Bile acids(BA)are synthesized from cholesterol in the liver.They are essential for promotion of the absorption of lipids,cholesterol,and lipid-soluble vitamins from the intestines.BAs are hormones that regulate nutrient metabolism by activating nuclear receptors(farnesoid X receptor(FXR),pregnane X receptor,vitamin D)and G protein-coupled receptors(e.g.,TGR5,sphingosine-1-phosphate receptor 2(S1PR2))in the liver and intestines.In the liver,S1PR2 activation by conjugated BAs activates the extracellular signal-regulated kinase 1/2 and AKT signaling pathways,and nuclear sphingosine kinase 2.The latter produces sphingosine-1-phosphate(S1P),an inhibitor of histone deacetylases 1/2,which al-lows for the differential up-regulation of expression of genes involved in the metabolism of sterols and lipids.We discuss here the emerging concepts of the interactions of BAs,FXR,insulin,S1P signaling and nutrient metabolism.