222. Unlocking Canine Gut Health: Assessing Probiotic Modulation of Gut Microbiota Using Colonic Fermentation Model.

Abstract Introduction: Considering the importance of gastrointestinal health in overall well-being, both in humans and animals, research has focused on identifying causes of digestive distress and developing strategies to improve and maintain healthy canine intestinal conditions [1]. Probiotics use is one strategy for improving and maintaining gut health. The objective of this study was to assess the impact of a probiotic containing a mixture of Lacticaseibacillus casei, Limosilactobacillus fermentum, Levilactobacillus brevis, and Enterococcus faecium on the gut microbiota of six dogs using short-term colonic simulations. Animals, materials and methods: two groups were included, i.e., blank versus supplementation with the test product, and incubated for 48 h. The test product was a mixture of four encapsulated live probiotic bacteria, Lacticaseibacillus casei K9-1, Limosilactobacillus fermentum K9-2, Levilactobacillus brevis WF-1B, and Enterococcus faecium PCEF02 at 1 × 109 colony forming units (CFU)/g total, with 2.5 × 108 CFU/g of each strain individually, and maltodextrin. Fermentative activity, microbial metabolite production and microbial community composition were assessed. Comparisons between the test product and blank control samples were conducted using paired two-sided Students t-tests in Microsoft Excel. P-value of < 0.05 was considered statistically significant. Results and discussion: our results showed that Probiotic supplemented reactors had significantly greater fermentative activity compared with the blank, as shown by lower pH levels and higher gas pressure after 6 h, 24 h, and 48 h of incubation (p < 0.05 for all). Saccharolytic fermentation also increased, with a significantly higher level of acetate at 24 h and propionate at 6 h, 24 h, and 48 h with the test product versus blank (p < 0.05 for all). There was no significant effect of the test product on alpha diversity, but beta-diversity analysis revealed a clear separation in the microbial community composition between the test product and blank. Eight bacterial taxa were enriched with test product supplementation, including the probiotic test strains as well as Megamonas and Bacteroides species. Conclusion: this study demonstrated the potential beneficial effects on the canine microbiome following supplementation with lactic acid probiotics (L. casei, L. fermentum, L. brevis, and E. faecium) using in vitro simulations of the dog colon. Considering the current need to develop strategies to improve and maintain colonic health in pet dogs, the current data support further research to assess the potential health outcomes following supplementation with the probiotic mixture.