Influence of a fiber mixture on serum and liver lipids and on fecal fat excretion in rats

Male Sprague-Dawley rats (8 per group) were fed a modified AIN-76A diet containing either 10% cellulose or 10% of a proprietary fiber mixture for 21 days. Weight gain and liver weight were similar in the 2 groups but feed efficiency was higher in the test group. Serum cholesterol and triglycerides were lowered by 11% and 15%, respectively, by the test diet. Liver cholesterol was lowered significantly in the fiber-fed rats whereas liver triglycerides were elevated. Twenty-four–hour fecal collections were made on days 12 and 19. The weight of feces was unaffected by the test diet, but water content and fecal fat were increased by 27% and 44% and by 99% and 100%, respectively, on days 12 and 19. The amount of Liebermann-Burchard–positive material in the feces was significantly higher in rats fed the test material. The increases on days 12 and 19 were 139% and 105%, respectively.