The effect of a nonabsorbable lipid, sucrose polyester, on the absorption of dietary cholesterol by the rat.

The absorption of cholesterol from diets containing various proportions of triglycerides and an unabsorbable fat, sucrose polyester (SPE), was determined in rats. Each replacement of 1% dietary triglyceride with SPE resulted in a 1.2% decrease in cholesterol absorption. The SPE was a mixture of the hexa-, hepta- and octa-esters of long chain fatty acids. The physical properties of this material are similar to those of the usual dietary triglycerides. Relative to these studies, cholesterol was found to be equally soluble in triolein or SPE. If water was present as well, the solubility of the sterol was decreased by the same amount in both fats. The distribution coefficients of cholesterol between an oil phase of either triolein or SPE and a micellar phase simulating that found in the lumen of the intestinal tract were identical. These two types of fats differ in that SPE is neither digested nor absorbed. The decrease in cholesterol absorption is attributed to the continued presence of an oil phase of SPE in the lumen of the intestine. Dietary cholesterol distributes itself between this oil phase and the micellar phase. That portion in the oil phase is not absorbed but is egested in the feces.