Probiotic fermentation of Ganoderma lucidum fruiting body extracts promoted its immunostimulatory activity in mice with dexamethasone-induced immunosuppression

Ganoderma lucidum is a legendary traditional Chinese medicine with various bioactivities. This study was conducted (a) to explore the in vitro fermentation of the water extracts of G. lucidum fruiting body with Lactobacillus acidophilus and Bifidobacterium breve and (b) to investigate the effect of fermentation broth (GLFB) on dexamethasone (DEX)-induced immunosuppressed mice. Our results demonstrated that probiotic fermentation of G. lucidum fruiting body extracts underwent structural changing of major ganoderic acid components, such as ganoderic acid A (GA) into GC2, and this fermentation process involves changing of several metabolic pathways in the probiotic strains. GLFB could significantly improve the immunity, intestinal integrity, and gut microbiota dysbiosis in DEX-treated mice, and the immunostimulatory activity of GLFB was found closely related to its direct regulation on the expansion of CD4+ T cells in Peyer's patches of mice. These data implied that probiotic fermentation of G. lucidum fruiting body extracts promoted its immunostimulatory activity via biotransformation of components such as GA. This research provides a theoretical support for the development and application of G. lucidum fermentation by probiotics.

Automated summary

This study explored the in vitro fermentation of Ganoderma lucidum fruiting body extracts with probiotics, demonstrating significant improvement in immunity, intestinal integrity, and gut microbiota dysbiosis in dexamethasone-treated mice. The immunostimulatory activity of the fermentation broth was found closely related to its direct regulation on CD4+ T cell expansion in mice's Peyer's patches. The research provides theoretical support for the development and application of G. lucidum fermentation by probiotics.