2-Fucosyllactose

What is 2'-Fucosyllactose? 2'-Fucosyllactose (2'-FL) is a fucosylated neutral trisaccharide composed of L-fucose, D-galactose, and D-glucose units. It is the most prevalent human milk oligosaccharide (HMO) naturally present in human breast milk, making up about 30% of all HMOs. This oligosaccharide is known for its ability to protect against infectious diseases by preventing the epithelial-level adhesion of toxins and pathogens, and it also stimulates the growth of certain bifidobacteria. 2'-FL can be biosynthesized in quantity using genetically modified strains of Escherichia coli[1][2][3]. Common Uses in Food and Beverages 2'-Fucosyllactose is commonly used as an ingredient in various food and beverage products, particularly those intended for infants and young children. It is used in infant formulas, follow-on formulas, and formulated milks to mimic the nutritional and protective benefits found in human breast milk. Additionally, 2'-FL is incorporated into toddler formulas, other drinks for young children, and a range of conventional food products such as dairy products, beverages, grain products, pastas, and bakery wares. The use levels vary, but it is generally added at concentrations that reflect its natural occurrence in human milk, such as up to 1.6 grams per liter in infant formulas and up to 20 grams per kilogram in other food products[4][5].

The production of 2′-Fucosyllactose (2′-FL) involves several key steps, particularly when using microbial fermentation as the production method. This process typically relies on the expression of specific genes in engineered microorganisms, such as _Escherichia coli_. The biosynthesis of 2′-FL requires the concurrent presence of three essential components: the donor substrate GDP-L-fucose, the acceptor lactose, and the enzyme α-1,2-fucosyltransferase (FT). To achieve this, genes involved in the GDP-L-fucose biosynthesis pathway, such as _manB_, _manC_, _gmd_, _wcaG_, and _futC_, are co-expressed in the host organism. Additionally, the introduction of heterologous α-1,2-fucosyltransferase, which catalyzes the transfer of fucose from GDP-L-fucose to lactose, is crucial for the synthesis of 2′-FL[1][2].

To optimize 2′-FL production, various engineering strategies are employed. These include the deletion of genes involved in the degradation of GDP-L-fucose and GDP-mannose precursors, the introduction of positive regulators to enhance GDP-L-fucose formation, and the optimization of fermentation conditions. For example, feeding inexpensive glycerol as a carbon source and adjusting fermentation parameters such as temperature, pH, and oxygen levels can significantly boost 2′-FL production. The use of novel α-1,2-fucosyltransferases, like WbgL from _E. coli_ O126, which exhibits high kinetic efficiency for lactose, further enhances the synthesis process[1][3][2].

The safety profile for human consumption of 2-Fucosyllactose (2'-FL) is well-established through various studies and regulatory assessments. 2'-FL, a synthetic trisaccharide that mimics a naturally occurring component of human milk, has been evaluated for its safety in multiple contexts. It has been found to be safe for use in infant and follow-on formulae, as well as in foods and food supplements for both infants and adults. Studies, including sub-chronic 90-day toxicity tests in rats and clinical trials in infants, have shown no adverse effects at the proposed consumption levels. The European Food Safety Authority and other regulatory bodies have concluded that 2'-FL does not raise safety concerns regarding genotoxicity or other toxicological endpoints, and its intake levels are within the range found in mature breast milk[1][2][3].

Regarding potential contamination risks, the production and quality control of 2'-FL are strictly regulated to minimize such hazards. The manufacturing process, often involving microbial fermentation using genetically modified strains of Escherichia coli, includes rigorous testing for contaminants such as heavy metals, pesticides, and pathogens. Specifications for 2'-FL include limits for arsenic, cadmium, lead, and mercury, which must be below defined thresholds to ensure safety. Additionally, the product must comply with standards for aerobic plate count, yeast and mould, Enterobacteriaceae, and Salmonella spp. to prevent microbial contamination. The use of high-performance analytical techniques like liquid chromatography – tandem mass spectrometry (LC–MS/MS) and nuclear magnetic resonance (NMR) spectroscopy further ensures the purity and safety of the final product[2][3].