Hesperidin mitigates stress in poodles via modulation of tryptophan metabolism and gut microbiota
Hesperidin (HES) is a bioflavonoid with numerous pharmacological activities, which have been rarely investigated in pet dogs and cats. This study aimed to evaluate the efficacy of HES in relieving anxiety and depressive symptoms in poodles experiencing stress. Thirty poodles experiencing chronic stress were divided into three groups, including the negative control group (CON), the fluoxetine group (FLU, 1 mg/kg), and the hesperidin groups (HES, 50 mg/kg). The study lasted for 60 days. Hair cortisol increased in all groups by the end of the study compared to baseline, indicating that the poodles were stressed during the study period. The addition of HES significantly reduced salivary cortisol levels in poodles compared to the CON group on day 60. Dietary supplementation with HES and FLU reduced canine depression-like behavior. Serum glutathione peroxidase, interleukin-10, and brain-derived neurotrophic factor significantly increased over time from day 0 to day 60 in the HES group of Poodles, suggesting that HES has antioxidant properties. Addition of HES significantly increased serum tryptophan (Trp), indoleacrylic acid, and indolepropionic acid compared to the CON group. Poodles in the HES group had significantly higher levels of Odoribacter, Lactobacillus and Clostridium, and significantly lower levels of Bilophila and Phyromonas compared to the CON group. In addition, no deleterious effects of HES on serum biochemical indices were detected, which supports the safety of its addition to dog diets. These results suggest that dietary addition of HES may alleviate stress in poodles, possibly by modulating the gut microbiota and tryptophan metabolism.