It was found in the arteries of people victims of heart attack.
Nearly 100,000 French people make a myocardial infarction each year. This accident is serious since it involves the vital prognosis. He occurs when an artery of the heart clogs suddenly, most often because of a blood clot. Several risk factors are well identified by doctors: tobacco, cholesterol, hypertension, diabetes, excess weight, sedentary lifestyle and family history. But a study highlights an unexpected culprit: a bacteria. A discovery that calls into question the knowledge that we have so far had on infarction.
The researchers at the origin of this discovery were aimed at “To study the role of oral bacteria (…) and the immune system in the inflammation of atherosclerosis plates (fat deposits that clog arteries and promote infarction, editor’s note) as well as their role as a risk factor for mortal myocardial infarction” They explain in the Journal of the American Heart Association. They analyzed two types of human samples: coronary plates taken from 121 people who died of sudden death and atherosclerosis plates surgically removed in 96 operated patients.
Results: Researchers have found bacterial DNA – especially that of “viridan streptococci” present in the mouth – inside the atherosclerosis plates of subjects. 42% of plates contained it. These bacteria would group together in the form of biofilms, kinds of protective layers which make them invisible to the immune system and resistant to antibiotics. As long as the plate remains closed, the biofilm remains hidden. But when the plate cracks, bacteria come out, are recognized by the immune system and trigger an intense inflammatory reaction. This inflammation could weaken the plate and promote the formation of a clot responsible for fatal infarction.
Through these results, researchers show that a chronic bacterial infection in the mouth is dangerous for the heart. “We previously found that victims of sudden cardiac death suffered from poor oral health” they recall. Good oral hygiene is therefore important to limit the passage of bacteria such as viridan streptococci in blood circulation. The advice is simple: consult a dentist at least once a year, brush your teeth twice a day for 2 minutes, change your brush every 3 months (or before if the hair is worn) and use the dental wire once a day after brushing.
