Department of Applied Biology & Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
Department of Applied Biology & Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
Int J Biol Macromol. 2020 Feb 1;144:76-84. doi: 10.1016/j.ijbiomac.2019.12.072. Epub 2019 Dec 16.
This study was to investigate the potential prebiotic function of exopolysaccharide (EPS) from a medicinal fungus and the relationship to the molecular properties by in vitro human fecal fermentation. The EPS from Cordyceps sinensis Cs-HK1 mycelial fermentation was processed into three fractions with different monosaccharide contents, a higher molecular weight (MW) and a lower MW attained by two-step ethanol precipitation, and an intermediate MW by ultrasound-degradation of EPS. All the EPS fractions were well utilized during 24-48 h of fecal fermentation, leading to significant increases in the short chain fatty acid (SCFA) production. The consumption rate and production level of SCFAs varied slightly with the different EPS fractions. The EPS also influenced the composition and diversity of the fecal microflora, increasing the relative abundance of Firmicutes but suppressing that of Proteobacteria, which may be a beneficial effect for human health. Overall the results have shown that the Cs-HK1 EPS has significant prebiotic activity which is dependent on its molecular properties.
本研究通过体外人体粪便发酵，探究了一种药用真菌胞外多糖（EPS）的潜在益生元功能及其与分子特性的关系。采用两步乙醇沉淀法将虫草素 Cs-HK1 菌丝发酵的 EPS 处理成三种单糖含量不同、分子量较高和较低的分级，以及一种通过超声降解 EPS 获得的中分子量分级。所有 EPS 分级在粪便发酵的 24-48 小时内均被很好地利用，导致短链脂肪酸（SCFA）的产生显著增加。不同 EPS 分级的 SCFA 消耗率和产生水平略有差异。EPS 还影响粪便微生物群的组成和多样性，增加厚壁菌门的相对丰度，但抑制变形菌门的相对丰度，这可能对人体健康有益。总的来说，研究结果表明，Cs-HK1 EPS 具有显著的益生元活性，这与其分子特性有关。
