Structure characterization of soluble dietary fiber fractions from mushroom Lentinula edodes (Berk.) Pegler and the effects on fermentation and human gut microbiota in vitro

Aimed to evaluate the changes of three soluble dietary fibers from Lentinula edodes by-products (LESDF) with different molecular weights in the digestive system and their effects on large intestinal fermentation, fermentation products and the types of gut microbiota were determined. The 1D/2D NMR results showed that main form of glucose in LESDF-1 was methyl glycopyranosides and LESDF-3 had distinct branching structures in possible repetitive unit. LESDF-2 showed the beneficial fermentation performance with the slower changes of total carbohydrate consumption and highest production of propionic acid and butyric acid. Results suggested that branched chain structure could increase the consumption rate of LESDF, but not affect the concentration of total SCFAs produced. LESDF-3 was found to promote the production of Bacteroides, which indicated LESDF was one of the nutritional components with the influence on the composition and relative abundance of intestinal microbial community.