Showing papers on "Butyrate-Producing Bacteria published in 2015"

Steering Endogenous Butyrate Production in the Intestinal Tract of Broilers as a Tool to Improve Gut Health.

Abstract: The ban on antimicrobial growth promoters and efforts to reduce therapeutic antibiotic usage has led to major problems of gastrointestinal dysbiosis in livestock production in Europe. Control of dysbiosis without the use of antibiotics requires a thorough understanding of the interaction between the microbiota and the host mucosa. The gut microbiota of the healthy chicken is highly diverse, producing various metabolic end products, including gases and fermentation acids. The distal gut knows an abundance of bacteria from within the Firmicutes Clostridium clusters IV and XIVa that produce butyric acid, which is one of the metabolites that is sensed by the host as a signal. The host responds by strengthening the epithelial barrier, reducing inflammation, and increasing the production of mucins and antimicrobial peptides. Stimulating the colonization and growth of butyrate producing bacteria thus may help optimizing gut health. Various strategies are available to stimulate butyrate production in the distal gut. These include delivery of prebiotic substrates that are broken down by bacteria into smaller molecules which are then used by butyrate producers, a concept called cross-feeding. Xylo-oligosaccharides (XOS) are such compounds as they can be converted to lactate which is further metabolized to butyrate. Probiotic lactic acid producers can be supplied to support the cross-feeding reactions. Direct feeding of butyrate producing Clostridium cluster IV and XIVa strains are a future tool provided that large scale production of strictly anaerobic bacteria can be optimized. Current results of strategies that promote butyrate production in the gut are promising. Nevertheless, our current understanding of the intestinal ecosystem is still insufficient, and further research efforts are needed to fully exploit the capacity of these strategies.

Consumption of partially hydrolysed guar gum stimulates Bifidobacteria and butyrate-producing bacteria in the human large intestine.

Abstract: Partially hydrolysed guar gum (PHGG) is a water-soluble dietary fibre that is non-digestible in the upper gastrointestinal tract. It is believed that PHGG benefits the health of hosts by altering the colonic microbiota and stimulating short-chain fatty acid (SCFA) production. However, it remains unclear which bacteria ferment PHGG in the human large intestine. In this study, the effect of PHGG on faecal bacteria was analysed to specify the bacteria that contribute to the fermentation of PHGG in the human large intestine. Ten healthy volunteers consumed PHGG (6 g/day) for 2 weeks. Faeces were collected at 2 weeks prior to consumption, at the end of 2 weeks of consumption, and 2 weeks after consumption of PHGG. Bacterial DNA was extracted from these collected faeces and subjected to real-time PCR using bacterial group- or species-specific primers. The copy number of the butyryl-CoA CoA-transferase gene and the 16S rRNA gene copy numbers of Bifidobacterium, the Clostridium coccoides group, the Roseburia/ Eubacterium rectale group, Eubacterium hallii, and butyrate-producing bacterium strain SS2/1 were significantly increased by the intake of PHGG. Other bacteria and bacterial groups were not significantly influenced by the intake of PHGG. It was believed that the Roseburia/E. rectale group bacteria, Bifidobacterium, the lactate-utilising, butyrate-producing bacteria, E. hallii and bacterium strain SS2/1, would contribute to the fermentation of PHGG in the human large intestine. PHGG may benefit health by stimulating Bifidobacterium and butyrate-producing bacteria in the human large intestine.

Mouse gut microbiomics of short chain fatty acid metabolism and mucosal responses

Abstract: Summary The microbiota of the gastrointestinal (GI) tract plays a key role in the digestion of our food. The human gut microbiota can be studied using in vitro and animal models. In this thesis the mouse model is used to study the microbiota interaction with the diet and the host in different regions along the GI tract. These interacting microbes in the GI tract of humans and other mammals yield a wide range of metabolites, among which the short chain fatty acids (SCFA), in particular butyrate, acetate, and propionate, are the most abundant products of carbohydrate fermentation. Fermentable carbohydrates can modify the composition of the gut microbiota and change the SCFA concentrations in the gut. Opportunities for increasing specific SCFA by targeting their producers with carbohydrates are discussed. Five different fibres – resistant starch, inulin, fructooligosaccharides, arabinoxylan and guar gum – are tested for their modification of the mucosal tissue transcriptome, luminal microbiota composition and SCFA concentrations in the murine colon. The fibres inulin, fructooligosaccharides, arabinoxylan and guar gum led to increased SCFA concentrations and induced similar changes in relative abundance of microbial groups as determined by the MITChip, a phylogenetic microarray targeting the 16S ribosomal RNA of mouse intestinal microorganisms. Furthermore, these four fibres induced regulation of overlapping sets of genes in the mouse intestinal mucosa, where the transcription factor PPARγ was predicted to be a prominent upstream regulator of these processes. Multivariate data integration revealed strong correlations between the expression of genes involved in energy metabolism and the relative abundance of bacteria belonging to Clostridium cluster XIVa. Similar analyses were done for the caeca of the same mice, and were complemented with metatransciptome analyses. To comprehensively analyse RNAseq data of complex natural microbial communities, a de novo metatranscriptome assembly pipeline was developed and applied to unravel the activity profiles of the microbiota residing in the mouse cecum. This revealed distinct contributions of bacterial families to the fermentation of fibres into SCFA, involving the Bifidobacteriaceae, Lachnospiraceae, Clostridiaceae, Bacteroidaceae, Erysipelotrichaceae and Ruminococcaceae in some or all stages of the overall fibre fermentation activity. All families expressed genes encoding enzymes involved in the production of SCFA in different ratios. Specifically, butyrate producing bacteria correlated with a set of host genes involved in processes such as energy metabolism, transcriptional regulation and the mucosal immune system. In addition to complex carbohydrates, amino acids derived from dietary proteins can also serve as substrates for SCFA formation, leading to expansion of the fermentation end-product palet by including branched-SCFA. The long-term effects of high protein-diets on microbial community composition and activity were analysed. The caecal microbiota composition was changed by the high dietary protein. Most of the gene functions detected by metatranscriptomics in these caecal samples were assigned to the Lachnospiraceae, Erysipelotrichaceae and Clostridiaceae. High protein diets induced a decrease of Lachnospiraceae activity, but stimulated the activity of the Erysipelotrichaceae, while the Clostridiaceae appeared to express the broadest range of amino acid metabolism associated pathways. In conclusion, this thesis describes dietary interventions to modulate the mouse intestinal microbiota and mucosa. The data provides expansion of the knowledge on interactions between the diet, microbiota and host. This information can be used to optimize the design and validation on dietary intervention studies in humans.

Probiotics and inflammatory bowel diseases.

Abstract: Intestinal microbiota is composed by symbiotic innocuous bacteria and potential pathogens also called pathobionts. Even if the mechanism of action of intestinal bacteria remain still unknown, specific microbial species seem to have important role in the maintenance of immunological equilibrium in the gut through the direct interaction with immune cells. Some studies have found a dysregulated interaction between the intestinal bacteria, the gut barrier, and the intestinal associated immune system in Inflammatory Bowel Disease (IBD) patients and in the pathogenesis of these pathologies. In IBD patients some Butyrate producing bacteria, as Faecalibacterium Prausnitzii, are under represented and this could be related with their chronic inflammatory state.

Probiotic potency of butyrate-producing bacteria for modulating the microbiome and epithelial barrier in inflammatory bowel disease

Abstract: Inflammatory bowel diseases (IBD) are characterized by a severe chronic, relapsing intestinal inflammation. An imbalance in structural and functional properties of the gut microbiota that can disrupt host-microbe homeostasis – defined as microbial dysbiosis – is associated with the etiology of IBD. Modulation of the dysbiosed gut microbiota in IBD is gaining more attention as a novel strategy to control the disease and to support current therapy. Butyrate-producing bacteria are considered as the future probiotics for IBD because butyrate has anti-inflammatory functions and has the capacity to strengthen the intestinal barrier. Before setting up clinical trials in humans with these novel probiotic candidates, more knowledge of their behavior under gastrointestinal conditions is required. The aim of this PhD research was to characterize and evaluate the potency of butyrate-producing bacteria, and especially of Butyricicoccus pullicaecorum, to modulate the microbiome and epithelial barrier in IBD. By using an in vitro intestinal technology platform, simulating the conditions from the stomach to the colon, we provided more insights in the potential of applying B. pullicaecorum or a mix of butyrate-producing bacteria as future probiotic for IBD.

Investigation of Butyrate-producing Bacteria and Genes from Fecal Samples of Thai Volunteers

Abstract: Butyrate, produced by intestinal anaerobic bacteria via dietary carbohydrate fermentation, is an important energy source for gut epithelial cells. The butyrate also plays a crucial role in homeostasis of intestinal epithelial cells including cellular proliferation, differentiation, and apoptosis. Butyrate production depends on the type of diet and availability of butyrate-producing bacteria. Bacteria of Clostridial cluster IV (CIV) and cluster XIVa (CXIVa) are major butyrate producers. This study investigated: i) the availability of Faecalibacterium prausnitzii (a representative of CIV) and Clostridium coccoides – Eubacterium rectale group (a representative of CXIVa), and ii) the presence of the butyrate-producing genes, butyryl-CoA: acetate CoA-transferase ( but ) and butyrate kinase ( buk ), in fecal samples of butyrate-producing volunteers using quantitative PCR. The samples were obtained from six normal (BMI23) and eight overweight (BMI23) Thai volunteers. The results showed the trend toward higher levels of Faecalibacterium prausnitzii found in the overweight volunteers as compared to the normal-weight volunteers. However, the proportion of Clostridium coccoides – Eubacterium rectale was not different between the two groups. Interestingly, the availability of Faecalibacterium prausnitzii showed significant positive correlation to the presence of but (r=0.752, p 23) จำนวน 8 คน ผลการศกษาพบวา สดสวนปรมาณแบคทเรย Faecalibacterium prausnitzii ในอจาระของอาสาสมครทมดชนมวลกายเกนปกตมแนวโนมสดสวนแบคทเรยชนดดงกลาวสงกวาในอจจาระของอาสาสมครทมดชนมวลกายปกต อยางไรกตามสดสวนแบคทเรยกลม Clostridium coccoides-Eubacterium rectale ไมแตกตางกนระหวางสองกลม จากการประมวลทางสถตเพอหาความสมพนธระหวางสดสวนของแบคทเรย ยนและคาดชนมวลกาย พบวาสดสวนของแบคทเรย Faecalibacterium prausnitzii มความสมพนธทางบวกอยางมนยสำคญกบสดสวนของยน but (r = 0.752, p <0.05) และคาดชนมวลกายมความสมพนธเชงบวกกบสดสวนของยน buk (r = 0.812, p <0.01)