The micellar hypothesis of fat absorption: must it be revisited?

Abstract

In 1962, Hofman & BorgstroUm (1, 2) applied the then available knowledge of detergent chemistry to the problem of the physicochemical status of intestinal content during digestion of fat. In vitro studies indicated that the products of pancreatic lipolysis of triglyceride fat–mainly 2-mono-glyceride and fatty acid–form mixed micelles with bile salts in an isotropic (optically clear) solution. Ultracentrifugation of intestinal content after a fatty meal fed to man yielded an oil phase and a clear aqueous phase. The former contained mostly unchanged triglyceride and some diglyceride, the latter mainly fatty acid and mono-glyceride. It was concluded that intestinal content during digestion is a detergent solution above its critical micellar concentration (CMC). The results were consistent with the hypothesis that intestinal lipids, during fat digestion, are partitioned between a micellar and an oil phase and that absorption of dietary lipid takes place from a micellar solution containing chiefly fatty acid a...