Impact of acute choline loading on circulating trimethylamine N-oxide levels.

Despite recent efforts to reduce cardiovascular disease risk by dietary intervention,1few markers are useful to assess the efficiency and progress of this. Circulating levels of trimethylamine N-oxide (TMAO) are associated with poor outcomes of cardiovascular disease.2–6TMAO is generated via hepatic flavin monooxygenase 3 (FMO3) mediated oxidation of trimethylamine (TMA),7derived largely from carnitine and choline through gut microbial metabolism. These substrates are found in red meat and eggs, which are representative of a Western diet. Therefore, TMAO levels could be used to monitor the effect of dietary intervention, particularly for the consumption of a Western diet. In this study, we examined the effect of acute choline loading on TMAO levels in healthy adult volunteers.