Faecal microbiota transplantation to decolonize vancomycin-resistant Enterococcus: A pilot study to evaluate safety and clinical outcome.

Objectives: Faecal microbiota transplantation (FMT) has shown promise as a treatment for recurrent or refractory Clostridioides difficile infections. This study aimed to evaluate the decolonization effects of FMT on vancomycin-resistant Enterococcus (VRE).

Methods: This feasibility trial prospectively recruited patients with more than three recurrent VRE infections. FMT was performed by infusing faecal microbiota solutions from healthy, unrelated donors into the participants' guts via colonoscopy. Faecal microbiota profiles before and after FMT were analysed.

Results: Three of the six patients (50%) experienced VRE decolonization after FMT, lasting over 6 months. Baseline analysis revealed that patients who achieved decolonization had greater microbial diversity compared to those with persistent VRE colonization. Throughout the study, there were no adverse events observed in the patients after FMT. Elevated alpha diversity persisted in responders, while non-responders showed no significant changes. In responders, the abundance of genera within the phylum Firmicutes (Bacillota), including Anaerostipes, Blautia, Faecalibacterium, and Ruminococcus, and the genus Collinsella within the phylum Actinobacteriota increased steadily through 180 days post-FMT.

Conclusions: FMT may leverage bacterial strain competition to facilitate decolonization of drug-resistant organisms, with successful VRE decolonization potentially linked to increased abundance of phyla Firmicutes and Actinobacteriota over 6 months.