Food Allergies May Have Everything To Do With Gut Bacteria, Study Finds

According to the Food Allergy Research & Education organization, 32 million Americans now suffer from some kind of food allergy. That includes one in 13 children under the age of 18, and the prevalence of kids diagnosed has increased by over 50% in the last two decades alone. There are a handful of theories on what's to blame for this steady rise: Overly sterilized home environments, antibiotics, and pollution being some of the most widely accepted.

First, the team at Boston Children's Hospital collected stool samples from 56 young patients who suffered from food allergies and 98 who didn't. They found that the stool from the food allergy sufferers did indeed have some different bacteria than the control stool. 

From there, they extracted fecal bacteria from both groups and transplanted it to mice who suffered from egg allergies. That's where things got interesting: The team found that the mice who were given the bacteria from the control stool didn't have an allergic reaction when subsequently fed small doses of chicken egg protein. 

"If you give them the right bacteria, they're completely resistant to food allergy," Talal Chatila, M.D., director of the Food Allergy Program at Boston Children's and a senior author on the paper, wrote.

Chatila and the other researchers then worked with Brigham and Women's Hospital to isolate the specific bacteria that was protecting the mice, and they identified Clostridiales and Bacteroidales as two particularly beneficial types. It seems that these "good" bacteria prepare a child's immune system to accept certain foods by triggering a train reaction in regulatory T-cells in the gut. 

Though this initial study used stool from children, its authors are hopeful that its findings will be applicable to adults who suffer from allergies too. "Remember, in adult mice that had become food-allergic, we could suppress their disease by introducing the good bacteria, which means to us there is the potential to treat somebody with established food allergy and reset their immune system in favor of tolerance," Chatila says.