Mechanism of action

Eating foods high in choline and L-carnitine, your gut microbiome produce a chemical compound, called trimethylamine (TMA). In the liver, TMA is converted to trimethylene N-oxide (TMAO), a harmful agent. 

People with high blood levels of TMAO is shown to have higher risk of premature death. In addition, they have four-fold increased risk of all-cause death.