Incidence of antimicrobial-resistant infections has increased dramatically worldwide in the past few decades. To combat this alarming problem, strategies preventing colonization with resistant pathogens have been proposed. Fecal microbiota transplantation(FMT)may help in decolonizing multidrug-resistant organisms(MRO) and in preventing recurrent infections. In this study, efficacy of FMT against multidrug resistance was assessed. Three patients that suffered from multidrug resistance complicated with diarrhea were enrolled from January 2019 to September 2020. All had severe pulmonary infections. Standard FMT was given, and whole metagenome sequencing of stool was conducted before and after FMT.All patients accepted FMT, and 12 samples were harvested. All treatments were successful, and there were no adverse events. All patients showed a decrease in species of intestinal flora, but FMT could recover some of the diversity. Normal people had the lowest abundance of antimicrobial-resistant genes (ARGs), but the patients had the highest abundance before FMT. FMT decreased ARGs to some extent. Nineteen ARG subtypes were significantly different between the normal group and the patients.Patients with MRO infections had increased abundance of ARGs and low bacterial diversity. FMT eradicated ARGs and restored microbial diversity, and there were no serious adverse events.