The serum cholesterol level in rats was significantly decreased in a group fed on a soyprotein peptic hydrolyzate (SPH) when compared with a group fed on a casein tryptic hydrolyzate (CTH). The fecal excretion of total steroids was significantly greater with rats fed on the SPH diet when compared with the CTH diet. The results of CaCo-2 studies clearly suggest that the suppression of cholesterol absorption in the intestinal epithelia is part of the mechanism for the hypocholesterolemic action induced by SPH.