Abstract
Dietary stearic acid (18:0) lowers plasma and liver cholesterol concentration by reducing intestinal cholesterol absorption. We tested the hypothesis that dietary 18:0 reduces cholesterol absorption by altering hepatic bile acid synthesis and gallbladder bile acid composition. Male Syrian hamsters were fed modified NIH-07 open formula diets, enriched (5 g/100 g diet) in one of the following fatty acids: 18:0, palmitic acid (16:0), trans fatty acids (18:1t), oleic acid (18:1c) or linoleic acid (18:2). After 18 wk, gallbladders were removed and bile acid composition determined by HPLC. The distribution of primary bile acids (mol/ 100 mol) was unaffected by treatment. In contrast, dietary 18:0 significantly reduced the proportion of hydrophobic secondary bile acids, resulting in a lower hydrophobicity index of the bile. These data suggest that reduced cholesterol absorption by dietary 18:0 is due, at least in part, to reduced cholesterol solubility. The data further suggest that 18:0 may have altered the microflora populations that synthesize secondary bile acids. Although cholesterol 7α-hydroxylase (CYP7A1) activity was significantly higher in hamsters fed 18:0 compared with 16:0, this finding is most likely due to increased fecal bile acid output in the 18:0 group rather than transcriptional regulation of CYP7A1 by 18:0 or specific bile acids.
Original language | English (US) |
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Pages (from-to) | 3119-3122 |
Number of pages | 4 |
Journal | Journal of Nutrition |
Volume | 132 |
Issue number | 10 |
DOIs | |
State | Published - Oct 1 2002 |
Externally published | Yes |
Keywords
- Bile acids
- Cholesterol absorption
- Hamsters
- Microflora
- Stearic acid
ASJC Scopus subject areas
- Medicine (miscellaneous)
- Nutrition and Dietetics