Reduction of bile acid loss in cystic fibrosis by dietary means.

Abstract

SUMMARY On a 'normal' diet increased faecal bile acid excretion was found in 14 of 16 children with cystic fibrosis who had steatorrhoea, but excretion was normal in 2 such children without steatorrhoea. The 16 children with steatorrhoea took 3 regimens of diet and therapy: a 'normal' diet with pancreatic enzyme supplements, a diet of reduced long-chain triglycerides with added mediumchain triglycerides, and the same diet with added pancreatic enzyme supplements. On each of these three regimens steatorrhoea and faecal bile acid loss were significantly less than on no treatment, with the lowest excretions occurring on the diet of reduced long-chain triglycerides with added medium-chain triglycerides and pancreatic enzyme supplements. Although a reduction in steatorrhoea was nearly always accompanied by a decrease in bile acid excretion, the initial bile acid loss was very variable and could not be predicted for any given degree of steatorrhoea. This suggests that at least one other factor, possibly liver disease or bile acid pool size, influences bile acid loss in the faeces.

Intestinal bile acid malabsorption in cystic fibrosis.

“…Similarly no correlation was seen between faecal fat expressed as g fat/g stool/24 hours and faecal bile acids expressed as mg bile acid glycocholate equivalent/g stool/24 hours (data not shown). Three offour patients with the highest faecal bile acid losses had normal or near normal fat excretions of 4 5, 6 9, and 7-1 gl24 hours. …”

Ileal mucosal bile acid absorption is increased in Cftr knockout mice

“…Bile acid malabsorption in cystic fibrosis appears to be due in part to diminished secretion of pancreatic enzymes and the presence of un-hydrolyzed triglycerides. Supplementation with pancreatic enzymes and a low-fat diet can markedly reduce the fecal excretion of bile acids [9,10,20,23]. Other evidence, however, suggests that a diminished capacity of the ileal mucosa for bile acid uptake plays a significant role in bile acid malabsorption associated with cystic fibrosis that is independent of triglyceride concentrations.…”

“…However, in several studies the correlation between fecal fat excretion and fecal bile acid loss could not be demonstrated, suggesting that additional factors are responsible for bile acid malabsorption in cystic fibrosis [9,10]. In vitro studies using brush border membrane vesicles or bathed tissue samples from patients with cystic fibrosis have shown that total ileal bile acid uptake is diminished [11,12].…”

Bile Acid Metabolism

“…In cystic fibrosis, a decrease in bile acid loss has been achieved by a decrease in the amount of dietary long-chain triglycerides with an increase in the amount of medium-chain triglyceride as well as in pancreatic enzymes (99). Nutrients in liquid form (elemental diets) have been employed in the therapy of patients with small bowel resection and have been used in patients with bile acid diarrhea (100,101).…”