In spite of being a technique that professionals began to practice and research decades ago, gut microbiota transplantation is an issue that is sparking considerable interest right now as a possible treatment for infections of the intestine (especially those produced by the Clostridium difficile bacteria). Professor Lawrence Brandt, of the Albert Einstein College of Medicine (USA), is one of the pioneers of this method. We interviewed him during the 2nd Gut Microbiota and Health Summit and he explained what the treatment (also called ‘faecal transplantation’) involves, when and how it is carried out and the scientific evidence available regarding this technique – an issue that generates both debate within the scientific community and interest in the media.