Prebiotic potential of Ceratonia siliqua polysaccharides: Ultrasound-assisted extraction enhances gut microbial diversity and metabolic activity

Ultrasound-assisted extraction was optimized for efficient recovery of plant-based polysaccharides from Ceratonia siliqua pulp. The extracted polysaccharide underwent purification via deproteinization, dialysis, and DEAE-52 ion exchange chromatography, yielding UPS-3, a monodispersed polymer (Mw 1.3 × 10³ kDa) composed of mannose, glucuronic acid, glucose, xylose, arabinose, and galactose. UPS-3 exhibited potent antioxidant properties, confirmed by DPPH, ABTS, FRAP, RP, and TAC assays, along with significant α-amylase (98.2 %) and α-glucosidase (95.1 %) inhibition at 2000 μg/mL, highlighting its anti-diabetic potential. Additionally, UPS-3 displayed in vitro anticancer activity against Caco-2 cells and exhibited antibacterial effects against common pathogens. Its prebiotic properties were evidenced by the selective promotion of beneficial gut microbial taxa belonging to the classes Clostridia, Actinobacteria, and Bacteroidia, while inhibiting the potentially pathogenic organisms such as Escherichia and Klebsiella. Fecal fermentation analysis revealed increased production of short-chain fatty acids (SCFAs), including acetate, propionate, and butyrate, emphasizing its role in gut health. Rheological analysis showed its potential as a functional food ingredient with excellent water and oil-holding capacities. These findings suggest that UPS-3 could serve as a natural therapeutic agent for managing metabolic disorders and promoting gut health.