Study: Bacterium may protect against asthma

A researcher said he's concerned about how many antibiotics children get.
SCRIPPS HOWARD NEWS SERVICE
When it comes to preventing or controlling asthma and other ills, new research is finding that things that are bad for us may also be good for us.
Exhibit one is a study by researchers at the New York University School of Medicine. They found that people infected with a strong strain of the stomach bacterium Helicobacter pylori, which causes stomach cancer and peptic ulcers, were 40 percent less likely to have asthma before age 5 than people who didn't carry it.
The study also found that the germ is associated with protection against ragweed, pollen and mold allergies, particularly among young adults.
"Ultimately, the potentially protective properties of Helicobacter are consistent with one another and point to a much more complex view of the organism," said Dr. Martin Blaser, a professor of internal medicine and microbiology at NYU who has been studying H. pylori for more than two decades. The bug lives in the mucus lining of the stomach, where it persists for decades. People usually get it before age 10, and it mainly spreads within families.
Ulcer culprit
Other scientists discovered more than a decade ago that H. pylori, rather than stress or spicy foods, was the main culprit for ulcers in the lining of the stomach and upper intestine. Extended use of anti-inflammatory drugs like ibuprofen and aspirin also took part of the blame.
Blaser's earlier research has linked the bacterium to stomach cancer, but he also suggests that H. pylori helps protect us against disease of the upper gastrointestinal tract, such as gastric reflux disease and esophageal cancer.
The bug has become less common in younger people due to improved sanitation and the widespread use of antibiotics that tend to do collateral damage to many germs in the gut.
Today, fewer than 10 percent of children in developed countries carry the organism, but about 90 percent of kids in developing nations still are infected, usually by age 5. And asthma and allergy rates remain low in those countries, for the most part.
Although more studies need to be done to confirm that colonization by the germ, particularly with a strain called cagA, gives protection against asthma, Blaser said the results already give him cause for concern about whether children should be given as many antibiotics as they get.
Blaser's findings, published this week in the Archives of Internal Medicine, seem to fit a still-evolving theory that asthma has become much more widespread in the past four or five decades as people in developed countries live in cleaner, less-well-ventilated homes and spend less time outdoors and particularly around farms and livestock.
On the other side of the asthma battle is a compound called chitin, a substance that toughens the shells of insects and creatures like crabs, lobsters and shrimp, as well as molds.
Researchers at the University of California-San Francisco, led by Dr. Richard Locksley, have found that even though humans and other creatures with internal skeletons don't have chitin, they make special enzymes in the lining of the lungs that breaks the compound down.
Now, scientists are working to see if patients with asthma are more likely to have a less-active version of the genes that prompts manufacture of the anti-chitin enzyme.