A Refined Method for Fecal Microbiota Transplantation Using Nutella

Fecal microbiota transplantation (FMT) in mice is an evolving research field, often employing oral gavage, which can be stressful and harmful for the animals and time-consuming for technicians. Voluntary intake methods, such as delivery in Nutella, have successfully been used for drug administration in mice and may likewise be a promising tool to refine traditional FMT techniques. Nutella-based FMT may improve animal welfare, reduce workload, and enhance animal safety without compromising microbiota engraftment rates. This study compared microbiota engraftment after mouse-to-mouse FMT in antibiotic-treated BALB/c mice using three methods: oral gavage, pipette delivery, and voluntary intake of a Nutella-inoculum mixture. Feces collected before and after FMT were analyzed using GridION Nanopore 16S rRNA gene amplicon sequencing. Nutella-based FMT showed similar engraftment rates as traditional methods i.e., oral gavage and pipette delivery. Oral gavage delivery resulted in greater variability and divergence from the donor composition compared to pipette delivery. Notably, the oral gavage group had the highest number of genera differing from the donor. Single-dose FMT restored microbial diversity in one study, while it was less effective in another, suggesting to add a second dose of FMT. Nutella-based FMT appears to be an efficient, reproducible, and less stressful alternative to forced-feeding methods, warranting further exploration.