In vitro digestion and fermentation of jujube-derived polysaccharide PZMP3 and its modulatory effect on gut microbiota and metabolic pathways

This study evaluated the digestion and fermentation characteristics of PZMP3, polysaccharide rich in galacturonic acid purified from <i>Z. jujuba cv. Muzao</i>, and its modulatory effects on the gut microbiota and associated metabolites. <i>In vitro</i> simulated gastrointestinal digestion confirmed that PZMP3 resisted enzymatic hydrolysis in the upper gastrointestinal tract and reached the colon intact. During subsequent fecal fermentation with human microbiota (using inulin as a positive control), PZMP3 was degraded by gut microbiota, leading to a gradual reduction in pH and a substantial increase in short-chain fatty acids (SCFAs), reaching a total concentration of 142.06 ± 0.58 mmol/L at 48 h. After digestion and glycolysis, the overall trend of gases shows an increase, while H₂S is inhibited. Microbiota analysis revealed that PZMP3 selectively promoted the proliferation of <i>Firmicutes</i> and <i>Bifidobacterium</i> while <i>Klebsiella</i> and <i>Bacteroides</i> are inhibited. Metabolomic profiling further demonstrated enriched pathways related to bile acids and amino acids, indicating its potential role in regulating host metabolic homeostasis. These findings could highlight the potential of PZMP3 as a gut-targeted functional ingredient for improving intestinal health.