Valorizing renewable biomass into potential prebiotic oligosaccharides: Enzymatic, microbial, and synthetic biology...

Biomass valorization has become a central strategy in the transition toward a circular bioeconomy, enabling the conversion of underutilized terrestrial and marine resources into value-added functional ingredients. The production of prebiotic oligosaccharides (POs) has garnered increasing attention owing to their demonstrated health benefits, scalability, and compatibility with existing food systems. This review summarizes recent advances in enzymatic and microbial technologies for producing potential POs-including neo- and agarooligosaccharides, cellooligosaccharides, xylooligosaccharides, and pectin oligosaccharides-from renewable biomass, such as marine macroalgae, lignocellulosic residues, and pectin-rich crops. These oligosaccharides act as prebiotics that modulate the gut microbiota and promote the formation of bioactive metabolites, which include short-chain fatty acids, indole-3-lactic acid, and spermidine. With advances in metabolic engineering and synthetic biology, progress has also enabled the microbial biosynthesis of lacto-N-neotetraose and 2'-fucosyllactose, which are human milk oligosaccharides, from biomass-derived sugars using GRAS-designated microbial hosts. These biotechnologies offer sustainable and scalable alternatives to conventional extraction or chemical synthesis. We also discuss recent developments in enzyme engineering, bioprocess optimization, and microbial co-culture systems aimed at enhancing product yield and specificity. This review highlights the industrial applications and beneficial health effects of biomass-derived oligosaccharides, emphasizing their role as next-generation functional ingredients in personalized nutrition and microbiome-targeted therapies.