Soft matter-engineered pH-responsive hydrogels for encapsulation, protection, and controlled intestinal release of probiotics (Lacticaseibacillus paracasei YWC-01)

pH-responsive hydrogel microcapsules were fabricated from pea protein isolate (PPI) and low-methoxyl pectin (LMP) for the targeted intestinal delivery of Lacticaseibacillus paracasei YWC-01, a probiotic capable of biodegrading uric acid precursors in vitro . Microgels with interpenetrating networks were fabricated via emulsion-templating: probiotics, PPI, LMP, CaCl₂, and glucono-δ-lactone were emulsified in oil and crosslinked by Ca 2+ . Optimized formulation (5% w / v PPI) achieved 94.80% encapsulation efficiency. Microgel size (43–63 μm) was controlled by adjusting Span 80 surfactant concentration. FTIR confirmed probiotic encapsulation via noncovalent interactions, while TEM revealed bacterial clustering within hydrogel voids. In vitro digestion demonstrated exceptional protection: encapsulated probiotics maintained >9 log 10 CFU/g viability (<0.4 log reduction), versus 3.2 log reduction in free cells. Metabolomics indicated encapsulation preserved bioactivity and significantly upregulated functional metabolites potentially enhancing gut microbiota modulation and anti-inflammatory effects. This work establishes an effective oral delivery platform that significantly enhances probiotic gastrointestinal survival and enables targeted release.