Human intestinal specificity toward dietary sterols studied by balance methods

Human intestinal specificity toward sterols was studied by a balance method in 10 hyperlipoproteinemic patients fed plant sterol mixture with chromium sesquioxide as fecal flow marker. The mean fecal recovery of campesterol (C₂₈) was 20% less than that of β-sitosterol (C₂₂). This difference persisted when corrected for fecal flow (by marker recovery), indicating differences in their intestinal uptake (C₂₈ > C₂₂). The ratio of fecal cholesterol to its 5β-reduction products was lower than that of β-sitosterol in all patients; in vitro, 5β-reduction of both sterols was similar. The recovery of sterols from patients was unrelated to their 5β-reduction in the intestine.