Dietary supplementation with polysaccharides from Ziziphus Jujuba cv. Pozao intervenes in immune response via regulating peripheral immunity and intestinal barrier function in cyclophosphamide-induced mice

Ziziphus Jujuba cv. Pozaohas been consumed as a traditional fruit with regional characteristics in China for a long time; however, fewer studies on polysaccharides fromZiziphus Jujuba cv. Pozao(JP) have been documented. This study aimed to evaluate the effect of oral administration of JP on cyclophosphamide-induced ICR mice for 28 days. The results showed that oral administration of JP could significantly improve the lymphocyte proliferation in the spleen and decrease the proportion of CD3+ and CD4+ and the ratio of CD4+/CD8+ in cyclophosphamide-induced mice in a dose-dependent manner. JP treatment also increased the levels of IL-2, IL-4, IL-10, IFN-gamma, and TNF-alpha in serum and the intestine, and the improvement effects were proportional to the dose of JP. Similarly, JP significantly increased the levels of IgA and SIgA, as well as the expressions of Claudin-1 and Occludin in the intestine. Particularly, the expressions of Claudin-1 and Occludin were the best in the M-JP group. Furthermore, JP positively regulated the gut microbiota as indicated by the enriched microbiota diversity. At the phylum level, the relative abundance ofFirmicuteswas significantly decreased by JP, while that ofBacteroideteswas increased by JP treatment. More importantly, the ratio ofFirmicutes/Bacteroideteswas significantly increased. And a high dose of JP is the most effective. At the genus level, the abundances of theBacteroidales-S24-7-group,Lachnospiraceae,Alloprevotella,AlistipesandBacteroideswere increased by JP treatment. These results provided evidence for the regulating effect of JP on the peripheral immunity and intestinal barrier function in cyclophosphamide-induced hypoimmune mice.