Rates of antimicrobial resistance are increasing worldwide. There is increasing evidence that physiological gut microbiota is a large reservoir of antibiotic-resistance genes. Healthy gut microbiota is known to prevent the colonization of the gastrointestinal tract by pathogens, the so-called mechanism of colonization resistance, but this protective mechanism can be altered by therapies that impair gut microbiota, including antibiotics or chemotherapeutics, with consequent colonisation of gut pathogens, including multi-drug resistant bacteria (MDRB). MDRB carriers represent an epidemiological threat to other hospitalized patients and to the whole community, but are also at risk of developing clinical consequences of this colonization, including bloodstream infections from these pathogens. Fecal microbiota transplantation (FMT) has shown high efficacy in the eradication of recurrent C. difficile infection, and initial evidence suggests that this procedure could be useful in eradicating also MDRB, mainly carbapenem-resistant Enterobacteriaceae. However, current evidence is mostly limited to case reports and case series, and to a single randomised trial, which was stopped early and did not draw clear conclusion. In a systematic review of 21 studies and 192 patients, eradication rates ranged from 0% to 100%, and authors concluded that larger, well designed randomised controlled trials are needed to further explore this therapy. The aim of this study is to investigate the efficacy of FMT, compared with placebo FMT, in eradicating gut colonisation from MDRB, focusing on CRE. The investigators will randomize patients colonized by CRE (diagnosed by rectal swab) to FMT from healthy donors or placebo, by colonoscopy. Then, patients will be followed up, rectal swabs will be repeated, and stool samples for culture and microbiome analysis will be collected, up to 3 months after FMT.