Impact of Enterococcus faecium Kimate-X on Reducing Stress in Dogs Through Gut Microbiota Modulation

Stress in dog breeding leads to significant physiological and psychological burdens, including anxiety, reduced appetite, weakened immune function, gut microbiota imbalance, and even death. Currently, there are various pharmacological interventions for stress management, but few focus on gut health. This study evaluates the potential of a novel strain, <i>Enterococcus faecium</i> Kimate-X, in alleviating transport stress and improving gut health in dogs, providing an alternative to traditional pharmacological treatments. In vitro experiments showed that Kimate-X significantly enhanced the activities of superoxide dismutase (SOD) and catalase (CAT) while reducing the levels of malondialdehyde (MDA) and tumor necrosis factor-α (TNF-α) in RAW 264.7 macrophage cells. In vivo, dogs supplemented with Kimate-X exhibited significantly lower cortisol levels after transport, indicating reduced stress. Metagenomic analysis revealed increased gut microbiota diversity and higher concentrations of short-chain fatty acids (acetate, propionate, and butyrate) in fecal samples. This study systematically uncovers the mechanism by which <i>Enterococcus faecium</i> Kimate-X alleviates transport stress through modulation of the gut microbiota. These findings provide new scientific evidence supporting the use of probiotics as a novel approach to stress management in animals.