H. pylori may protect against asthma, other respiratory conditions

Helicobacter Pylori bacteria that occur naturally in the stomach may help protect against allergic rhinitis, dermatitis, eczema, and even asthma, data presented at the Infectious Disease Society of America annual meeting suggest.

H. pylori bacteria have been the dominant organism in human stomachs for thousands of years but have nearly disappeared from our systems, most likely because of improved living conditions and the frequent use of antibiotics, according to a new nationwide study of more than 3,000 children and adolescents. Today, fewer than 1 to 10 children under age 13 have the organism.

It is clear that there is a biological cost to having H pylori in an increased risk of getting ulcers and stomach cancer, but these typically occur relatively late in life, the coinvestigator, chairman of the Department of Medicine at New York University School of Medicine said. Meanwhile, asthma is a serious diagnosis, especially in young children, and can be deadly.

Previous research team demonstrated that children aged 3 to 13 years who had H pylori in their stomachs were 53% less likely to have ever had asthma than those who did not have the bacteria. And while H pylori infection has been on the decline, childhood asthma has been rising at an alarming pace; 13% of American children now have chronic asthma.

It is possible that there is benefit from having H pylori in the stomach and, until this is clarified, they should not be too anxious to eradicate it. Second, it is possible that the gradual disappearance of H pylori, because of widespread antibiotic use for a variety of conditions in childhood, may be in part fueling the rise in childhood asthma.

This new study was based on results from the 1999-2000 National Health and Nutrition Examination Survey. Participants (aged 3-19 years) who were tested for H pylori were compared with those who had ever been diagnosed with asthma. Overall, those with H pylori in their stomachs were 35% less likely to have ever had asthma and 44% less likely to have ever had asthma before the age of 5 years.

The investigators theorize that H pylori may in some indirect way protect against asthma by priming the immune system. H pylori could be beneficial in other ways. For instance, they found that people with the bacteria were less likely to have had recent bouts of wheezing, allergic rhinitis, dermatitis, eczema, or rash, the coinvestigator said, also of the New York University School of Medicine. And other studies have shown that it may protect against gastroesophageal reflux disease and esophageal cancer.

Although more research is needed, there may be treatment implications, and primary care physicians should stay tuned as this story further unfolds. If future studies confirm and extend their findings, one concept to consider is introducing H pylori or something similar into the system to provide a protective effect.

It is well documented that H pylori bacteria are transmitted from person to person. Although it has not yet been proved, the relatively quick disappearance of H pylori from our systems is consistent with the idea that widespread antibiotic use is changing human microbiology. If that is the case, then there could be serious consequences. Additional factors related to the decline of H pylori include improvements in childhood living conditions and a smaller family size.

Many studies show that early childhood use of antibiotics is associated with an increased risk of asthma. In this study, more than 1 in 10 children under the age of 10 (1%) were found to have taken antibiotics in the previous month. That translates on an annual basis to an extremely high rate of antibiotic use in childhood.