Aspects of bile acid metabolism in cystic fibrosis.

Previous reports have indicated that cystic fibrosis (CF) patients with pancreatic enzyme insufficiency have a raised faecal bile acid output. In this study, 18 out of 29 CF patients and 2 out of the 4 non-CF patients with pancreatic enzyme insufficiency had raised faecal bile acid levels. In the CF patients no correlation was found between faecal bile acid and faecal fat excretion, but an inverse relation was shown between faecal bile acid values and age. Those CF patients with overt liver disease tended to have the lowest faecal bile acid values. Duodenal aspiration in 5 CF patients and in one non-CF patient with pancreatic enzyme insufficiency (Shwachman-Diamond syndrome), produced very small fluid volumes. Duodenal fluid mean total bile acid concentrations were within normal limits. Estimation of serum bile acids in these 6 patients showed that 3 patients had raised serum bile acid values. It is suggested that excessive chronic faecal bile acid loss may produce a contraction of the bile acid pool, and lead eventually to a reduction of intraduodenal bile acid concentrations. Measures which curtail faecal bile acid loss may have a particular significance in the management of CF.