Saliva is mainly secreted through the salivary glands, and some foods can promote the secretion of the salivary glands to a certain extent, thus increasing the role of saliva, such as citrus fruits, bitter green vegetables and chewing gum. 1. Citrus fruits: mainly including lemons, oranges, mandarin oranges, tangerines and grapefruit, these fruits contain a lot of water, vitamins and citric acid, in the process of chewing these fruits, can effectively stimulate the secretion of the salivary glands, thus increasing the saliva content in the mouth. However, people who have too much stomach acid or suffer from stomach problems are advised not to consume them freely. 2. Bitter green vegetables: such as bitter melon, bitter vegetables, lettuce and bitter chrysanthemum. These bitter foods can stimulate the taste buds of the tongue to a certain extent, prompting the taste nerves to play a role in order to increase the secretion of saliva. 3. Chewing gum: by constantly chewing gum, can effectively promote the secretion of saliva, however, in order to avoid the burden on the teeth, it is best to choose some sugar-free gum, so as to avoid excessive sugar in the body. The role of food to increase saliva is limited, if the body is uncomfortable, it is recommended to seek medical attention.