A common bacterium in the stomach is Helicobacter pylori, which is the bacterium found to be able to survive in the stomach. H. pylori can survive in the stomach because it utilizes a helical structure to burrow through the mucus on the surface of the gastric mucosa and parasitize in the relatively neutral environment of the mucus near the gastric mucosal epithelium. H. pylori is mainly transmitted through oral-oral and fecal-oral infections, and can be transmitted to others through kissing and sharing utensils. Some of the H. pylori in the stomach can be excreted with feces, contaminating water and food and causing infection. Bad dietary habits can also cause H. pylori infection, such as drinking raw water and eating raw meat are easy to cause infection. Infection with H. pylori can cause a series of gastrointestinal diseases, such as peptic ulcer, atrophic gastritis, gastric cancer and so on. It is recommended to develop good hygiene habits and pay attention to dietary hygiene to prevent H. pylori infection.