Modulating effects of Hericium erinaceus polysaccharides on the immune response by regulating gut microbiota in cyclophosphamide‐treated mice

Abstract BACKGROUND The gut microbiota (GM) is recognized as a significant contributor to the immune system. In the present study, the effects of Hericium erinaceus polysaccharides (HEP) on immunoregulation and GM in cyclophosphamide (CTX)‐treated mice were investigated to elucidate the attenuate of immunosuppression by modulating GM. RESULTS The results revealed that HEP significantly improved the body weight and immune organ index in immunodeficient mice ( P < 0.05). They significantly increased operational taxonomic units (OTUs) ( P < 0.05), adjusted the α and β diversity of the GM, and the bacterial community structure was more similar to that of control group. Taxonomic composition analysis found that HEP increased the abundance of Alistipse , uncultured_bacterium_f_Muribaculaceae , Lachnospiraceae_NK4A136_group , uncultured_bacterium_f_Lachnospiracea , uncultured_bacterium_f_Ruminococcaceae and Ruminococcaceae_UCG‐014, and decreased Lactobacillus , Bacteroides, and Alloprevotella , suggesting that HEP can improve the GM structure and inhibit CTX‐induced GM dysregulation. Moreover, HEP increased short‐chain fatty acid (SCFA)‐producing bacteria, recovered SCFA levels, alleviated immunosuppression caused by CTX, enhanced the serum immune cytokine factors, and upregulated TLR4/NF‐κB pathway key proteins (TLR4, NF‐κB p65) at mRNA and protein levels. CONCLUSION Hericium erinaceus polysaccharides effectively regulated GM and enhancement of intestinal immune function, so they have the potential to be developed as functional ingredients or foods to modulate immune responses. © 2022 Society of Chemical Industry.