Median percent of primary bile acids in feces: CIE vs controls?

• A. 30.5% vs 8.2%
• B. 8.2% vs 30.5%
• C. 15% vs 10%
• D. 25% vs 5%

Answer: (A)

The key idea is how bile acid handling in the gut changes with disease. Primary bile acids are made by the liver and normally most are reabsorbed in the ileum; the bile acids that reach the colon are largely converted by gut bacteria into secondary bile acids. When ileal function is impaired, as can happen with chronic inflammatory enteropathy, reabsorption drops and a larger portion of primary bile acids escape reabsorption and are excreted in feces. That shift shows up as a higher median percent of primary bile acids in feces in disease. Here, the CIE group has about 30.5% primary bile acids in feces versus 8.2% in controls, which aligns with bile acid malabsorption in disease.