Polysaccharide from natural Ophiocordyceps sinensis alleviated dextran sulfate sodium-induced colitis through modulating sIgA formation and gut microbiota

From the paper

Abstract

Polysaccharide from natural Ophiocordyceps sinensis (NCSP-50) significantly modulated the gut microbiota composition and elevated the levels of sIgA in dextran sodium sulfate (DSS)-induced colitis mice. However, the in-depth mechanism remains unknown. Therefore, this study aimed to investigate how NCSP-50 influenced sIgA formation and the role of gut microbiota in colitis mice. Results showed that administration of NCSP-50 dramatically improved the expressions of IgA, pIgR and AID, the key factors of sIgA formation in colitis mice. NCSP-50 significantly decreased the quantity of dendritic cells and mRNA expression of tlr-2, tlr-4 and tlr-6, april and raldh-1, while improved the expression of vapc2, raldh-2 and iNOS, indicating the involvement in T-cell independent pathway. NCSP-50 reduced the amount of CD4⁺ T cells, and adjusted the expression of nuclear transcription factors of T cells subsets and the release of IL-13, indicating the involvement in T-cell dependent pathway. In addition, fecal microbiota transplantation revealed that gut microbiota from mice administrated with NCSP-50 obviously alleviated colitis-related symptoms and increased the concentration of sIgA, whereas antibiotic cocktails treatments abolished those effects. In conclusion, NCSP-50 attenuated DSS-induced colitis through intestinal microbiota and promoting the T-cell dependent and independent sIgA secretion influenced by gut microbiota.