Immunoregulatory Activity of Chinese Yam Polysaccharides on Cyclophosphamide-Induced Immunosuppression Mice via Regulating Gut Microbiota and Metabolic Pathway

Abstract

This study investigated the regulatory effects and underlying the mechanisms of microbial-fermented Chinese yam polysaccharides (CYPs) in a cyclophosphamide (CTX)-induced immunosuppressed mouse model. Our findings demonstrated that CYPs mitigated weight loss, elevated immune organ indices, and modulated the secretion of cytokines (TNF-α, IL-6, and IL-1β) and immunoglobulins (IgA, IgG, and IgM). Histopathological observations showed that CYPs alleviated CTX-induced morphological alterations in immune organs, as indicated by improved thymic and splenic tissue architecture. Moreover, 16 S rRNA sequencing revealed that CYPs altered gut microbiota composition and were associated with partial recovery of CTX-induced microbial dysbiosis. Integrated metabolic profiling indicated that the immunomodulatory efficacy of CYPs was partially associated with the regulation of arachidonic acid metabolism, as well as the amino acid and aminoacyl-tRNA biosynthesis. Briefly, these results suggest that CYPs potentially improve the immune-related indicators in CTX-induced immunosuppressed mice, accompanied by changes in immune organ integrity, gut microbiota composition, and host metabolic pathways.