Integrated gut microbiota and serum metabolomic analysis to investigate the mechanism of the immune-enhancing effect of SVS formula in mice

• SVS effectively enhances both cellular and humoral immunity in normal mice. • SVS alleviates fatigue and enhance immunity in mice with exercise-induced immunosuppression. • SVS enhances immunity by regulating metabolic balance and improving gut microbial diversity. A functional food formula named SVS consists of serum-derived bovine immunoglobulin protein isolate, vitamin C, and selenium-enriched yeast. Here, we aimed to investigate the immunoregulatory effects of SVS in vivo and to elucidate its underlying mechanism. In normal mice, administration of SVS significantly enhanced delayed-type hypersensitivity responses, increased hemolysis plaque counts, and elevated serum hemolysin levels, indicating boosted cellular and humoral immunity. Furthermore, in a murine model of exercise-induced immunosuppression, SVS administration resulted in reduced serum BUN levels and increased IgG concentrations, suggesting a dual role in alleviating fatigue and enhancing immune function. Additionally, SVS balanced T cell differentiation by increasing IFN-γ levels while decreasing IL-4 levels. Gut microbiota analysis showed that SVS increased species diversity in immunosuppressed mice. Notably, an increase in the abundance of beneficial bacterial taxa was observed, specifically including Bacteroides , Akkermansia , and Lachnospiraceae_NK4A136_group . Metabolomic analysis revealed that SVS reversed immunosuppression-induced disturbances in metabolites, particularly in sphingolipid and glycerophospholipid pathways. Correlation analysis suggested that the immune-enhancing effects of SVS are linked to its regulatory impact on gut microbiota and metabolism. These findings support the potential of SVS as a therapeutic immune-enhancing health food.