Chewing your food could protect against infection.

A study, recently published in the journal Immunity, found that chewing food also known as mastication can stimulate the release of T helper 17 (Th17) cells in the mouth. Th17 cells form a part of the adaptive immune system, which uses specific antigens to defend against potentially harmful pathogens, while enduring "friendly" bacteria that can be beneficial to health. According to the study team, in the gut and the skin, Th17 cells are produced in the presence of beneficial bacteria. However, the researchers note that the mechanisms by which Th17 cells are produced in the mouth have been unclear, they noted that the mechanical force required by mastication leads to physiological abrasion and damage in the mouth. The researchers came to their findings by feeding weaning mice soft-textured foods, which required less chewing, until they reached 24 weeks of age. At 24 weeks, the release of Th17 cells in the rodents' mouths was measured. A significant reduction in oral Th17 cell production was noted, which the team speculated was down to a reduction in mastication-induced physiological damage. The researchers found that increasing the levels of physiological damage in the rodents' mouths by rubbing the oral cavity with a sterile cotton applicator led to an increase in the production of Th17 cells and so the researchers believe these findings indicate that chewing food may help to protect us from illness. However, the researchers caution that increased oral Th17 cell production may not always be beneficial; too many of these cells can increase the risk of periodontitis, or gum disease, which has been associated with numerous other health conditions, including diabetes and rheumatoid arthritis. The team also found that long-term exposure to physiological damage caused by mastication can exacerbate the effects of periodontitis.