Immunomodulatory effects of fermented fig (Ficus carica L.) fruit extracts on cyclophosphamide-treated mice

Abstract

• Microbial second metabolites were identified existing in the extract from fig fermentation. • Extract efficiently modulate the immunity response in CTX-treated mice. • Both fig-original compounds and microbial second metabolites involved the immunoregulatory. Fermentation yields high concentrations of active compounds from vegetables and fruits, and figs are rich in compounds with immunomodulatory activity. Here, the composition and antioxidant activity of fermented fig extracts were determined, and their effects on the immune response and gut microbiota of cyclophosphamide (CTX)-treated mice were investigated. Coumaric acid, aconitic acid, methyl vanillate glucoside, and cyclic pentapeptides were identified. The antioxidant activity was not positively associated with the concentration of polyphenolics and flavonoids after 5 days. The extracts increased body weight, improved immune organ indexes, alleviated immune organ injuries, promoted the production of immune-related cytokines, improved the histopathological state of immune organs, and modulated the composition of the gut microbiota in mice. The relative abundance of Actinobacteria and Bacteroidetes was significantly increased, while that of Proteobacteria was remarkably decreased; abundance of Erysipelotrichaceae and Bacteroidaceae was closely correlated with immune traits. These findings demonstrated that fermented fig fruit could be developed as a potential immunomodulating functional food.