Effects of Oligosaccharide Fermentation on Canine Gut Microbiota and Fermentation Metabolites in an In Vitro Fecal Fermentation Model

Owing to the well-established application of prebiotics in human food products, there is a growing interest in their potential as dietary supplements for gut microbiota composition and improvement of the digestive health of dogs. However, targeted studies with dogs as research subjects are still limited. In the present study, an in vitro simulated gut microbiota fermentation system using canine feces from a healthy Border Collie breed was used to investigate the prebiotic effects of five different oligosaccharides and compare their regulatory effects on the gut microbiota structure and the resultant metabolites. Due to the addition of oligosaccharides, the fermented samples had lower pH and higher bacterial proliferation. The oligosaccharide-fermentation selectively boosted <i>Lactobacillus</i> spp., <i>Streptococcus</i> spp., <i>Enterococcus</i> spp., <i>Bacteroides</i> spp., and hindered <i>Escherichia</i>-<i>Shigella</i> spp., <i>Paeniclostridium</i>, spp., and <i>Bacteroides</i> spp. Each oligosaccharide showed distinct characteristics and preferences for regulating gut microbiota structure and abundance. Furthermore, the addition of oligosaccharides increased the production of short-chain fatty acids, particularly butyric acid. This study provides a preliminary basis for the rapid and rational selection of prebiotic oligosaccharides as canine dietary supplements and further explores the function of oligosaccharides and their combinations in canine health.