Structural analysis and prebiotic properties of the polysaccharides produced by YT013.

Exopolysaccharides (EPS) from YT013 were isolated, structurally characterized and evaluated for gastrointestinal stability and prebiotic potential. YT013-EPS-1 (57.51 kDa) demonstrated superior resistance to simulated gastrointestinal digestion and maintained structural integrity relative to YT013-EPS-2 (149.3 kDa). Both EPSs exhibited significantly increased antioxidant activity after digestion relative to their undigested forms. In an mouse fecal fermentation model, YT013-EPS-1 significantly increased SCFA production and promoted beneficial bacteria such as and , while reducing potentially pathogenic genera such as and . These microbial and metabolic shifts suggest that YT013-EPS-1 influences gut microbiota and promotes microbial metabolites associated with intestinal barrier function and host metabolic regulation. Notably, YT013-EPS-1 exerted more pronounced modulatory effects on gut microbiota composition and SCFA profiles than YT013-EPS-2. Collectively, these findings highlight the potential of YT013-EPS-1 as a prebiotic ingredient for modulating gut microbiota .