Helicobacter pylori (H. pylori) is a type of bacteria. These germs can enter your body and live in your digestive tract. After many years, they can cause sores, called ulcers, in the lining of your stomach or the upper part of your small intestine. For some people, an infection can lead to stomach cancer.
Infection with H. pylori is common. About two-thirds of the world’s population has it in their bodies. For most people, it doesn’t cause ulcers or any other symptoms. If you do have problems, there are medicines that can kill the germs and help sores heal.