THURSDAY, Aug. 12, 2004 (HealthDayNews) -- A new study finds that cells in the stomach make an antibiotic-like substance that fights the ulcer bacterium, a discovery that could lead to new treatments to prevent ulcers and even cancer caused by the bug.
The study, appearing in the Aug. 13 issue of Science, may also take a step toward explaining why many people carry the bacterium, Helicobacter pylori, yet never have any gastric problems.
"This is the first report that shows that an O-glycans glycoprotein acts as an antibiotic against H. pylori," said study co-author Minoru Fukuda, a professor of glycobiology at the Burnham Institute in La Jolla, Calif.
About one-half all humans are infected with H. pylori. In the United States, about 20 percent of people under 40, and 50 percent of those over 60, are infected, according to the National Institute of Diabetes and Digestive and Kidney Diseases.
However, most people have no symptoms, and most don't develop ulcers or stomach cancer.
Fukuda's team knew that H. pylori is usually not found in the stomach lining, where cells secrete mucus containing a particular O-glycans glycoprotein.
In laboratory experiments, the researchers studied whether this particular O-glycans can affect the growth of the bug. They found these proteins prevented the growth and activity of H. pylori by stopping it from reproducing.
This protein works the same way as antibiotics, Fukuda said. "The protein had devised a method to prevent the growth of this organism," he added.
Why some people are susceptible to H. pylori and others are not is still unknown, Fukuda said. Finding out the answer is the next step in the team's research.
It should be possible to make drugs or to use this protein as a drug itself to fight H. pylori infection, Fukuda said. "In addition, by using cows or goats to produce this protein in milk, we can prevent H. pylori infection," he said.
Fukuda added that other natural antibiotics may act against bacteria in other parts of the body, such as in the colon and lungs. "The colon and the lung have huge numbers of bugs," he said.
The study "offers a mechanism to explain why most people who harbor H. pylori live with it in perfect symbiosis," said Dr. Howard M. Spiro, a professor emeritus of internal medicine at Yale University. "They have more 'good' mucus that acts as the limiting factor. There just had to be something, reflecting the balances of nature, to render harmless a life form tough enough to withstand gastric acid."
The National Institute of Diabetes and Digestive and Kidney Diseases explains gastric ulcers and H. pylori.