Barry Marshall

An Australian physician who, with pathologist Robin Warren, identified the bacterium Helicobacter pylori in the stomach lining of ulcer and gastritis patients in 1982 and argued it was the cause of peptic ulcer disease against near-universal medical skepticism. Unable to establish an animal model, Marshall drank a culture of the bacterium himself in July 1984; within days he developed foul breath, bloating and vomiting, and an endoscopy ten days later confirmed the organism had colonized his stomach lining with signs of infection. He shared the 2005 Nobel Prize in Physiology or Medicine with Warren.