High levels of serum TCDCA induced by aging activate TMAO-associated signaling pathways via hepatic FXR.34 Previous experiments also revealed increased serum levels of TMAO in mice in the CAP group,25 suggesting that CAP may influence the development of atherosclerosis by modulating the metabolism of bile acids in the gut microbiota and affecting the serum TMAO concentration. This evidence concerns the gene NR1H4 and atherosclerosis.