Effect of sucrose polyester on fecal steroid excretion by 24 normal men

Abstract

The effect of the nonabsorbable fat-like substance, sucrose polyester (SPE), on neutral steroid excretion was determined in 24 healthy men. Initially the subjects received for 10 days a basal diet that was high (800 mg/day) or low (300 mg/day) in cholesterol or for 21 days a basal diet containing <50 mg cholesterol per day. These diets were isocaloric. Over three subsequent, consecutive periods of 10 days each, 8, 16, or 25 g/day of liquid SPE or 19, 38, or 62 g/day of an 80/20 mixture of SPE and completely hydrogenated palm oil was added to the diet. The amounts of C27 steroids, i.e., cholesterol and its conversion products formed by intestinal bacteria, were measured in the feces of each subject. Relative to the basal period, each gram of SPE that was ingested resulted in a 1.3% increased excretion, 6.3 mg, of these steroids. This increase probably was a consequence of SPE interfering with the absorption of endogenous enterohepatic circulating cholesterol in those subjects who received the diet containing <50 mg cholesterol per day. For those consuming the higher levels of dietary cholesterol, there likely was decreased absorption of both endogenous and exogenous cholesterol. The proportion of the C27 fecal steroids that had been converted to coprostanol and coprostanone by the intestinal bacteria was determined. Based on the extent of sterol conversion during the basal period, two distinct populations were identified. Of the 24 subjects, nine egested less than 30% of the neutral steroids as conversion products (low-converters), whereas more than 60% of the C27 steroids were egested as conversion products by the remaining 15 subjects (converters). In each individual, the intestinal bacteria converted β-sitosterol to its characteristic products in the same proportion as was cholesterol. The addition of SPE to the diet caused a lesser amount of the sterols to be modified by the bacteria. This could be measured more readily in the converter population. There, each gram of SPE that was ingested resulted in 1.1% decrease in conversion for those who received liquid SPE and a 0.6% decrease for those who received the SPE-hydrogenated palm oil mix. The decrease in conversion is a probable consequence of the sterols being dissolved in the oil phase of SPE in the lumen of the intestinal tract and hence unavailable to the bacteria.