IBD and CIE may impair bile acid metabolism due to which mechanism?

• A. Due to hepatic dysfunction
• B. Due to kidney failure
• C. Due to antibiotic use altering bile acid synthesis
• D. Due to intestinal dysbiosis leading to defective biotransformation of bile acids -> increased proportion of primary BAs in feces

Answer: (D)

Bile acid metabolism in the gut relies on resident microbes to transform primary bile acids produced by the liver into secondary bile acids. In inflammatory bowel disease or chronic inflammatory enteropathy, the intestinal microbial community becomes imbalanced (dysbiosis), which disrupts the bacterial enzymes responsible for this biotransformation. As a result, less conversion to secondary bile acids occurs and a larger proportion of primary bile acids remains in the feces, reflecting defective microbial processing. This mechanism fits IBD/CIE because the disease-driven dysbiosis directly alters how bile acids are metabolized in the gut, rather than pointing to liver dysfunction or non-gut factors. Although antibiotics can contribute to dysbiosis, the key idea is that intestinal microbial disruption leads to impaired biotransformation and an increased share of primary bile acids in feces.