Digestive system diseases: Intestinal bacteria are the only source of hydrogen in the body. A large number of intestinal flora in the body can ferment unabsorbed carbohydrates to produce about 150 ml of hydrogen every day, which is then excreted from the human body or by the colon. The flora is absorbed and further metabolized. Compared with other gaseous bacterial products, hydrogen can improve the motility of the intestinal tract and antibacterial treatment can significantly reduce the production of intestinal hydrogen. The concentration of hydrogen molecules in the stomach and liver of mice is 20-80 ptmol/L. These hydrogen molecules are absorbed by the blood and transported to various parts of the body to play the role of endogenous antioxidants.

Although the gastrointestinal tract of humans and many animals can produce hydrogen, so far, there is no evidence that it has obvious therapeutic effects. However, studies have shown that by inducing the gastrointestinal tract to produce more hydrogen, some diseases can be treated. Kajiya et al. found that by supplementing animals with hydrogen-producing bacteria, the gastrointestinal tract is induced to produce more hydrogen, which can inhibit the liver inflammation induced by Concanavalin A. The researcher also found that drinking hydrogen-rich water can achieve a more effective therapeutic effect than inducing hydrogen production in the gastrointestinal tract.