ABSTRACT
Objective@#To investigate the characteristics of dominant bacteria of colonic lavage fluid in patients with diarrhea-predominant irritable bowel syndrome (IBS).@*Methods@#Forty-six patients with diarrhea-predominant IBS (observation group) and 46 patients with abdominal pain or discomfort who was excluded IBS (control group) from January 2016 to January 2019 in Department of Gastroenterology, Shenzhen Longhua District People′s Hospital were selected. During colonoscopy, 2 pieces of descending colonic mucosal tissues were taken by forceps, then 4 ml of colonic lavage fluid was collected from the mucosa tissues to extract total DNA, and 10 dominant bacteria were detected by real-time fluorescence quantitative polymerase chain reaction (including Bacteroides, Bacteriodes prevotella, Bifidobacterium, Clostridium, Enteropathogenic Escherichia coli, Dialister pneumosintes, Firmicutes, Faecalibacterium prausnitzii, Salmonella, Lactobacillus, and data were selected for logarithm). The correlation of dominant bacteria between colonic mucosal tissues and colonic lavage fluid was analyzed by Spearman correlation analysis.@*Results@#The composition and change of dominant bacteria of colonic mucosal tissues and colonic lavage fluid were basically the same in 2 groups. The numbers of Bacteroides, Bacteriodes prevotella, Clostridium in colonic mucosal tissues and colonic lavage fluid, and the numbers of Faecalibacterium prausnitzii in colonic lavage fluid of observation group were significantly lower than those in the control group (colonic mucosal tissues: 3.68 ± 0.54 vs. 4.34 ± 0.27, 4.26 ± 0.28 vs. 5.33 ± 0.42, 4.46 ± 0.68 vs. 4.99 ± 0.61; colonic lavage fluid: 3.26 ± 0.61 vs. 4.09 ± 0.51, 3.10 ± 1.42 vs. 4.86 ± 1.03, 5.24 ± 0.54 vs. 5.95 ± 0.51, 2.24 ± 1.83 vs. 3.24 ± 1.46), and there were statistical differences (P<0.01 or <0.05). There was no statistical differences in other dominant bacteria in colonic mucosal tissues and colonic lavage fluid between 2 groups (P>0.05). Spearman correlation analysis result showed that the Bifidobacterium, Firmicutes, Faecalibacterium prausnitzii, Lactobacillus colonic mucosal tissues were positively correlated with colonic lavage fluid (r = 0.427, 0.689, 0.577 and 0.369; P = 0.041, 0.013, 0.024 and 0.035), and Enteropathogenic Escherichia coli and Salmonella were negatively correlated with colonic lavage fluid (r = -0.352 and -0.649, P = 0.026 and 0.013).@*Conclusions@#The composition of dominant bacteria in colonic mucosal tissues and colonic lavage fluid is basically the same, and an imbalance of the microbiota in colonic lavage fluid is found in diarrhea-predominant IBS patients. The numbers of Bacteroides, Bacteriodes prevotella, Clostridium and Faecalibacterium prausnitzii significantly decrease.
ABSTRACT
Objective To investigate the characteristics of dominant bacteria of colonic lavage fluid in patients with diarrhea-predominant irritable bowel syndrome (IBS).Methods Forty-six patients with diarrhea-predominant IBS (observation group) and 46 patients with abdominal pain or discomfort who was excluded IBS (control group) from January 2016 to January 2019 in Department of Gastroenterology,Shenzhen Longhua District People's Hospital were selected.During colonoscopy,2 pieces of descending colonic mucosal tissues were taken by forceps,then 4 ml of colonic lavage fluid was collected from the mucosa tissues to extract total DNA,and 10 dominant bacteria were detected by realtime fluorescence quantitative polymerase chain reaction (including Bacteroides,Bacteriodes prevotella,Bifidobacterium,Clostridium,Enteropathogenic Escherichia coli,Dialister pneumosintes,Firmicutes,Faecalibacterium prausnitzii,Salmonella,Lactobacillus,and data were selected for logarithm).The correlation of dominant bacteria between colonic mucosal tissues and colonic lavage fluid was analyzed by Spearman correlation analysis.Results The composition and change of dominant bacteria of colonic mucosal tissues and colonic lavage fluid were basically the same in 2 groups.The numbers of Bacteroides,Bacteriodes prevotella,Clostridium in colonic mucosal tissues and colonic lavage fluid,and the numbers of Faecalibacterium prausnitzii in colonic lavage fluid of observation group were significantly lower than those in the control group (colonic mucosal tissues:3.68 ± 0.54 vs.4.34 ± 0.27,4.26 ± 0.28 vs.5.33 ± 0.42,4.46 ± 0.68 vs.4.99 ± 0.61;colonic lavage fluid:3.26 ± 0.61 vs.4.09 ± 0.51,3.10 ± 1.42 vs.4.86 ± 1.03,5.24 ± 0.54 vs.5.95 ± 0.51,2.24 ± 1.83 vs.3.24 ± 1.46),and there were statistical differences (P ＜ 0.01 or ＜ 0.05).There was no statistical differences in other dominant bacteria in colonic mucosal tissues and colonic lavage fluid between 2 groups (P ＞ 0.05).Spearman correlation analysisresult showed that the Bifidobacterium,Firmicutes,Faecalibacterium prausnitzii,Lactobacillus colonic mucosal tissues were positively correlated with colonic lavage fluid (r =0.427,0.689,0.577 and 0.369;P =0.041,0.013,0.024 and 0.035),and Enteropathogenic Escherichia coli and Salmonella were negatively correlated with colonic lavage fluid (r =-0.352 and-0.649,P =0.026 and 0.013).Conclusions The composition of dominant bacteria in colonic mucosal tissues and colonic lavage fluid is basically the same,and an imbalance of the microbiota in colonic lavage fluid is found in diarrheapredominant IBS patients.The numbers of Bacteroides,Bacteriodes prevotella,Clostridium and Faecalibacterium prausnitzii significantly decrease.
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.