Serum, biliary, and fecal cholesterol and plant sterols in colectomized patients before and during consumption of stanol ester margarine

Abstract

Background: Cholesterol metabolic studies are simplified in colectomized patients because of rapid intestinal passage and reduced bacterial action. Objective: Our objective was to study the effect on cholesterol and plant sterol metabolism of feeding a margarine containing stanol ester to 11 colectomized patients. Design: A margarine containing 2 g stanol was consumed for 7-18 d. Serum, biliary, and fecal lipids were measured before and during consumption of the margarine. Results: Serum cholesterol concentrations and the ratio of plant sterol to cholesterol decreased after 1 d of consumption of stanol esters (P < 0.05). After 7 d, serum cholesterol decreased by 16% (P < 0.01), cholesterol absorption efficiency decreased by ≃40%, and fecal output of cholesterol as neutral sterois (but not as bile acids) increased by 36%. Biliary bile acid composition and the molar percentage of biliary cholesterol were unchanged. Increased ratios of cholesterol precursor sterols in serum and bile indicated enhanced cholesterol synthesis during consumption of stanol esters; the percentage absorption of plant sterols and the ratios of plant sterois to cholesterol decreased, whereas serum and biliary plant stanols and their biliary secretion gradually increased. In feces, 95% of cholesterol and 90% of plant stanols were in unesterified form. Conclusions: In colectomized patients, effective inhibition of cholesterol absorption and lowering of serum cholesterol concentrations and plant sterol ratios occurs within 1 d of the start of consumption of stanol esters. The composition of major bile lipids is unchanged, indicating that gallstone formation is unlikely. Small amounts of plant stanols are recovered in serum and bile during consumption of stanol esters but effectively are secreted through bile, thereby balancing the intake-induced increase in their absorption.