Project description:Digesta and mucosa samples from stomach, jejunum, ileum, cecum and colon of the porcine GIT from four animals were analysed by metaproteomics to obtain a deeper insight into the functions of bacterial groups with a concomitant analyses of host proteins.
Project description:In the DSS-induced colitis model, the epithelial damage and resulting inflammation is restricted to the colon, with a potential influence on the microbial composition in the adjacent cecum. Several studies have reported changes of the gut microbiota in the DSS-induced colitis model and other mouse models of IBD. Furthermore, metaproteomics analysis of the gut microbiome in a mouse model of Crohn’s disease demonstrated that disease severity and location are microbiota-dependent, with clear evidence for the causal role of bacterial dysbiosis in the development of chronic ileal inflammation. We have developed a refined model of chronic DSS-induced colitis that reflects typical symptoms of human IBD without a risky body weight loss usually observed in DSS models [Hoffmann et al., submitted]. In this study, we used metaproteomics to characterize the disease-related changes in bacterial protein abundance and function in the refined model of DSS-induced colitis. To assess the structural and functional changes, we applied 16S rRNA gene sequencing and metaproteomics analysis of the intestinal microbiota in three different entities of the intestinal environment, i.e. colon mucus, colon content and cecum content.
Project description:Objective: Roux-Y gastric bypass (RYGB) surgery is a last treatment resort to induce substantial and sustained weight loss in severe obesity. The anatomical rearrangement affects the intestinal microbiota but so far, little information is available how it interferes with microbial functionality and microbial-host interaction independent from weight loss. Design: A RYGB rat model was utilized and compared to sham-operated controls which were kept at matched body weight as RYGB animals by food restriction. We assessed microbial taxonomy by 16S rRNA gene sequencing and functional activity by metaproteomics and metabolomics on microbiota samples collected separately from the ileum, the cecum as well as the colon and separately analysed the lumen and mucus associated microbiota. Results: Altered gut architecture in RYGB strongly affected the occurrence of Actinobacteria, especially Bifidobacteriaceae and Proteobacteria which were increased, whereas Firmicutes were decreased, although Streptococcaceae and Clostridium perfringens were observed at higher abundances. A decrease of conjugated as well as secondary bile acids was observed in the RYGB-gut lumen. In addition the arginine biosynthesis pathway in the microbiota was altered, indicated by the changes in abundance of upstream metabolites and enzymes, resulting in lower levels of arginine and higher levels of aspartate in the colon after RYGB. Conclusion: The anatomical rearrangement in RYGB affects microbiota composition and functionality by changes in amino acid and bile acid metabolism, independent of weight loss. The shift in microbiota taxonomic structure after RYGB may be mediated by the resulting change in composition of the bile acid pool in the gut lumen.
Project description:Gut microbiota were assessed in 540 colonoscopy-screened adults by 16S rRNA gene sequencing of stool samples. Investigators compared gut microbiota diversity, overall composition, and normalized taxon abundance among these groups.
Project description:Here, we used reverse-phase liquid chromatography-coupled tandem mass spectrometry to study the pre-weaned lamb proteome and metaproteome in ten different gastrointestinal tracts: rumen, reticulum, omasum, abomasum, duodenum, jejunum, ileum, cecum, colon, and rectum.
Project description:C57BL/6Crl mice were fed 10 mg/kg BA or control for 13 days. Samples collected on day 14. Treatment groups included serocholate, serine + cholate, phenylalanocholate, phenylalanine + cholate, taurocholate, taurine + cholate, and a mock control.
Fecal, F; Colon, CL; Cecum, CE; Duodenum, DD; Gallbladder, GB; Ileum, IL; Liver, L
Project description:Gastrointestinal (GI) mucus is continuously secreted and lines the entire length of the GI tract. Essential for health, it keeps the noxious luminal content away from the epithelium and propels forward the digesta. The aim of our study was to characterize the composition and structures of mucus throughout the various GI segments in dog. Mucus from the stomach, small intestine (duodenum, jejunum, ileum), and large intestine (cecum, proximal and distal colon) was collected from 5 dogs. pH and water content of GI mucus and digesta were analyzed. Composition of all GI-tract segments from a domestic and a laboratory dog was determined by label-free global proteomics. A colonic-focussed composition analysis with TMT-labelled proteomics was used on jenunal and proximal and distal colonic mucus samples from 3 laboratory and 1 domestic dog. Finally, the composition of jejunal and colonic mucus samples of 3 laboratory and 1 domestic dog was evaluated with lipidomics and metabolomics. Structural properties were investigated using cryoSEM and rheology. The proteome was similar across the different GI segments. The highest abundant secreted gel-forming mucin in the gastric mucus was mucin 5AC, whether mucin 2 had highest abundance in the intestinal mucus. Lipid and metabolite abundance was generally higher in the jejunal mucus than the colonic mucus. In conclusion, the mucus is a highly viscous and hydrated material. The proteins, lipids and metabolites were similar throughout the GI tract, although abundances depended on location. These data provide an important baseline for future studies on human and canine intestinal diseases and the dog model in drug absorption.
Project description:The study investigated the impact of environment on the composition of the gut microbiota and mucosal immune development and function at gut surfaces in early and adult life. Piglets of similar genotype were reared in indoor and outdoor environments and in an experimental isolator facility. Mucosa-adherent microbial diversity in the pig ileum was characterized by sequence analysis of 16S rRNA gene libraries. Host-specific gene responses in gut ileal tissues to differences in microbial composition were investigated using Affymetrix microarray technology and Real-time PCR.