FMT Reduces Sensitivity to Peanuts Even in the Highly Allergic

A quick note this week to tell you about a very exciting clinical study that was just reported this weekend, out of Boston Children’s Hospital.  The trial was a phase one, and thus small – only 15 participants, aged 18-33, who have severe peanut allergy: that is, they had to demonstrate allergic reactions to 100 milligrams of peanut, which is about a half a peanut, or less.[i] The study was to determine the safety and potential efficacy of using fecal microbiota transplant (FMT) to alleviate the severe allergy symptoms. The FMT was delivered in a non-invasive form using pills provided by OpenBiome (a Boston-based nonprofit which provides approved donations for FMT around the country), from rigorously screened donors who were peanut-allergy free.

The subjects received FMT, swallowing 36 capsules over the course of three hours. In one arm of the study, 10 participants received a single dose of FMT alone. Believe it or not, 3 of the 10 were able to tolerate larger amounts of peanut — one as much as four peanuts — when challenged both one and four months after FMT!  That is amazing! The second arm of the study involved the other 5 subjects.  They were first given antibiotics to wipe out much of their existing gut bacteria, and then given the FMT.  In this case, 3 of the 5 became more peanut-tolerant.

It gets even more interesting, because the researchers also tested the participants’ immune systems before and after the FMT.  Those patients who responded to FMT had increases in the regulatory T cells associated with immune tolerance, and reductions in the T helper cells associated with allergy. The scientists took samples of their microbiomes, and transplanted these into a strain of allergy-prone mice.  The mice showed similar immune changes and were protected from anaphylaxis when challenged with food allergens.  However, when the non-responders’ microbiomes were transplanted, the allergic mice were not protected.  This, of course, provided proof that the protection from severe allergy is microbiome-related.

By the way, prior to this study, these researchers had already done proof-of-concept studies in mice.  In 2019, they published a study in which the microbiota of infants with allergy were transplanted into mice. Sure enough, the mice would suffer anaphylaxis when given allergic foods; control mice, given FMT from non-allergic babies, did not.

While improving tolerance from half a peanut or less to eating more than 2 peanuts before reacting may not sound like a dramatic improvement, in actuality, it may be life saving. That amount may be enough to eliminate concern about traces of peanuts in foods, which presently, can hospitalize or kill those with severe enough allergy.  The researchers are planning a phase II trial in children 12-17 years old. Those children will be given the antibiotics first – because that does appear to improve efficacy – and then a purified FMT preparation.

The more these kinds of studies appear with positive results, the more hopeful I become that at some point in the not-very-distant future, these kinds of non-invasive FMT products will become available for a wide variety of biome related illnesses.

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[i]  https://www.eurekalert.org/news-releases/944014