Gut Bacteria Could Protect You Against Food Allergies in the Future

Could there be a way to protect individuals against food allergies? Scientists have found that the presence of Clostridia, a common class of gut bacteria, protects against allergies in mice. The findings could open the way to preventing food allergies in humans.

The causes of food allergy are unknown, though it's possible that modern hygienic or dietary practices may play a role. What is known, though, is that food allergy rates are increasing; in fact, among children it's risen by about 50 percent between 1997 and 2011.

That's why scientists decided to take a closer look. The researchers investigated the response to food allergens in mice. They exposed germ-free mice and mice treated with antibiotics as newborns to peanut allergens. Both groups of mice had a strong immunocological response.

"Environmental stimuli such as antibiotic overuse, high fat diets, caesarean birth, removal of common pathogens and even formula feeding have affected the microbiota with which we've co-evolved," said Cathryn Nagler, one of the researchers, in a news release. "Our results suggest this could contribute to an increasing susceptibility to food allergies."

What was interesting, though, was the fact that the sensitization to food allergens could be reversed. When the researchers reintroduced a mix of Clostridia bacteria into the mix, they showed less sensitization. Yet another major group of intestinal bacteria, Bacteroides, failed to do the same.

"We've identified a bacterial population that protects against food allergen sensitization," said Nagler. "The first step in getting sensitized to a food allergen is for it to get into your blood and be presented to your immune system. The presence of these bacteria regulates that process."

The findings reveal a potential way to help deal with food allergies in the future. The identification of a bacteria-induced barrier-protective response represents a new potential method for preventing sensitization to food.

"It's exciting because we know what the bacteria are; we have a way to intervene," said Nagler. "There are of course no guarantees, but this is absolutely testable as a therapeutic against a disease for which there's nothing."

The findings are published in the journal Proceedings of the National Academy of Sciences.