Barry James Marshall, AC, FRS, FAA (born 30 September 1951) is an Australian doctor and winner of the 2005 Nobel Prize in Physiology or Medicine.  He is Professor of Clinical Microbiology at the University of Western Australia. Marshall is well known for proving that bacteria Helicobacter pylori are the cause of most stomach ulcers. This changed years of medical belief which said that ulcers were caused by stress, spicy foods, and too much acid. He has recently taken a part-time position at the Pennsylvania State University.

Early years
Marshall was born in Kalgoorlie, Western Australia. He lived in Kalgoorlie and Carnarvon until moving to Perth at the age of seven. He went to high school at Newman College, Perth. At the University of Western Australia, medicine and surgery. He married his wife, Adrienne, in 1972. In 1972 he was also the Western Australian state yo-yo champion.

Life and research
In 1979 Marshall became a Registrar in Medicine at the Royal Perth Hospital. At the hospital he met Robin Warren, a pathologist who was interested in gastritis. They were both training in internal medicine at Royal Perth Hospital in 1981. Together they looked at spiral bacteria in gastritis. In 1982 they grew a culture of H. pylori. They worked on their idea that there was a bacterial cause of peptic ulcer and stomach cancer. Their idea was laughed at by scientists and doctors who did not believe that any bacteria could live in the acidic stomach.  Marshall said that "Everyone was against me, but I knew I was right".  Other doctors said they wouldn't believe it until the H. pylori idea could be proved.

Marshall and Warren tried to give the bacteria to piglets in 1984, but it did not work. Marshall drank some of the bacteria and soon developed gastritis with achlorhydria. He had stomach discomfort, nausea, vomiting and bad smelling breath. On the 14th day of the infection, biopsies of Marshall's stomach did not show any bacteria. His body may have got rid of the bacteria without help. His wife made him take antibiotics immediately so there was no way of checking the negative result again. He did not develop antibodies to H.pylori. This means that natural immunity can sometimes get rid of H.pylori infection.  His illness and recovery, showed the link between H. pylori and gastritis, but not for peptic ulcer. This experiment was published in 1985 in the Medical Journal of Australia and is among the most cited articles from the journal.

After this work at Fremantle Hospital, Marshall did research at Royal Perth Hospital (1985-86) and at the University of Virginia, USA (1986-1996), before going back to Australia. He held a Burnet Fellowship at the University of Western Australia from 1998-2003. He is still looking at H. pylori and runs the H.pylori Research Laboratory at UWA.

Awards and honours
In 2005, the Karolinska Institute in Stockholm gave the Nobel Prize in Physiology or Medicine to Dr. Marshall and Dr. Warren for finding the bacterium Helicobacter pylori and its part in gastritis and peptic ulcer disease.

Marshall was given other awards including:
 Warren Alpert Prize in 1994
 Australian Medical Association Award in 1995
 Albert Lasker Award for Clinical Medical Research in 1995
 Gairdner Foundation International Award in 1996
 Paul Ehrlich and Ludwig Darmstaedter Prize in 1997
 Dr A.H. Heineken Prize for Medicine in 1998
 Florey Medal in 1998
 Buchanan Medal of the Royal Society in 1998
 Benjamin Franklin Medal for Life Sciences in 1999
 Keio Medical Science Prize in 2002
 Australian Centenary Medal in 2001.

He was made a Companion of the Order of Australia in 2007.

Related pages
List of biologists

Notes

References
 Marshall BJ, Warren JR. Unidentified curved bacillus on gastric epithelium in active chronic gastritis. Lancet 1983;1(8336):1273-1275. PMID 6134060.
 Marshall BJ, Warren JR. Unidentified curved bacilli in the stomach patients with gastritis and peptic ulceration. Lancet 1984;1(8390):1311-1315. PMID 6145023.

Other websites
 The Helicobacter Foundation Discussion Pages 
 The Helicobacter pylori Research Laboratory
 The Helicobacter Foundation

1951 births
Living people
Australian biologists
Australian medical doctors
Australian educators
Microbiologists
Autobiographers
People from Western Australia
Australian Nobel Prize winners
Order of Australia