In a novel clinical study underway at Boston Children’s Hospital, fecal microbiota transplants (FMT) from healthy, non-allergic donors are allowing some severely allergic young adults to safely ingest small amounts of peanut.
With a peanut allergy, an anaphylactic reaction within seconds to minutes of peanut exposure can mean life or death. The allergy is lifelong; it requires constant vigilance to avoid even the smallest trace of peanut. Just the fear of triggering a reaction can be debilitating. Intense research is constant, with hope that not another child or adult will be lost to a preventable cause.
Rima Rachid, MD is lead investigator and co-director of the Food Allergy Program at Boston Children’s Hospital. “These results are very encouraging,” she reported to the American Academy of Allergy, Asthma & Immunology (AAAAI) at its annual meeting in February.
The fecal transplant treatment took stool samples provided by healthy, non-allergic donors, and administered them in frozen capsules to the study participants. Previously, these subjects had allergic reactions to less than half a peanut. Following the FMTs, they could consume the equivalence of two peanuts before an allergic reaction occurred. She reported that this amount may be enough to eliminate concern about traces of peanut in foods.
Some participants were pretreated with antibiotics to kill their own microbiome and improve acceptance of the donor bacteria. Sixty percent of these subjects became more tolerant of peanut exposure after fecal microbiota transplant.
“A single FMT led to a significant increase in the threshold of reactivity to peanut at 1 month and 4 months after treatment,” Rachid says in a statement. She explains that these data show that the protective effect was prolonged.
“This study is offering hope that microbiome interventions may be effective in food allergy,” she adds.
Microbiome Interventions – a New Form of Treatment?
Currently, food allergies are often treated by oral immunotherapy, giving people gradually increasing amounts of the allergen under medical supervision. Medications to suppress their immune response may be given with the allergen. This method is not curative and is not effective in adults, says Rachid.
“The long-term effect is not clear, and many patients stop therapy over time,” she says.
The oral immunotherapy requires daily administration, and there are risks of allergic reactions. Rachid adds, “Microbiome interventions are very promising alternatives for treating food allergy.”
Rachid now hopes to conduct a clinical trial in 12- to 17-year-olds, with pretreatment antibiotics and a purified microbial transplantation therapy (MTT) preparation. The preparation can be stored in a home refrigerator, avoiding the need for patients to come to the clinic to be treated. “Home administration makes microbiome interventions very attractive,” says Rachid.