Summary: A new study finds that the bacteria Streptococcus anginosus is more abundant in the saliva and gut of people who have had a stroke and is associated with a higher risk of death and major cardiovascular events. Researchers compared 189 stroke patients with 55 non-stroke participants, finding that this bacterium increased stroke risk by 20%.

Meanwhile, beneficial bacteria like Anaerostipes hadrus and Bacteroides plebeius were linked to a reduced stroke risk. The findings highlight the importance of oral hygiene in stroke prevention, as Streptococcus anginosus contributes to tooth decay.