Previous findings suggest that Streptococcus mutans, a bacteria that causes tooth decay, is linked to a higher risk of bleeding in the brain. In the current study, researchers sought to identify other oral bacteria linked to stroke risk.
To do so, they analyzed data from 189 patients who had a stroke within the last seven days, and 55 non-stroke participants. All study participants were in Japan and had an average age of 70 years old. Those in the control group may have had other medical problems, including high blood pressure, diabetes, and high cholesterol.
The researchers used stool and saliva samples from the participants to analyze their oral and gut microbiomes. They then observed how many participants died or had new cardiovascular events over a two-year follow-up period.
Ultimately, the researchers found that the presence of bacteria Streptococcus anginosus in the gut was independently linked to a 20% higher risk of stroke. Meanwhile, bacteria Anaerostipes hadrus and Bacteroides plebeius were linked to an 18% and 14% lower risk.
The researchers additionally found that stroke survivors with Streptococcus anginosus in their guts had a significantly higher risk of death and major cardiovascular events over a two-year follow-up period.
"Both Streptococcus mutans and Streptococcus anginosus are bacteria that contribute to tooth decay by producing acids that break down tooth enamel. This highlights the importance of preventing tooth decay, which can be achieved by reducing sugar intake and using toothpaste that targets these bacteria. Maintaining good oral hygiene is essential," Shuichi Tonomura, M.D., lead author of the study and staff physician in the department of neurology at the National Cerebral and Cardiovascular Center in Osaka, Japan, said in a press release.
"Since this study was conducted after a stroke occurred, examining a larger group of people who have not yet had a stroke but do have risk factors could enhance our understanding of how these bacteria are related to stroke risk. This knowledge could help improve prevention strategies." Louise D. McCullough, M.D., P.H.D., FAHA, chief of neurology at Memorial Hermann Hospital-Texas Medical Center, not involved in the study, said in a press release.
Sources: Science Daily
