaccharides used as prebiotic agents: mode of production and beneficial effects on animal and human health.

    PubMed

    Grizard, D; Barthomeuf, C

    1999-01-01

    Prebiotic agents are food ingredients that are potentially beneficial to the health of consumers. The main commercial prebiotic agents consist of oligosaccharides and dietary fibres (mainly inulin). They are essentially obtained by one of three processes: 1) the direct extraction of natural polysaccharides from plants; 2) the controlled hydrolysis of such natural polysaccharides; 3) enzymatic synthesis, using hydrolases and/or glycosyl transferases. Both of these enzyme types catalyse transglycosylation reactions, allowing synthesis of small molecular weight synthetic oligosaccharides from mono- and disaccharides. Presently, in Europe, inulin-type fructans, characterised by the presence of fructosyl units bound to the beta-2,1 position of sucrose, are considered as one of the carbohydrate prebiotic references. Prebiotics escape enzymatic digestion in the upper gastrointestinal tract and enter the caecum without change to their structure. None are excreted in the stools, indicating that they are fermented by colonic flora so as to give a mixture of short-chain fatty acids (acetate, propionate and butyrate), L-lactate, carbon dioxide and hydrogen. By stimulating bifidobacteria, they may have the following implications for health: 1) potential protective effects against colorectal cancer and infectious bowel diseases by inhibiting putrefactive bacteria (Clostridium perfringens ) and pathogen bacteria (Escherichia coli, Salmonella, Listeria and Shigella ), respectively; 2) improvement of glucid and lipid metabolisms; 3) fibre-like properties by decreasing the renal nitrogen excretion; 4) improvement in the bioavailability of essential minerals; and 5) low cariogenic factor. These potential beneficial effects have been largely studied in animals but have not really been proven in humans. The development of a second generation of oligosaccharides and the putative implication of a complex bacterial trophic chain in the intestinal prebiotic fermentation process are also

  20. Effect of dietary supplementation of prebiotic, probiotic, and synbiotic on growth performance and carcass characteristics of broiler chickens

    PubMed Central

    Sarangi, Nihar Ranjan; Babu, L. K.; Kumar, A.; Pradhan, C. R.; Pati, P. K.; Mishra, J. P.

    2016-01-01

    Aim: The aim was to investigate the effects of dietary supplementations of prebiotic, probiotic, and synbiotic on growth performance and carcass characteristics of broiler chickens. Materials and Methods: A total of 360 1-day-old Vencobb broiler chickens of either sex were randomly assigned to four dietary treatments each consisting of three replicates and each replicate having 30 birds for 6 weeks. The dietary treatments were (1) control group with basal diet, (2) basal diet supplemented with prebiotic (at 400 g/tonne of starter as well as finisher ration), (3) basal diet supplemented with probiotic (at 100 g/tonne of starter ration and 50 g/tonne of finisher ration), and (4) basal diet supplemented with synbiotic(at 500 g/tonne of starter as well as finisher ration). The birds were provided with ad-libitum feed and drinking water during the entire experimental period. Results: The highest body weight observed in asynbiotic group, which was non-significantly (p>0.05) higher than thecontrol group. Prebiotic and probiotic groups showed lower body weight than synbiotic and control groups. A total feed intake did not show any significant (p>0.05) difference between experimental groups. There were no significant (p>0.05) differences in feed conversion ratio of broiler chickens in prebiotic, probiotic, and synbiotic groups as compared with control group. There was no significant (p>0.05) difference in the carcass traits with respect to dressing percentage, carcass percentage, heart weight, liver weight and gizzard weight, wing percentage, breast percentage, back percentage, thigh percentage, and drumstick percentage in Cobb broilers under study. Conclusion: The growth performance and percentage of carcass yield did not show any significant increase by the dietary inclusion of prebiotic, probiotic, and synbiotic compared with unsupplemented control in a commercial broiler chicken. PMID:27057118

  1. Nucleobases and other Prebiotic Species from the Ultraviolet Irradiation of Pyrimidine in Astrophysical Ices

    NASA Technical Reports Server (NTRS)

    Sandford, S. A.; Nuevo, M.; Materese, C. K.; Milam, S. N.

    2012-01-01

    Nucleobases are N-heterocycles that are the informational subunits of DNA and RNA, and are divided into two families: pyrimidine bases (uracil, cytosine, and thymine) and purine bases (adenine and guanine). Nucleobases have been detected in meteorites and their extraterrestrial origin confirmed by isotope measurement. Although no Nheterocycles have ever been observed in the ISM, the positions of the 6.2-m interstellar emission features suggest a population of such molecules is likely to be present. In this work we study the formation of pyrimidine-based molecules, including nucleobases, as well as other species of prebiotic interest, from the ultraviolet (UV) irradiation of pyrimidine in combinations of H2O, NH3, CH3OH, and CH4 ices at low temperature, in order to simulate the astrophysical conditions under which prebiotic species may be formed in the interstellar medium and icy bodies of the Solar System. Experimental: Gas mixtures are prepared in a glass mixing line (background pressure approx. 10(exp -6)-10(exp -5) mbar). Relative proportions between mixture components are determined by their partial pressures. Gas mixtures are then deposited on an aluminum foil attached to a cold finger (15-20 K) and simultaneously irradiated with an H2 lamp emitting UV photons (Lyman and a continuum at approx.160 nm). After irradiation samples are warmed to room temperature, at which time the remaining residues are recovered to be analyzed with liquid and gas chromatographies. Results: These experiments showed that the UV irradiation of pyrimidine mixed in these ices at low temperature leads to the formation of several photoproducts derived from pyrimidine, including the nucleobases uracil and cytosine, as well as their precursors 4(3H)-pyrimidone and 4-aminopyrimidine (Fig. 1). Theoretical quantum calculations on the formation of 4(3H)-pyrimidone and uracil from the irradiation of pyrimidine in pure H2O ices are in agreement with their experimental formation pathways. In

  2. Why Interstellar Ices Can Be Considered As Precursors For Prebiotic Chemistry

    NASA Astrophysics Data System (ADS)

    Hendecourt, Louis Le Sergeant d.; de Marcellus, Pierre; Meinert, Cornelia; Myrgorodska, Iuliia; Nahon, Laurent; Modica, Paola; Buhse, Thomas; Meierhenrich, Uwe J.

    2015-08-01

    Interstellar ices made of simple molecules (H2O, CO, CO2, CH3OH, NH3, CH4…) are abundant species observed in molecular clouds where stars and planetary systems form. Since the constitutive elements (H, O, C, N, S, P) are the most cosmically abundant and condensible, they favor the making of ices on grains. In the mantles formed, a rich organic chemistry develops, thanks to the protective nature of the grains. This chemistry leads to a high complexity. Radical chemistry generated by photo/thermo-chemical processes on the surfaces, leaves to the formation of organic residues as those produced in our laboratory using ice templates, and further studied, using methods that pertain mostly to analytical chemistry. The organic material formed may resemble the Soluble Organic Matter observed in pristine meteorites. From numerous amino acids [1], aldehydes and sugars [2] detected in these residues to chiral molecules and enantiomeric excesses produced by Vacuum Ultra-Violet Circularly Polarized Light from synchrotron radiation [3], one might seriously ask whether the chemistry of molecular clouds out of which stars, planetary systems and debris form, may not be seriously considered as the precursor of prebiotic chemistry in a given environment such as the surface of a telluric planet. I will present the general frame of these experiments in relation to the possibillity of feeding of the necessary prebiotic chemistry for the origin of life. Certainly, prebiotic chemistry is very different in itself than astrochemistry but the starting bricks issued from astrochemistry may well be necessary for the possibility of the emergence of life on planets under certain assumptions I will briefly discuss.REFERENCES[1] Meinert, C., Filippi, J.-J., de Marcellus, P., Le Sergeant d’Hendecourt, L. and Meierhenrich, U.J., ChemPlusChem, 77, 186-191 (2012).[2] de Marcellus, P., Meinert, C., Myrgorodska, I., Nahon, L., Buhse, T., Le Sergeantd’Hendecourt, L., Meierhenrich, U.J., PNAS

  3. Module Configuration

    DOEpatents

    Oweis, Salah; D'Ussel, Louis; Chagnon, Guy; Zuhowski, Michael; Sack, Tim; Laucournet, Gaullume; Jackson, Edward J.

    2002-06-04

    A stand alone battery module including: (a) a mechanical configuration; (b) a thermal management configuration; (c) an electrical connection configuration; and (d) an electronics configuration. Such a module is fully interchangeable in a battery pack assembly, mechanically, from the thermal management point of view, and electrically. With the same hardware, the module can accommodate different cell sizes and, therefore, can easily have different capacities. The module structure is designed to accommodate the electronics monitoring, protection, and printed wiring assembly boards (PWAs), as well as to allow airflow through the module. A plurality of modules may easily be connected together to form a battery pack. The parts of the module are designed to facilitate their manufacture and assembly.

  4. Dietary Casein and Soy Protein Isolate Modulate the Effects of Raffinose and Fructooligosaccharides on the Composition and Fermentation of Gut Microbiota in Rats.

    PubMed

    Bai, Gaowa; Ni, Kuikui; Tsuruta, Takeshi; Nishino, Naoki

    2016-08-01

    Although diet has an important influence on the composition of gut microbiota, the impact of dietary protein sources has only been studied to a minor extent. In this study, we examined the influence of different dietary protein sources regarding the effects of prebiotic oligosaccharides on the composition and metabolic activity of gut microbiota. Thirty female rats were fed casein and soy protein isolate with cellulose, raffinose (RAF), and fructooligosaccharides (FOS). Microbiota composition was examined by real-time qPCR and denaturing gradient gel electrophoresis. Dietary protein source affected cecum microbiota; acetic acid concentration and Lactobacillus spp. populations were greater with soy protein than with casein. Prebiotic oligosaccharides had distinctive effects on gut microbiota; RAF increased the acetic acid concentration and Bifidobacterium spp. populations, and FOS increased the butyric acid concentration regardless of the dietary protein. Likewise, Bifidobacterium sp., Collinsella sp., and Lactobacillus sp. were detected in microbiota of the rats fed RAF, and Bacteroides sp., Roseburia sp., and Blautia sp. were seen in microbiota of the rats fed FOS. Interactions between dietary proteins and prebiotic oligosaccharides were observed with Clostridium perfringens group populations and cecum IgA concentration. RAF and FOS decreased C. perfringens group populations in casein-fed rats, and the combination of soy protein and RAF substantially increased cecum IgA concentration. These results indicate that dietary proteins can differentially modulate the effects of prebiotic oligosaccharides on gut fermentation and microbiota, depending on the type of carbohydrate polymers involved. PMID:27434756

  5. From Prebiotics to Probiotics: The Evolution and Functions of tRNA Modifications.

    PubMed

    McKenney, Katherine M; Alfonzo, Juan D

    2016-01-01

    All nucleic acids in cells are subject to post-transcriptional chemical modifications. These are catalyzed by a myriad of enzymes with exquisite specificity and that utilize an often-exotic array of chemical substrates. In no molecule are modifications more prevalent than in transfer RNAs. In the present document, we will attempt to take a chemical rollercoaster ride from prebiotic times to the present, with nucleoside modifications as key players and tRNA as the centerpiece that drove the evolution of biological systems to where we are today. These ideas will be put forth while touching on several examples of tRNA modification enzymes and their modus operandi in cells. In passing, we submit that the choice of tRNA is not a whimsical one but rather highlights its critical function as an essential invention for the evolution of protein enzymes. PMID:26985907

  6. Micro-ion Traps for Detection of (Pre)-Biotic Organic Compounds on Comets

    NASA Technical Reports Server (NTRS)

    vanAmerom, Friso H. W.; Chaudhary, A.; Short, R. T.; Brinkerhoff, William; Glavin, Daniel; Mahaffy, Paul R.; Roman, Patrick A.

    2013-01-01

    Comets are currently believed to be a mixture of interstellar and nebular material. Many of the volatiles in comets are attributed to interstellar chemistry, because the same species of carbonaceous compounds are also observed in ices in interstellar molecular (ISM) clouds. Comets are thus likely to be a relatively pristine reservoir of primitive material and carbonaceous compounds in our solar system. They could be a major contributor to the delivery of prebiotic organic compounds, from which life emerged through impacts on early Earth. Mass spectrometers are very powerful tools to identify unknown chemicals, and much progress bas been made in miniaturizing mas spectrometers for space applications. Most miniatu rized mass spectrometers developed to date, however, are still relatively large, power hungry, complicated to assemble, and would have significant impact on space flight vehicle total payload and resource allocations.

  7. A novel approach of integrated bioprocessing of cane molasses for production of prebiotic and functional bioproducts.

    PubMed

    Sharma, Manisha; Patel, Satya Narayan; Lata, Kusum; Singh, Umesh; Krishania, Meena; Sangwan, Rajender S; Singh, Sudhir P

    2016-11-01

    In this work, the sugar industry by-product cane molasses was investigated as feedstock for acceptor reactions by dextransucrase from Leuconostoc mesenteroides MTCC 10508, leading to the biosynthesis of oligosaccharides. The starch industry corn fiber residue was used as a source for acceptor molecules, maltose, in the reaction. Production of approximately 124g oligosaccharides (DP3-DP6) per kg of fresh molasses was achieved. Further, cane molasses based medium was demonstrated as a sole carbon source for L. mesenteroides growth and dextransucrase production. d-Fructose released by dextransucrase activity as processing by-product was transformed into the functional monosaccharide with zero caloric value, d-psicose, by inducing its epimerization. Quantitative analysis approximated 37g d-psicose per kg of fresh molasses. Thus, the study established a novel approach of integrated bioprocessing of cane molasses into prebiotic and functional food additives. PMID:27498012

  8. Clays as possible catalysts for peptide formation in the prebiotic era

    NASA Technical Reports Server (NTRS)

    Paecht-Horowitz, M.

    1976-01-01

    From the point of view of prebiotic synthesis, clays might have performed functions of concentration, catalysis, and protection of molecules. The degrees of polymerization obtained, when amino acid adenylates are added to montmorillonite suspensions in water, are much higher than those obtained by polymerization in the absence of such a clay. In addition, they are of a discrete spectrum, usually multiples of 6 or 7, and reach values of up to 40 mers. In the absence of clay a continuous spectrum of degrees of polymerization is obtained, and usually up to 4-6 mers only. Copolymerization in the absence of clays yields mostly random copolymers, in their presence mostly block copolymers are obtained. Optical density measurements show that after adsorption has taken place on the clay, stacking of its layers occurs. Polymerization starts only after these stacked layers have been formed

  9. From Prebiotics to Probiotics: The Evolution and Functions of tRNA Modifications

    PubMed Central

    McKenney, Katherine M.; Alfonzo, Juan D.

    2016-01-01

    All nucleic acids in cells are subject to post-transcriptional chemical modifications. These are catalyzed by a myriad of enzymes with exquisite specificity and that utilize an often-exotic array of chemical substrates. In no molecule are modifications more prevalent than in transfer RNAs. In the present document, we will attempt to take a chemical rollercoaster ride from prebiotic times to the present, with nucleoside modifications as key players and tRNA as the centerpiece that drove the evolution of biological systems to where we are today. These ideas will be put forth while touching on several examples of tRNA modification enzymes and their modus operandi in cells. In passing, we submit that the choice of tRNA is not a whimsical one but rather highlights its critical function as an essential invention for the evolution of protein enzymes. PMID:26985907

  10. Synthesis of Organic Matter of Prebiotic Chemistry at the Protoplanetary Disc

    NASA Astrophysics Data System (ADS)

    Snytnikov, Valeriy; Stoynovskaya, Olga; Rudina, Nina

    We have carried out scanning electron microscopic examination of CM carbonaceous chondrites meteorites Migey, Murchison, Staroe Boriskino aged more than 4.56 billion years (about 50 million years from the beginning of the formation of the Solar system). Our study confirmed the conclusion of Rozanov, Hoover and other researchers about the presence of microfossils of bacterial origin in the matrix of all these meteorites. Since the time of the Solar system formation is 60 - 100 million years, the primary biocenosis emerged in the protoplanetary disc of the Solar system before meteorites or simultaneously with them. It means that prebiological processes and RNA world appeared even earlier in the circumsolar protoplanetary disc. Most likely, this appearance of prebiotic chemistry takes place nowday in massive and medium-massive discs of the observed young stellar objects (YSO) class 0 and I. The timescale of the transition from chemical to biological evolution took less than 50 million years for the Solar system. Further evolution of individual biocenosis in a protoplanetary disc associated with varying physico-chemical conditions during the formation of the Solar system bodies. Biocenosis on these bodies could remove or develop under the influence of many cosmic factors and geological processes in the case of Earth. To complete the primary biosphere formation in short evolution time - millions of years - requires highly efficient chemical syntheses. In industrial chemistry for the efficient synthesis of ammonia, hydrogen cyanide, methanol and other organic species, that are the precursors to obtain prebiotic compounds, catalytic reactors of high pressure are used. Thus (1) necessary amount of the proper catalyst in (2) high pressure areas of the disc can trigger these intense syntheses. The disc contains the solids with the size from nanoparticle to pebble. Iron and magnesium is catalytically active ingredient for such solids. The puzzle is a way to provide hydrogen

  11. Probiotics and prebiotics in inflammatory bowel disease: microflora ‘on the scope’

    PubMed Central

    Damaskos, Dimitrios; Kolios, George

    2008-01-01

    The intestinal microflora is a large bacterial community that colonizes the gut, with a metabolic activity equal to an organ and various functions that affect the physiology and pathology of the host's mucosal immune system. Intestinal bacteria are useful in promotion of human health, but certain components of microflora, in genetically susceptible individuals, contribute to various pathological disorders, including inflammatory bowel disease. Clinical and experimental observations indicate an imbalance in protective and harmful microflora components in these disorders. Manipulation of gut flora to enhance its protective and beneficial role represents a promising field of new therapeutic strategies of inflammatory bowel disease. In this review, we discuss the implication of gut flora in the intestinal inflammation that justifies the role of probiotics and prebiotics in the prevention and treatment of inflammatory bowel disease and we address the evidence for therapeutic benefits from their use in experimental models of colitis and clinical trials. PMID:18279467

  12. Prebiotic coordination chemistry: The potential role of transition-metal complexes in the chemical evolution

    NASA Technical Reports Server (NTRS)

    Beck, M.

    1979-01-01

    In approaching the extremely involved and complex problem of the origin of life, consideration of the coordination chemistry appeared not only as a possibility but as a necessity. The first model experiments appear to be promising because of prebiotic-type synthesis by means of transition-metal complexes. It is especially significant that in some instances various types of vitally important substances (nucleic bases, amino acids) are formed simultaneously. There is ground to hope that systematic studies in this field will clarify the role of transition-metal complexes in the organizatorial phase of chemical evolution. It is obvious that researchers working in the fields of the chemistry of cyano and carbonyl complexes, and of the catalytic effect of transition-metal complexes are best suited to study these aspects of the attractive and interesting problem of the origin of life.

  13. Earth's Phosphides in Levant and insights into the source of Archean prebiotic phosphorus

    PubMed Central

    Britvin, Sergey N.; Murashko, Michail N.; Vapnik, Yevgeny; Polekhovsky, Yury S.; Krivovichev, Sergey V.

    2015-01-01

    Natural phosphides - the minerals containing phosphorus in a redox state lower than zero – are common constituents of meteorites but virtually unknown on the Earth. Herein we present the first rich occurrence of iron-nickel phosphides of terrestrial origin. Phosphide-bearing rocks are exposed in three localities in the surroundings of the Dead Sea, Levant: in the northern Negev Desert, Israel and Transjordan Plateau, south of Amman, Jordan. Seven minerals from the ternary Fe-Ni-P system have been identified with five of them, NiP2, Ni5P4, Ni2P, FeP and FeP2, previously unknown in nature. The results of the present study could provide a new insight on the terrestrial origin of natural phosphides – the most likely source of reactive prebiotic phosphorus at the times of the early Earth. PMID:25667163

  14. Gamma-irradiation of malic acid in aqueous solutions. [prebiotic significance

    NASA Technical Reports Server (NTRS)

    Negron-Mendoza, A.; Graff, R. L.; Ponnamperuma, C.

    1980-01-01

    The gamma-irradiation of malic acid in aqueous solutions was studied under initially oxygenated and oxygen-free conditions in an attempt to determine the possible interconversion of malic acid into other carboxylic acids, specifically those associated with Krebs cycle. The effect of dose on product formation of the system was investigated. Gas-liquid chromatography combined with mass spectrometry was used as the principal means of identification of the nonvolatile products. Thin layer chromatography and direct probe mass spectroscopy were also employed. The findings show that a variety of carboxylic acids are formed, with malonic and succinic acids in greatest abundance. These products have all been identified as being formed in the gamma-irradiation of acetic acid, suggesting a common intermediary. Since these molecules fit into a metabolic cycle, it is strongly suggestive that prebiotic pathways provided the basis for biological systems.

  15. Possible Origin for Porphin Derivatives in Prebiotic Chemistry a Computational Study

    NASA Astrophysics Data System (ADS)

    Aylward, Nigel; Bofinger, Neville

    2005-08-01

    A set of chemical reactions is postulated to account for the formation of the macrocyclic porphin structure, basic to the pyrrole derivatives chlorophyll, protoporphyrin, heme and bilirubin, important in photosynthesis, respiration and digestion. A set of equations is given for the prebiotic synthesis of porphin derivatives from the simple molecules; cyanoacetylene, diacetylene, carbon monoxide and ammonia that have been detected in space. A number of isomers of hydrogenated porphin arise which may lose hydrogen to give ultimately porphin and its dehydrogenated derivative. The reactions, while not unique, provide a pathway which has been shown to be feasible from the overall enthalpy changes in the ZKE approximation at the HF and MP2/6-31G* level

  16. Unified reaction pathways for the prebiotic formation of RNA and DNA nucleobases.

    PubMed

    Jeilani, Yassin Aweis; Williams, Phoenix N; Walton, Sofia; Nguyen, Minh Tho

    2016-07-27

    The reaction pathways for the prebiotic formation of nucleobases are complex and lead to the formation of a mixture of products. In the past 50 years, there has been a concerted effort for identifying a unified mechanism for the abiotic origin of the biomolecules but with little success. In the present theoretical study, we identified two prominent precursors for the building up of RNA and DNA nucleobases under prebiotic conditions: (a) 1,2-diaminomaleonitrile (DAMN), which is a tetramer of hydrogen cyanide (HCN), and (b) formamide, a hydrolysis product of HCN; it is important to emphasize that HCN is the source of both precursors. We find that free radical pathways are potentially appropriate to account for the origin of nucleobases from HCN. The current study unites the formamide pathways with the DAMN pathways. The mechanisms for the formation of the RNA and DNA nucleobases (uracil, adenine, purine, cytosine) were studied by quantum chemical computations using density functional theory at the B3LYP/6-311G(d,p) level. All the routes involved proceed with relatively low energy barriers (within the error margin of DFT methods). We showed that the radical mechanisms for the formation of nucleobases could be unified through common precursors. The results demonstrated that 4-aminoimidazole-5-carbonitrile (AICN), which is a known precursor for nucleobases, is a product of DAMN. The overall mechanisms are internally consistent with the abiotic formation of the nucleobases, namely (a) under a meteoritic impact scenario on the early Earth's surface that generated high internal energy, and/or (b) in the (gas phase) interstellar regions without the presence of catalysts. PMID:27220279

  17. Prebiotic effect of fruit and vegetable shots containing Jerusalem artichoke inulin: a human intervention study.

    PubMed

    Ramnani, P; Gaudier, E; Bingham, M; van Bruggen, P; Tuohy, K M; Gibson, G R

    2010-07-01

    The present study aimed to determine the prebiotic effect of fruit and vegetable shots containing inulin derived from Jerusalem artichoke (JA). A three-arm parallel, placebo-controlled, double-blind study was carried out with sixty-six healthy human volunteers (thirty-three men and thirty-three women, age range: 18-50 years). Subjects were randomised into three groups (n 22) assigned to consume either the test shots, pear-carrot-sea buckthorn (PCS) or plum-pear-beetroot (PPB), containing JA inulin (5 g/d) or the placebo. Fluorescent in situ hybridisation was used to monitor populations of total bacteria, bacteroides, bifidobacteria, Clostridium perfringens/histolyticum subgroup, Eubacterium rectale/Clostridium coccoides group, Lactobacillus/Enterococcus spp., Atopobium spp., Faecalibacterium prausnitzii and propionibacteria. Bifidobacteria levels were significantly higher on consumption of both the PCS and PPB shots (10.0 (sd 0.24) and 9.8 (sd 0.22) log10 cells/g faeces, respectively) compared with placebo (9.3 (sd 0.42) log10 cells/g faeces) (P < 0.0001). A small though significant increase in Lactobacillus/Enterococcus group was also observed for both the PCS and PPB shots (8.3 (sd 0.49) and 8.3 (sd 0.36) log10 cells/g faeces, respectively) compared with placebo (8.1 (sd 0.37) log10 cells/g faeces) (P = 0.042). Other bacterial groups and faecal SCFA concentrations remained unaffected. No extremities were seen in the adverse events, medication or bowel habits. A slight significant increase in flatulence was reported in the subjects consuming the PCS and PPB shots compared with placebo, but overall flatulence levels remained mild. A very high level of compliance (>90 %) to the product was observed. The present study confirms the prebiotic efficacy of fruit and vegetable shots containing JA inulin. PMID:20187995

  18. In Situ Prebiotics for Weaning Piglets: In Vitro Production and Fermentation of Potato Galacto-Rhamnogalacturonan

    PubMed Central

    Strube, Mikael Lenz; Ravn, Helle Christine; Ingerslev, Hans-Christian; Meyer, Anne Strunge

    2014-01-01

    Postweaning diarrhea (PWD) in pigs is a leading cause of economic loss in pork production worldwide. The current practice of using antibiotics and zinc to treat PWD is unsustainable due to the potential of antibiotic resistance and ecological disturbance, and novel methods are required. In this study, an in vitro model was used to test the possibility of producing prebiotic fiber in situ in the gastrointestinal (GI) tract of the piglet and the prebiotic activity of the resulting fiber in the terminal ileum. Soluble fiber was successfully produced from potato pulp, an industrial waste product, with the minimal enzyme dose in a simulated upper GI tract model extracting 26.9% of the initial dry matter. The fiber was rich in galactose and galacturonic acid and was fermented at 2.5, 5, or 10 g/liter in a glucose-free medium inoculated with the gut contents of piglet terminal ileum. Fermentations of 5 g/liter inulin or 5 g/liter of a purified potato fiber were used as controls. The fibers showed high fermentability, evident by a dose-dependent drop in pH and an increase in the organic acid content, with lactate in particular being increased. Deep sequencing showed a significant increase in the numbers of Lactobacillus and Veillonella organisms and an insignificant increase in the numbers of Clostridium organisms as well as a decrease in the numbers of Streptococcus organisms. Multivariate analysis showed clustering of the treatment groups, with the group treated with purified potato fiber being clearly separated from the other groups, as the microbiota composition was 60% Lactobacillus and almost free of Clostridium. For animal studies, a dosage corresponding to the 5-g/liter treatment is suggested. PMID:25527557

  19. Guanine-Centric Self-Assembly of Nucleotides in Water: An Important Consideration in Prebiotic Chemistry

    PubMed Central

    Cassidy, Lauren M.; Burcar, Bradley T.; Stevens, Wyatt; Moriarty, Elizabeth M.

    2014-01-01

    Abstract Investigations of plausible prebiotic chemistry on early Earth must consider not only chemical reactions to form more complex products such as proto-biopolymers but also reversible, molecular self-assembly that would influence the availability, organization, and sequestration of reactant molecules. The self-assembly of guanosine compounds into higher-order structures and lyotropic liquid crystalline “gel” phases through formation of hydrogen-bonded guanine tetrads (G-tetrads) is one such consideration that is particularly relevant to an RNA-world scenario. G-tetrad-based gelation has been well studied for individual guanosine compounds and was recently observed in mixtures of guanosine with 5′-guanosine monophosphate (GMP) as well. The present work investigates the self-assembly of GMP in the presence of the other RNA nucleotides. Effects of the total concentration and relative proportion of the nucleotides in the mixtures, the form (disodium salt vs. free acid) of the nucleotides, temperature, pH, and salt concentration were determined by visual observations and circular dichroism (CD) spectroscopy. The results show that formation of cholesteric G-tetrad phases is influenced by interactions with other nucleotides, likely through association (e.g., intercalation) of the nucleotides with the G-tetrad structures. These interactions affect the structure and stability of the G-tetrad gel phase, as well as the formation of alternate self-assembled GMP structures such as a continuous, hydrogen-bonded GMP helix or dimers and aggregates of GMP. These interactions and multiple equilibria are influenced by the presence of cations, especially in the presence of K+. This work could have important implications for the emergence of an RNA or proto-RNA world, which would require mixtures of nucleotides at sufficiently high, local concentrations for abiotic polymerization to occur. Key Words: RNA world—Prebiotic chemistry—RNA polymerization

  20. A Possibility for Piece-wise Ignitions of a TCA Cycle in a Prebiotic Hydrothermal Environment

    NASA Astrophysics Data System (ADS)

    Nemoto, A.; Ikeya, R.; Imai, E.; Hatori, K.; Honda, H.; Matsuno, K.

    We previously reported that formic and acetic acids were synthesized from the mixture of carbon dioxide and water in the presence of heated metal oxide serving as a catalyst (1). Fixation of carbon dioxide and monoxide could have been conceivable in the hydrothermal environment in the primitive ocean. We then considered a possibility of synthesizing major metabolites appearing in a TCA cycle in prebiotic conditions. Focused in this attempt was the vicinity of hydrothermal vents in the primitive ocean. We used a flow reactor to simulate hydrothermal circulation of seawater through hot vents (2). The experimental conditions we chose were that the hot chamber at 200 °C was connected to the cold chamber at 0 °C through a thin nozzle of its diameter 0.8 mm. The total volume of the reaction solution was 500 mL. The fluid was circulated through the flow reactor at the rate of 8 mL / min. As an initial attempt, we prepared the solution of acetic and formic acids. When iron chloride and copper sulfide were present in the solution, the products precipitated on the filter placed in the low-temperature chamber included di-carboxylic acids such as malic acid. We then proceeded to the reaction solution dissolving three different kinds of carboxylic acids, namely, succinate, fumarate, and oxoglutarate. We found that malic acid was in the solution after the operation of the flow-reactor. Formation and transformation of carboxylic acids were observed in our flow reactor. These observations, when combined together, may suggest a possibility of piece-wise ignitions of a TCA cycle even in the prebiotic ocean on the primitive earth. References (1) R. Terada, E. Imai, H. Honda, K. Hatori, and K. Matsuno.: Viva Origino 27, 197-208(1999). (2) E. Imai, H. Honda, K. Hatori, A. Brack, and K. Matsuno.: Science 283, 831-833(1999).

  1. In situ prebiotics for weaning piglets: in vitro production and fermentation of potato galacto-rhamnogalacturonan.

    PubMed

    Strube, Mikael Lenz; Ravn, Helle Christine; Ingerslev, Hans-Christian; Meyer, Anne Strunge; Boye, Mette

    2015-03-01

    Postweaning diarrhea (PWD) in pigs is a leading cause of economic loss in pork production worldwide. The current practice of using antibiotics and zinc to treat PWD is unsustainable due to the potential of antibiotic resistance and ecological disturbance, and novel methods are required. In this study, an in vitro model was used to test the possibility of producing prebiotic fiber in situ in the gastrointestinal (GI) tract of the piglet and the prebiotic activity of the resulting fiber in the terminal ileum. Soluble fiber was successfully produced from potato pulp, an industrial waste product, with the minimal enzyme dose in a simulated upper GI tract model extracting 26.9% of the initial dry matter. The fiber was rich in galactose and galacturonic acid and was fermented at 2.5, 5, or 10 g/liter in a glucose-free medium inoculated with the gut contents of piglet terminal ileum. Fermentations of 5 g/liter inulin or 5 g/liter of a purified potato fiber were used as controls. The fibers showed high fermentability, evident by a dose-dependent drop in pH and an increase in the organic acid content, with lactate in particular being increased. Deep sequencing showed a significant increase in the numbers of Lactobacillus and Veillonella organisms and an insignificant increase in the numbers of Clostridium organisms as well as a decrease in the numbers of Streptococcus organisms. Multivariate analysis showed clustering of the treatment groups, with the group treated with purified potato fiber being clearly separated from the other groups, as the microbiota composition was 60% Lactobacillus and almost free of Clostridium. For animal studies, a dosage corresponding to the 5-g/liter treatment is suggested. PMID:25527557

  2. Effects of prebiotic supplementation on the expression of proteins regulating iron absorption in anaemic growing rats.

    PubMed

    Marciano, Renata; Santamarina, Aline Boveto; de Santana, Aline Alves; Silva, Maísa de Lima Correia; Amancio, Olga Maria Silvério; do Nascimento, Claudia Maria da Penha Oller; Oyama, Lila Missae; de Morais, Mauro Batista

    2015-03-28

    Prebiotics may increase intestinal Fe absorption in anaemic growing rats. The present study evaluated the effects of high-performance (HP) inulin and oligofructose on factors that regulate Fe absorption in anaemic rats during the growth phase. Male Wistar rats aged 21 d of age were fed AIN-93G ration without Fe for 2 weeks to induce Fe-deficiency anaemia. The rats were fed on day 35 a control diet, or a diet with 10 % HP inulin, or a diet with 10 % oligofructose, without Fe supplementation. The animals were euthanised after 2 weeks, and segments of the duodenum, caecum, colon and liver were removed. The expression levels of proteins in the intestinal segments were assessed using Western blotting. The levels of serum, urine and liver hepcidin and the concentrations of IL-10, IL-6 and TNF-α in the caecum, colon and liver were measured using the ELISA test. HP inulin increased the expression of the divalent metal transporter 1 protein in the caecum by 162 % (P= 0·04), and the expression of duodenal cytochrome b reductase in the colon by 136 % (P= 0·02). Oligofructose decreased the expression of the protein ferroportin in the duodenum (P= 0·02), the concentrations of IL-10 (P= 0·044), IL-6 (P= 0·036) and TNF-α (P= 0·004) in the caecum, as well as the level of urinary hepcidin (P< 0·001). These results indicate that prebiotics may interfere with the expression of various intestinal proteins and systemic factors involved in the regulation of intestinal Fe absorption in anaemic rats during the growth phase. PMID:25745840

  3. Radical Pathways for the Prebiotic Formation of Pyrimidine Bases from Formamide.

    PubMed

    Nguyen, Huyen Thi; Jeilani, Yassin A; Hung, Huynh Minh; Nguyen, Minh Tho

    2015-08-20

    The prebiotic formation of nucleobases, the building blocks of RNA/DNA, is of current interest. Highly reactive radical species present in the atmosphere under irradiation have been suggested to be involved in the prebiotic synthesis of nucleobases from formamide (FM). We studied several free radical reaction pathways for the synthesis of pyrimidine bases (cytosine, uracil, and thymine) from FM under cold conditions. These pathways are theoretically determined using density functional theory (DFT) computations to examine their kinetic and thermodynamic feasibilities. These free radical reaction pathways share some common reaction types such as H-rearrangement, (•)H/(•)OH/(•)NH2 radical loss, and intramolecular radical cyclization. The rate-determining steps in these pathways are characterized with low energy barriers. The energy barriers of the ring formation steps are in the range of 3-7 kcal/mol. Although DFT methods are known to significantly underestimate the barriers for addition of (•)H radical to neutral species, many of these reactions are highly exergonic with energy release of -15 to -52 kcal/mol and are thus favorable. Among the suggested pathways for formation of cytosine (main route, routes 7a and 1a), uracil (main route, routes 7b and 1b), and thymine (main route and route 26a), the main routes are in general thermodynamically more exergonic and more kinetically favored than other alternative routes with lower overall energy barriers. The reaction energies released following formation of cytosine, uracil, and thymine from FM via the main radical routes amount to -59, -81, and -104 kcal/mol, respectively. Increasing temperature induces unfavorable changes in both kinetic and thermodynamic aspects of the suggested routes. However, the main routes are still more favored than the alternative pathways at the temperature up to the boiling point of FM. PMID:26196536

  4. Photochemistry of Pyrimidine in Astrophysical Ices: Formation of Nucleobases and Other Prebiotic Species

    NASA Technical Reports Server (NTRS)

    Nuevo, Michel; Sandford, Scott A.; Materese, Christopher K.; Milam, Stefanie N.

    2012-01-01

    Nucleobases are N-heterocycles that are the informational subunits of DNA and RNA. They are divided into two molecular groups: pyrimidine bases (uracil, cytosine, and thymine) and purine bases (adenine and guanine). Nucleobases have been detected in meteorites, and their extraterrestrial origin confirmed by isotopic measurements. Although no N-heterocycles have ever been observed in the ISM, the positions of the 6.2- m interstellar emission features suggest a population of such molecules is likely to be present. However, laboratory experiments have shown that the ultraviolet (UV) irradiation of pyrimidine in ices of astrophysical relevance such as H2O, NH3, CH3OH, CH4, CO, or combinations of these at low temperature (less than or equal to 20 K) leads to the formation of several pyrimidine derivatives including the nucleobases uracil and cytosine, as well as precursors such as 4(3H)-pyrimidone and 4-aminopyrimidine. Quantum calculations on the formation of 4(3H)-pyrimidone and uracil from the irradiation of pyrimidine in pure H2O ices are in agreement with their experimental formation pathways.10 In those residues, other species of prebiotic interest such as urea as well as the amino acids glycine and alanine could also be identified. However, only very small amounts of pyrimidine derivatives containing CH3 groups could be detected, suggesting that the addition of methyl groups to pyrimidine is not an efficient process. For this reason, the nucleobase thymine was not observed in any of the samples. In this work, we study the formation of nucleobases and other photo-products of prebiotic interest from the UV irradiation of pyrimidine in ices containing H2O, NH3, CH3OH, and CO, mixed in astrophysical proportions.

  5. The effect of wheat prebiotics on the gut bacterial population and iron status of iron deficient broiler chickens

    PubMed Central

    2014-01-01

    Background Currently, there is a lot of interest in improving gut health, and consequently increasing Fe absorption, by managing the colonic microbial population. This is traditionally done by the consumption of probiotics, live microbial food supplements. However, an alternative, and often very effective approach, is the consumption of food ingredients known as prebiotics. Fructans and arabinoxylans are naturally occurring non-digestible oligosaccharides in wheat that exhibit prebiotic properties and may enhance intestinal iron (Fe) absorption. The aim of this study was to assess the effect of prebiotics from wheat on Fe bioavailability in vitro (Caco-2 cells) and in vivo (broiler chickens, Gallus gallus). Methods In the current study, the effect of intra-amniotic administration of wheat samples extracts at 17 d of embryonic incubation on the Fe status and possible changes in the bacterial population in intestinal content of broiler hatchlings were investigated. A group of 144 eggs were injected with the specified solution (1 ml per egg) into the amniotic fluid. Immediately after hatch (21 d) and from each treatment group, 10 chicks were euthanized and their small intestine, liver and cecum were removed for relative mRNA abundance of intestinal Fe related transporters, relative liver ferritin amounts and bacterial analysis of cecal content, respectively. Results The in vivo results are in agreement with the in vitro observations, showing no differences in the hatchling Fe status between the treatment groups, as Fe bioavailability was not increased in vitro and no significant differences were measured in the intestinal expression of DMT1, Ferroportin and DcytB in vivo. However, there was significant variation in relative amounts of bifidobacteria and lactobacilli in the intestinal content between the treatments groups, with generally more bifidobacteria being produced with increased prebiotic content. Conclusions In this study we showed that prebiotics naturally

  6. Effects of Probiotic and Prebiotic on Average Daily Gain, Fecal Shedding of Escherichia Coli, and Immune System Status in Newborn Female Calves

    PubMed Central

    Roodposhti, Pezhman Mohamadi; Dabiri, Najafgholi

    2012-01-01

    Thirty two Holstein female calves (initial body weight = 40±3.0 kg) were used to investigate the effects of probiotic and prebiotic on average daily gain (ADG), fecal E. coli count, white blood cell count, plasma IgG1 level and cell-mediated immune response to injection of phytohemagglutinin in suckling female calves. Calves were assigned randomly to one of the four treatments, including whole milk without additives (control), whole milk containing probiotic, whole milk containing prebiotic and whole milk containing probiotic and prebiotic (synbiotic). Average daily gain was greater in calves fed probiotic, prebiotic and synbiotic at weeks 6, 7 and 8 (p<0.05). E. coli count was significantly lower in calves fed probiotic, prebiotic and synbiotic on d 56 (p<0.05). There was no significant difference between treatments in blood samples and cell-mediated response. This study showed that addition of probiotic, prebiotic and combination of these additives to milk enhanced ADG and reduced fecal E. coli count in preruminant calves. PMID:25049688

  7. Effect of dietary prebiotic supplementation on advanced glycation, insulin resistance and inflammatory biomarkers in adults with pre-diabetes: a study protocol for a double-blind placebo-controlled randomised crossover clinical trial

    PubMed Central

    2014-01-01

    Background Advanced glycation endproducts (AGEs) contribute to the development of vascular complications of diabetes and have been recently implicated in the pathogenesis of diabetes. Since AGEs are generated within foodstuffs upon food processing, it is increasingly recognised that the modern diet is replete with AGEs. AGEs are thought to stimulate chronic low-grade inflammation and promote oxidative stress and have been linked to the development of insulin resistance. Simple therapeutic strategies targeted at attenuating the progression of chronic low-grade inflammation and insulin resistance are urgently required to prevent or slow the development of type 2 diabetes in susceptible individuals. Dietary modulation of the human colonic microbiota has been shown to confer a number of health benefits to the host, but its effect on advanced glycation is unknown. The aim of this article is to describe the methodology of a double-blind placebo-controlled randomised crossover trial designed to determine the effect of 12 week consumption of a prebiotic dietary supplement on the advanced glycation pathway, insulin sensitivity and chronic low-grade inflammation in adults with pre-diabetes. Methods/Design Thirty adults with pre-diabetes (Impaired Glucose Tolerance or Impaired Fasting Glucose) aged between 40–60 years will be randomly assigned to receive either 10 grams of prebiotic (inulin/oligofructose) daily or 10 grams placebo (maltodextrin) daily for 12 weeks. After a 2-week washout period, study subjects will crossover to receive the alternative dietary treatment for 12 weeks. The primary outcome is the difference in markers of the advanced glycation pathway carboxymethyllysine (CML) and methylglyoxal (MG) between experimental and control treatments. Secondary outcomes include HbA1c, insulin sensitivity, lipid levels, blood pressure, serum glutathione, adiponectin, IL-6, E-selectin, myeloperoxidase, C-reactive protein, Toll-like Receptor 4 (TLR4), soluble receptor

  8. Combination of soya pulp and Bacillus coagulans lilac-01 improves intestinal bile acid metabolism without impairing the effects of prebiotics in rats fed a cholic acid-supplemented diet.

    PubMed

    Lee, Yeonmi; Yoshitsugu, Reika; Kikuchi, Keidai; Joe, Ga-Hyun; Tsuji, Misaki; Nose, Takuma; Shimizu, Hidehisa; Hara, Hiroshi; Minamida, Kimiko; Miwa, Kazunori; Ishizuka, Satoshi

    2016-08-01

    Intestinal bacteria are involved in bile acid (BA) deconjugation and/or dehydroxylation and are responsible for the production of secondary BA. However, an increase in the production of secondary BA modulates the intestinal microbiota due to the bactericidal effects and promotes cancer risk in the liver and colon. The ingestion of Bacillus coagulans improves constipation via the activation of bowel movement to promote defaecation in humans, which may alter BA metabolism in the intestinal contents. BA secretion is promoted with high-fat diet consumption, and the ratio of cholic acid (CA):chenodeoxycholic acid in primary BA increases with ageing. The dietary supplementation of CA mimics the BA environment in diet-induced obesity and ageing. We investigated whether B. coagulans lilac-01 and soya pulp influence both BA metabolism and the maintenance of host health in CA-supplemented diet-fed rats. In CA-fed rats, soya pulp significantly increased the production of secondary BA such as deoxycholic acid and ω-muricholic acids, and soya pulp ingestion alleviated problems related to plasma adiponectin and gut permeability in rats fed the CA diet. The combination of B. coagulans and soya pulp successfully suppressed the increased production of secondary BA in CA-fed rats compared with soya pulp itself, without impairing the beneficial effects of soya pulp ingestion. In conclusion, it is possible that a combination of prebiotics and probiotics can be used to avoid an unnecessary increase in the production of secondary BA in the large intestine without impairing the beneficial functions of prebiotics. PMID:27464459

  9. Quantum chemical study of relative reactivities of a series of amines and nitriles - Relevance to prebiotic chemistry

    NASA Technical Reports Server (NTRS)

    Loew, G. H.; Berkowitz, D.; Chang, S.

    1975-01-01

    Using the Iterative Extended Huckel Theory (IEHT) calculations of the electron distribution and orbital energies of a series of thirteen amines, nitriles and amino-nitriles relevant to prebiotic and cosmo-chemistry have been carried out. Ground state properties such as the energy and nature of the highest occupied (HOMO) and lowest empty (LEMO) molecular orbitals, net atomic charges and number of nonbonding electrons have been identified as criteria for correlating the relative nucleophilicity of amine and nitrile nitrogens and the electrophilicity of nitrile and other unsaturated carbon atoms. The results of such correlations can be partially verified by known chemical behavior of these compounds and are used to predict and understand their role in prebiotic organic synthesis.

  10. Chemical characterization and prebiotic activity of fructo-oligosaccharides from Stevia rebaudiana (Bertoni) roots and in vitro adventitious root cultures.

    PubMed

    Sanches Lopes, Sheila Mara; Francisco, Mariane Grigio; Higashi, Bruna; de Almeida, Rafaela Takako Ribeiro; Krausová, Gabriela; Pilau, Eduardo Jorge; Gonçalves, José Eduardo; Gonçalves, Regina Aparecida Correia; Oliveira, Arildo José Braz de

    2016-11-01

    Stevia rebaudiana (Bertoni) is widely studied because of its foliar steviol glycosides. Fructan-type polysaccharides were recently isolated from its roots. Fructans are reserve carbohydrates that have important positive health effects and technological applications in the food industry. The objective of the present study was to isolate and characterize fructo-oligosaccharides (FOSs) from S. rebaudiana roots and in vitro adventitious root cultures and evaluate the potential prebiotic effect of these molecules. The in vitro adventitious root cultures were obtained using a roller bottle system. Chemical analyses (gas chromatography-mass spectrometry, (1)H nuclear magnetic resonance, and off-line electrospray ionization-mass spectrometry) revealed similar chemical properties of FOSs that were obtained from the different sources. The potential prebiotic effects of FOSs that were isolated from S. rebaudiana roots enhanced the growth of both bifidobacteria and lactobacilli, with strains specificity in their fermentation ability. PMID:27516323

  11. Prebiotic potential of gum odina and its impact on gut ecology: in vitro and in vivo assessments.

    PubMed

    Mitra, Debmalya; Jena, Aditya Kr; De, Arnab; Das, Mousumi; Das, Bhaskar; Samanta, Amalesh

    2016-07-13

    The use of prebiotics to escalate certain gut flora is a current aspect of research for effective gut ecology. In the present study we appraise the efficacy of gum odina obtained from the bark of Odina wodier (Anacardiaceae), which is not fully degraded (16%) in the upper GI tract and becomes available to the lower region, as a prebiotic. An in vitro prebiotic activity assay established a quantitative score to describe the extent to which gum odina supports the selective growth of probiotics with a maximum of 5.60 ± 0.11 for Lactobacillus plantarum MTCC 6160. The polysaccharide, upon fermentation, also liberates lactic acid (0.46 ± 0.003 mg ml(-1)) and acetic acid (1.03 ± 0.003 mg ml(-1)). In vivo studies revealed that natural gum selectively stimulates Lactobacillus sp., and eliminates enteric pathogens with a C.F.U. of 384.48 ± 0.11 and 40.56 ± 0.17 respectively on the 8(th) day. The changes in the level of β-galactosidase signify maturation of macrophages in the gut environment. It also boosts the immune system by increasing sIgA upon infection from the 5(th) day in the gut, when incorporated into the feed of mice. Moreover an increase in levels of IFNγ on the 5(th) day also manifest additional protection against various pathogen-induced primary and secondary infections. Thus, gum odina is a potential prebiotic which not only provides nutrition but also improves gut ecology. PMID:27251027

  12. Nucleobases bind to and stabilize aggregates of a prebiotic amphiphile, providing a viable mechanism for the emergence of protocells.

    PubMed

    Black, Roy A; Blosser, Matthew C; Stottrup, Benjamin L; Tavakley, Ravi; Deamer, David W; Keller, Sarah L

    2013-08-13

    Primordial cells presumably combined RNAs, which functioned as catalysts and carriers of genetic information, with an encapsulating membrane of aggregated amphiphilic molecules. Major questions regarding this hypothesis include how the four bases and the sugar in RNA were selected from a mixture of prebiotic compounds and colocalized with such membranes, and how the membranes were stabilized against flocculation in salt water. To address these questions, we explored the possibility that aggregates of decanoic acid, a prebiotic amphiphile, interact with the bases and sugar found in RNA. We found that these bases, as well as some but not all related bases, bind to decanoic acid aggregates. Moreover, both the bases and ribose inhibit flocculation of decanoic acid by salt. The extent of inhibition by the bases correlates with the extent of their binding, and ribose inhibits to a greater extent than three similar sugars. Finally, the stabilizing effects of a base and ribose are additive. Thus, aggregates of a prebiotic amphiphile bind certain heterocyclic bases and sugars, including those found in RNA, and this binding stabilizes the aggregates against salt. These mutually reinforcing mechanisms might have driven the emergence of protocells. PMID:23901105

  13. Nucleobases bind to and stabilize aggregates of a prebiotic amphiphile, providing a viable mechanism for the emergence of protocells

    PubMed Central

    Black, Roy A.; Blosser, Matthew C.; Stottrup, Benjamin L.; Tavakley, Ravi; Deamer, David W.; Keller, Sarah L.

    2013-01-01

    Primordial cells presumably combined RNAs, which functioned as catalysts and carriers of genetic information, with an encapsulating membrane of aggregated amphiphilic molecules. Major questions regarding this hypothesis include how the four bases and the sugar in RNA were selected from a mixture of prebiotic compounds and colocalized with such membranes, and how the membranes were stabilized against flocculation in salt water. To address these questions, we explored the possibility that aggregates of decanoic acid, a prebiotic amphiphile, interact with the bases and sugar found in RNA. We found that these bases, as well as some but not all related bases, bind to decanoic acid aggregates. Moreover, both the bases and ribose inhibit flocculation of decanoic acid by salt. The extent of inhibition by the bases correlates with the extent of their binding, and ribose inhibits to a greater extent than three similar sugars. Finally, the stabilizing effects of a base and ribose are additive. Thus, aggregates of a prebiotic amphiphile bind certain heterocyclic bases and sugars, including those found in RNA, and this binding stabilizes the aggregates against salt. These mutually reinforcing mechanisms might have driven the emergence of protocells. PMID:23901105

  14. Prebiotics effect on immune and hepatic oxidative status and gut morphology of white sea bream (Diplodus sargus).

    PubMed

    Guerreiro, Inês; Couto, Ana; Machado, Marina; Castro, Carolina; Pousão-Ferreira, Pedro; Oliva-Teles, Aires; Enes, Paula

    2016-03-01

    The aim of this study was to evaluate the effects of short-chain fructooligosaccharides (scFOS), xylooligosaccharides (XOS) and galactooligosaccharides (GOS) on immune and hepatic oxidative status, and gut morphology of white sea bream juveniles. Four diets were formulated: a control diet with fish meal (FM) and plant feedstuffs (PF) (30FM:70PF) and three test diets similar to the control but supplemented with 1% of scFOS, XOS or GOS. Dietary prebiotic incorporation did not affect total blood cell counts, hematocrit, hemoglobin, red blood indices or differential white blood cell counts. Fish fed GOS had lower ACH50 and nitric oxide than fish fed control diet. XOS enhanced immune status through the increase in alternative complement pathway (ACH50), lysozyme and total immunoglobulin. The higher activity of glucose 6-phosphate dehydrogenase in fish fed FOS compared to the other dietary groups was the only related antioxidant enzyme affected by prebiotics in the liver. GOS ameliorated the precocious adverse effects of PF based diet on gut histomorphology, as denoted by the lower incidence of histological alterations in fish fed GOS for 15 days. In conclusion, XOS and GOS at 1% might have potential to be used as prebiotics in white sea bream juveniles. PMID:26802896

  15. Early intestinal development and mucin transcription in the young poult with probiotic and mannan oligosaccharide prebiotic supplementation.

    PubMed

    Hutsko, S L; Meizlisch, K; Wick, M; Lilburn, M S

    2016-05-01

    Alternative and adjunctive approaches to decreasing the use of dietary antibiotics are becoming popular areas of study. Supplemental probiotics (commensal microbes) and prebiotics (indigestible complex carbohydrates) are 2 dietary approaches to facilitating the intestinal colonization of beneficial bacteria to compete with potential pathogens, thus creating a healthy mucosal environment. The intestinal mucosa is composed of mucin glycoproteins, which play a key role in preventing the attachment of pathogenic bacteria. At hatch, the neonatal turkey intestine is relatively aseptic and vulnderable to bacterial colonization by both commensal and pathogenic microbes. In the current study, we determined the transcription of MUC2, the primary mucin protein produced by goblet cells within the small intestine, and we also measured intestinal morphology immediately post-hatch through d 11. Poults were fed a conventional starter diet, the starter diet supplemented with one of 2 commercial probiotics (A, B), or a commercial mannan oligosaccharide. MUC2 transcription increased from d zero to d 4 post-hatch (P< 0.05), but there was no effect of probiotic or prebiotic supplementation. Villus height and villus area both increased with Probiotic B and mannan oligosaccharide supplementation (P<0.05) and there was a significant d X treatment interaction effect for crypt depth (P=0.007). These results suggest that probiotic and prebiotic supplementation can positively alter the intestinal microenvironment. PMID:26944966

  16. Effects of prebiotic inulin-type fructans on structure, quality, sensory acceptance and glycemic response of gluten-free breads.

    PubMed

    Capriles, Vanessa D; Arêas, José A G

    2013-01-01

    The effect of adding increasing levels of prebiotic inulin-type fructans (ITFs) (0, 4, 8, 10 and 12%) on the sensory and nutritional quality of gluten-free bread (GFB) was assessed. ITFs can provide structure and gas retention during baking, thus improving GFB quality by yielding better specific volume, softer crumb, improved crust and crumb browning with enhanced sensory acceptance. During baking, approximately one-third of the ITFs was lost. The addition of 12% ITFs to the basic formulation is required in order to obtain GFB enriched with 8% ITFs (4 g of fructans per 50 g bread serving size), levels that can provide health benefits. 12% ITFs-addition level decreased GFB glycemic index (from 71 to 48) and glycemic load (from 12 to 8). Prebiotic ITFs are a promising improver for GFB that can provide nutritional (11% dietary fiber content, low glycemic response) and functional benefits to patients with celiac disease, since ITFs are prebiotic ingredients that can also increase calcium absorption. PMID:23032642

  17. Detection of Potential TNA and RNA Nucleoside Precursors in a Prebiotic Mixture by Pure Shift Diffusion-Ordered NMR Spectroscopy

    PubMed Central

    Islam, Saidul; Aguilar, Juan A; Powner, Matthew W; Nilsson, Mathias; Morris, Gareth A; Sutherland, John D

    2013-01-01

    In the context of prebiotic chemistry, one of the characteristics of mixed nitrogenous-oxygenous chemistry is its propensity to give rise to highly complex reaction mixtures. There is therefore an urgent need to develop improved spectroscopic techniques if onerous chromatographic separations are to be avoided. One potential avenue is the combination of pure shift methodology, in which NMR spectra are measured with greatly improved resolution by suppressing multiplet structure, with diffusion-ordered spectroscopy, in which NMR signals from different species are distinguished through their different rates of diffusion. Such a combination has the added advantage of working with intact mixtures, allowing analyses to be carried out without perturbing mixtures in which chemical entities are part of a network of reactions in equilibrium. As part of a systems chemistry approach towards investigating the self-assembly of potentially prebiotic small molecules, we have analysed the complex mixture arising from mixing glycolaldehyde and cyanamide, in a first application of pure shift DOSY NMR to the characterisation of a partially unknown reaction composition. The work presented illustrates the potential of pure shift DOSY to be applied to chemistries that give rise to mixtures of compounds in which the NMR signal resolution is poor. The direct formation of potential RNA and TNA nucleoside precursors, amongst other adducts, was observed. These preliminary observations may have implications for the potentially prebiotic assembly chemistry of pyrimidine threonucleotides, and therefore of TNA, by using recently reported chemistries that yield the activated pyridimidine ribonucleotides. PMID:23371787

  18. Prebiotic replicase evolution in a surface-bound metabolic system: parasites as a source of adaptive evolution

    PubMed Central

    2008-01-01

    Background The remarkable potential of recent forms of life for reliably passing on genetic information through many generations now depends on the coordinated action of thousands of specialized biochemical "machines" (enzymes) that were obviously absent in prebiotic times. Thus the question how a complicated system like the living cell could have assembled on Earth seems puzzling. In seeking for a scientific explanation one has to search for step-by-step evolutionary changes from prebiotic chemistry to the emergence of the first proto-cell. Results We try to sketch a plausible scenario for the first steps of prebiotic evolution by exploring the ecological feasibility of a mineral surface-bound replicator system that facilitates a primitive metabolism. Metabolism is a hypothetical network of simple chemical reactions producing monomers for the template-copying of RNA-like replicators, which in turn catalyse metabolic reactions. Using stochastic cellular automata (SCA) simulations we show that the surface-bound metabolic replicator system is viable despite internal competition among the genes and that it also maintains a set of mild "parasitic" sequences which occasionally evolve functions such as that of a replicase. Conclusion Replicase activity is shown to increase even at the expense of slowing down the replication of the evolving ribozyme itself, due to indirect mutualistic benefits in a diffuse form of group selection among neighbouring replicators. We suggest possible paths for further evolutionary changes in the metabolic replicator system leading to increased metabolic efficiency, improved replicase functionality, and membrane production. PMID:18826645

  19. In vitro determination of prebiotic properties of oligosaccharides derived from an orange juice manufacturing by-product stream.

    PubMed

    Manderson, K; Pinart, M; Tuohy, K M; Grace, W E; Hotchkiss, A T; Widmer, W; Yadhav, M P; Gibson, G R; Rastall, R A

    2005-12-01

    Fermentation properties of oligosaccharides derived from orange peel pectin were assessed in mixed fecal bacterial culture. The orange peel oligosaccharide fraction contained glucose in addition to rhamnogalacturonan and xylogalacturonan pectic oligosaccharides. Twenty-four-hour, temperature- and pH-controlled, stirred anaerobic fecal batch cultures were used to determine the effects that oligosaccharides derived from orange products had on the composition of the fecal microbiota. The effects were measured through fluorescent in situ hybridization to determine changes in bacterial populations, fermentation end products were analyzed by high-performance liquid chromatography to assess short-chain fatty acid concentrations, and subsequently, a prebiotic index (PI) was determined. Pectic oligosaccharides (POS) were able to increase the bifidobacterial and Eubacterium rectale numbers, albeit resulting in a lower prebiotic index than that from fructo-oligosaccharide metabolism. Orange albedo maintained the growth of most bacterial populations and gave a PI similar to that of soluble starch. Fermentation of POS resulted in an increase in the Eubacterium rectale numbers and concomitantly increased butyrate production. In conclusion, this study has shown that POS can have a beneficial effect on the fecal microflora; however, a classical prebiotic effect was not found. An increase in the Eubacterium rectale population was found, and butyrate levels increased, which is of potential benefit to the host. PMID:16332825

  20. An Introduction to the Avian Gut Microbiota and the Effects of Yeast-Based Prebiotic-Type Compounds as Potential Feed Additives

    PubMed Central

    Roto, Stephanie M.; Rubinelli, Peter M.; Ricke, Steven C.

    2015-01-01

    The poultry industry has been searching for a replacement for antibiotic growth promoters in poultry feed as public concerns over the use of antibiotics and the appearance of antibiotic resistance has become more intense. An ideal replacement would be feed amendments that could eliminate pathogens and disease while retaining economic value via improvements on body weight and feed conversion ratios. Establishing a healthy gut microbiota can have a positive impact on growth and development of both body weight and the immune system of poultry while reducing pathogen invasion and disease. The addition of prebiotics to poultry feed represents one such recognized way to establish a healthy gut microbiota. Prebiotics are feed additives, mainly in the form of specific types of carbohydrates that are indigestible to the host while serving as substrates to select beneficial bacteria and altering the gut microbiota. Beneficial bacteria in the ceca easily ferment commonly studied prebiotics, producing short-chain fatty acids, while pathogenic bacteria and the host are unable to digest their molecular bonds. Prebiotic-like substances are less commonly studied, but show promise in their effects on the prevention of pathogen colonization, improvements on the immune system, and host growth. Inclusion of yeast and yeast derivatives as probiotic and prebiotic-like substances, respectively, in animal feed has demonstrated positive associations with growth performance and modification of gut morphology. This review will aim to link together how such prebiotics and prebiotic-like substances function to influence the native and beneficial microorganisms that result in a diverse and well-developed gut microbiota. PMID:26664957

  1. Pre-biotic organic molecules in hydrothermal quartz veins from the Archaean Yilgarn province, Australia

    NASA Astrophysics Data System (ADS)

    Mayer, Christian; Schreiber, Ulrich; Dyker, Gerald; Kirnbauer, Thomas; Mulder, Ines; Sattler, Tobias; Schöler, Heinfried; Tubbesing, Christoph

    2013-04-01

    According to a model recently published by Schreiber et al. (OLEB 2012), pre-biotic organic molecules as earliest markers for a chemical evolution have been formed in tectonic faults of the first Archaean cratons. These faults are often documented by quartz- and other hydrothermal vein mineralization. During the growth of these quartzes, small portions of hydrothermal fluids are enclosed which conserve the chemical composition of the given fluid medium. According to our model, the preconditions for the geochemical formation of organic molecules are a suitable carbon source (e.g. carbon dioxide), varying P/T conditions, and catalysts. This given, rising hydrothermal fluids such as mineral-rich water and supercritical carbon dioxide in deep faults with contacts to the upper earth mantle offer conditions which allow for reactions similar to the Fischer-Tropsch synthesis. So far, the inclusions which possibly have conserved the products of these reactions have not been analyzed for possible organic constituents. First analytical results of a Mesozoic hydrothermal quartz vein from central Germany (Taunus) reveal that several organic compounds are found in fluid inclusions. However, the true origin of these compounds is unclear due to possible contamination by adjacent Corg-rich metasediments. Therefore, we have extended the study to hydrothermal quartz veins from the Archaean Yilgarn craton, to impact-generated quartz veins of the Shoemaker-Crater as well as to hydrothermal quartz boulders from a 2.7 to 3 billion years old conglomerate near Murchison (Western Australia). In one of the samples from the conglomerate, a wide spectrum of organic compounds such as bromomethane, butane, isoprene, benzene, and toluene have been detected. The time interval between the quartz formation, its erosion and its sedimentation is unknown. Possibly, the analyzed quartz sample was formed in a hydrothermal vein long before any living cells have existed on earth. In this case, the given

  2. Prebiotic Oligosaccharides: Comparative Evaluation Using In Vitro Cultures of Infants' Fecal Microbiomes

    PubMed Central

    Stiverson, J.; Williams, T.; Chen, J.; Adams, S.; Hustead, D.; Price, P.; Guerrieri, J.; Deacon, J.

    2014-01-01

    The objective of this study was to systematically assess the bifidogenic effect of three commonly used prebiotic products using in vitro cultures of infant fecal samples. Fresh stool samples collected from six term infants, each exclusively fed human milk (n = 3) or infant formula (n = 3), at 28 days of age were used as inocula. The following prebiotic products were added at concentrations applicable to infant formula: Vivinal GOS 15 (containing 28.5% galacto-oligosaccharide [GOS]) at 7.2 g/liter, Beneo HP (99.5% long-chain inulin [IN]) at 0.8 g/liter, Beneo Synergy 1 (enriched oligofructose and inulin [OF-IN]) at 4 g/liter, and a combination of Vivinal GOS 15 (7.2 g/liter) and Beneo HP (0.8 g/liter) (GOS-IN). The growth of total bacteria, Bifidobacterium, Bacteroides, Bifidobacterium longum, and Escherichia coli was quantified using specific quantitative PCR (qPCR). Bifidobacterium was also enumerated on selective Beerens agar plates, with representative colonies identified by sequencing of their 16S rRNA genes. Volatile fatty acids (VFA) and pH in the cultures were also determined. Irrespective of the feeding methods, the GOS product, either alone or in combination with Beneo HP, resulted in substantially higher growth of total bifidobacteria, and much of this growth was attributed to growth of B. longum. Beneo Synergy 1 also increased the abundance of total bifidobacteria and B. longum. Corresponding to the increases in these two bacterial groups, acetic acid concentrations were higher, while there was a trend of lower E. coli levels and pH. The lower pH and higher acetic acid concentration might be directly responsible for the lower E. coli population. At the concentrations studied, the GOS product was more bifidogenic and potent in inhibiting E. coli than the other products tested. These results suggest that supplementation of infant formula with GOS may increase intestinal bifidobacteria and benefit infant health. PMID:25239906

  3. Quantum Chemistry Meets Spectroscopy for Astrochemistry: Increasing Complexity toward Prebiotic Molecules.

    PubMed

    Barone, Vincenzo; Biczysko, Malgorzata; Puzzarini, Cristina

    2015-05-19

    For many years, scientists suspected that the interstellar medium was too hostile for organic species and that only a few simple molecules could be formed under such extreme conditions. However, the detection of approximately 180 molecules in interstellar or circumstellar environments in recent decades has changed this view dramatically. A rich chemistry has emerged, and relatively complex molecules such as C60 and C70 are formed. Recently, researchers have also detected complex organic and potentially prebiotic molecules, such as amino acids, in meteorites and in other space environments. Those discoveries have further stimulated the debate on the origin of the building blocks of life in the universe. Many efforts continue to focus on the physical, chemical, and astrophysical processes by which prebiotic molecules can be formed in the interstellar dust and dispersed to Earth or to other planets.Spectroscopic techniques, which are widely used to infer information about molecular structure and dynamics, play a crucial role in the investigation of planetary atmosphere and the interstellar medium. Increasingly these astrochemical investigations are assisted by quantum-mechanical calculations of structures as well as spectroscopic and thermodynamic properties, such as transition frequencies and reaction enthalpies, to guide and support observations, line assignments, and data analysis in these new and chemically complicated situations. However, it has proved challenging to extend accurate quantum-chemical computational approaches to larger systems because of the unfavorable scaling with the number of degrees of freedom (both electronic and nuclear).In this Account, we show that it is now possible to compute physicochemical properties of building blocks of biomolecules with an accuracy rivaling that of the most sophisticated experimental techniques, and we summarize specific contributions from our groups. As a test case, we present the underlying computational machinery

  4. Synthesis of goethite in solutions of artificial seawater and amino acids: a prebiotic chemistry study

    NASA Astrophysics Data System (ADS)

    Carneiro, Cristine E. A.; Ivashita, Flávio F.; de Souza, Ivan Granemann; de Souza, Cláudio M. D.; Paesano, Andrea; da Costa, Antonio C. S.; di Mauro, Eduardo; de Santana, Henrique; Zaia, Cássia T. B. V.; Zaia, Dimas A. M.

    2013-04-01

    This study investigated the synthesis of goethite under conditions resembling those of the prebiotic Earth. The artificial seawater used contains all the major elements as well as amino acids (α-Ala, β-Ala, Gly, Cys, AIB) that could be found on the prebiotic Earth. The spectroscopic methods (FT-IR, EPR, Raman), scanning electron microscopy (SEM) and X-ray diffraction showed that in any condition Gly and Cys favoured the formation of goethite, artificial seawater plus β-Ala and distilled water plus AIB favoured the formation of hematite and for the other synthesis a mixture of goethite and hematite were obtained. Thus in general no protein amino acids (β-Ala, AIB) favoured the formation of hematite. As shown by surface enhanced Raman spectroscopy (SERS) spectra the interaction between Cys and Fe3+ of goethite is very complex, involving decomposition of Cys producing sulphur, as well as interaction of carboxylic group with Fe3+. SERS spectra also showed that amino/CN and C-CH3 groups of α-Ala are interacting with Fe3+ of goethite. For the other samples the shifting of several bands was observed. However, it was not possible to say which amino acid groups are interacting with Fe3+. The pH at point of zero charge of goethites increased with artificial seawater and decreased with amino acids. SEM images showed when only goethite was synthesized the images of the samples were acicular and when only hematite was synthesized the images of the samples were spherical. SEM images for the synthesis of goethite with Cys were spherical crystal aggregates with radiating acicular crystals. The highest resonance line intensities were obtained for the samples where only hematite was obtained. Electron paramagnetic resonance (EPR) and Mössbauer spectra showed for the synthesis of goethite with artificial seawater an isomorphic substitution of iron by seawater cations. Mössbauer spectra also showed that for the synthesis goethite in distilled water plus Gly only goethite was

  5. Influence of in ovo prebiotic and synbiotic administration on meat quality of broiler chickens.

    PubMed

    Maiorano, G; Sobolewska, A; Cianciullo, D; Walasik, K; Elminowska-Wenda, G; Slawinska, A; Tavaniello, S; Zylinska, J; Bardowski, J; Bednarczyk, M

    2012-11-01

    A trial was conducted to evaluate the effect of in ovo injection of prebiotic and synbiotics on growth performance, meat quality traits (cholesterol content, intramuscular collagen properties, fiber measurements), and the presence of histopathological changes in the pectoral muscle (PS) of broiler chickens. On d 12 of incubation, 480 eggs were randomly divided into 5 experimental groups treated with different bioactives, in ovo injected: C, control with physiological saline; T1 with 1.9 mg of raffinose family oligosaccharides; T2 and T3 with 1.9 mg of raffinose family oligosaccharides enriched with different probiotic bacteria, specifically 1,000 cfu of Lactococcus lactis ssp. lactis SL1 and Lactococcus lactis ssp. cremoris IBB SC1, respectively; T4 with commercially available synbiotic Duolac, containing 500 cfu of both Lactobacillus acidophilus and Streptococcus faecium with the addition of lactose (0.001 mg/embryo). Among the hatched chickens, 60 males were randomly chosen (12 birds for each group) and were grown to 42 d in collective cages (n = 3 birds in each 4 cages: replications for experimental groups). Broilers were fed ad libitum commercial diets according to age. In ovo prebiotic and synbiotic administration had a low effect on investigated traits, but depend on the kind of bioactives administered. Commercial synbiotic treatment (T4) reduced carcass yield percentage, and the feed conversion ratio was higher in T3 and T4 groups compared with other groups. The abdominal fat, the ultimate pH, and cholesterol of the PS were not affected by treatment. Broiler chickens of the treated groups with both slightly greater PS and fiber diameter had a significantly lower amount of collagen. The greater thickness of muscle fibers (not significant) and the lower fiber density (statistically significant), observed in treated birds in comparison with those of the C group, are not associated with histopathological changes in the PS of broilers. The incidence of

  6. A prebiotic galactooligosaccharide mixture reduces severity of hyperpnoea-induced bronchoconstriction and markers of airway inflammation.

    PubMed

    Williams, Neil C; Johnson, Michael A; Shaw, Dominick E; Spendlove, Ian; Vulevic, Jelena; Sharpe, Graham R; Hunter, Kirsty A

    2016-09-01

    Gut microbes have a substantial influence on systemic immune function and allergic sensitisation. Manipulation of the gut microbiome through prebiotics may provide a potential strategy to influence the immunopathology of asthma. This study investigated the effects of prebiotic Bimuno-galactooligosaccharide (B-GOS) supplementation on hyperpnoea-induced bronchoconstriction (HIB), a surrogate for exercise-induced bronchoconstriction, and airway inflammation. A total of ten adults with asthma and HIB and eight controls without asthma were randomised to receive 5·5 g/d of either B-GOS or placebo for 3 weeks separated by a 2-week washout period. The peak fall in forced expiratory volume in 1 s (FEV1) following eucapnic voluntary hyperpnoea (EVH) defined HIB severity. Markers of airway inflammation were measured at baseline and after EVH. Pulmonary function remained unchanged in the control group. In the HIB group, the peak post-EVH fall in FEV1 at day 0 (-880 (sd 480) ml) was unchanged after placebo, but was attenuated by 40 % (-940 (sd 460) v. -570 (sd 310) ml, P=0·004) after B-GOS. In the HIB group, B-GOS reduced baseline chemokine CC ligand 17 (399 (sd 140) v. 323 (sd 144) pg/ml, P=0·005) and TNF-α (2·68 (sd 0·98) v. 2·18 (sd 0·59) pg/ml, P=0·040) and abolished the EVH-induced 29 % increase in TNF-α. Baseline C-reactive protein was reduced following B-GOS in HIB (2·46 (sd 1·14) v. 1·44 (sd 0·41) mg/l, P=0·015) and control (2·16 (sd 1·02) v. 1·47 (sd 0·33) mg/l, P=0·050) groups. Chemokine CC ligand 11 and fraction of exhaled nitric oxide remained unchanged. B-GOS supplementation attenuated airway hyper-responsiveness with concomitant reductions in markers of airway inflammation associated with HIB. PMID:27523186

  7. Microbial Composition and In Vitro Fermentation Patterns of Human Milk Oligosaccharides and Prebiotics Differ between Formula-Fed and Sow-Reared Piglets123

    PubMed Central

    Li, Min; Bauer, Laura L.; Chen, Xin; Wang, Mei; Kuhlenschmidt, Theresa B.; Kuhlenschmidt, Mark S.; Fahey, George C.; Donovan, Sharon M.

    2012-01-01

    The microbial composition and in vitro fermentation characteristics of human milk oligosaccharides (HMO), lacto-N-neotetraose (LNnT), a 2:1 mixture of polydextrose (PDX) and galactooligosaccharides (GOS), and short-chain fructooligosaccharides (scFOS) by pooled ascending colonic microbiota from 9- and 17-d-old formula-fed (FF) and sow-reared (SR) piglets were assessed. pH change and gas, SCFA, and lactate production were determined after 0, 2, 4, 8, and 12 h of incubation. In most donor groups, the pH change was greater for scFOS fermentation and lower for PDX/GOS than for other substrates. LNnT fermentation produced larger amounts of gas, total SCFA, acetate, and butyrate than did the other substrates, whereas HMO and scFOS produced higher amounts of propionate and lactate, respectively. In general, pH change, total SCFA, acetate, and propionate production were greater in pooled inoculum from FF and 9-d-old piglets, whereas SR-derived inoculum produced higher amounts of butyrate and lactate after 4 h fermentation. Gut microbiota were assessed by 16S ribosomal RNA V3 gene denaturing gradient gel electrophoresis analysis and real-time qPCR. Microbial structures differed among the 4 groups before fermentation, with higher counts of Bifidobacterium in SR piglets and higher counts of Clostridium cluster IV, XIVa, and Bacteroides vulgatus in FF piglets. Lactobacillus counts were higher in 9-d-old piglets than in 17-d-old piglets, regardless of diet. Bifidobacterium, Bacteroides, and clostridial species increased after 8 and 12 h fermentation on most substrates. In summary, piglet diet and age affect gut microbiota, leading to different fermentation patterns. HMO have potential prebiotic effects due to their effects on SCFA production and microbial modulation. PMID:22399522

  8. Modulation of microbiota as treatment for intestinal inflammatory disorders: An uptodate.

    PubMed

    Gallo, Antonella; Passaro, Giovanna; Gasbarrini, Antonio; Landolfi, Raffaele; Montalto, Massimo

    2016-08-28

    Alterations of intestinal microflora may significantly contribute to the pathogenesis of different inflammatory and autoimmune disorders. There is emerging interest on the role of selective modulation of microflora in inducing benefits in inflammatory intestinal disorders, by as probiotics, prebiotics, synbiotics, antibiotics, and fecal microbiota transplantation (FMT). To summarize recent evidences on microflora modulation in main intestinal inflammatory disorders, PubMed was searched using terms microbiota, intestinal flora, probiotics, prebiotics, fecal transplantation. More than three hundred articles published up to 2015 were selected and reviewed. Randomized placebo-controlled trials and meta-analysis were firstly included, mainly for probiotics. A meta-analysis was not performed because of the heterogeneity of these studies. Most of relevant data derived from studies on probiotics, reporting some efficacy in ulcerative colitis and in pouchitis, while disappointing results are available for Crohn's disease. Probiotic supplementation may significantly reduce rates of rotavirus diarrhea. Efficacy of probiotics in NSAID enteropathy and irritable bowel syndrome is still controversial. Finally, FMT has been recently recognized as an efficacious treatment for recurrent Clostridium difficile infection. Modulation of intestinal flora represents a very interesting therapeutic target, although it still deserves some doubts and limitations. Future studies should be encouraged to provide new understanding about its therapeutical role. PMID:27621567

  9. Modulation of microbiota as treatment for intestinal inflammatory disorders: An uptodate

    PubMed Central

    Gallo, Antonella; Passaro, Giovanna; Gasbarrini, Antonio; Landolfi, Raffaele; Montalto, Massimo

    2016-01-01

    Alterations of intestinal microflora may significantly contribute to the pathogenesis of different inflammatory and autoimmune disorders. There is emerging interest on the role of selective modulation of microflora in inducing benefits in inflammatory intestinal disorders, by as probiotics, prebiotics, synbiotics, antibiotics, and fecal microbiota transplantation (FMT). To summarize recent evidences on microflora modulation in main intestinal inflammatory disorders, PubMed was searched using terms microbiota, intestinal flora, probiotics, prebiotics, fecal transplantation. More than three hundred articles published up to 2015 were selected and reviewed. Randomized placebo-controlled trials and meta-analysis were firstly included, mainly for probiotics. A meta-analysis was not performed because of the heterogeneity of these studies. Most of relevant data derived from studies on probiotics, reporting some efficacy in ulcerative colitis and in pouchitis, while disappointing results are available for Crohn’s disease. Probiotic supplementation may significantly reduce rates of rotavirus diarrhea. Efficacy of probiotics in NSAID enteropathy and irritable bowel syndrome is still controversial. Finally, FMT has been recently recognized as an efficacious treatment for recurrent Clostridium difficile infection. Modulation of intestinal flora represents a very interesting therapeutic target, although it still deserves some doubts and limitations. Future studies should be encouraged to provide new understanding about its therapeutical role. PMID:27621567

  10. In situ prebiotics: enzymatic release of galacto-rhamnogalacturonan from potato pulp in vivo in the gastrointestinal tract of the weaning piglet.

    PubMed

    Strube, Mikael Lenz; Jensen, Tim Kåre; Meyer, Anne Strunge; Boye, Mette

    2015-12-01

    Prebiotics may be efficient for prevention of intestinal infections in humans and animals by increasing the levels of beneficial bacteria and thereby improving gut health. Using purified prebiotics may however not be cost-effective in the livestock production industry. Instead, prebiotic fibres may be released directly in the gastro-intestinal tract by feeding enzymes with a suitable substrate and allowing the prebiotics to be produced in situ. Using low doses, 0.03 % enzyme-to-substrate ratio, of the enzymes pectin lyase and polygalacturonase in combination with potato pulp, a low-value industrial by-product, we show that high molecular weight galacto-rhamnogalacturonan can be solubilized in the stomach of weaning piglets. The release of this fiber is in the order of 22-38 % of the theoretical amount, achieved within 20 min. The catalysis takes place mainly in the stomach of the animal and is then followed by distribution through the small intestines. To our knowledge, this is the first paper describing targeted production of prebiotics in an animal model. PMID:26475351

  11. Proton-induced damage on 2-aminooxazole, a potential prebiotic compound.

    PubMed

    Bacchus-Montabonel, Marie-Christine

    2015-01-29

    Among the complex organic molecules detected in space, in the interstellar medium, on meteorites or comets, special interest is devoted to the potentially exobiologic-relevant species. In the hypothesis, widely discussed, of a possible exogen origin of life, the transport of such compounds and their survival is indeed a fundamental question. Recently, suggestion has been made that 2-aminooxazole could be a possible precursor of RNA nucleotides on early earth and its stability to UV radiation or to collisions may be determinant. We have thus undertaken a detailed theoretical study of the charge transfer collision dynamics induced by the impact of 2-aminooxazole with protons, which could be an important process in particular in proton-rich environments. The theoretical treatment has been developed through ab initio quantum chemistry molecular calculations followed by semiclassical collision dynamics. The results are compared to previous investigations on DNA and RNA building blocks in order to extract some qualitative trends in the damage of prebiotic species under spatial radiation. PMID:25574775

  12. Redox History of the Earth's Interior since ~3900 Ma: Implications for Prebiotic Molecules

    NASA Astrophysics Data System (ADS)

    Delano, John W.

    2001-08-01

    The history of the oxidation state in the Earth's mantle has been constrained using (a) the whole-rock abundances of Cr and V in ancient volcanics, and (b) the composition of Cr-rich spinels in ancient volcanics. Results indicate that the Earth's mantle has been at-or-near its current oxidation state (+/-0.5 log-unit fO_2) since at least 3600 Ma, and probably since at least 3960 Ma. Volatiles released into the Earth's atmosphere by high-temperature (T >= 1300 K) volcanism during this time have been dominated by H_2O, CO_2, and SO_2. This blend of volatiles is known to provide smaller yields of prebiotic, organic molecules by atmospheric and surface processes than gas mixtures containing higher concentrations of reduced species such as H_2, CO, and H_2S (e.g., Miller, 1998; Zolotov and Shock, 2000). The results discussed in this article independently support the conclusion of Canil (1997, 1999). f the atmosphere was reducing (e.g., CH_4, H_2, H_2S, NH_3, CO) at any time during the last ~3900 Ma, high-temperature volcanic outgassing was not the cause of it.

  13. Redox Energy and Sulfur Chemistry in Prebiotic Polymer Synthesis and Replication

    NASA Technical Reports Server (NTRS)

    Weber, Arthur L.

    1997-01-01

    In the past year we have made significant progress in three research areas: (1) Most importantly, we discovered a new pathway of prebiotic amino acid synthesis in which formaldehyde and glycolaldehyde (substrates of the formose reaction) react with ammonia yielding alanine and homoserine in the presence of thiol catalysts. This thiol-dependent synthesis of amino acids undoubtedly occurs via amino acid thioester intermediates capable of forming peptides. This 'one-pot' reaction system operates under mild aqueous conditions, and like modern amino acid biosynthesis, uses sugar intermediates which are converted to amino acids by energy-yielding redox disproportionation. (2) Finally, in preparation for the analysis of Martian meteorite samples, we upgraded our HPLC system and developed an improved method capable of detecting a I femtomole of amino acid enantiomers. (3) We completed our analysis of the energetics of metabolism that revealed that life depends on biosynthetic processes driven by chemical energy made available by the redox disproportionation of carbon groups of sugars. We established that the favorable energy of redox disproportionation is based on the universal reduction potentials of carbon groups. We concluded that it is hard to imagine any other organic molecule besides sugars (formaldehyde oligomers) having the energy and reactivity needed to drive either modem biosynthesis or the chemical processes behind its origin.

  14. Temperature oscillations near natural nuclear reactor cores and the potential for prebiotic oligomer synthesis

    NASA Astrophysics Data System (ADS)

    Adam, Zachary R.

    2016-06-01

    Geologic settings capable of driving prebiotic oligomer synthesis reactions remain a relatively unexplored aspect of origins of life research. Natural nuclear reactors are an example of Precambrian energy sources that produced unique temperature fluctuations. Heat transfer models indicate that water-moderated, convectively-cooled natural fission reactors in porous host rocks create temperature oscillations that resemble those employed in polymerase chain reaction (PCR) devices to artificially amplify oligonucleotides. This temperature profile is characterized by short-duration pulses up to 70-100 °C, followed by a sustained period of temperatures in the range of 30-70 °C, and finally a period of relaxation to ambient temperatures until the cycle is restarted by a fresh influx of pore water. For a given reactor configuration, temperature maxima and the time required to relax to ambient temperatures depend most strongly on the aggregate effect of host rock permeability in decreasing the thermal expansion and increasing the viscosity and evaporation temperature of the pore fluids. Once formed, fission-fueled reactors can sustain multi-kilowatt-level power production for 105-106 years, ensuring microenvironmental longevity and chemical output. The model outputs indicate that organic synthesis on young planetary bodies with a sizeable reservoir of fissile material can involve more sophisticated energy dissipation pathways than modern terrestrial analog settings alone would suggest.

  15. Ammonia on the prebiotic Earth: Iron(II) reduction of nitrite. [Abstract only

    NASA Technical Reports Server (NTRS)

    Summers, David P.; Chang, Sherwood

    1994-01-01

    Theories for the origin of life require the availability of reduced nitrogen. In the non-reducing atmosphere suggested by geochemical evidence, production in the atmosphere and survival of NH3 against photochemical destruction are problematic. Electric discharges and impact shocks would produce NO rather than HCN or NH3. Conversion of NO to nitrous and nitric acid (by way of HNO) and precipitation in acid rain would provide a source of fixed nitrogen to the early ocean. One solution to the NH3 problem may have been the reduction of nitrite/nitrate in the ocean with aqueous ferrous iron, Fe(2+): 6Fe(+2) + 7 H2O + NO2(-) yields 3Fe2O3 + 11 H(+) + NH3. We have measured the kinetics of this reaction as a function of temperature, pH, and concentrations of salts, Fe(+2), and NO2(-). Cations (Na(+), Mg(2+), K(+)) and anions (Cl(-), Br(-), SO4(2-)) increase the rate by factors of 4 to 8. Although a competing pathway yields N2, the efficiency of the conversion of nitrite to ammonia ranges from 25% to 85%. Nitrate reduction was not consistently reproducible; however, when it was observed, its rate was slower by at least 8X than that of nitrite reduction. If the prebiotic atmosphere contained 0.2 to 10 atmospheres CO2 as suggested by Walker (1985), the Fe(+2) concentration and the rate would have been limited by siderite (FeCO3) solubility.

  16. Temperature oscillations near natural nuclear reactor cores and the potential for prebiotic oligomer synthesis.

    PubMed

    Adam, Zachary R

    2016-06-01

    Geologic settings capable of driving prebiotic oligomer synthesis reactions remain a relatively unexplored aspect of origins of life research. Natural nuclear reactors are an example of Precambrian energy sources that produced unique temperature fluctuations. Heat transfer models indicate that water-moderated, convectively-cooled natural fission reactors in porous host rocks create temperature oscillations that resemble those employed in polymerase chain reaction (PCR) devices to artificially amplify oligonucleotides. This temperature profile is characterized by short-duration pulses up to 70-100 °C, followed by a sustained period of temperatures in the range of 30-70 °C, and finally a period of relaxation to ambient temperatures until the cycle is restarted by a fresh influx of pore water. For a given reactor configuration, temperature maxima and the time required to relax to ambient temperatures depend most strongly on the aggregate effect of host rock permeability in decreasing the thermal expansion and increasing the viscosity and evaporation temperature of the pore fluids. Once formed, fission-fueled reactors can sustain multi-kilowatt-level power production for 10(5)-10(6) years, ensuring microenvironmental longevity and chemical output. The model outputs indicate that organic synthesis on young planetary bodies with a sizeable reservoir of fissile material can involve more sophisticated energy dissipation pathways than modern terrestrial analog settings alone would suggest. PMID:26680444

  17. Prebiotic Metabolisms: Photo catalysis of the rTCA cycle by sphalerite colloids

    NASA Astrophysics Data System (ADS)

    Mangiante, D. M.; Bowen, B.; Northen, T.; Banfield, J. F.

    2010-12-01

    Explorations of mineral catalyzed reverse tricarboxylic acid (rTCA) cycle reactions provide a window into possible mechanisms for prebiotic metabolisms and the origins of life. The excitation of nano-scale semiconducting sphalerite minerals by ultra-violate light results in reducing electrons capable of catalyzing the reduction reactions present in the rTCA cycle. Current literature has utilized ion chromatography methods to characterize catalysis of two of the five redox active rTCA cycle compounds with high yield. This technique is unable to produce the untargeted analysis required to anticipate the myriad side reactions driven by excited photoelectrons and their ensuing radicals. By employing liquid chromatography coupled to mass spectrometry (LC-MS) we can examine the complete range of metabolites present across a reaction time series. The three dimensional LC-MS data set allows for the qualitative determination of individual metabolite features, while the comparison of intensities yields quantitative rates. These results allow us to describe the complete set of reactions resultant from a single rTCA cycle organic acid on a photo-activated sphalerite surface and provide a possible mechanism for how metabolic pathways could operate in enzyme free environments.

  18. On the origin of molecular 'handedness' in living systems. [paleomagnetic effects in prebiotic enantiomer synthesis

    NASA Technical Reports Server (NTRS)

    Noyes, H. P.; Bonner, W. A.

    1975-01-01

    Elementary particle effects (beta-decay) provide only a weakly handed radiation in the biologically effective energy ranges. Global magnetic effects coupled to sunlight are randomized by paleomagnetic reversals. A persistent terrestrial handed bias at possible local biopoetic sites offers a more promising explanation for the origin of the 'handedness' of the molecules found among living systems on earth. Magnetite in lava flows maintains a handed bias for surface catalysis through many magnetic reversals. Indirect evidence for the hypothesis that magnetite contaminated with sulfur is a possible biopoetic site (Granick, 1957) has been provided by the molecular structure of ferredoxin - a single strand of the 14 primordial amino acids wrapped around an FeS core. Lava flows have been suggested as biopoetic sites by Fox (1964), since their temperature and chemical composition might allow for the rapid synthesis of prebiotic compounds at the surface of the primitive earth. The additional fact that magetite in lava flows also provides a persistent handed site for surface catalysis offers a further argument for the experimental investigation of this specific biopoetic environment.

  19. Comments on `Concentration by Evaporation and the Prebiotic Synthesis of Cytosine'

    NASA Astrophysics Data System (ADS)

    Shapiro, Robert

    2002-06-01

    The claim by Nelson et al. (2001) that the reaction of cyanoacetaldehyde and urea provides `an efficient prebiotic synthesis' of cytosine is disputed. The authors have not dealt with the important points presented in a criticism of this reaction (Shapiro, 1999): (1) The reactants undergo side reactions with common nucleophiles that appear to proceed more rapidly than cytosine formation, and (2) No reactions have been described thus far that would produce cytosine at a rate sufficient to compensate for its decomposition by deamination, and permit accumulation over extended periods of time. Instead, Nelson et al. have conducted `drying-down' experiments, in an effort to simulate evaporations on the early Earth, but the design of these experiments is flawed. The initial reactant concentrations are much higher than might be expected in a natural setting, and potentially interfering substances such as glycine, cyanide and thiols have been excluded. `Drying beaches and drying lagoons' have been invoked as sites for such a reaction but no effort has been made to describe the characteristics of such sites or to estimate their frequency with reference to the present Earth. In the absence of contradictory data, the conclusion put forward in Shapiro (1999) remains valid: `It was quite unlikely that cytosine played a role in the origin of life'.

  20. Prebiotic-Like Condensations of Cyanamide and Glyoxal: Revisiting Intractable Biotars.

    PubMed

    Lavado, Nieves; Escamilla, Juan Carlos; Ávalos, Martín; Babiano, Reyes; Cintas, Pedro; Jiménez, José Luis; Palacios, Juan Carlos

    2016-09-12

    We report a detailed investigation into the nature of products that are generated by the reactions of cyanamide and glyoxal, two small molecules of astrochemical and prebiotic significance, under different experimental conditions. The experimental data suggest that the formation of oligomeric structures is related in part to the formation of insoluble tholins in the presence of oxygen-containing molecules. Although oligomerization proceeds well in water, product isolation turned out to be impractical. Instead, solid precipitates were obtained easily in acetone. Crude mixtures have been thoroughly scrutinized by spectroscopic methods, in particular NMR and mass spectroscopy (ESI mode), which are all consistent with the generation of a few functional groups that are embedded into regular chains of five- and six-membered rings, thereby pointing to a supramolecular organization. Three different models of cross-condensation and chain growth are suggested. These synthetic explorations provide further insights into the formation of complex organic matter in interstellar scenarios and extraterrestrial bodies that might have played a pivotal role in chemical evolution. PMID:27455123