Why did they think bateria caused stomach ulcers?

The belief that bacteria caused stomach ulcers emerged primarily from research conducted in the 1980s by Australian doctors Barry Marshall and Robin Warren. They discovered that the bacterium Helicobacter pylori was present in many patients with peptic ulcers, challenging the long-held notion that stress and diet were the primary causes. Their findings demonstrated that H. pylori could survive in the acidic environment of the stomach and lead to inflammation and ulcer formation. This groundbreaking research ultimately revolutionized the understanding and treatment of stomach ulcers, shifting the focus to antibiotic therapies.