Background: Fecal microbiota transplantation (FMT) is used to address gut dysbiosis-related diseases in companion animals. Lyophilization and powdering of fecal material offer a convenient alternative to fresh transfers, but the mechanisms of action remain poorly understood. This study aimed to identify viable bacterial species in lyophilized FMT powder obtained from cats and dogs contributing to a stool bank.
Objectives: To determine the diversity and viability of bacterial species in lyophilized fecal material from domestic cats and dogs. Animals: Lyophilized fecal samples were collected non-invasively from five healthy cats and five healthy dogs enrolled in a stool bank in Northern California.
Methods: Fecal samples were mixed with glycerol before freeze-drying and powdering. We employed culturomics techniques, including direct inoculation in various culture media and pre-incubation in blood culture bottles, to isolate anaerobic, aerobic, fastidious, and slow-growing bacteria. Identification was performed using MALDI-TOF mass spectrometry, 16S rRNA gene sequencing, and whole genome sequencing of unique isolates.
Results: In cats, 72 bacterial species were isolated, including 32 from the core microbiome, 17 novel species, and seven novel genera. In dogs, more than 70 species were identified, including short-chain fatty acid (SCFA) producers, inflammation reducers, and known probiotics for companion animals.
Conclusions: Lyophilized stool retains a diverse assemblage of viable bacteria, particularly spore formers capable of surviving freeze-drying. These findings support the potential of lyophilized FMT as a viable therapeutic option for gut microbiome restoration.
.jpg "Holly H. Ganz, PhD (she/her/hers) photo")
