Helicobacter pylori lives in the stomachs of over half the people in the world. How can something survive in our churning, acid-soaked stomachs? Helicobacter pylori does it by digging deep under the stomach’s mucus lining. This works well forHelicobacter pylori, but not so well for us. Helicobacter pylori inflames the stomach lining, which can sometimes cause ulcers and other problems.