Every three minutes in the United States, there is a food-related allergic reaction that requires a trip to the emergency room. Right now, people with food allergies only have one recourse, and that is to avoid the food that they’re allergic to. Researchers are trying to find new treatments for food allergies that could prevent a reaction or even reverse the allergy entirely.
Now, a new study published in Nature Medicine suggests that the microbiome (microorganisms that live in the gut) might play a role in how people develop food allergies. The study, led by scientists from Brigham and Women’s Hospital and Boston Children’s Hospital, has identified a species of bacteria present in the gut of infants that protects against food allergies. The research team did preclinical studies in a mouse model of food allergies, and they found that giving five or six species of bacteria protected against food allergies and even reversed an established food allergy.
Senior co-author and director of the Massachusetts Host-Microbiome Center at the Brigham, Dr. Lynn Bry, says: “This represents a sea change in our approach to therapeutics for food allergies. We've identified the microbes that are associated with protection and ones that are associated with food allergies in patients. If we administer defined consortia representing the protective microbes as a therapeutic, not only can we prevent food allergies from happening, but we can reverse existing food allergies in preclinical models. With these microbes, we are resetting the immune system."
The scientists studied 56 infants who developed food allergies and collected fecal samples every four to six months. They also studied 98 infants without food allergies and found a lot of differences from those infants with food allergies. Then, they transplanted the fecal microbiota samples from both sets of infants into mice who had been sensitized to eggs. The mice who got microbiota from infants without allergies were more protected against an egg allergy than mice who got microbiota from infants with allergies.
Co-first author Georg Gerber, MD, PhD, MPH, co-director of the Massachusetts Host-Microbiome Center and chief of the Division of Computational Pathology in the Department of Pathology at the Brigham, commented: “It's very complicated to look at all of the microbes in the gut and make sense of what they may be doing in food allergy, but by using computational approaches, we were able to narrow in on a specific group of microbes that are associated with a protective effect. Being able to drill down from hundreds of microbial species to just five or six or so has implications for therapeutics and, from a basic science perspective, means that we can start to figure out how these specific bacteria are conferring protection."