Note: Single-source report; awaiting corroboration.
Millions of Americans suffer from food allergies, including potentially life-threatening reactions. Recent research suggests that microbes in the digestive system may influence these allergies, raising the possibility that altering the gut microbiome could provide therapeutic benefit.
An NIH-funded clinical trial led by researchers at Boston Children's Hospital evaluated the safety and efficacy of fecal microbiota transplantation in 15 peanut-allergic individuals. Participants ingested oral capsules containing gut microbes from non-allergic donors. Five participants received antibiotics before treatment to reduce their native gut microbes and potentially enhance colonization by transplanted microbes.
The treatment caused no serious adverse effects. Among those who did not receive antibiotics, 3 out of 10 showed increased tolerance for peanut consumption without allergic reactions four months after treatment. Similarly, 3 of the 5 participants who received antibiotics achieved increased tolerance.
Immunological analysis showed that successful transplants correlated with more regulatory T cells producing the protein RORγt for up to a year. Another type of T cell decreased initially post-transplant but returned to prior levels within a month.
Further experiments involved transferring microbiomes from human participants into germ-free mice. Microbes from responders protected mice against food allergies and induced similar immune profiles. Notably, these mice had higher levels of Bacteroides bacteria, which appeared to contribute to protection by enhancing regulatory T cells expressing RORγt.