Common Oral Bacteria Linked to Higher Stroke Mortality Risk, Study Finds

A new study from Japan's National Cerebral and Cardiovascular Center has identified a significant link between a common oral bacteria and increased stroke risk, potentially revolutionizing how healthcare providers assess and prevent stroke risk in patients.

The research, to be presented at the American Stroke Association's International Stroke Conference 2025, found that stroke patients with elevated levels of Streptococcus anginosus in their gut had 20% higher odds of stroke and faced significantly higher mortality rates over a two-year follow-up period. This bacteria, commonly found in the mouth and gastrointestinal tract, was notably more prevalent in stroke patients compared to healthy individuals.

The findings could have far-reaching implications for stroke prevention and risk assessment. Dr. Shuichi Tonomura, the study's lead author, suggests that future quick tests detecting harmful bacteria could become a valuable tool in calculating stroke risk. The research also emphasizes the critical role of dental hygiene in stroke prevention, as S. anginosus contributes to tooth decay by producing enamel-eroding acids.

While the study's sample size was relatively small and focused on a Japanese population, its implications for global health care are significant. The research suggests that maintaining good oral health could be a crucial factor in stroke prevention strategies. It also opens new avenues for therapeutic interventions targeting specific bacterial populations in the gut and mouth.

The study's findings align with previous research linking oral bacteria to cardiovascular health, potentially offering new approaches to stroke prevention through dental care and microbiome management. For the healthcare industry, this could mean developing new diagnostic tools and preventive strategies focusing on oral and gut bacterial populations as indicators of stroke risk.