Food allergies occur when the body’s immune system overreacts to certain foods, but the underlying cause may be linked to a protein called RELMb, which affects the balance of gut microbes. A groundbreaking study from Boston Children’s Hospital, published in Nature, explores how excess RELMb triggers food allergies by disrupting the intestinal microbiome. This discovery could offer hope for preventing or even curing food allergies.

Dr. Talal Chatila, who co-led the study, along with Dr. Seth Rakoff-Nahoum, found that elevated levels of RELMb in children with food allergies deplete beneficial gut bacteria that produce indoles—compounds that help generate protective T regulatory cells. These cells are responsible for recognizing food allergens as harmless. When RELMb levels are too high, it leads to an imbalance in gut bacteria and a weakened immune response to food antigens.

In mouse models, inhibiting RELMb restored immune tolerance to food allergens and prevented the development of food allergies and anaphylaxis. Conversely, introducing RELMb into mice not prone to allergies triggered allergic reactions. This suggests that targeting RELMb or its receptor could potentially provide a lasting solution, rather than merely treating allergy symptoms.

Current food allergy therapies don’t offer permanent relief, but this new research holds promise for developing treatments that can permanently reduce allergic reactions. The team plans further studies to confirm RELMb as a biomarker and explore inhibitors in clinical trials.