Research published in the March, 2003 issue of the journal, Infection and Immunity shows a connection between bacterial infection and subsequent allergies. Mice who were infected with the bacteria, Mycoplasma pneumoniae had a decreased reaction to allergens. If the mice were sensitive to the allergens prior to the infection, they had a stronger response.
Mice were injected with either the bacterium, M. pneumonia or a saline solution. Both groups of mice were then made to be allergic to ovalbumin (an egg protein). Two weeks after the injections, the mice were exposed to the allergen again. The mice that were inoculated with the bacterium had milder allergic responses than did the mice who were not infected. If, however, the mice were inoculated with the bacterium after the allergy had been established, they had stronger allergic responses than the control group.
The research shows that bacterial infection can affect allergic response. Dr. Martin, Vice Chair of the Department of Medicine at National Jewish Medical and Research Center said, “Timing is everything, however. Our results suggest that M. pneumoniae, or a related pathogen, could help prevent asthma and other allergic diseases, but only if the infection occurs before a person is sensitized to an allergen.”