Ulcer bug may prevent asthma

From San Diego, at a meeting of the Infectious Diseases Society of America

HIDDEN BENEFIT. Helicobacter pylori, the tube-like bacterium shown here colonizing a human stomach, causes ulcers but also may prevent childhood asthma. Blaser

Call it a bad-bug, good-bug story. Children whose stomachs carry the bacterium Helicobacter pylori are at lower risk for asthma than children who don’t have the bug, according to an analysis of a nationwide study.

Starting in the 1980s, H. pylori gained notoriety as the cause of most stomach ulcers. The bug also increases the risk for stomach cancer.

Increasing antibiotic use has cleared H. pylori from more than 90 percent of children, says Martin Blaser, a physician and microbiologist at the New York University School of Medicine in New York City. But his research shows that this microbial annihilation may carry a price.

In 3,327 children ages 3 to 13, those with H. pylori in their stomachs were 53 percent less likely to have asthma than were children who didn’t have the stomach bug, according to Blaser’s analysis. Being positive for H. pylori also decreased the risk for dermatitis, eczema, and bouts of wheezing among the children. The researchers drew their data from the long-running federal National Health and Nutrition Examination Survey.

About 13 percent of children in the United States have been diagnosed with asthma, according to the Centers for Disease Control and Prevention in Atlanta. The disease is a chronic inflammation of the airways thought to be triggered by a malfunctioning immune system.

Blaser says that H. pylori colonization may prime the immune system to prevent asthma in some children.

The findings “point toward a much more complex view of the organism—not just as an ulcer pathogen or cancer pathogen, but as an organism that has its costs and benefits to us,” he says.

More Stories from Science News on Health & Medicine

From the Nature Index

Paid Content