Not just J. Darwin
In the summer of 1984, the Australian scientist Neil Noakes took some bacteria from a petri dish, mixed them with lukewarm beef extract – the normal nutrient solution for bacteria in the lab – and filled a little more than one cup into a beaker. Then he handed this mix to his colleague, the gastroenterologist Barry Marshall, who downed it without complaining.
Three days later, Marshall felt nauseated and his mother told him he had bad breath. Next he started vomiting. But he still waited a few days before taking the antibiotics that were supposed to kill the bacteria in his stomach. A gastroscopy not only clarified his diagnosis, but ultimately resulted in his winning the Nobel Prize in Physiology and Medicine about twenty years later.
With his famous self-experiment, Marshall was able to demonstrate that Helicobacter pylori bacteria can cause acute gastritis which in turn may cause ulcers. He had asked neither an ethics commission nor his wife for permission to conduct this experiment. His colleagues thought him completely insane to take a risk like that.
Back in the 1980s, the prevailing theory was that gastric ulcers were mostly a psychosomatic affliction caused by too much stress. Accordingly, patients were treated with tranquillizers, anti-depressants, psychotherapy or antacids. Instead the young doctor Marshall treated them all with antibiotics, and his results were impressive. From his clinical practice, he developed the theory that the spiral-shaped Helicobacter bacterium causes gastritis, painful stomach ulcers and even stomach cancer. Because he had had no suitable test animals at hand, he used his own body for the described experiment.
LINK
And ...
https://www.science.org.au/learning/general-audience/history/interviews-australian-scientists/professor-barry-marshall/teacher
