Barry Marshall and Robin Warren, two Australian scientists, have been awarded the Nobel Prize for Medicine for their discovery that a bacteria can trigger stomach ulcers. The bacterium, Helicobacter pylori, or H. pylori as it is known, is found in the stomach of about 50% of all humans. Warren and Marshall discovered that although most people experience no symptoms from the bacteria, in 10 to 15% of people H. pylori can trigger a stomach or duodenal ulcer.
It is believed that the helicobacter pylori stimulates acid production in the stomach that leads to the lining of the stomach and duodenum becoming damaged. This results in inflammation & ulceration. H.pylori causes more than 90% of duodenal ulcers and up to 80% of gastric (stomach) ulcers.
For the people whose ulcer has been caused by H.pylori it has revolutionized their treatment. The inflammation caused by the bacteria can be treated with antibiotics.
Barry Marshall and Robin Warren had a battle to get recognition for their new theory. It was a good example of the difficulties that doctors can have moving away from an established approach to a disease. At one point in their research Dr Marshall deliberately infected himself with the bacterium to show that the H.pylori caused stomach and duodenal ulcers.
It had previously been believed that stress and lifestyle were the main cause of ulcers and that stress resulted in the overproduction of gastric acids. Barry Marshall and Robin Warren produced one of the most radical and important changes in the causation, diagnosis and treatment of stomach and duodenal ulcers. It showed that ulcers were the result of an inflammatory process, not a psychological illness.