The in vitro bacterial viability and microbial composition of commercially available canine and feline fecal microbial transplantation products

Fecal microbial transplantation (FMT) is the transfer of feces from a healthy donor into the gastrointestinal tract of a diseased recipient to confer a health benefit. FMT is increasingly utilized in veterinary medicine and is offered commercially by AnimalBiomeTM. This study aims to quantitate the colony forming units per gram (CFU/g) in lyophilized AnimalBiomeTM FMT products compared to fresh and lyophilized in-house FMT; and to evaluate microbial compositions across multiple FMT products. FMT products were cultured in aerobic and anaerobic environments. 16s rRNA amplicon sequencing (V4 region) was performed on FMT products and colonies taken from FMT cultures. Three lots each of AnimalBiomeTM DoggyBiomeTM (DB), DoggyBiomeTM from raw fed dogs (DBR), and KittyBiomeTM (KB) were evaluated. Freshly processed stool from screened donors enrolled in The Ohio State University Companion Animal Fecal Bank (CAFB) were used as controls. Freshly processed feces yielded significantly greater total CFU/g compared to all lyophilized products (dogs, P<0.01; cats, P<0.01). KB and feline CAFB lyophilized products exhibited comparable viability (P=0.14). Canine CAFB lyophilized FMT yielded significantly greater CFU/g than DB (P=0.17) and DBR (P=0.018). Each donor has a unique microbial profile (PERMANOVA; dogs, P=0.001; cats, P=0.03). DBR FMT products have a significantly greater abundance of Enterobacteriaceae compared to other canine products (P<0.01); however, no AnimalBiomeTM product showed detectable growth of Gram-negative microbes. These findings will provide evidence for practitioners when choosing FMT products for their patients. Further research is needed to determine the impact of FMT processing on engraftment and clinical outcome.