关键词: 人乳寡糖, 生物活性, 合成方法, 体外生物转化

Abstract:

Human milk oligosaccharides (HMOs) are naturally occurring bioactive oligosaccharides existed in human milk, playing a critical role in neonatal health. These oligosaccharides confer multiple health benefits, including prebiotic activity, anti-inflammatory effects, antimicrobial activity, and antiviral properties, as well as the promotion of cognitive development in newborns. Consequently, HMOs have emerged as essential components in infant formula, clinical nutrition products, dietary supplements, and functional foods. The escalating commercial value of HMOs has driven intensive research into scalable production technologies. Traditional extraction and chemical synthesis methods for HMOs face challenges such as low efficiency, high costs, and limited yields. Accordingly, biotechnological approaches leveraging metabolic engineering and enzyme catalysis have become mainstream strategies for HMOs production. Although metabolic engineering of microbial strains improves HMOs yields and lowers production costs, challenges including inefficient substrate transport, byproduct accumulation, and product purification hurdles remain unresolved.In vitro Bio-Transformation (ivBT) integrates the advantages of enzymatic catalysis and microbial fermentation, enabling efficient extracellular biosynthesis and has emerged as an innovative biomanufacturing strategy. This approach addresses bottlenecks in traditional microbial synthesis, including low substrate utilization efficiency and byproduct formation—through enzyme discovery, pathway reconstruction, and optimization of reaction systems. Through enzyme engineering for novel substrate specificity and de novo multienzyme pathway design, ivBT enhances both product purity and yield while reducing complexity and costs, thereby providing novel methodologies for scalable HMOs synthesis.This paper reviews the structure, functional properties, and synthesis methods of human milk oligosaccharides, with a focus on the research progress of ivBT in the large-scale preparation of HMOs. It highlights the recent advances in ivBT technology, particularly in enzyme discovery and engineering, the construction of in vitro multi-enzyme catalytic pathways, and the scaling up of reaction systems. Furthermore, it analyzes the challenges and future trends of ivBT in the industrial production of HMOs, aiming to provide a theoretical basis and technical reference for related basic research and industrial transformation.

Key words: human milk oligosaccharides, biological activities, synthesis method, in vitro Bio-Transformation