Heart attacks and stroke linked to “gut bugs”

A surprising new study out this week may turn what’s going on in your gut into a way to fight heart disease.

The report published in the New England Journal of Medicine shows that trillions of bacteria and other microbes living in the human gut can actually turn lecithin, a common nutrient found in liver, wheat germ, pork and egg yolks, into an artery clogging compound called, TMAO or trimethylamine-N-oxide.

Scientists from the Cleveland Clinic’s Learner Research Institute say the finding is important because blood levels of TMAO have been shown to predict stroke, heart attack and even death. However, they say results of the study don’t change other risk factors associated with heart disease such as high blood pressure, high cholesterol, obesity, diabetes and smoking.

According to the American Heart Association, there are thousands of heart attack victims every year who do not have any of these risk factors. In fact, in an online statement, one of the lead authors of the study said, “TMAO might help identify people who are at risk (for heart attacks and strokes) despite having no other risk factors.”

Researchers say the discovery may also lead to a new approach to help prevent these types of cardiovascular events by altering gut bacteria so they churn out less TMAO.

The study is among a growing list of research findings that tie human microbes in the gut, genital track, nose and skin to health and disease—including a 2011 Cleveland Clinic study where gut bacteria in lab mice turned lecithin found in food to TMAO, resulting in heart disease.

A closer look at the study

As part of the study, researchers set out to uncover answers to two burning questions among others, including: Does human gut bacteria actually trigger the lecithin to become TMAO? And can the presence of high levels of TMAO actually predict heart attacks and stroke in people over time?

To answer the first question, the team had 40 healthy adults consume two hard-boiled eggs daily, which have high amounts of lecithin. They found that TMAO levels in the blood did rise. However, after participants were given broad-spectrum antibiotics, their TMAO levels barely budged after eating the eggs.

Scientists say this shows that the intestinal bacteria, which were killed by the antibiotics, are essential for forming TMAO.

Next, in order to determine whether TMAO can predict cardiovascular events, the researchers measured TMAO levels in 4,007 heart patients. Taking into account risk factors such as age and history of a past heart attack, they discovered that high levels of TMAO were in fact predictive of stroke, heart attacks and death over a period of three years that the patients were followed.

For now more studies are needed to show whether TMAO levels can predict cardiovascular crises more precisely than other blood tests. And the jury is still out on which antibiotics, prebiotics or probiotics might be able to help control TMAO levels.

Scientists say the best approach may be to work on developing compounds that decrease the ability of the bacteria to turn lecithin into TMAO.