Immuno- and gut microbiota-modulatory activities of β-1,6-glucans from Lentinus edodes

The β-1,6-glucans from Lentinus edodes have a variety of biological activities. However, the research on extraction and separation of β-1,6-glucans from L. edodes is limited and the yield is low. In the present study, we obtained the high-yield and -purity β-1,6-glucans (ALEPA) from L. edodes by using a sequential extraction and separation process, which is simple and suitable for industrialization. ALEPA significantly promoted the proliferation of splenic T lymphocytes and enhanced the phagocytosis activity of peritoneal macrophages in vivo. 16S rRNA sequencing results showed that ALEPA significantly increased the α diversity of gut microbiota and upregulated the relative abundances of short chain fatty acids (SCFAs)-producing bacterial species. Consistently, the SCFAs in the cecum of mice were upregulated. On a mechanical level, we found that the immunomodulatory effect of ALEPA depended on gut microbiota. Collectively, ALEPA is a promising functional food ingredient that regulates gut microbiota and enhances immune function. [Display omitted] •A high-yield and -purity β-1,6-glucan fraction (ALEPA) was obtained from L. edodes.•Sequential water, alkali extraction and AEC were established to extract ALEPA.•ALEPA significantly promoted the immune functions of mice.•ALEPA increased the relative abundances of SCFAs-producing bacterial species.•The immunomodulatory effects of ALEPA depended on the gut microbiota.