Six people who were highly allergic to peanuts can tolerate the nut after receiving a faecal transplant, reports a study published on 5 August in Science Translational Medicine.

The small trial1 of 15 people is the first evidence that faecal transplants — the transfer of gut bacteria harvested from the stool samples of healthy donors — can treat a food allergy. “Up until now, it’s been in mouse models. Now we have people. And that’s exciting,” says Cathryn Nagler, an immunology researcher at the University of Chicago in Illinois.