Bacteria are often maligned as the causes of human and animal disease. Lately, it had been revealed that a bacteria to protect children from devloping asthma and is a major cause of ulcer and stomach cancer.

The children infected with the bacteria is called Helicobacter pylori, and they’re very less liely to have asthma rather than the uninfected children.

“Our findings suggest that absence of H. pylori may be one explanation for the increased risk of childhood asthma,” said Yu Chen, assistant professor of epidemiology at New York University School of Medicine, who worked on the study.

“Among teens and children ages 3 to 19 years, carriers of H. pylori were 25 percent less likely to have asthma.”

“If you look at the people born in 1919, 60 percent are positive. That’s a huge change,” Blaser said in a telephone interview. “I have referred to this as global warming of the stomach.”

At the same time , among the children age 3 to 19 ub the study , shows that 23 per cent had asthma, Blaser said.

“It’s good and it’s bad,” Blaser said.

“The disappearance of Helicobacter … is consistent with the decline of both ulcer disease and stomach cancer. It is also consistent with the rise of asthma and esophageal diseases like GERD (gastric reflux disease) and adenocarcinoma (cancer) of the esophagus.”

What needs to be studied, said Blaser, is whether Helicobacter infections directly affect a tendency to asthma.

“It is possible to H. pylori is a marker for something, just as blond hair is a marker for having been born in Scandinavia,” he said

“Maybe the same antibiotics that made H. pylori go away make something else go away.” Or perhaps the bacteria somehow protects against asthma directly, perhaps by changing the body’s immune response.

“One explanation for this phenomenon has been termed the ‘hygiene hypothesis,’ which considers that humans are more prone to allergic disorders because of a lifestyle that may be too ‘clean’,” Blaser’s team wrote.