Dr. Marshall and Dr. Warren get Nobel Prize for stomach ulcer discovery

This year’s Nobel Prize for medicine and physiology was awarded to two Australian scientists for their remarkable and unexpected discovery that inflammation in the stomach (gastritis) as well as ulceration of the stomach or duodenum (peptic ulcer disease) is the result of an infection of the stomach by the bacterium Helicobacter pylori.

They should be given credit for it is thanks to their pioneering work that peptic ulcer is no longer a chronic, frequently disabling condition, but a disease that can be cured by a short regimen of antibiotics and acid secretion inhibitors.images.jpg

In 1982, when H. pylori was discovered by Dr Marshall and Dr Warren, stress and lifestyle were considered the major causes of stomach and intestinal ulcers. The link between Helicobacter pylori infection and subsequent gastritis and peptic ulcer disease has been made through studies of human volunteers, antibiotic treatment studies and epidemiological studies over the years and it is now firmly established that the bacterium causes more than 90% of duodenal (intestinal) ulcers and up to 80% of gastric (stomach) ulcers.helicobacter_eng.jpg

Dr Warren, a pathologist from Perth, paved the way for the breakthrough when he observed small curved bacterial colonies in the lower part of the stomach in about 50% of the patients whose biopsies were studied. He made the crucial observation that signs of inflammation were always present in the gastric mucosa close to where the bacteria were seen.

Dr Marshall, a young clinical fellow, too became interested and together they initiated a study of biopsies from 100 patients.

After several attempts, Marshall succeeded in cultivating a hitherto unknown bacterial species (later denoted Helicobacter pylori) from several of these biopsies.

Even though stomach ulcers could be healed by inhibiting gastric acid production, they frequently relapsed, since bacteria and chronic inflammation of the stomach remained. However Dr Marshall and Dr Warren showed patients could only be properly cured when H. pylori was eradicated from the stomach.

Dr Marshall proved that H. pylori caused gastric inflammation by going to the wild extreme of intentionally infecting himself with the bacterium. In spite of this crazy behavior the Nobel citation praises the doctors for their tenacity, and willingness to challenge prevailing dogmas.

By using technologies generally available (fibre endoscopy, silver staining of histological sections and culture techniques for microaerophilic bacteria), they made an irrefutable case that the microaerophilic bacteria), they made an irrefutable case that the bacterium Helicobacter pylori is causing disease and by culturing the bacteria they made them amenable to scientific study.

It is thought that H. pylori infection can trigger an ulcer by stimulating increased acid production in the stomach, leading to damage to the stomach or intestinal lining.

Lord May of Oxford, President of the Royal Society, said: "The work by Barry Marshall and Robin Warren produced one of the most radical and important changes in the last 50 years in the perception of a medical condition. Their results led to the recognition that gastric disorders are infectious diseases, and overturned the previous view that they were physiological illnesses."

Helicobacter pylori is a spiral-shaped Gram-negative bacterium that colonizes the stomach in about 50% of all humans and has adapted to the stomach environment. In countries with I n developing countries where virtually everyone may be infected.

After Marshall’s and Warren’s discovery, research has been intense. Details underlying the exact pathogenetic mechanisms are continuously being unraveled. For not until recently has an animal model been established, the Mongolian gerbil in which the studies of peptic ulcer disease and malignant transformation promise to give more detailed information on disease mechanisms.

The discovery that one of the most common diseases of humankind, peptic ulcer disease, has a microbial cause, has stimulated the search for microbes as possible causes of other chronic inflammatory conditions.

Even though no definite answers are at hand, recent data clearly suggest that a dysfunction in the recognition of microbial products by the human immune system can result in disease development. The discovery of Helicobacter pylori has also led to an increased understanding of the connection between chronic infection, inflammation and even cancer. The relevance of the discovery and the persistent determination of the two scientists truly make it a well-deserved award.