Helicobacter pylori is a type of bacteria that infects the stomach lining and is one of the major causes of peptic ulcers and gastritis. It is estimated that over half of the world's population is infected with H. pylori. Research in this area focuses on understanding the mechanisms of H. pylori infection, its role in the development of various gastrointestinal diseases, and developing treatments and vaccines to combat H. pylori infections. The discovery of H. pylori's role in causing ulcers has led to significant changes in the treatment and prevention of these conditions.