Elevated TMAO is likely caused by diabetes and kidney disease, implying reverse causality where TMAO is a consequence of insulin resistance, not a cause of cardiovascular disease.

“so there was a great study that came out recently and it was a I think it was a Mendelian randomization and it was statistics it was epidemiology but they what they were able to show in that study was that elevated TMAO was likely being caused by diabetes and caused by kidney disease suggesting what we would call reverse causality so that in the studies that associate high TMAO with cardiovascular disease it's not the TMAO causes cardiovascular disease it's that insulin resistance associated with cardiovascular disease probably causes a high TMAO”