Prebiotic potential of exopolysaccharide-derived oligosaccharides prepared using sandwich-integration bioprocess of acidolysis-electrodialysis and microbial fermentation

Fucosylated oligosaccharides (FCOs) from human milk and fucoidan are potential prebiotics. This study established a sandwich-integration bioprocess combining acidolysis-electrodialysis and microbial fermentation to obtain novel prebiotic FCOs from fucose-containing exopolysaccharide (EPS) with a specific backbone structure →3)-β-d-Glc<i>p</i>-(1 → 4)-α-l-Fuc<i>p</i>-(1 → 3)-α-l-Fuc<i>p</i>-(1 → and α-d-Gal<i>p</i> branches. The prebiotic activity of FCOs was analyzed through single-strain cultivation and colonic fermentation. Acidolysis of EPS generated residual acid and free monosaccharides. After electrodialysis for acid removal, <i>Lactococcus lactis</i> fermentation removed over 96 % of glucose and galactose, increasing the fucose molar ratio of FCOs by 25 % compared to the initial hydrolysates. Secondary electrodialysis removed 96.2 % of fermentation-derived organic acids. FCOs promoted lactic acid bacteria in mono-culture, and enhanced <i>Bifidobacterium</i>, <i>Parabacteroides</i>, and <i>Megasphaera</i> in colonic fermentation, enriching short-chain fatty acids (SCFAs) metabolism pathway, especially butyrate metabolism. This study developed an integrated process for EPS-derived FCOs preparation and monosaccharides byproduct removal and provided insights to the development of fucose-rich prebiotic.