［［Objective ］］ This study investigated the in vitro fermentation characteristics and gut microbiota modulation effects of polysaccharides extracted from mulberries at different maturity stages.［［Methods ］］ Polysaccharides from green,red and purple mulberries were subjected to in vitro fermentation using human fecal microbiota.Changes in pH values,short -chain fatty acids (SCFA ) levels and substrate composition were monitored.Gut microbiota composition was analyzed through 16S rDNA sequencing.［［Results］］ Polysaccharides from all three mulberry types were effectively degraded and utilized during fermentation,generating significant levels of SCFAs,including acetic acid,propionic acid,and butyric acid.Purple and red mulberry polysaccharides demonstrated a superior capacity for SCFA production compared to those from green mulberries.Additionally,they selectively modulated gut microbiota,promoting the growth of beneficial bacteria such as Bacteroides,Parabacteroides,and Phascolarctobacterium,while suppressing harmful bacteria like Fusobacterium.［［Conclusion ］］ Polysaccharides derived from mulberries at three different maturity stages exhibit notable prebiotic activity by enhancing beneficial metabolic products and positively influencing gut microbiota composition.Fully ripe purple mulberries exhibited the most pronounced effects,suggesting their potential as a superior source of functional ingredients.