Studies have shown that oral diseases are not caused by one or several harmful bacteria, but are caused by the imbalance of oral microecology.

There are more than 700 kinds of microorganisms in the human mouth, which is the second largest microbial community habitat after the gut. A relative balance is maintained between various bacteria, and at the same time, each group of bacteria maintains a dynamic balance with the host. The fast-paced lifestyle of modern people will lead to the disorder of the oral flora. When the internal balance of the oral system is broken, various oral diseases will be caused. For example, when the bacteria such as Streptococcus mutans overgrowth, it will lead to the occurrence of caries. When the bacteria such as Porphyromonas gingivalis and Prevotella intermedia grow too fast, it will lead to gingivitis, periodontitis and other diseases.

Probiotics can directly or indirectly affect various immune cell functions, play a role in immune regulation and control the development of inflammation, and these effects are mainly related to the regulation of lymphocytes and dendritic cells.