How brushing your teeth well can lower stroke risk: A simple life-saving habit that you can't take lightly

What if a simple daily routine like brushing your teeth could help lower your risk of stroke? A recent study presented at the American Stroke Association’s International Stroke Conference 2025 reveals an unexpected link between oral health and stroke risk—suggesting that the bacteria in your mouth and gut could play a significant role in whether or not you suffer a stroke—and even how well you recover if you do.

A hidden stroke risk factor: Streptococcus Anginosus

The study uncovered a concerning fact: Streptococcus anginosus, a bacterium often found in the mouth and gut, is more prevalent in individuals who have suffered a stroke. Even more alarming, this bacterium is linked to a higher risk of death and severe cardiovascular problems in stroke survivors.

What’s the connection? Researchers found that Streptococcus anginosus was significantly more abundant in the mouths and intestines of stroke patients compared to those who had never experienced a stroke. Among 189 stroke patients and 55 healthy individuals, those with higher levels of this bacterium had a 20 per cent increased chance of suffering a stroke. Over a follow-up period of two years, those with this bacterium faced a higher risk of death and other serious cardiovascular events.

So, what does this mean for you? This research suggests that Streptococcus anginosus might not just harm your teeth—it could harm your overall health, affecting your heart and brain.

The silver lining: Protective bacteria

Not all bacteria are harmful, though. The study also highlighted two beneficial bacteria—Anaerostipes hadrus and Bacteroides plebeius—which were linked to a reduced risk of stroke. Those with higher levels of these protective bacteria saw reductions in stroke risk by 18% and 14% respectively. In contrast to the harmful effects of Streptococcus anginosus, individuals with these beneficial bacteria had no increased risk of death or cardiovascular complications.

These findings offer a ray of hope: Maintaining a balanced microbiome—by fostering the growth of beneficial bacteria and reducing harmful ones—could play a crucial role in stroke prevention.

How oral health affects stroke risk

For years, poor oral hygiene has been linked to various health issues, from gum disease to heart disease. Now, we can add stroke risk to that list. Mansi Chandran, a Dubai-based physician, explains, “The bacteria in the mouth don’t just stay there, they can travel through the bloodstream and affect various parts of the body. Streptococcus mutans and Streptococcus anginosus, for example, release toxins that cause inflammation in blood vessels, making them more susceptible to plaque buildup.”

When plaque accumulates in the arteries, blood flow becomes restricted. This can lead to blood clots forming, which could block blood vessels in the brain—causing an ischemic stroke, the most common type. Inflammation caused by oral bacteria may even contribute to hemorrhagic stroke (when a blood vessel ruptures in the brain) because inflamed blood vessels are weaker and more likely to burst.

A simple way to  protect your heart and brain

So, what’s the takeaway? By taking better care of your teeth, through regular brushing, flossing, and reducing sugar intake, you may be able to lower inflammation in your body, reducing your stroke risk and protecting your long-term health.

 Taking care of your mouth and gut isn’t just about fresh breath or digestive health—it could be an essential part of maintaining a healthy heart and brain. Small lifestyle changes, like brushing and flossing daily or eating more gut-friendly foods, can make a big difference in preventing strokes and improving overall health.

The connection between oral hygiene and stroke may surprise many, but it serves as a reminder, that something as simple as brushing your teeth twice a day could have profound effects on your health. By taking care of your mouth, you're not just preventing cavities—you might also be reducing your risk of stroke and securing your long-term wellbeing.