A small pilot study suggests that fecal microbiota transplants (FMT) may help reduce severe peanut allergies by changing the mix of bacteria living in the gut.
Researchers studied 10 young adults with severe peanut allergies who could experience reactions after consuming even tiny amounts of peanuts. Participants swallowed frozen capsules containing fecal material from healthy donors, including potentially beneficial gut bacteria.
After three months, three participants were able to eat multiple peanuts without experiencing an allergic reaction, according to the researchers.
In a second phase, five additional participants received antibiotics before undergoing the fecal transplant. The researchers wanted to determine whether reducing participants’ existing gut bacteria would allow the donor bacteria to establish themselves more effectively.
Three of those five participants showed improved peanut tolerance and were able to consume more than four peanuts before developing a reaction.
Blood tests also revealed changes in bile salts, substances that help the small intestine digest and absorb fats. Researchers found that beneficial bacteria introduced through the transplant appeared better able to process these bile salts than the bacteria originally present in participants with peanut allergies.
Further laboratory experiments suggested that changes in bile-salt metabolism may influence immune cells involved in protecting the body against allergic reactions.
Dr Rima Rachid of Boston Children’s Hospital, who led the study, said the research provides early evidence that microbiome-based treatments could potentially improve food allergies while offering insights into how gut bacteria, their chemical products and the immune system interact.
However, the researchers stressed that the findings are preliminary and come from a very small study. Larger clinical trials will be needed to determine whether fecal microbiota transplantation is safe and effective for treating peanut allergies and which patients could benefit most.
Scientists are also exploring whether specific beneficial bacteria identified in the research could eventually be developed into targeted probiotic treatments for food allergies.
