Animal products, including meat, cheese, and eggs contain carnitine and choline, metabolites that are converted by gut bacteria into TMA, which is then converted by the liver into TMAO. Plasma levels of TMAO are associated with an increased risk of disease and death, so should we limit intake of these animal products? Separately, fish contains relatively high levels of TMAO, and blood levels of TMAO spike after fish consumption, but there is a decreased all-cause mortality risk for fish consumers. To explain these disparate findings, other factors may be involved in the TMAO-health and disease story. In the video, I discuss the impact of kidney function on plasma levels of TMAO, disease and mortality risk.