Food allergies aren't just inconvenient, they can be really scary – imagine being out in a crowded restaurant and feeling your throat closing up. Allergies can even be deadly for those with severe reactions, and since they're inherently unpredictable, you never know when a previously moderate allergy can turn severe. All of that causes plenty of anxiety in people with allergies, especially parents and kids. Researchers have come a long way in developing treatments for food allergies, with oral immunotherapies and skin patches both helping desensitize kids to peanuts, protecting them if they were to ingest small amounts.Another potential way to retrain the immune system is through the gut, which houses a vast collection of bacteria and other microbes that can either help or hinder health.In a new trial, scientists gave 15 adults with peanut allergies capsules containing fecal microbiota – essentially, carefully processed communities of gut bacteria extracted from healthy donors' poop.This technique, called fecal microbiota or fecal matter transplant (FMT), is a promising therapy that aims to 'reset' the gut microbiome. In human trials, it has helped alleviate depression, inflammatory bowel disease, type 2 diabetes, and more (though it doesn't work for everyone).Research also shows that treating mice with a cultured selection of gut bacteria suppresses their food allergies. Now we have some human data suggesting that poop transplants may help in a similar way.