The Feature Of Mucosal-Associated And Faecal Microbiota In Diarrhoea-Predominant Irritable Bowel Syndrome Patients

Objective:The aim of our research was to analyse the feature of mucosal-associated and faecal microbiota in diarrhoea-predominant irritable bowel syndrome.Methods:Mucosal biopsies and faeces were collected from 20 IBS-D patients and 20 healthy controls. Global DNA was isolated from every samples, and the V3-V4 region of 16 S bacterial r DNA was sequenced on the Mi Seq Illumina platform. Then, bioinformatic analysis of sequencing data was conducted mainly upon the mothur software, and compared the difference of mucosal-associated and faecal microbiota between IBS-D groups and control groups.Results:The Shannon diversity in the IBS-D patients mucosal tissue was 2.05±1.32,significantly lower than the 2.87±1.13 in the normal controls mucosal tissue(P<0.05). At the phylum level, The most prevalent phyla were Bacteroidetes 、 Firmicutes and Proteobacteria both in IBS-D and control groups, and no significantly difference. At the genera level, statistics indicated the significant decrease of Faecalibacterium(5.8%) and increase of Prevotella(12.4%) in faecal-associated microbiota of IBS-D groups than the proportion of Faecalibacterium(11.5%) and Prevotella(0.58%) in faecal microbiota of control groups(P<0.05). Besides, The result described that the differences in the mucosal-associated microbiota between IBS-D and healthy control are different from the differences in the faecal microbiota.Conclusions:The intestinal microbiota has a closely relationship with IBS-D, with the reduction of microbial community diversity and alterations of specific bacterial groups. And highlighting the importance of investigating both luminal and mucosal niches in the intestine of IBS subjects.