Nondigestible Carbohydrates Isolated from Medicinal Mushroom Sclerotia as Novel Prebiotics

Nondigestible carbohydrates (NDCs) extracted from two medicinal mushroom sclerotia, including Poria cocos (PC) and Polyporus rhinocerus (PR), were 98.4% and 100.0% carbohydrate by weight, respectively. These sclerotial NDCs were incubated separately with Bifidobacterium longum, Lactobacillus brevis, and Clostridium celatum for in vitro fermentation, with lactulose as the positive control. The sclerotial NDCs stimulated the growth of B. longum and L. brevis more preferentially than C. celatum after 24 hours of fermentation. The short-chain fatty acids (SCFAs) profile of sclerotial NDCs was dominated by acetate (98.4% of total SCFAs). The utilization of the sclerotial NDCs in terms of organic matter disappearance (OMD) by the bacteria during fermentation was consistent with the bacterial growth. The potential application of NDCs from mushroom sclerotia as novel prebiotics for gastrointestinal health was discussed.