Scientists discover ‘stealth bacteria’ from your mouth are hiding in your arteries and triggering heart attacks

by DailyHealthPost EditorialSeptember 10, 2025

When you think about the causes of a heart attack, your mind probably jumps to high cholesterol, stress, or high blood pressure. But what if a hidden threat has been lurking in your arteries for years, originating from something as simple as your daily tooth-brushing routine? New research from Finland reveals that common mouth bacteria can form stealthy colonies inside heart arteries, evading your immune system until they suddenly activate, triggering the inflammation that can lead to a deadly heart attack.

This groundbreaking study, published in the Journal of the American Heart Association, examined arterial tissue from over 200 individuals, including victims of sudden death. Scientists found that these oral bacteria, known as viridans streptococci, establish hidden communities called biofilms within arterial plaques. These colonies can remain undetected for long periods before dispersing and setting off an inflammatory cascade that can rupture an artery.