The in vitro bacterial viability and microbial composition of commercially available  canine and feline fecal microbial transplantation products
Only viable and functional microbial populations have the capacity to colonize and integrate into the gut microbiome, which is essential for restoring eubiosis and function for FMT recipients. In human medicine, the technique used to process and store FMT products impacts microbial viability and lyophilized FMT products are proven to be biologically active and a practical alternative to freshly prepared FMT. However, there is currently no evidence quantitating the viability of microbes in lyophilized veterinary FMT products. Given the importance of microbial viability in the proposed mechanism of action of FMT products, this study first aimed to compare and quantify the viability of microbes in commercially available AnimalBiome lyophilized FMT products with those from our in-house companion animal fecal bank (CAFB) lyophilized FMT products. Additionally, we compared these lyophilized FMT products to freshly processed FMT to assess the impact of lyophilization on microbial viability and composition in canine and feline feces. Our secondary aim was to compare the overall microbial community structure between raw-fed and standard-fed canine fecal donors using 16S rRNA amplicon sequencing