Regulatory effects of jujube (Ziziphus jujuba) polysaccharides on intestinal microbiota before and after α-galactosidase-mediated degradation

This study employed ultrasonic-assisted DES technology to extract jujube polysaccharides (ZJP) and investigated the effects of α-galactosidase modification on their structural characteristics and prebiotic functions. The modified polysaccharide (α-ZJP) exhibited significant alterations in physicochemical properties, including reduced neutral sugar and protein content, increased reducing sugars and uronic acids, and a shifted molecular weight distribution due to selective cleavage of galactose and rhamnose residues. Structural analysis confirmed the retention of key functional groups and revealed a transformed morphology from smooth sheets to a porous, sponge-like architecture. In vitro fermentation demonstrated that α-ZJP promoted rapid initial microbial growth and short-chain fatty acid (SCFA) production, by enriching Firmicutes and Lachnospiraceae. In contrast, unmodified ZJP showed sustained fermentation, yielding higher total SCFAs and selectively promoting butyrate-producing bacteria like Coriobacteriaceae. Both polysaccharides enhanced microbial diversity and SCFA accumulation, indicating their potential as prebiotics for gut health through distinct structure-dependent mechanisms.