Feature articles
27 July 2004
Helicobacter pylori:The key to a cure for peptic ulcer patients?
The acid test
Why was this discovery so controversial? Today, the link between H. pylori and peptic ulcers is widely accepted by experts. For most of the twentieth century, however, stomach ulcers were thought to be caused by the overproduction of stomach acid, which is needed to digest food, and a weakening of the stomach lining, which is usually protected by a layer of mucus. Doctors believed that this imbalance was brought about by stress or eating spicy foods, and therefore treated ulcers with drugs that reduced acid secretion and promoted healing of the stomach lining. But none of these treatments guaranteed that an ulcer would not return. In fact, before H. pylori was discovered, 80% of patients given these medications to treat their ulcer would develop another ulcer within a year.
The proof is in the eating
When Drs Marshall and Warren first announced they had discovered a bacterium that lived in stomachs, most experts dismissed the notion outright. After all, the stomach juices are so acidic that surely no living organism could survive in such a hostile environment? But the Australians persisted with their belief. First, Dr Warren showed that H. pylori was present in the stomachs of the vast majority of patients with peptic ulcers and grew the bacterium in the laboratory so that it could be studied further. Then, in the face of significant scepticism from gastroenterology specialists, Dr Marshall earned himself a place in medical history by swallowing an H. pylori-laced broth. One week later he began suffering headaches and stomach pains, felt nauseous and vomited, and an examination of his stomach revealed the classic signs of gastritis – the first stage in the development of a peptic ulcer.
An infectious disease
Luckily, Marshall recovered from his risky experiment. But, by proving that H. pylori infection could cause peptic ulcers, Drs Marshall and Warren pioneered a totally new approach to the diagnosis and treatment of the condition. Instead of being viewed as a “lifestyle” illness, ulcers are now known to be an infectious disease, and can therefore be treated with widely available antibiotics. Moreover, once the infection has been treated successfully it rarely comes back, sparing countless people the pain and suffering of a lifelong ulcer.
Almost all ulcers caused by H. pylori
Since the discovery of H. pylori, several tests have been developed that can tell whether someone is infected with the bacterium. These show that a staggering 90% of all patients with an ulcer are infected and are therefore eligible for antibiotic treatment. Intriguingly, however, not everyone who is infected with H. pylori develops a peptic ulcer. In fact, it is estimated that around two-thirds of the world’s population harbours the bacterium, yet most people do not have ulcers. This suggests that other factors must also be present for the damage to take place.
Role of triggering factors
So H. pylori is not the whole story, and researchers are currently trying to identify other “triggers” necessary for an ulcer to develop. Interestingly, one in 10 people with a peptic ulcer test negative for H. pylori infection. These individuals are often heavy users of common painkilling drugs, such as aspirin or ibuprofen, which irritate the stomach lining. Additional factors that may influence the course of the disease include spicy foods, caffeine, alcohol, smoking, and stress. While none of these can cause an ulcer by themselves, they may boost people’s susceptibility to the condition, irritate an existing ulcer, or increase the time it takes for an ulcer to heal.
Combination cures
Nowadays, patients with peptic ulcers are routinely checked for H. pylori infection and those who test positive are treated with antibiotics. Although antibiotics ensure that the ulcer will not return, they do not protect the stomach against further damage. For this reason, peptic ulcers are generally treated with a combination of drugs to kill the bacteria, reduce stomach acid, protect the stomach lining and improve symptoms. Medications commonly used to treat people with peptic ulcers are summarised in the table below.
Medications used to treat peptic ulcers
| Drug type | What they do |
| Antibiotics | Kill H. pylori bacteria |
| Proton pump inhibitors | Reduce acid production in the stomach |
| Histamine2-receptor antagonists | Reduce acid production in the stomach |
| Antacids | Neutralise stomach acid |
| Prostaglandin analogues | Mimic the action of naturally occurring chemicals to reduce acid production and promote ulcer healing |
| Stomach protectors | Protect the lining of the stomach |
Further information:
H. pylori Research Laboratory
http://www.hpylori.com.au/
The American Gastroenterological Association
http://www.gastro.org/generalPublic.html
National Digestive Diseases Information Clearinghouse
http://digestive.niddk.nih.gov/ddiseases/pubs/gerd/
Digestive Disorders Foundation
http://www.bdf.org.uk/
MedlinePLUS:
http://medlineplus.gov/
References:
Hamilton G. Dead man walking. New Scientist 2001; 2303: 30–33.
Marshall BJ, Goodwin CS, Warren JR et al. A prospective double-blind trial of duodenal ulcer relapse after eradication of Campylobacter pylori. Lancet 1988; 2: 1437–1442.
Marshall BJ, Royce H, Annear DI et al. Original isolation of Campylobacter pyloridis from human gastric mucosa. Microbios Letters 1984; 25: 83–88.
Marshall BJ, Warren JR. Unidentified curved bacilli in the stomach of patients with gastritis and peptic ulceration. Lancet 1994; 1: 1311–1315.
Marshall BJ. Unidentified curved bacillus on gastric epithelium in active chronic gastritis. Lancet 1983; 1: 1273–1275.
National Institutes of Health. Helicobacter pylori in peptic ulcer disease. NIH Consensus Statement 1994; 12: 1–23.
Normark S, Nilsson C, Normark BH et al. Persistent infection with Helicobacter pylori and the development of gastric cancer. Adv Cancer Res 2003; 90: 63–89.
Warren JR. Spiral bacteria of the gastric antrum. Med J Aust 1984 141: 477–478.
