Gut Microbes Increase Risk of Heart Disease When They Act Upon Certain Food Compounds

Obesity, high cholesterol, high blood pressure and lifestyle factors like smoking, lack of exercise are the most commonly suspected causes for heart attack or stroke. However, every now and then we come across cases of heart attack where the patients were found to have none of the risk factors of heart disease. This proves that there are other mechanisms involved, which are yet to be explored.

Dr. Stanley Hazen, chairman of the department of cellular and molecular medicine at the Cleveland Clinic Lerner Research Institute and his colleagues in their experiments with blood samples of heart patients have reported an interesting finding that intestinal microbes may play a role in triggering heart disease when they act upon certain food components.

Previously the team, based on animal studies, had reported that a metabolic compound, trimethylamine N-oxide (TMAO) increased the deposition of plaques on arterial walls eventually increasing the risk of heart disease. With further research, they had observed that bacteria in the gut interacted with carnitine, a compound commonly found in red meat products like steak and pork, to increase the blood TMAO levels.

In the recent research, scientists have demonstrated that, lecithin found mainly in eggs, is broken down by intestinal microbes to release substances that the liver converts into TMAO.

The study involved 40 healthy individuals who were asked to eat two hard boiled eggs. This experiment was repeated after an antibiotic dose for a week. Researchers did not find any significant increase in the blood TMAO levels following the antibiotic dosage. This reveals that intestinal bacteria are necessary to convert lecithin to TMAO. 

Scientists had also followed up with 4007 heart patients for three years and found that high levels of TMAO doubled the risk of heart attack and stroke.

It is thus seen that intestinal bacteria are a potential threat for heart disease. Could that mean taking antibiotics can fix the problem? Definitely not, as bacteria become resistant to antibiotics. Moreover, the type of bacteria causing the risk needs to be identified. According to Dr. Hazen, developing compounds to control the production of TMAO could be one possible solution.

As both carnitine and lecithin are recommended as supplements for certain health conditions, further analysis is requirements to determine the effects of these supplements on cardiac health.

Though these studies have opened up a new perspective of cardiac health, many questions remain unanswered and need to be explored further.