Fat Absorption in Bile Fistula Man

Abstract

Patients with an external biliary fistula absorb most of their dietary fatty acids. We studied the duodenojejunal contents of biliary fistula patients after a fatty meal to determine to what extent dietary triglycerides are digested and the resulting free fatty acids (FFA) are solubilized. Serial small bowel biopsies were examined by electron microscopy to determine whether fatty acids traverse jejunal absorptive cells in a morphologically normal manner. Lipolysis seemed to be unimpaired when bile salts were absent; the concentration of FFA in the aqueous phase of intestinal contents, however, was reduced 100-fold. Despite these low concentrations of FFA, the pathway of fat absorption through the absorptive cell and into the lacteal was normal. If the luminal fat load was low, or of short duration, no difference could be discerned between the quantity of fat in jejunal absorptive cells of bile fistula patients and normal man. However, when the luminal fat load was increased, the amount of fat in the absorptive cells was clearly less during bile fistula than it was after restoration of biliary flow into the intestine. The considerable capacity of man to absorb fat in the absence of bile salts is not surprising because the two most essential features of the absorptive process appear to be intact: luminal hydrolysis of triglycerides and mucosal absorption of the resulting FFA.