The combination of TMA lyase and FMO3 inhibitors provides several beneficial effects: (1) it reduces the risk of fish odor syndrome during the use of FMO3 inhibitors, (2) a lower TMA concentration consequently lowers TMAO concentration, thus potentially improving the outcomes, (3) lower doses of FMO3 inhibitor is required to achieve the target TMAO concentration, minimizing the risk of hepatotoxicity, (4) both FMO3 inhibitors and TMA lyase inhibitors have a protective effect against atherosclerosis and plaque rupture, so the use of their combination may lead to a better outcome. The gene discussed is FMO3; the disease is trimethylaminuria.