Project description:The objectives of this study were to establish a microbiome profile for oral epithelial dysplasia using archival lesion swab samples to characterize the community variations and the functional potential of the microbiome using 16S rRNA gene sequencing
Project description:Compositional changes in the microbiota (dysbiosis) may be a basis for Irritable Bowel Syndrome (IBS) but biomarkers are currently unavailable to direct microbiota-directed therapy. We therefore examined whether changes in fecal β-defensin could be a marker of dysbiosis in a murine model. Experimental dysbiosis was induced using four interventions relevant to IBS: a mix of antimicrobials, westernized diets (high-fat/high-sugar and, high salt diets), or mild restraint stress. Fecal mouse β-defensin-3 and 16S rRNA-based microbiome profiles were assessed at baseline, during and following these interventions. Each intervention, except for mild restraint stress, altered compositional and diversity profiles of the microbiota. Exposure to antimicrobials or a high-fat/high-sugar diet, but not mild restraint stress, resulted in decreased fecal β-defensin-3 compared to baseline. In contrast, exposure to the high salt diet increased β-defensin-3 compared to baseline but this was not accompanied by discernible inflammatory changes in the host.
2023-07-11 | GSE225272 | GEO
Project description:Relationship between rectal swab and tissue samples for analysis of mucosa-associated microbiota in patients with inflammatory bowel disease
Project description:This study aimed to analyze changes in gut microbiota composition in mice after transplantation of fecal microbiota (FMT, N = 6) from the feces of NSCLC patients by analyzing fecal content using 16S rRNA sequencing, 10 days after transplantation. Specific-pathogen-free (SPF) mice were used for each experiments (N=4) as controls.
Project description:Relationship between rectal swab and tissue samples in the analysis of mucosa-associated microbiota in patients with inflammatory bowel disease
Project description:Study 1: Transcriptomic profiles in colon tissue from inflammatory bowel diseases patients in relation to N-nitroso compound exposure and colorectal cancer risk Study 1: N-nitroso compounds (NOC) have been suggested to play a role in human cancer development but definitive evidence is still lacking. In this study we investigated gene expression modifications induced in human colon tissue in relation to NOC exposure to gain insight in the relevance of these compounds in human colorectal cancer (CRC) development. Since there are indications that inflammation stimulates endogenous NOC formation, the study population consisted of patients with inflammatory bowel disease (IBD) and irritable bowel syndrome patients as controls without inflammation. Strong transcriptomic differences were identified in colonic biopsies from IBD patients and compared to controls that enhance the understanding of IBD pathophysiology. However, fecal NOC levels were not increased in IBD patients, suggesting that inflammation did not stimulate NOC formation. By relating gene expression changes of all subjects to fecal NOC levels, we did, however, identify a NOC exposure-associated transcriptomic response that suggests that physiological NOC concentrations may induce genotoxic responses and chromatin modifications in human colon tissue, both of which are linked to carcinogenicity. In a network analysis, chromatin modifications were linked to 11 significantly modulated histone genes, pointing towards a possible epigenetic mechanism that may be relevant in comprehending the molecular basis of NOC-induced carcinogenesis. We conclude that NOC exposure is associated with gene expression modifications in the colon that may increase CRC risk in humans. Study 2: Red meat intake-induced increases in fecal water genotoxicity correlate with pro-carcinogenic gene expression changes in the human colon Study 2: Red meat consumption is associated with an increased colorectal cancer (CRC) risk, which may be due to an increased endogenous formation of genotoxic N-nitroso compounds (NOCs). To assess the impact of red meat intake on potential risk factors of CRC, we investigated the effect of a 7-day dietary red meat intervention in human subjects on endogenous NOC formation and fecal water genotoxicity in relation to transcriptomic changes induced in colonic tissue. In order to evaluate the potential effect of an inflamed colon on endogenous nitrosation, the study population consisted of inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) control subjects without inflammation. The intervention had no effect on fecal NOC formation but fecal water genotoxicity significantly increased in response to red meat intake. Since IBD patients showed no difference in fecal NOC formation or fecal water genotoxicity levels as compared to IBS controls, for transcriptomic analyses, all subjects were grouped together. Genes significantly correlating with the increase in fecal water genotoxicity were involved in biological pathways indicative of genotoxic effects, including modifications in DNA damage, cell cycle, and apoptosis pathways. Moreover, WNT signaling and nucleosome remodeling pathways were modulated that are known to play a part in the carcinogenic process in the human colon. These results are in line with a possible oxidative effect of dietary heme. We conclude that the gene expression changes identified in this study corroborate the genotoxic potential of diets high in red meat and point towards a possible risk of CRC development in humans. The study investigated transcription levels in human colon biopsies obtained during a colonoscopic exam in 32 subjects suffering from either inflammatory bowel disease (IBD) or irritable bowel syndrome (IBS). IBS patients served as control patients for comparison with IBD patients (see Study 1). 12 of these patients (6 IBD and 6 IBS) also followed a 7-day diet high in red meat (300 grams/day) after which a second colonscopic exam was performed to obtain colon biopsies to investigate the effect of the red meat intervention (Study 2). For each subject, cRNA copies of mRNA isolated from the colon biopsies were labeled with one dye (Cy3) and each sample was hybridized on a separate array. One replicate per subject or before/after red meat intervention (so 44 arrays in total, i.e. 20 before patients and 12 before and after patients).
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:The impact of mono-chronic S. stercoralis infection on the gut microbiome and microbial activities in infected participants was explored. The 16S rRNA gene sequencing of a longitudinal study with 2 sets of human fecal was investigated. Set A, 42 samples were matched, and divided equally into positive (Pos) and negative (Neg) for S. stercoralis diagnoses. Set B, 20 samples of the same participant in before (Ss+PreT) and after (Ss+PostT) treatment was subjected for 16S rRNA sequences and LC-MS/MS to explore the effect of anti-helminthic treatment on microbiome proteomes.
2023-11-07 | PXD037975 | JPOST Repository
Project description:Bacterial 16S rRNA in gut microbiota of pediatric inflammatory bowel disease