The Nobel Committee described their discovery that stomach inflammation and ulcers were the result of an infection caused by the bacterium as “remarkable and unexpected”.
They will share the prize sum of 10 million kronor.
In his work as a pathologist, Robin Warren, 68, observed small curved bacteria colonizing the lower part of the stomach in about 50% of patients from which biopsies had been taken. He noticed that signs of inflammation were always present close to where the bacteria were seen.
Barry Marshall, 54, a young clinical fellow, followed up Warren’s findings and together they studied biopsies from 100 patients. Marshall managed to cultivate a hitherto unknown bacterial species (later named Helicobacter pylori) from several of these biopsies.
Together they found that the organism was present in almost all patients with gastric inflammation, duodenal ulcer or gastric ulcer – and they concluded that Helicobacter pylori is behind these diseases.
“Thanks to the pioneering discovery by Marshall and Warren, peptic ulcer disease is no longer a chronic, frequently disabling condition,” wrote the Nobel Committee at the Karolinska Institute.
The pair made the discovery in 1982 and the award was seen by many as long overdue.
Barry J Marshall works at the Heliobacter pylori Research Laboratory in Nedlands, Western Australia, while J Robbin Warren most recently worked as a pathologist at the Royal Perth Hospital in Perth, Western Australia.