AUTHOR=Tian Baoming , Geng Yan , Xu Tianrui , Zou Xianguo , Mao Rongliang , Pi Xionge , Wu Weicheng , Huang Liangshui , Yang Kai , Zeng Xiaoxiong , Sun Peilong 

TITLE=Digestive Characteristics of Hericium erinaceus Polysaccharides and Their Positive Effects on Fecal Microbiota of Male and Female Volunteers During in vitro Fermentation

JOURNAL=Frontiers in Nutrition

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2022.858585

DOI=10.3389/fnut.2022.858585

ISSN=2296-861X

ABSTRACT=<p><italic>Hericium erinaceus</italic> polysaccharides (HEPs) have attracted widespread attention in regulating gut microbiota (GM). To investigate digestibility and fermentation of HEPs and their effects on GM composition, three polysaccharide fractions, namely, HEP-30, HEP-50, and HEP-70, were fractionally precipitated with 30%, 50%, and 70% ethanol concentrations (v/v) from hot water-soluble extracts of <italic>Hericium erinaceus</italic>, respectively. Three kinds of prepared HEPs were structurally characterized and simulated gastrointestinal digestion, and their effects on human fecal microbiota fermentations of male and female and short-chain fatty acid (SCFA) production <italic>in vitro</italic> were clarified. Under digestive conditions simulating saliva, stomach, and small intestine, HEPs were not significantly influenced and safely reached the distal intestine. After 24 h of <italic>in vitro</italic> fermentation, the content of SCFAs was significantly enhanced (<italic>p</italic> &lt; 0.05), and the retention rates of total and reducing sugars and pH value were significantly decreased (<italic>p</italic> &lt; 0.05). Thus, HEPs could be utilized by GM, especially HEP-50, and enhanced the relative abundance of SCFA-producing bacteria, e.g., <italic>Bifidobacterium</italic>, <italic>Faecalibacterium</italic>, <italic>Blautia</italic>, <italic>Butyricicoccus</italic>, and <italic>Lactobacillus</italic>. Furthermore, HEPs reduced the relative abundances of opportunistic pathogenic bacteria, e.g., <italic>Escherichia-Shigella</italic>, <italic>Klebsiella</italic>, and <italic>Enterobacter</italic>. This study suggests that gradual ethanol precipitation is available for the preparation of polysaccharides from <italic>Hericium erinaceus</italic>, and the extracted polysaccharide could be developed as functional foods with great development value.</p>