H. pylori is a common type of bacteria that grows in the digestive tract and has a tendency to attack the stomach lining. It infects the stomachs of roughly 60 percent of the world’s adult population. H. pylori infections are usually harmless, but they’re responsible for the majority of ulcers in the stomach and small intestine.
The “H” in the name is short for Helicobacter. “Helico” means spiral, which indicates that the bacteria are spiral shaped.