Gender Differences in Bile Acid Kinetics After Dietary Challenges

Apart from their role in lipid digestion and sterol homeostasis, bile acids (BA) are known to affect metabolism via FXR and TGR5 receptors. They also modulate energy expenditure and thus became a target in obesity research. As part of the Nutritech project, we analyzed the plasma kinetics of BA after dietary challenges. Healthy volunteers in fasting state underwent an oral glucose tolerance test (OGTT) with 75 g of glucose and blood withdrawals at 0, 15, 30, 60, 90, 120 and 240 minutes. In the following day, the same volunteers endured a mixed meal test (MMT) receiving a liquid meal and having blood samples collected at 0, 30, 60, 120, 240 and 360 minutes. Bile acids were analyzed in plasma by a LC-MS/MS based method with stable-isotope labeled reference standards. Both dietary challenges increased the plasma concentration of BA (around 3.85-fold after the MMT and around 2-fold after the OGTT). The increase of glycine-conjugated BA was twice more pronounced than that of taurine-conjugated entities, while ...