Saliva contains a variety of proteins, and the types of salivary proteins are divided into glycoproteins and mucins, while mucins are the main organic components of saliva, and the largest protein is the proline-rich protein of glycoproteins. In addition, it also contains immunoglobulins, inorganic salts, salivary enzymes, etc. The main roles of saliva are digestion and antibacterial, which have important synergistic effects on chewing and swallowing, and help soften food and also help digestion. Saliva has a cleansing effect. Saliva is a natural rinse in the mouth, which can dilute and rinse and remove bacteria and food debris from the dental surface of the mouth, and has the effect of keeping the mouth clean. Saliva also has a buffering and protective effect, which can play an immune protective function for the oral cavity, and has an antagonistic effect on Candida albicans, and can neutralize the acid produced by bacteria to reduce and prevent the occurrence of caries, and saliva also has a dilution and excretion of metabolic products or toxic substances, which can play a role in endocrine regulation.