Soluble dietary fiber and cholesterol influence in vivo hepatic and intestinal cholesterol biosynthesis in rats.

Ninety-six male Sprague-Dawley rats were randomly assigned to eight dietary treatments. Rats were fed, with ad libitum access, diets containing 10% dietary fiber as cellulose (control), pectin, psyllium or oat bran with or without 0.3% added cholesterol for 3 wk. Among cholesterol-fed rats, liver total cholesterol was significantly lower in rats fed diets supplemented with either pectin or psyllium compared with those fed cellulose. In contrast, rats fed oat bran with cholesterol had significantly higher liver cholesterol concentrations compared with cellulose-fed animals. Liver total lipid concentrations were significantly lower in groups fed pectin and psyllium with or without dietary cholesterol compared with cellulose-fed controls. Pectin feeding with or without dietary cholesterol significantly lowered plasma total cholesterol compared with cellulose feeding. Oat bran had no effect on plasma total cholesterol compared with control diets. Hepatic sterol synthesis was significantly greater for animals fed soluble dietary fibers compared with those fed cellulose, but the effect on intestinal sterol synthesis was less pronounced.