Baked rye products modify cholesterol metabolism and crypt cell proliferation rates in rats

Young adult male rats were made hypercholesterolemic by feeding cholesterol (+ cholic acid). The effect of rye crispbread on hepatic and plasma cholesterol concentrations, hepatic cholesterol synthesis, small intestinal cell turnover and fecal output was investigated. Diets containing 50 and 75% rye crispbread (g dry wt) were compared with positive control diets of similar gross composition, in which the insoluble component of rye was matched with cellulose and the soluble component with guar gum. A negative control diet containing no non-starch polysaccharide was also included. Cholesterol supplementation was maintained in half the rats on each diet. Rye caused a marked increase in fecal output that was greater than that seen in the positive control groups. However, crypt cell proliferation in the small intestine was less than that seen in the high fiber control groups. Rye reduced total plasma cholesterol concentrations only in those rats that continued to receive the high cholesterol diet. However, whether or not cholesterol was fed, the presence of nonstarch polysaccharide caused a decrease in liver cholesterol concentrations. Rye caused a marked increase in hepatic cholesterol synthesis over both the positive controls and the rats fed a fiber-free diet. This implies that rye causes a loss of cholesterol from the body, probably due to malabsorption of bile acids and cholesterol.