Some studies show that they can kill bacteria and inhibit viruses like the influenza virus, potentially lowering your risk of infections.
Streptococcus mutans is the primary harmful bacteria in the mouth. It causes plaque formation and is a leading contributor to cavities and tooth decay. Studies show that the catechins in green tea can inhibit the growth of Streptococcus mutans. Green tea consumption is associated with improved dental health and a lower risk of caries.
Multiple studies also show that green tea can reduce bad breath.