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.