Altered Bile Acid and Pouch Microbiota Composition in Patients With Chronic Pouchitis

Area of Science:

• Gastroenterology
• Microbiome Research
• Metabolomics

Background:

• Ulcerative colitis patients with ileal pouch-anal anastomosis face significant risks of pouchitis.
• Chronic pouchitis affects 5-10% of these patients, impacting quality of life.

Purpose of the Study:

• To compare pouch microbiota and stool bile acid composition.
• To investigate differences in patients with normal pouch, chronic pouchitis, and chronic pouchitis with primary sclerosing cholangitis.

Main Methods:

• Recruited patients with ulcerative colitis and ileal pouch-anal anastomosis.
• Analyzed stool samples using 16S rRNA gene sequencing and bile acid quantification.
• Performed statistical comparisons of microbiota diversity and bile acid abundance.

Main Results:

• Significant differences in pouch microbiota alpha-diversity (species richness) and beta-diversity were observed among patient groups.
• Lithocholic acid levels were significantly lower in patients with chronic pouchitis/primary sclerosing cholangitis compared to other groups.
• Decreased alpha-diversity correlated with an increased primary to secondary bile acid ratio, which also associated with altered beta-diversity.

Conclusions:

• Pouch microbiota diversity and bile acid profiles differ significantly across patient groups.
• Lithocholic acid levels and bile acid ratios are strongly associated with pouch microbiota composition.
• Findings suggest decreased secondary bile acids in chronic pouchitis, highlighting links between microbiota, bile acid metabolism, and dysbiosis.