Preparation, bioactivities, and application potential of water-soluble cello-oligosaccharides: A review

Cello-oligosaccharides (COS) are β-1,4-linked dextrins with a degree of polymerization (DP) below 10, and those with DP ≤ 6 generally show good water solubility. Derived from renewable biomass, COS are low-cost compounds with promising biological activities, including prebiotic, antioxidant, and immunomodulatory functions. These properties highlight their potential applications in food, agriculture, and materials science. However, compared to well-studied functional oligosaccharides like fructo- and galacto-oligosaccharides, research on COS remains limited due to difficulties in efficient production and limited mechanistic understanding. This review provides a comprehensive summary of COS preparation strategies, focusing on enzymatic degradation and bottom-up biosynthesis via enzymatic and microbial approaches. Key factors affecting yield and product specificity are discussed. Although significant progress has been made in laboratory-scale production, technical and economic challenges hinder industrial-scale application. The review also discusses current advances in COS biological activities, emphasizing their relevance across different fields. However, studies remain fragmented, and the structure-function relationship and mechanisms of action require further exploration. Future research should focus on improving the structural diversity of COS, particularly those with higher DP, and elucidating their biological pathways. Such efforts will support broader application of COS in functional food development, biomedical delivery systems, and sustainable biomaterials.