Researchers at Boston Children's Hospital found that fecal transplant pills increased peanut tolerance in young adults with severe food allergies months after a single treatment. Up to 6 million people experience allergic reactions to peanuts, making it one of the most common food allergies.
The study, published last week in Science Translational Medicine, showed that subjects with peanut allergies gained greater tolerance several months after receiving fecal transplants from healthy donors without allergies. Fecal pills, also known as crapsules, are already used to reduce toxic side effects from certain cancer drugs and have been tested to improve survival chances in pancreatic cancer.
Prior research by the team showed that transferring stool samples from infants with food allergies to allergy-prone mice triggered severe allergic reactions in the animals. Stool samples taken from healthy infants protected mice from allergic responses instead.
Donor bacteria and dosage
For the new study, researchers collected strains of beneficial gut bacteria from healthy infants and placed them into frozen fecal pills. Researchers administered 36 pills within a few hours as a one-time treatment to 10 young adults with severe peanut allergies.
Four months after treatment, three participants could eat many peanuts before developing an allergic reaction. In a second round of the study, researchers added antibiotics to the fecal transplant pills, which showed that antibiotics may boost the effectiveness of the microbiome transfer.
Bile salts and immune response
The treatment reduced food allergies by increasing bile salts produced by the liver, which break down fats for body absorption. Beneficial gut bacteria metabolized bile salts more effectively, raising the number of immune cells that protect against allergic reactions.
Talal Shatila, director of translational immunology at Boston Children's Hospital and a lead author of the study, stated in a press release that food allergy reflects a failure of oral tolerance, which is the process where the gut immune system learns to accept food. He explained that proper bacteria help restore this process by using bile acid metabolites to strengthen immune cells that enforce tolerance.
According to a report by the New York Post, researchers are developing a modified version of the pills that uses clean, concentrated microorganisms stored in refrigerators for easier access. Larger studies are still required to confirm the findings, determine which patients benefit most, and identify additional bacteria for probiotic food allergy treatments.
