ABSTRACT: Metagenome assembly of PRJEB10391 data set (Impact of ciprofloxacin pertubation on the intestinal resistome and microbiota in two healthy volunteers)
Project description:Proteases constitute the largest enzyme gene family in vertebrates with intracellular and secreted proteases having critical roles in cellular and organ physiology. Intestinal tract contains diverse set of proteases mediating digestion, microbial responses, epithelial and immune signaling. Transit of chyme through the intestinal tract results in significant suppression of proteases. Although endogenous protease inhibitors have been identified, the broader mechanisms underlying protease regulation in the intestinal tract remains unclear. The objective of this study was to determine microbial regulation of proteolytic activity in intestinal tract using phenotype of post-infection irritable bowel syndrome, a condition characterized by high fecal proteolytic activity. Proteases of host pancreatic origin (chymotrypsin like pancreatic elastase 2A, 3B and trypsin 2) drove proteolytic activity. Of the 14 differentially abundant taxa, high proteolytic activity state was characterized by complete absence of the commensal Alistipes putredinis. Germ free mice had very high proteolytic activity (10-fold of specific-pathogen free mice) which dropped significantly upon humanization with microbiota from healthy volunteers. In contrast, high proteolytic activity microbiota failed to inhibit it, a defect that corrected with fecal microbiota transplant as well as addition of A. putredinis. These mice also had increased intestinal permeability similar to that seen in patients. Microbiota β-glucuronidases mediate bilirubin deconjugation and unconjugated bilirubin is an inhibitor of serine proteases. We found that high proteolytic activity patients had lower urobilinogen levels, a product of bilirubin deconjugation. Mice colonized with β-glucuronidase overexpressing E. coli demonstrated significant inhibition of proteolytic activity and treatment with β-glucuronidase inhibitors increased it. The findings establish that specific commensal microbiota mediates effective inhibition of host pancreatic proteases and maintains intestinal barrier function through the production of β-glucuronidases. This suggests an important homeostatic role for commensal intestinal microbiota.
Project description:In human volunteers, we evaluated changes in gene expression profiles, immunological indices, and intestinal microbiota of blood cells in subjects consuming a S.reticulata extract. Thirty healthy Japanese males were split randomly into a group ingesting 240 mg/day of S.reticulata extract -containing tablets for 4 weeks and a control group ingesting placebo tablets. Ingestion of the S.reticulata extract improved T cell proliferation and other immunological indices, and changed intestinal microbiota, increasing Bifidobacterium and Lactobacillales and decreasing Clostridium bacteria. Expression levels of many immuno-relevant genes were altered. We have shown the S.reticulata extract to enhance human immune functions.
Project description:Probiotic bacteria, specific representatives of bacterial species that are a common part of the human microbiota, are proposed to deliver health benefits to the consumer by modulation of intestinal function via largely unknown molecular mechanisms. To explore in vivo mucosal responses of healthy adults to probiotics, we obtained transcriptomes in an intervention study following a double-blind placebo-controlled cross-over design. In the mucosa of the proximal small intestine of healthy volunteers, probiotic strains from the species Lactobacillus acidophilus, L. casei and L. rhamnosus each induced differential gene regulatory networks and pathways in the human mucosa. Comprehensive analyses revealed that these transcriptional networks regulate major basal mucosal processes, and uncovered remarkable similarity to response profiles obtained for specific bioactive molecules and drugs. This study elucidates how intestinal mucosa of healthy humans perceive different probiotics and provides avenues for rationally designed tests of clinical applications. Keywords: mucosal response of healthy adult humans to lactic acid bacteria This study was set up according to a randomised double-blind cross-over placebo-controlled design. It contains transcriptional profiles from biopsies from 7 healthy individuals after oral intake of three different Lactobacillus species or placebo control. In total, this study includes data from 7 individuals x 4 treatments=28 arrays.
Project description:Interventions: Case (colorectal cancer) group:a newly diagnosed colorectal cancer( CRC ) by colonoscopy and pathology;Control group:Clinically healthy volunteers with no symptoms or history of intestinal disease(e.g. colonic adenomatous polyps, CRC or inflammatory bowel disease)
Primary outcome(s): composition of gut microbiota;intestinal microbial phytase activity;16s rRNA metagenomic sequencing;diet surveys;phytic acid intake
Study Design: Case-Control study
Project description:Enterococcus faecium has emerged as a major opportunistic pathogen for two decades, with the spread of hospital-adapted multidrug-resistant clones. Members of the intestinal microbiota, they are subjected to numerous bacterial stresses, including antibiotics at subinhibitory concentrations (SICs). Since fluoroquinolones are extensively prescribed, SICs are very likely to occur in vivo with potential effects on bacterial metabolism with subsequent modulation of opportunistic traits. The aim of the study was to evaluate globally the impact of subinhibitory concentrations (SICs) of ciprofloxacin on antimicrobial resistance and pathogenicity of E. faecium. Transcriptomic analysis was performed by RNA-seq (HiSeq 2500, Illumina) using the vanB-positive reference strain E. faecium Aus0004 in the absence or presence of ciprofloxacin SIC (0.38 mg/L, i.e. MIC 1/8). Several genetic and phenotypic tests were used for validation. In the presence of ciprofloxacin SIC, 196 genes were significantly induced whereas 286 were significantly repressed, meaning that 16.8% of the E. faecium genome was altered. Amongst upregulated genes, EFAU004_02294 (fold change of 14.3) encoded a protein (EfmQnr) homologue of Qnr proteins involved in quinolone resistance in Gram-negative bacilli. Its implication in intrinsic and adaptive FQ resistance in E. faecium was experimentally ascertained. Moreover, EFAU004_02292 coding for the collagen adhesin Acm was also induced by SIC of ciprofloxacin (fold change of 8.2), and higher adhesion capabilities were demonstrated phenotypically. Both Efmqnr and Acm determinants may play an important role in the transition from a commensal to a pathogenic state of E. faecium that resides in the gut of patients receiving a fluoroquinolone therapy.
2017-02-04 | GSE94507 | GEO
Project description:Gut microbiota of Korean healthy volunteers
Project description:The connection between imbalances in the human gut microbiota, known as dysbiosis, and various diseases has been well established. Current techniques for sampling the small intestine are both invasive for patients and costly for healthcare facilities. Most studies on human gut microbiome are conducted using faecal samples, which do not accurately represent the microbiome in the upper intestinal tract. A pilot clinical investigation, registered as NCT05477069 and sponsored by the Grenoble Alpes University Hospital, is currently underway to evaluate a novel ingestible medical device (MD) designed for collecting small intestinal liquids by Pelican Health. This study is interventional and monocentric, involving 15 healthy volunteers.
Project description:Probiotic bacteria, specific representatives of bacterial species that are a common part of the human microbiota, are proposed to deliver health benefits to the consumer by modulation of intestinal function via largely unknown molecular mechanisms. To explore in vivo mucosal responses of healthy adults to probiotics, we obtained transcriptomes in an intervention study following a double-blind placebo-controlled cross-over design. In the mucosa of the proximal small intestine of healthy volunteers, probiotic strains from the species Lactobacillus acidophilus, L. casei and L. rhamnosus each induced differential gene regulatory networks and pathways in the human mucosa. Comprehensive analyses revealed that these transcriptional networks regulate major basal mucosal processes, and uncovered remarkable similarity to response profiles obtained for specific bioactive molecules and drugs. This study elucidates how intestinal mucosa of healthy humans perceive different probiotics and provides avenues for rationally designed tests of clinical applications. Keywords: mucosal response of healthy adult humans to lactic acid bacteria
Project description:Literature suggests that the route of feeding may impact the immune system. This study examines changes in gene expression due to route of feeding in healthy volunteers. Healthy volunteers were fed contniuous parenteral diet or continuous enteral diet for 72 hours