Cholesterol and bile acid biodynamics after total small bowel resection and bile diversion in humans

Abstract

Background: In humans, the patterns of cholesterol and bile acid biodynamics in the absence of the small intestine are not yet known. They are described in two parenterally fed patients several months after total enterectomy and bile diversion. Methods: After an intravenous pulse of [3H]cholesterol, a long-term study involved the analysis of both the decay in the specific activity of plasma cholesterol and the biliary outputs of sterols and bile acids. Results: Plasma cholesterol input reached 2–3 g/day (vs. 1 g/day in healthy patients), mostly from synthesis. As assessed by sterol balance, whole body cholesterol synthesis approximated 6 g/day (vs. 0.6–0.8 g/day). Unusually, about 60% of the newly synthesized cholesterol was eliminated, without prior transit into the bloodstream, from the liver into the bile. Bile acid conversion concerned over 90% (vs. 40%–50%) of the cholesterol meant to be excreted, issued from plasma or hepatic synthesis. In addition to cholic and chenodeoxycholic acids, one patient secreted up to 1 g/day of 7-epicholic acid. Conclusions: The stimulation (up to 10-fold) of the cholesterol and bile acid synthesis, stronger than that observed following ileal bypass or resection or complete bile diversion, could well be partially linked to the absence of small bowel tissue per se.