A Cleveland Clinic-led study announced on July 24 shows a connection between elevated blood levels of TMAO (trimethylamine N-oxide), a byproduct of gut bacteria digestion of nutrients found in red meat and other animal products, and a higher risk of atrial fibrillation.
The research team, led by Robert Koeth, M.D., Ph.D., analyzed blood samples from more than 5,000 people undergoing heart procedures. Laboratory studies in cells were also conducted to better understand how TMAO may influence the heart. The researchers discovered that gut microbe-produced TMAO changes the heart's electrical environment, increasing susceptibility to abnormal rhythms. Findings were published in the Journal of Clinical Investigation.
Atrial fibrillation is described as the most common type of rhythm disorder that begins in the upper chambers of the heart, with at least 2.7 million Americans living with it. Symptoms include fatigue, heart palpitations, trouble breathing, and dizziness. Risk factors include high blood pressure, coronary artery disease, and obesity. Medications and procedures such as ablation can lower stroke risk for those affected.
The study builds on more than a decade of Cleveland Clinic research related to the gut microbiome's role in cardiovascular health and disease, including adverse effects associated with TMAO. The research team has previously published numerous studies linking high TMAO levels to increased risk for chronic kidney disease and cardiovascular events like heart attack and stroke.
TMAO testing is now widely available and has been incorporated into clinical practice.
