Dendrobium officinale leaf polysaccharides regulation of immune response and gut microbiota composition in cyclophosphamide-treated mice

In this study, the polysaccharides extracted from Dendrobium officinale leaf (DOLP) was used in immune deficiency mice to evaluate the bioactivity. Thymus and spleen indices were calculated while the alleviation of the colon and liver histopathological progression was evaluated by H&E staining. The data indicated that DOLP improved immunity status by restoring the gut barrier and atrophy of immune organs. Cytokines levels as marker of inflammation were determined using ELISA in serum and colon. Which proved that DOLP inhibited the expression of pro-inflammatory cytokines (TNF-α, TGF- β1, IL-6, IL-1β) and promoted the expression of anti-inflammatory cytokines (IL-10). Short chain fatty acids (SCFAs) levels and microbial composition in feces were determined using GS and high-throughput sequencing. DOLP improved gut microbiota by increasing the relative abundance of total bacteria and probiotics such as Bacteroides, Lactobacillus and Lachnospiraceae. Therefore, DOLP has potential effect for the treatment of chronic immune diseases.