Resistant starch is more effective than cholestyramine as a lipid-lowering agent in the rat

摘要: Amylase-resistant starch (RS) represents a substrate for the bacterial flora of colon, and question arises as whether RS shares with soluble fibers common mechanisms their lipid-lowering effects. It is uncertain cholesterol-lowering effect depends basically on an enhanced rate steroid excretion or colonic fermentations also play role in this effect. In present study, (25% raw potato starch), sequestrant (0.8% cholestyramine), both were compared bile acid lipid metabolism rats fed semipurified diets. diets led to marked rise cecal size pool short-chain fatty acids (SCFA), well SCFA absorption; cholestyramine did not noticeably affect fermentation. Whereas was particularly effective at enhancing excretion, more lowering plasma cholesterol (−32%) triglycerides (−29%). The activity 3-hydroxy-3-methylglutaryl-CoA reductase increased fivefold by twofold RS. This induction concomittant depressed synthase activity. diet, there lower concentration all lipoprotein fractions, especially (d=1.040−1.080) fraction high-density (HDL1), while those had only significant reduction HDL1 cholesterol. contrast cholestyramine, triglyceride-rich fraction. There no noticeable synergy between effects when diet. suggests that limited its capacity enhance excretion. difference could relate fermentation end-products counteract upregulation biosynthesis. Thus, absence large intestine, high always sufficient elicit