Gut Bacteria May Protect Against Food Allergies

New research has shown that gut bacteria can protect against food allergies in mice - a discovery that's possibly the first step towards developing probiotic therapies against this untreatable condtion.

Clostridia, a common class of gut bacteria, can minimize allergen exposure and prevent sensitization - a key step in the development of food allergies.

Food allergies affect 15 million Americans. In recent years, food allergy rates among children have risen sharply - increasing approximately 50 percent between 1997 and 2011. Previous studies indicate that modern hygienic or dietary practices may play a role by disturbing the body's natural bacterial composition.

"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," study senior author Cathryn Nagler, from the University of Chicago, said in a press release. "Our results suggest this could contribute to the increasing susceptibility to food allergies."

Nagler and her team investigated the response to food allergens in mice to determine what role gut bacteria play in the condition. They exposed germ-free and mice treated with antibiotics as newborns - which significantly reduces gut bacteria - to peanut allergens.

Both groups exhibited a strong immunological response to the peanut allergen; however, introducing Clostridia bacteria back into the mice helped alleviate this sensitization.

"We've identified a bacterial population that protects against food allergen sensitization," Nagler explained. "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."

Clostridia bacteria are common in humans and so are desirable targets for potential therapeutics that prevent or treat food allergies. Nagler and her colleagues do note, however, that their findings are preliminary and do not demonstrate a cause-and-effect relationship.

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