Fecal neutral sterols in omnivorous and vegetarian women.

The purpose of this study was to investigate the effect of a vegetarian diet on human fecal neutral sterol excretion. Free and esterified fecal neutral sterols were analyzed by capillary gas-chromatography in healthy North-American white women who were consuming either a mixed Western diet (n = 19) or a vegetarian diet (n = 20). Vegetarians had lower mean concentrations of bacterial metabolites of cholesterol, coprostanol, and coprostanone, and their relative amounts of esterified neutral sterol metabolism in both populations. Most of the subjects in both groups excreted their neutral sterols mainly as metabolites. However, 25% of the omnivores and 21% of the vegetarians had exceptionally low amounts of these metabolites in their feces. The vegetarians in this study differed only slightly from omnivores with regard to intestinal bacterial metabolism of neutral sterols.