PSIX-10 Evaluation of a probiotic with psyllium using canine and feline-specific intestinal in vitro fermentation assays.

Abstract Background: Digestive health benefits of fibers and synbiotics are dependent on host microbiome fermentation ability. In vitro fermentation can be a useful tool to predict ingredients that provide digestive health benefits, including a synbiotic. Hypothesis/Objectives: To evaluate the combination of Enterococcus faecium SF68 and psyllium husk fiber (synbiotic), using species-specific intestinal in vitro fermentation studies to determine potential digestive health benefits. Animals: Fresh fecal inoculum was collected from colony-housed healthy dogs and cats. Methods: Substrates included psyllium husk fiber (PHF) and the synbiotic. Measurements of pH and targeted bacteria via qPCR were corrected by blank and 0-h tubes to assess the incremental effect of the specific ingredient alone. Microbiome analysis via 16S Illumina sequencing was compared to the 0-h timepoint. Results: A decrease in pH following 12-h of in vitro fermentation compared to blank was observed for both PHF and the synbiotic in dogs and cats. An increase in Lactobacillus spp. was observed after 12-h of fermentation of both PHF and the synbiotic in both dogs and cats when compared to blank. An increase in Bifidobacterium spp. was observed after 12-h of fermentation with the synbiotic in both dogs and cats and for PHF in cats. Microbial diversity analysis indicated that for both dog and cat, a clear separation was noted after 12-h of fermentation of PHF and the synbiotic. Conclusions and clinical importance: In vitro fermentation results indicate that both PHF and the synbiotic are readily fermented by dog and cat fecal bacteria, resulting in changes in microbial diversity.