Structural Characterization and In Vitro Fermentation Properties of Polysaccharides from Polygonatum filipes

In this study, a homogeneous polysaccharide, designated as PFP-80, was isolated from the dried root of Polygonatum filipes using enzymatic extraction combined with graded ethanol precipitation. Structural characterization suggested that PFP-80 was a fructan polysaccharide with a molecular weight of 4.06 kDa. The analysis with gas chromatograph–mass spectrometer (GC–MS) and nuclear magnetic resonance (NMR) further confirmed that PFP-80 consisted of →1)-β-D-Fruf-(2→ and →1,6)-β-D-Fruf-(2→ linkages, with branching occurring at the O-6 position. After 48 h of fermentation, the pH was decreased while SCFAs were increased significantly due to the utilization of PFP-80. Furthermore, PFP-80 was found to modulate the gut microbiota by enhancing microbial abundance and diversity, and by impeding the growth of deleterious pathogens such as Ruminococcus gnavus. In summary, the present results provide a scientific basis for the subsequent development of PFP-derived functional food products.