Structural programmability of jujube polysaccharides: Extraction, molecular architecture, and microbiota-mediated fermentation Design for gut-Brain-Axis-Relevant Applications.

Jujube polysaccharides (JPs) are heterogeneous food pectic glycans, but how extraction and post-isolation modification define their molecular architecture and microbiota-accessible functionality remains insufficiently integrated. This review critically synthesizes evidence linking extraction conditions to JP structural templates and evaluates how post-isolation remodeling tunes molecular weight, RG-I/HG balance, side-chain architecture, esterification, charge, conformation, and assembly state. Using an evidence-stratified framework, we distinguish direct JP findings from mechanisms inferred from broader pectin and dietary-fiber literature. We propose that backbone architecture, RG-I-associated side chains, esterification, and supramolecular organization may shape microbial accessibility, fermentation kinetics, selective utilization, short-chain fatty acid production, and gastrointestinal substrate availability. This structure-microbiota-metabolite perspective supports a validation pipeline based on defined JP fractions, matched pectin controls, standardized fermentation models, and causal microbiome designs. Gut-brain-axis relevance is discussed as an indirect, evidence-limited downstream implication rather than an established JP mechanism.