Effects of Glucose Oxidase and Macleaya cordata Extract on Immune Function, Antioxidant Capacity, and Gut Microbiota in British Shorthair Cats.

OBJECTIVES: The objective of the present study was to investigate the effects of Glucose oxidase (GOx) and Macleaya cordata extract (MCE) on immune response, antioxidant capacity, gut microbiota, and metabolome in cats. METHODS: Twenty-four cats were randomly divided into four groups: basal diet (CON group), basal diet + 0.03% GOx (GOD group), basal diet + 0.03% MCE (MCE group), and basal diet + 0.03% GOx and 0.03% MCE (GM group). RESULTS: Compared to the CON group, the GOD group exhibited elevated levels of total antioxidant capacity (T-AOC) and secretory immunoglobulin A (sIgA), and decreased levels of interleukin-6 (IL-6) and immunoglobulin A (IgA) (p < 0.05). MCE increased concentrations of IgA, immunoglobulin G (IgG) and sIgA, alongside a reduction in interleukin-2 (IL-2). The GM group exhibited markedly elevated concentrations of IL-2 and IgG, and decreased levels of interleukin-10 (IL-10). Moreover, 16S rRNA sequencing showed differences in the fecal microbiota among the four dietary groups. Analyses of fecal and serum metabolomics demonstrated that differential metabolites were primarily associated with cat amino acid metabolism and fatty acid metabolism. CONCLUSIONS: These findings suggest that Gox and MCE may enhance immune function, mitigate oxidative stress in cats, and increase the relative abundance of beneficial gut microbiota. Moreover, our results may provide evidence for GOx and MCE as novel nutritional additives in pet food. It should be noted that this study is limited by its sample size; while the results provide promising insights, future studies with larger-scale studies are warranted to confirm these observations.