Recent advances in a functional deoxy hexose l-fucose: Occurrence, physiological effects, and preparation

l-Fucose is a functional deoxyhexose prevalent in various organisms. Particularly, it is the general backbone unit of the polysaccharides of many edible brown algae; it is also a human-identical milk monosaccharide and has been proposed for use in infant formula as a functional ingredient. This review aims to provide a detailed overview of the occurrence and physiological effects of l-fucose. We have reviewed various strategies for preparing l-fucose, including algal extraction, enzymatic production, and microbial synthesis using metabolic engineering approaches. l-Fucose is an important polysaccharide obtained from various microorganisms, algae, and plants. In mammals, they occur as N- and O-linked glycans in glycoproteins and glycolipids that perform important physiological functions. l-Fucose has prebiotic activity, protects intestinal barrier function, improves lipid metabolism, exhibits antitumor activity, and slows skin aging; thus, it can potentially be used as a bioactive component in the pharmaceutical, nutraceutical, and cosmetic industries. l-Fucose is easily manufactured from algae and can be produced via chemical, enzymatic, and microbial synthesis.