The investigators propose to use autologous fecal microbiota transplantation (AFMT) to acute myeloid leukemia (AML) patients treated with intensive chemotherapy and antibiotics in order to restore the balance of their intestinal microbiome and thereby eradicate treatment-induced multidrug resistant bacteria (MDRB), infection-related complications, as well as sequelae to the gastrointestinal tract. Therefore, the investigators propose to perform a single-arm multicentre prospective fecal microbiota transplantation (FMT) trial in AML patients receiving intensive chemotherapy, and who are usually heavily treated with broad-spectrum antibiotics during aplasia that generate a profound status of dysbiosis. For this purpose, at the time of admission and AML diagnosis, patients will be requested to donate stools that will be comprehensively screened, and if deemed appropriate according to protocol criteria, conditioned and stored frozen until future processing and transplantation after aplasia completion.