Anti-Obesity Potential of Barley Sprouts in Dog Diets and Their Impact on the Gut Microbiota

Barley sprouts, the germinated and grown leaves of barley, contain various bioactive compounds, including policosanol, saponarin, and lutonarin. The ingestion of barley sprouts may benefit canine weight management, potentially owing to the anti-obesity properties of bioactive compounds. However, there is limited evidence on the efficacy and safety of barley sprout supplementation in dogs. Therefore, through this study, we assessed the impact of barley-sprout-supplemented diet on body weight and health markers in healthy adult beagles over a 16-week period. The results showed a 7.2% reduction in body weight in dogs fed the barley sprout diet. Hematology, complete blood cell count, and blood biochemistry analyses confirmed that all parameters remained within normal ranges, with no significant differences observed between the control and experimental groups. Although the levels of IFN-γ, IL-6, and insulin remained stable, leptin, a hormone associated with body fat, significantly decreased. Further analysis of alterations in the gut microbiota following barley sprout supplementation revealed no significant differences between the control and experimental groups with respect to alpha and beta diversity analysis. The shift at the phylum level, with a decrease in Firmicutes and an increase in Bacteroidetes, resulted in a reduced Firmicutes/Bacteroidetes ratio. Additionally, the abundance of the Ruminococcus gnavus group was high in the experimental group. Functional predictions indicated an enhancement in carbohydrate, amino acid, and cofactor and vitamin metabolism. These findings suggest that a barley sprouts diet is safe for dogs and may offer benefits for weight management through favorable alterations in body weight, hormone levels, and gut microbiota composition.