Bloodstream infections in patients with acute graft-versus-host disease treated with fecal microbiota transplantation a strain level source analysis

High rates of bloodstream infections were observed post-fecal microbiota transplantation (FMT) for graft-versus-host-disease. Using a metagenomic bioinformatic pipeline, we identified bacterial strains in patients' stool samples before emerging in the blood. Offending strains were absent from FMT donations. We present an approach for evaluating BSI origin following microbiota-based interventions. Our results support FMT safety in immunocompromised patients but do not rule out FMT as an inducer of bacterial translocation.