Scientists discovered genetic traces of oral bacteria in a significant portion of arterial plaques. Lead researcher Dr. Pekka Karhunen said: "The role of bacteria in coronary artery disease has long been suspected, but direct and convincing evidence was lacking until now. Our study showed that the DNA of many oral bacteria was present inside arterial plaques."
The research focused on atherosclerosis, one of the main causes of heart attacks, in which plaques composed of fat, cholesterol, calcium, and other substances build up in artery walls. Over time, arteries narrow, blood flow is restricted, and sometimes plaques rupture, cutting off oxygen to the heart muscle.
Tests conducted on samples from 121 sudden-death cases and 96 surgery patients frequently found "viridans streptococci," a group of oral bacteria. These bacteria were present in 42.1% of arterial plaques in sudden-death cases and 42.9% of those in surgery patients.
The bacterial biofilms were usually located at the center of plaques, hidden from the immune system. Researchers noted that under stress, poor diet, respiratory infections, or certain hormones, these silent bacteria could trigger inflammation, causing plaque rupture and leading to a heart attack.
The findings show that oral health is far more closely linked to heart health than previously thought. Researchers concluded: "Our results suggest that oral bacteria may play a role in making stable arterial plaques more prone to rupture over time, increasing the risk of heart attack."
The study was published in the Journal of the American Heart Association.
