Characteristics of microbiota of colonic lavage fluid from patients with diarrhea-predominant irritable bowel syndrome / 中华消化杂志

ABSTRACT

Objective To investigate the characteristics of the microbiota of colonic lavage fluid from patients with diarrhoea-predominant irritable bowel syndrome (D-IBS).Methods From August 2014 to March 2015,at the Department of Gastroenterology Shanxi Provincial People's Hospital,39 patients with D-IBS were enrolled and during the same period 39 patients with self-reported symptoms such as occasional abdominal discomfort or abdominal pain but were excluded from the diagnosis of irritable bowel syndrome (IBS) were selected as control group.The colonic mucosal tissues and colonic lavage fluid of two groups of patients were collected.DNA was extracted from tissues and colonic fluid.Ten dominant bacteria,including Bacteriodes prevotella,Bacteroidetes,Clostridium,Bifidobacterium,Dialister pneumosintes,Enteropathogenic Escherichia coli,Faecalibacterium prausnitzii,Firmicutes,Lactobacillus and Salmonella,were analyzed by real-time fluorescence quantitative polymerase chain reacticn (RT-PCR).T test and Spearman correlation analysis were performed for statistical analysis.Results The numbers of Bacteriodes prevotella in colonic lavage fluid and the descending colon mucosal tissues of patients in D-IBS group were 3.096 ± 1.462 and 4.278 ± 0.290,respectively,which were lower than those of control group (4.842 ± 1.032 and 5.341 ± 0.433,respectively),and the differences were statistically significant (t =6.093 and 12.657,both P ＜ 0.01).Correspondingly,the numbers of Bacteroidetes were 3.259 ± 0.607 and 3.698 ± 0.554,respectively,which were lower than those of control group (4.085 ± 0.504 and 4.339 ± 0.263,respectively),and the differences were statistically significant (t =6.538 and 6.528,both P ＜ 0.01).The numbers of Clostridium were 5.254 ± 0.522 and 4.471 ± 0.690,which were lower than those of control group (5.949 ± 0.505 and 4.950 ± 0.604,respectively),and the differences were statistically significant (t =5.976,P ＜ 0.0l;t =3.262,P =0.002).The number of Faecalibacterium prausnitzii from colonic lavage fluid of patients in D-IBS group was 2.238 ± 1.845,which was lower than that of control group (3.222 ± 1.450),and the difference was statistically significant (t =2.619,P =0.011).The Firmicutes (r =0.678,P =0.012),Lactobacillus (r =0.358,P =0.034),Bifidobacterium (r =0.418,P =0.042) and Faecalibacterium prausnitzii (r =0.568,P =0.022) from colonic mucosal tissues were all positively correlated with those from colonic lavage fluid.However,Salmonella (r =-0.638,P =0.012) and Enteropathogenic Escherichia coli (r =-0.343,P =0.025) were negatively correlated with those from mucosal tissues.Conclusions An imbalance of the microbiota in colonic lavage fluid is found in D-IBS patients.The numbers of Bacteriodes prevotella,Bacteroidetes,Clostridium and Faecalibacterium prausnitzii significantly decrease.