ADDITIVE HYPOCHOLESTEROLEMIC EFFECT OF PSYLLIUM AND CHOLESTYRAMINE INTHE HAMSTER - INFLUENCE ON FECAL STEROL AND BILE-ACID PROFILES

Recent findings suggest that the effects of cholestyramine and psylliu m in combination could be additive for cholesterol-lowering. We theref ore examined the effect of both agents, alone and in combination, on l ipoprotein cholesterol and neutral and acidic steroid excretion in the hamster. Animals (n = 8/group) were fed for 21 days, either a basal c how diet supplemented with 10% palm oil and 0.2% cholesterol, or one o f four treatments consisting of the basal diet plus: 5.5% cellulose; 5 % psyllium with 0.5% cellulose; 0.5% cholestyramine with 5% cellulose; or 5% psyllium with 0.5% cholestyramine. Psyllium and cholestyramine both had significant hypocholesterolemic effects, but in combination p roduced additive reductions in lipoprotein and hepatic cholesterol. Ps yllium, cholestyramine, and the combination increased total bile acid excretion by 26%, 57%, and 79%, respectively. Psyllium affected only u nconjugated bile acid excretion while cholestyramine also increased th e excretion of conjugated and primary bile acids. Neither agent, nor t he combination, affected fecal neutral sterol excretion. We conclude t hat, while both agents lower cholesterol by a mechanism of increased b ile acid excretion, these studies indicate that psyllium does not bind bile acids in vivo and lend further support for the concomitant use o f these agents for cholesterol-lowering.