New therapy could reverse food allergies: study

A new oral therapy containing six species of bacteria may be able to prevent or cure food allergies in children, according to a study. 

Previous research has shown that an altered gut microbiome, the complex ecosystem of microorganisms that live in the gut, could play an important role in the development of food allergies.

Published in Nature Medicine, researchers from Brigham and Women's Hospital and Boston Children's Hospital used computational approaches to identify a specific group of microbes in the gut that are associated with a protective effect. They found an enriched oral formulation of five or six species of bacteria protected against food allergies and reversed established disease by reinforcing tolerance of food allergens.

"This represents a sea change in our approach to therapeutics for food allergies," said Lynn Bry, co-senior author and Director of the Massachusetts Host-Microbiome Center at the Brigham.

"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 researchers compared the faecal microbiota of 56 infants who developed food allergies to 98 infants who did not, and found a number of differences. Faecal microbiota samples from infants with and without food allergies were transplanted into mice who were sensitised to eggs. Mice who received microbiota from healthy controls were more protected against egg allergy than those who received microbiota from the infants with food allergies.

They found two separate consortia of five or six species of bacteria that belong to species within the Clostridiales or the Bacteroidetes could suppress food allergies in the mouse model, while other species of bacteria did not provide the same protection.

Unlike oral immunotherapy — which aims to increase the threshold for triggering an allergic reaction by giving an individual small but increasing amounts of a food allergen to desensitise them — the bacteriotherapy changes the immune system's wiring, with potential to broadly treat food allergies.

"When you can get down to a mechanistic understanding of what microbes, microbial products and targets on the patient side are involved, not only are you doing great science, but it also opens up the opportunity for finding a better therapeutic and a better diagnostic approach to disease. With food allergies, this has given us a credible therapeutic that we can now take forward for patient care," Bry said.

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