According to the National Institutes of Health, your mouth is home to 700 species of microorganisms or bacteria that live on your teeth, tongue, and even the pockets between your tooth and gum. While the good microbes help your mouth manage bad microbes' growth and protect against the harmful bacteria in food, the bad microbes form communities with other germs and can form plaque and acid. That’s because these bacteria are living, growing, eating, and reproducing.
These bacteria feed on the sugars in the food and drinks we consume and leave behind waste or plaque. And the bacteria that are attracted to sugar turn it into acid, which can lead to decay on the surface of your teeth and lead to plaque development.
Streptococcus mutans is the bacteria you've probably heard the most about. It lives in your mouth, specifically on tooth surfaces and difficult-to-clean areas like pits and fissures on the teeth, and feeds on the sugars and starches you eat, leading to the formation of cavities. That’s because it produces enamel-eroding acids and thrives in a low pH, according to the Microbiology Spectrum, making it the main cause of tooth decay in humans.
Porphyromonas gingivalis is usually not present in a healthy mouth, but when it does appear, it has been strongly linked to periodontitis, according to Frontiers in Microbiology. Periodontitis is a serious inflammatory disease that affects the tissues and the alveolar bone that support the teeth. While periodontal disease is typically due to several bacteria and not the result of just porphyromonas gingivalis, this disease should not be taken lightly. It can cause significant dental pain and can eventually lead to tooth loss.