Friendly bacteria living in the gut might contribute to heart disease
because it helps to digest dietary fats that are found in meat, dairy and some
fish. Researchers from the Cleveland Clinic state that these fats set off a
chain reaction which leads to the buildup of an artery-clogging substance in
the blood. Since this study points at the culprit which causes hardening of arteries
it may lead to new treatments for heart disease. Though scientists have still
maintained that microbial flora might not be a major factor like diabetes or
smoking in causing heart diseases but it could be important in tipping some
people toward sickness.
During the study blood plasma from healthy people was compared with blood plasma of people who had heart attacks. Among people with a history of heart attack scientists found 18 small molecules associated with fat buildup in the arteries, out of which one was a by-product (trimethylamine N-oxide or TMAO) made when gut bacteria break down a fat called choline (lecithin). The proportion of this by-product is directly proportional to the risk of heart disease.
Scientists also found that when mice that were genetically prone to heart diseases were fed with lots of lecithin-rich egg yolks and were given antibiotics which eliminated most of the mice's gut microbes, the mice did not get clogged arteries. However they have not been able to ascertain which types of gut bacteria make TMAO.