Chemical structure and prebiotic activity of a Dictyophora indusiata polysaccharide fraction

This study aimed to investigate the chemical structure and prebiotic activity of a Dictyophora indusiata polysaccharide fraction DIP0_p. Our results indicated that DIP0_p belongs to a heteropolysaccharide composed of glucose, galactose, mannose and xylose, accounting for 53.25 %, 24.18 %, 19.19 % and 3.37 %, respectively. Methylation and NMR results suggested that the main glycosidic bonds of DIP0_p is →3)-Glcp-(1 → with →4)-Glcp-(1→, →3,4)-Glcp-(1→, →3,4)-Galp-(1 → and →6)-Manp-(1 → branches. In addition, DIP0_p increased the abundance of benificial bacteria during the in vitro fecal fermentation, including Phascolarctobacterium, Parabacteroides and Bifidobacterium. It is remarkable that DIP0_p improved the level of acetic acid, propionic acid, and butyric acid of the fermentation system, which were 1.31, 1.52, and 2.64 folds higher than the Controls, respectively. In summary, this study comprehensively analyzed the structure and probiotic activity of DIP0_p, which providing a theoretical basis for the development of the functional foods.