Trimethylamine-N-oxide: a link between the gut microbiome, bile acid metabolism, and atherosclerosis

Purpose of review This article evaluates the link between trimethylamine-N-oxide (TMAO) and bile acids and the consequent impact on the development of atherosclerosis. Recent findings Elevation in plasma TMAO concentrations is associated with an increased risk of cardiovascular disease in many different patient cohorts. In addition to the recently identified direct effects of TMAO on the development of atherosclerosis, other components involved in TMAO metabolism may also have an impact. Furthermore, the relationship between TMAO and bile acid regulation is emerging as a possible mediator of atherosclerosis. Studies that are emerging highlight the mechanistic relationship of TMAO to the development atherosclerosis in addition to its role as disease biomarker. The interplay between TMAO and bile acid metabolism mediated through multiple factors, such as the gut microbiome, farnesoid X receptor signaling, and flavin monooxygenase 3 activity may help identify another pathway by which atherosclerosis occurs. In this review, we discuss the most recent data regarding atherosclerosis, TMAO, and bile acid metabolism.