Low-fat, high-carbohydrate and high-fat, low-carbohydrate diets decrease primary bile acid synthesis in humans

PH Bisschop*, RHJ Bandsma, F Stellaard, AJ Meijer, HP Sauerwein, F Kuipers, JA Romijn

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

29 Citations (Scopus)

Abstract

Background: Dietary fat content influences bile salt metabolism, but quantitative data from controlled studies in humans are scarce.

Objective: The objective of the study was to establish the effect of dietary fat content on the metabolism of primary bile salts.

Design: The effects of eucaloric extremely low-fat (0%), intermediate-fat (41%; control diet), and extremely high-fat (83%) diets on kinetic values of cholate and chenodeoxycholate metabolism were determined after 11 d by using stable isotope dilution in 6 healthy men. All diets contained identical amounts of cholesterol.

Results: The total primary bile salt pool size was not significantly affected by dietary fat content, although the chenodeoxycholate pool was significantly higher during the low-fat diet. Fractional turnover rates of both primary bile salts were 30-50% lower during the low- and high-fat diets than during the control diet. Total hepatic bile salt synthesis was approximate to30% lower during both the high- and low-fat diets, but synthesis rates of the 2 primary bile salts were differentially affected. The molar ratio of cholate to total bile salt synthesis increased from 0.50 +/- 0.05 ((x) over bar +/- SD) to 0.59 +/- 0.05 and 0.66 +/- 0.04 with increasing fat intake, whereas the molar ratio of chenodeoxycholate to total bile salt synthesis decreased from 0.50 0.05 to 0.41 +/- 0.05 and 0.34 +/- 0.04. The relative concentration of deoxycholate in plasma increased during the low-fat period, which indicated increased absorption from the colon.

Conclusions: Both low- and high-fat diets reduce the synthesis and turnover rates of primary bile salts in humans, although probably through different mechanisms, and consequently they affect the removal of cholesterol from the body.

Original languageEnglish
Pages (from-to)570-576
Number of pages7
JournalAmerican Journal of Clinical Nutrition
Volume79
Issue number4
Publication statusPublished - Apr-2004

Keywords

  • diet
  • dietary fat
  • dietary carbohydrate
  • bile salt
  • cholate
  • chenodeoxycholate
  • deoxycholate
  • stable isotope
  • ACTIVATED RECEPTOR-ALPHA
  • CHOLESTEROL 7-ALPHA-HYDROXYLASE GENE
  • FRACTIONAL TURNOVER RATES
  • CHOLIC-ACID
  • BINDING-PROTEIN
  • PPAR-ALPHA
  • CHENODEOXYCHOLIC ACID
  • DEOXYCHOLIC-ACID
  • MESSENGER-RNA
  • POOL SIZES

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