How Gut Bacteria Impacts Heart Health

The human gut is a truly marvelous place, but did you know that your gut has its own nervous system, and your intestinal health affects your brain health, mood, immune system, bones, and muscles?

The human gut is a truly marvelous place. Not only does your gut have its own nervous system (the enteric nervous system), but your intestinal health affects the health of your brain, your mood, your immune system, your bones, your muscles, and pretty much your entire body. The bacteria in your gut break down your food, but they play a role in your health overall.

According to a new study, your gut bacteria may play a role in assessing your risk of cardiovascular death. A simple molecule in your gut could help doctors to quickly diagnose chest pains and assess the threat to a patient’s life. Trimethylamine N-oxide (TMAO) is a molecule produced by your gut in response to the consumption of red meat, dairy products, and eggs. TMAO levels in the body may be able to predict a higher risk of serious cardiovascular problems, and may even point to a greater chance of cardiovascular death (CVD).

A team of Swiss and American researchers analyzed blood TMAO levels among more than 2200 patients admitted with chest pains. Close to 1,700 patients received coronary angiography within five days of being admitted. The researchers followed up on the patients for several years in order to monitor their health. The research proved that those with higher levels of TMAO in their blood had a higher chance of major adverse cardiovascular events at 30 days, six months, and even seven years after coming to the hospital for chest pains. Those with the highest levels of TMAO (in the top 25%) had a risk of cardiovascular problems—stroke, heart attack, revascularization, or death— six times higher than those who had lower TMAO levels. Their risk of cardiovascular death within seven years was twice as high as those with lower TMAO levels.

How much is too much TMAO? According to the research, anything among 2.5 μm (1 millionth of a meter) increased the risk. However, cracking the four μm mark definitely led to a significantly higher risk of cardiovascular health problems.

Clearly, TMAO is directly linked to cardiovascular problems and could provide doctors with clear proof of a patient’s risk of heart problems and CVD. A quick blood test for TMAO could point to higher risk factors among patients. Doctors will be better able to treat potential cardiovascular problems knowing that their patient is at risk, thanks to the TMAO testing.


1. Li, Xinmin S., Slayman Obeid, Roland Klingenberg, Baris Gencer, François Mach, Lorenz Räber, Stephan Windecker, et al. “Gut Microbiota-Dependent Trimethylamine N-Oxide in Acute Coronary Syndromes: A Prognostic Marker for Incident Cardiovascular Events beyond Traditional Risk Factors.” European Heart Journal 38, no. 11 (March 14, 2017): 814–24. doi:10.1093/eurheartj/ehw582.