A Comprehensive Review of Fucosylated Human Milk Oligosaccharides: Biological Functions, Production Technologies, and Safety Regulation With Commercial Translation in Infant Nutrition.

Human milk oligosaccharides (HMOs) are important functional bioactive components of human milk. Fucosylated HMOs (FHMOs) represent a major subclass, accounting for approximately 35%-50% of total HMOs, and have attracted increasing attention in infant nutrition and health. Current evidence indicates that FHMOs play important roles in shaping the infant gut microbiota, modulating host-microbe interactions, supporting intestinal barrier function, and maintaining immune and metabolic homeostasis. However, their commercialization still faces several challenges, including high production costs, difficulties in the scalable manufacture of structurally complex members, uneven functional evidence across individual compounds, incomplete safety and regulatory evaluation frameworks, and the need to further validate processing stability and application performance in final products. From an industrial perspective, microbial fermentation has become the main production route for 2'-fucosyllactose and 3-fucosyllactose, whereas the large-scale production of more structurally complex or low-abundance FHMOs remains technically and economically challenging. Regulatory approvals in major markets indicate acceptable safety at authorized use levels, but uncertainties remain regarding long-term intake, vulnerable infant populations, matrix-dependent stability, and the combined use of multiple HMOs. This review summarizes recent advances in the structural characteristics, biological functions, production technologies, safety assessment, regulatory status, and commercial applications of FHMOs, with emphasis on 2'-fucosyllactose, 3-fucosyllactose, and selected structurally related members. It also discusses commercialization challenges and future research priorities to support their responsible application in infant nutrition.