Cobra Effect · Body and medicine
The doctor who drank the germ
How a doctor drank a germ to prove that bacteria, not stress, cause most ulcers.
7 cards, read aloud in 3:09, with a test and sources.
For most of the twentieth century, stomach ulcers were blamed on stress and acid.
Ulcers are painful sores in the lining of the stomach or the gut. Doctors believed they came from too much stomach acid, brought on by stress, spicy food and worry. Patients took medicines to cut acid, but their ulcers often came back. Most doctors thought no germ could survive for long in a stomach full of acid.
In 1979, the pathologist Robin Warren saw spiral bacteria in samples from stomachs.
Warren worked at Royal Perth Hospital in Australia, examining tissue taken from patients. Under the microscope, he found curved, spiral bacteria living in the stomach lining. They were often found where the lining was inflamed. A young doctor, Barry Marshall, joined him to find out what the bacteria were doing there.
Marshall and Warren suspected that the bacteria caused ulcers.
They found the bacteria in most of the patients they studied who had ulcers. In 1984 they published their findings in the medical journal The Lancet. Many doctors were deeply sceptical. Marshall tried to show the bacteria could cause disease by infecting piglets, but the piglets stayed healthy.
In July 1984, Marshall drank a broth full of the bacteria.
He was a thirty two year old doctor, and first had his own stomach checked, to show that it was healthy. Then he swallowed a broth made from two dishes of the bacteria. A few days later he felt sick, and his stomach lining became inflamed. Tests showed that the bacteria had taken hold.
Antibiotics cleared the infection.
Marshall treated the illness with antibiotics, and his stomach recovered. He had shown that the bacteria could infect a healthy stomach and inflame it. The bacterium was later named Helicobacter pylori. In the years that followed, trials showed that clearing it with antibiotics could cure most of these ulcers for good.
In 2005, Marshall and Warren shared the Nobel Prize.
The prize recognised their discovery of Helicobacter pylori and its role in ulcers. The bacterium has also been linked to stomach cancer. Today, ulcers caused by the bacterium are routinely treated with antibiotics. A disease long blamed on worry turned out largely to be an infection.
So when everyone knows the cause of something, ask what the evidence actually shows.
The idea that stress caused ulcers seemed obvious, and it was repeated for decades. Two doctors in Perth noticed something that did not fit. When others would not believe them, Marshall found a direct way to test it. Common knowledge can be wrong, even among experts.
Sources
- Barry J. Marshall: Nobel lecture, NobelPrize.org. Marshall’s own account of the bacteria, the doubts, and the experiment on himself.
- Gut feeling, Lasker Foundation. How two Australian doctors overturned the stress theory of ulcers.
- One hundred years of discovery and rediscovery of Helicobacter pylori, NCBI Bookshelf. Why the bacterium was seen and missed for decades before Warren and Marshall.
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- The extract that saved a boy. How a quarrelling team in Toronto turned a deadly disease into one people could live with.
- Germs do not come from nowhere. How a swan-neck flask and a country doctor proved that germs cause disease.
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