A common mouth and gut bacteria may be linked with increased stroke risk American Stroke Association International Stroke Conference 2025 - Abstract 106

https://newsroom.heart.org/news/a-common-mouth-and-gut-bacteria-may-be-linked-with-increased-stroke-risk?preview=94b1&preview_mode=True&utm_campaign=morning_rounds&utm_medium=email&_hsenc=p2ANqtz-9ROoWucCuPH2xg-1GEFHLI8r4InHFU8qUkY1Ch-IpgtDZXMEwM3kn6oFRoieiXjRgddHGVFNEuAJu7MDyhrQfH4B9YHQ&_hsmi=344824080&utm_content=344824080&utm_source=hs_email What our mouths could teach us about stroke risk Researchers already know that there’s an association between oral infections and stroke. Two study abstracts being presented at the American Stroke Association international conference next week could further that understanding: One study of more than 6,200 people without a prior history of stroke or atrial fibrillation found that those who flossed were at significantly lower risk of ischemic stroke (when a blood clot blocks an artery in the brain), cardioembolic heart (when the clot starts in the heart then travels to the brain), and atrial fibrillation. The researchers followed up with participants for 25 years and found a significant dose-effect between flossing and ischemic stroke risk, meaning the more they flossed, the lower their chances of stroke. The other research is in earlier stages — there’s a common mouth and gut bacteria called Streptococcus anginosis that may proliferate in the guts of people who have a stroke. Researchers analyzed the salivary and gut microbiomes of 189 acute stroke patients and 55 people who hadn’t had a stroke. Over two years of follow-up, survivors with this bacteria in their gut had significantly higher risk of death and major cardiovascular events than those without. Overall, having the bacteria in the gut was associated with a 20% higher odds of stroke. The researchers hope that the findings can someday lead to a test for harmful oral bacteria.