FMT Shows Promise for Peanut Allergy Tolerance in Phase I Trial

A study conducted at Boston Children’s Hospital has shown promising results for using fecal microbiome transplantation (FMT) as a potential treatment for peanut allergy tolerance. The Phase I open-label trial, published in Science Translational Medicine, enrolled 15 adults who had a low tolerance to peanut protein. Ten participants received a one-time dose of FMT capsules, while three of them exhibited increased peanut reactivity threshold after treatment.

Another five participants received antibiotics before FMT, and three of them also showed increased tolerance without any safety issues.

The study revealed that the response to FMT was associated with an increase in tolerogenic regulatory T cells and a decrease in type 2 helper T cells, which are crucial for restoring oral tolerance. Moreover, the researchers found that post-FMT microbiomes from responding participants were able to protect allergy-prone mice from food allergy, while those given microbiomes from nonresponders did not show protection.

This protective effect was linked to an increase in Bacteroides genus colonization and higher bile acid metabolite levels in both humans and mice.

The study's lead author, Talal Chatila, MD, suggests that the right bacteria may help restore oral tolerance by influencing immune cells that enforce tolerance. Chatila also notes that understanding how bacteria restore tolerance to food in allergic individuals could lead to optimized therapies for more effective outcomes. However, the authors acknowledge that the trial was small, open-label, and limited to adults, and they urge for larger studies to confirm these findings and identify the most beneficial patients and bacteria for future targeted probiotic therapies.