Canine-derived Weissella confusa ZJUIDS-D034 and Enterococcus faecalis ZJUIDS-D016 combat aging by regulating gut microbiota

Old age raises the susceptibility of age-related disease in domestic dogs. Discovering effective anti-aging interventions is key for mitigating age-related disease and conserving "healthspan" in pet dogs. In this study, 2 bacterial strains were isolated from canine feces. After screening and identifying the strains, <i>Weissella confusa</i> ZJUIDS-D034 and <i>Enterococcus faecalis</i> ZJUIDS-D016 were chosen to intervene during <i>d-</i>galactose-induced senescence in mice. We found that administering <i>Weissella confusa</i> ZJUIDS-D034 and <i>Enterococcus faecalis</i> ZJUIDS-D016 improved the aging phenotype of mice, including an increase in antioxidant activity, a decrease in pro-inflammatory cytokines, and the restoration of intestinal and liver tissue damage. In addition, <i>Weissella confusa</i> ZJUIDS-D034 and <i>Enterococcus faecalis</i> ZJUIDS-D016 lead to changes in the structure of intestinal microbiota in aging mice. Specifically, there was a decrease in the abundance of the <i>Cyanobacteria</i> and an increase in the abundance of <i>Akkermansia</i> and <i>Lactobacillus</i>. More importantly, there was a significant increase in acetic acid, a short-chain fatty acid, due to intervention with the 2 strains. This increase might be attributed to higher <i>Akkermansia</i>. We show that the modulation of gut microbiota and metabolism in aging mice may be a promising strategy through which <i>Weissella confusa</i> ZJUIDS-D034 and <i>Enterococcus faecalis</i> ZJUIDS-D016 might exert their anti-aging effects.