Study links oral bacteria to heart attacks: What you should know
A new 2025 study in the Journal of the American Heart Association found that Viridans streptococci—bacteria usually found in your mouth—showed up in over 40% of artery plaques from people who died of sudden cardiac arrest or had clogged arteries.
This connection could help shape future ways to spot and prevent heart problems.
Research details
Researchers looked at samples from people who died suddenly and from patients who had artery surgery.
They found bacterial DNA in over 40% of advanced atherosclerotic plaques—the gunk that clogs arteries and can trigger heart attacks.
The takeaway: what's going on in your mouth might actually affect your heart.
How do these bacteria trigger heart problems?
Viridans streptococci form protective biofilms inside plaque, making it tough for immune cells to clear them out.
When these bacteria escape into other parts of the plaque, they spark inflammation, which weakens artery walls and makes them more likely to rupture—leading to blood clots and possibly a heart attack.
What can you do?
Antibiotics aren't recommended just for prevention, but keeping up with brushing, flossing, and dental check-ups can help lower harmful oral bacteria.
Alongside regular exercise and healthy eating, good oral hygiene is now another reason to look after yourself—your heart will thank you!