# Barry Marshall
**Barry James Marshall** (born 1951, [Kalgoorlie](https://www.edgepedia.org/kalgoorlie), Western Australia) is an Australian physician and clinical microbiologist who, with pathologist [J. Robin Warren](https://www.edgepedia.org/j-robin-warren), discovered in 1982 that the bacterium *Helicobacter pylori* causes gastritis and most peptic ulcer disease, overturning the belief that ulcers arose from stress, diet, and excess acid. The two shared the 2005 [Nobel Prize in Physiology or Medicine](https://www.edgepedia.org/nobel-prize-in-physiology-or-medicine) for the discovery.[1](https://barrymarshall.org/barry-marshall/about-prof-marshall/) • [2](https://www.nobelprize.org/prizes/medicine/2005/marshall/biographical/)
| Key fact | Detail |
|---|---|
| Born | 1951, Kalgoorlie, Western Australia[2](https://www.nobelprize.org/prizes/medicine/2005/marshall/biographical/) |
| Medical degree | Bachelor of Medicine and Surgery, University of Western Australia, 1974[3](https://www.wa.gov.au/government/media-statements/Court%20Coalition%20Government/Eminent-scientist-Dr-Barry-Marshall-to-take-up-Burnet-scholarship-at-UWA-19980419) |
| Discovery | *H. pylori* cultured with Robin Warren at Royal Perth Hospital, 1982; initially named *Campylobacter pylori*, renamed *Helicobacter pylori* in 1989[4](https://www.lemonde.fr/planete/article/2005/10/04/barry-j-marshall-et-j-robin-warren-prix-nobel-2005-de-medecine_695619_3244.html) |
| Self-experiment | 1984: drank a culture of the bacterium, developing gastritis within days[5](https://oralhistories.arts.uwa.edu.au/items/show/74) |
| Nobel Prize | 2005, shared with J. Robin Warren, for the discovery of *H. pylori* and its role in gastritis and peptic ulcer disease[1](https://barrymarshall.org/barry-marshall/about-prof-marshall/) |
| Disease burden | *H. pylori* causes more than 90% of duodenal ulcers, up to 80% of gastric ulcers, and up to 89% of intestinal-type gastric adenocarcinomas[6](https://www.nhmrc.gov.au/about-us/resources/impact-case-studies-curing-stomach-ulcers) |
| Honors | Companion of the Order of Australia (2007); inaugural WA Premier's Prize for Achievement in Science (2002)[6](https://www.nhmrc.gov.au/about-us/resources/impact-case-studies-curing-stomach-ulcers) • [7](https://www.wa.gov.au/government/media-statements/Gallop%20Labor%20Government/State-Government-congratulates-Nobel-winners-20051004) |
## Early life and training
Marshall was born in 1951 in Kalgoorlie, a gold-mining town about 370 miles east of Perth. His father was a fitter and turner and his mother a trainee nurse; the family moved several times during his childhood, including a period near the whaling station at Carnarvon.[2](https://www.nobelprize.org/prizes/medicine/2005/marshall/biographical/) He graduated from the [University of Western Australia](https://www.edgepedia.org/university-of-western-australia) with a Bachelor of Medicine and Surgery in 1974, and in 1979 was appointed Registrar in Medicine at Royal Perth Hospital.[3](https://www.wa.gov.au/government/media-statements/Court%20Coalition%20Government/Eminent-scientist-Dr-Barry-Marshall-to-take-up-Burnet-scholarship-at-UWA-19980419) • [6](https://www.nhmrc.gov.au/about-us/resources/impact-case-studies-curing-stomach-ulcers)
## The discovery
In 1979 the pathologist Robin Warren, at Royal Perth Hospital, noticed curved bacteria in stomach biopsy specimens. In 1981 he recruited Marshall, then a gastroenterology registrar, to help study the organism.[8](https://espace.curtin.edu.au/bitstream/handle/20.500.11937/1114/146336_McWilliams%20full.pdf?isAllowed=y&sequence=2) The prevailing view held that the stomach was too acidic for bacteria to survive and that ulcers were caused by stress, lifestyle, or excess acid.[9](https://barrymarshall.org/barry-marshall/helicobacter-research/)
In 1982 Marshall contacted microbiologists at the [University of New South Wales](https://www.edgepedia.org/university-of-new-south-wales) for help identifying the spiral-shaped bacterium he and Warren had obtained from the human stomach and grown in the laboratory using a method the UNSW team had developed.[6](https://www.nhmrc.gov.au/about-us/resources/impact-case-studies-curing-stomach-ulcers) The organism was initially named *Campylobacter pylori* and renamed *Helicobacter pylori* in 1989.[4](https://www.lemonde.fr/planete/article/2005/10/04/barry-j-marshall-et-j-robin-warren-prix-nobel-2005-de-medecine_695619_3244.html) Warren and Marshall submitted a 100-patient study to *The Lancet* in January 1984.[10](https://www.mja.com.au/system/files/issues/183_11_051205/van11000_fm.pdf)
**The self-experiment.** After failing to infect pigs, and with animal models unavailable, Marshall drank a mix of the bacteria in 1984. The infection developed dramatically within a few days, with nausea, vomiting, and bacteria visible in biopsy samples, and he then cured himself with antibiotics. The experiment, reported as an attempt to fulfill [Koch's postulates](https://www.edgepedia.org/kochs-postulates) for the organism, demonstrated that the bacterium caused gastritis.[5](https://oralhistories.arts.uwa.edu.au/items/show/74)
Acceptance came slowly. Marshall reported in late 1988, in a *Lancet* article covering 100 patients with gastroduodenal ulcer, that persistence of the bacterium in untreated patients was associated with ulcer recurrence, supporting treatment that combined antibiotics with acid-suppressing agents.[4](https://www.lemonde.fr/planete/article/2005/10/04/barry-j-marshall-et-j-robin-warren-prix-nobel-2005-de-medecine_695619_3244.html) In February 1994 a National Institutes of Health consensus meeting in Washington, DC concluded that the key to treatment of duodenal and gastric ulcer was detection and eradication of *Helicobacter pylori*.[2](https://www.nobelprize.org/prizes/medicine/2005/marshall/biographical/)
## Career in the United States and return to Australia
In 1985 Marshall began a partnership with the US drug firm Procter and Gamble, and in 1986 he moved to the [University of Virginia](https://www.edgepedia.org/university-of-virginia) as a research fellow.[11](https://science.org.au/our-focus/history-australian-science/conversations-australian-scientists/professor-barry-marshall-gastroenterologist) Between 1986 and 1996 he rose from research fellow to tenured professor there, as Professor of Research of Internal Medicine.[7](https://www.wa.gov.au/government/media-statements/Gallop%20Labor%20Government/State-Government-congratulates-Nobel-winners-20051004) • [3](https://www.wa.gov.au/government/media-statements/Court%20Coalition%20Government/Eminent-scientist-Dr-Barry-Marshall-to-take-up-Burnet-scholarship-at-UWA-19980419)
In 1998 he returned to the University of Western Australia on the five-year, $1.25 million NHMRC Burnet Fellowship, worth $250,000 a year, continuing his research with facilities at Sir Charles Gairdner Hospital.[3](https://www.wa.gov.au/government/media-statements/Court%20Coalition%20Government/Eminent-scientist-Dr-Barry-Marshall-to-take-up-Burnet-scholarship-at-UWA-19980419) In 2007 he was appointed Co-Director of the Marshall Centre for Infectious Diseases Research and Training and a Companion of the [Order of Australia](https://www.edgepedia.org/order-of-australia).[6](https://www.nhmrc.gov.au/about-us/resources/impact-case-studies-curing-stomach-ulcers) His laboratory at UWA developed non-invasive diagnostic methods, including rapid breath tests and retrieval of the organism from a swallowed string.[12](https://research-repository.uwa.edu.au/en/persons/barry-marshall/) In 1994 he founded the Helicobacter Foundation to provide public information about the bacterium, its diagnosis, and treatment.[9](https://barrymarshall.org/barry-marshall/helicobacter-research/)
## Impact on medicine
The discovery replaced lifelong acid suppression and surgery with short antibiotic cures. The treatment that became known as Triple Therapy, two antibiotics plus a proton pump inhibitor, was in extensive use in Australia by 1986 and was quickly adopted overseas; a 1994 follow-up found ulcers remained healed years after eradication, with reinfection of only about 0.1% per annum.[6](https://www.nhmrc.gov.au/about-us/resources/impact-case-studies-curing-stomach-ulcers)
The discovery also reshaped cancer research. An International Agency for Research on Cancer working group concluded in 1994 that *H. pylori* causes cancer, making it the first recognized microbial carcinogen.[6](https://www.nhmrc.gov.au/about-us/resources/impact-case-studies-curing-stomach-ulcers) Chronic infection is now treated as a risk factor for gastric cancer as well as ulcer disease.[9](https://barrymarshall.org/barry-marshall/helicobacter-research/)
**By the numbers.** An Australian economic assessment estimated that between 1990 and 2015, Triple Therapy treatment of peptic ulcer disease prevented 18,665 deaths, saved 258,887 life years, and produced total savings of $10.03 billion, an average of $393 million a year.[6](https://www.nhmrc.gov.au/about-us/resources/impact-case-studies-curing-stomach-ulcers) In 2004 the *Medical Journal of Australia* reported that 4 of its 10 most-cited articles over the previous 90 years related to *H. pylori*.[6](https://www.nhmrc.gov.au/about-us/resources/impact-case-studies-curing-stomach-ulcers)
## Recognition
Marshall and Warren were named Nobel laureates in October 2005, honored for research conducted during their time as registrars at Royal Perth Hospital.[7](https://www.wa.gov.au/government/media-statements/Gallop%20Labor%20Government/State-Government-congratulates-Nobel-winners-20051004) Marshall was the inaugural winner of the Western Australian Premier's Prize for Achievement in Science in 2002.[7](https://www.wa.gov.au/government/media-statements/Gallop%20Labor%20Government/State-Government-congratulates-Nobel-winners-20051004) He holds professional memberships including the Australian Academy of Science, the British Royal Society, and the [Institute of Medicine](https://www.edgepedia.org/institute-of-medicine) (USA), and in 2017 to 2024 expanded research partnerships across the Asia-Pacific region, particularly China, on *H. pylori*, gastric cancer, and medical innovation.[12](https://research-repository.uwa.edu.au/en/persons/barry-marshall/) • [1](https://barrymarshall.org/barry-marshall/about-prof-marshall/)
## References
1. [Professor Barry Marshall – Nobel Laureate, Official Biography](https://barrymarshall.org/barry-marshall/about-prof-marshall/)
2. [Barry J. Marshall – Biographical, NobelPrize.org](https://www.nobelprize.org/prizes/medicine/2005/marshall/biographical/)
3. [Eminent scientist Dr Barry Marshall to take up Burnet scholarship at UWA, Western Australian Government (1998)](https://www.wa.gov.au/government/media-statements/Court%20Coalition%20Government/Eminent-scientist-Dr-Barry-Marshall-to-take-up-Burnet-scholarship-at-UWA-19980419)
4. [Barry J. Marshall et J. Robin Warren, Prix Nobel 2005 de médecine, Le Monde (2005)](https://www.lemonde.fr/planete/article/2005/10/04/barry-j-marshall-et-j-robin-warren-prix-nobel-2005-de-medecine_695619_3244.html)
5. [Barry Marshall interview, UWA Historical Society Oral Histories (2014)](https://oralhistories.arts.uwa.edu.au/items/show/74)
6. [Curing stomach ulcers, NHMRC impact case study (2025)](https://www.nhmrc.gov.au/about-us/resources/impact-case-studies-curing-stomach-ulcers)
7. [State Government congratulates Nobel winners, Western Australian Government (2005)](https://www.wa.gov.au/government/media-statements/Gallop%20Labor%20Government/State-Government-congratulates-Nobel-winners-20051004)
8. [The Discovery of H. pylori, School of Biomedical Sciences (Curtin)](https://espace.curtin.edu.au/bitstream/handle/20.500.11937/1114/146336_McWilliams%20full.pdf?isAllowed=y&sequence=2)
9. [Helicobacter Research, barrymarshall.org](https://barrymarshall.org/barry-marshall/helicobacter-research/)
10. [The Medical Journal of Australia, 183(11) (2005)](https://www.mja.com.au/system/files/issues/183_11_051205/van11000_fm.pdf)
11. [Professor Barry Marshall, gastroenterologist, Australian Academy of Science](https://science.org.au/our-focus/history-australian-science/conversations-australian-scientists/professor-barry-marshall-gastroenterologist)
12. [Barry Marshall, UWA Profiles and Research Repository](https://research-repository.uwa.edu.au/en/persons/barry-marshall/)
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*Topic: Encyclopedia › Life and health › Life and health scientists › Life scientists › Researchers in immunology, microbiology, and virology › Bacteriology and bacterial pathogenesis*
*Initially written Sep 17, 2026 · Reviewed: Sep 17, 2026; Sep 21, 2026; Sep 30, 2026; Oct 21, 2026 · Edited: Sep 21, 2026; Sep 30, 2026; Oct 12, 2026; Oct 15, 2026; Oct 21, 2026 · Last review: Oct 21, 2026*
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