1.
Faecal bile acids and colonic bile acid membrane receptor correlate with symptom severity of diarrhoea-predominant irritable bowel syndrome: A pilot study.
Wei, W, Wang, H, Zhang, Y, Zhang, Y, Niu, B, Chen, S, Zhang, W, Yao, S
Digestive and liver disease : official journal of the Italian Society of Gastroenterology and the Italian Association for the Study of the Liver. 2021;(9):1120-1127
Abstract
AIMS: To compare both the faecal bile acids (BAs) and the levels of two bile acid receptors, Takeda G protein-coupled receptor 5 (TGR5) and vitamin D receptor (VDR), in the colonic mucosa between patients with irritable bowel syndrome with predominant diarrhea (IBS-D) and healthy controls, and explore the correlations among clinical characteristics, bile acid receptors expression, and BAs. METHODS The severity of abdominal pain and diarrhoea was assessed in IBS-D patients using validated questionnaires, faecal BAs were measured by ultraperformance liquid chromatography coupled to tandem mass spectrometry, and rectosigmoid biopsies were taken for the analyses of TGR5 and VDR expression using immunohistochemistry. RESULTS The level of TGR5 immunoreactivity in rectosigmoid mucosal biopsies was significantly higher in IBS-D patients than in controls, while the VDR immunoreactivity displayed no significant difference between patients and controls. The patients with more severe or more frequent abdominal pain had significantly higher TGR5 level. Faecal primary BAs were significantly increased in IBS-D patients and were positively correlated with the severity of diarrhoea. The level of TGR5 was positively associated with primary BAs and negatively associated with secondary BAs among all participants providing both mucosal and stool samples. CONCLUSIONS Colonic mucosal TGR5 protein expression and faecal bile acids were correlated with the symptom severity of IBS-D patients.
2.
Partners of patients with ulcerative colitis exhibit a biologically relevant dysbiosis in fecal microbial metacommunities.
Chen, GL, Zhang, Y, Wang, WY, Ji, XL, Meng, F, Xu, PS, Yang, NM, Ye, FQ, Bo, XC
World journal of gastroenterology. 2017;(25):4624-4631
Abstract
AIM: To investigate alterations in the fecal microbiome using 16S rRNA amplicon sequencing in couples in the same cohabitation environment. METHODS Fecal samples were collected from eight ulcerative colitis (UC) patients and their healthy partners at Lishui People's Hospital, Zhejiang Province, China. DNA was extracted and the variable regions V3 and V4 of the 16S rRNA genes were PCR amplified using a two-step protocol. Clear reads were clustered into operational taxonomic units (OTUs) at the 97% sequence similarity level using UCLUST v1.2.22. The Wilcoxon rank-sum test (R v3.1.2) was used to compare inter-individual differences. Differences with a P value < 0.05 were considered statistically significant. RESULTS Fecal microbial communities were more similar among UC patients than their healthy partners (P = 0.024). UC individuals had a lower relative abundance of bacteria belonging to the Firmicutes, especially Blautia, Clostridium, Coprococcus and Roseburia (P < 0.05). Microbiota dysbiosis was detected in UC patients and their healthy partners. Relevant genera included Akkermansiam, Bacteroides, Escherichia, Lactobacillales, Klebsiella and Parabacteroides. The enriched pathways in fecal samples of UC patients were related to lipid and nucleotide metabolism. Additionally, the pathways involved in membrane transport and metabolism of cofactors and vitamins were more abundant in the healthy partners. CONCLUSION Our results suggested that the microbial composition might be affected in healthy partners cohabiting with UC patients, especially in terms of microbiota dysbiosis.