Every doctor said ulcers were caused by stress. He said bacteria. To prove it, he drank a Petri dish of the pathogen — then won the Nobel Prize.
For most of the 20th century, the medical establishment was certain: peptic ulcers were caused by stress, spicy food, and too much stomach acid. The cure was antacids and lifestyle changes. Barry Marshall, a young Australian physician, was equally certain they were wrong.
In 1982, Marshall and pathologist Robin Warren discovered a spiral-shaped bacterium — later named Helicobacter pylori — living in the stomach lining of ulcer patients. Their colleagues dismissed the idea. Bacteria couldn't survive in stomach acid, everyone knew that.
Unable to prove his theory in animal models (most animals don't get H. pylori naturally), Marshall took matters into his own hands. In 1984, he drank a Petri dish culture of the bacterium, waited, and within days developed gastritis — inflammation of the stomach lining — exactly as predicted.
He documented his self-infection with endoscopies, proved the bacterium had colonized his stomach, then cured himself with antibiotics. His wife was reportedly not pleased with the experiment. He published the results — and the medical community still largely ignored him for nearly a decade.
The turning point came when pharmaceutical companies began noticing that antibiotic treatment was actually curing ulcers — patients who should have been on antacids for life were getting better permanently. The commercial reality finally forced acceptance of what Marshall had been saying for years.
In 2005, Barry Marshall and Robin Warren were awarded the Nobel Prize in Physiology or Medicine. Their discovery transformed ulcer treatment from lifelong acid management to a simple antibiotic course — and it's estimated that recognizing H. pylori as the cause prevents hundreds of thousands of stomach cancer cases each year.