Bile acid metabolism in children with cystic fibrosis

Recycling of bile acids through the enterohepatic cycle is very efficacious. Bile acids contribute to bile formation and, by forming micelles, participate in lipid solubilization and absorption. The small fraction which escapes in the feces, is synthesized daily by the liver to compensate for losses. In CF, bile acid malabsorption has been documented; these large losses are accompanied by an interruption in the enterohepatic circulation with concomitant reduction in bile acid pool and disturbances in biliary composition. The various intraluminal factors implicated in bile acid malabsorption include: unhydrolysed triglycerides and phospholipids, precipitation of bile acids in acidic duodenal content, adsorption to residues and modification of colonic microflora. A defect in bile acid ileal uptake has also been advocated. These disturbances in bile acid metabolism associated with CF might lead to aggravation of diarrhea and steatorrhea, cholelithiasis and perhaps liver disease.