2'-Fucosyllactose
2′-Fucosyllactose is a fucosylated neutral trisaccharide composed of L-fucose, D-galactose, and D-glucose units. It is the most prevalent human milk oligosaccharide naturally present in human breast milk, making up about 30% of all of HMOs. It was first discovered in the 1950s in human milk. The oligosaccharide's primary isolation technique has been in use since 1972.
Structure
2′-FL consists of an L-fucose monomer in the α stereochemical configuration linked at the first carbon to a monomer of D-galactose in the β stereochemical configuration at the second carbon, which is in turn linked at the first carbon to a monomer of D-glucose at the fourth carbon.Production
The compound may be biosynthesized in quantity using E. coli.Metabolism
Human systemic metabolism of intact 2'-FL is limited. Like other HMOs, it is resistant to human digestive enzymes in the upper gut, meaning it reaches the colon relatively intact.The key site of 2'-FL metabolism is the intestinal microbiome. First, fucose is cleaved by α-fucosidases produced by gut bacteria such as Bifidobacterium spp. and Akkermansia spp.. The remaining lactose moiety is processed by β-galactosidases and other glycosidases.
Further microbial fermentation results in short-chain fatty acids, such as acetate, as well as lactate, 1,2-propanediol, and butyrate.