DFL (Difucosyllactose/Lactodifucotetraose)

DFL (Difucosyllactose/Lactodifucotetraose), primarily 2,2′-DFL, ranks among key fucosylated human milk oligosaccharides (HMOs), present as a white amorphous powder crucial for infant gut health and immunity via Bifidobacterium promotion. This tetrasaccharide (Fucα1-2Galβ1-4Glcβ1-4(Fucα1-2)Glc or variants like 2,3-DFL) is commercially fermented in engineered E. coli at titers >30 g/L, offering prebiotic benefits superior to mono-fucosyl HMOs like 2′-FL, with slower Bifidobacterium growth but enhanced metabolite diversity (SCFAs, acetate); purity 96-99%, 5-year shelf life lyophilized, validated for infant formula by EFSA/FDA, and researched for NEC prevention, microbiota modulation, and neurodevelopment support.

Appearance

• White to off-white, homogeneous amorphous powder; neutral to slightly sweet taste.​
• Highly water-soluble (>200 g/L); spray-dried or lyophilized form.​

Source

• Constitutes 5-10% of HMOs in secretor mothers’ milk; highest fucose content (2:1 ratio).
• Microbial fermentation using engineered E. coli with α1-2/1-3/4-fucosyltransferases.

Molecular Weight and Structure

• 634.58 g/mol, formula C₂₄H₄₂O₁₉ (CAS 20768-11-0).
• Fucα1-2Galβ1-4Glc(1←4)βGalβ1-4(Fucα1-2)Glc or positional isomers.​

Sugar Specificity

• Dual fucose for Bifidobacterium fucosidases (AfcA/B, AlfA/B); selective over Bacteroides.​
• Binds fucose-specific lectins (e.g., UEA-I); resists host hydrolases.​

Biological Activity

• Amplifies Bifidobacterium infantis growth/metabolites (acetate, butyrate); anti-NEC effects.
• Inhibits pathogens (E. coli, Salmonella); supports barrier integrity, immunity.​

Purity and Microbial Contamination

• 96-99% combined (DFL+precursors) by HPLC/NMR; endotoxins <10 EU/g.
• Total plate count <1000 CFU/g; heavy metals/moisture per pharmacopeia.​

Identity and Quality Control

• ¹H-NMR/HPLC for isomer ratio; LC-MS for MW; Karl Fischer for moisture.​
• ICP-MS residuals; COA confirms HMO profile.​

Shelf Life and Storage

• 5 years from production, sealed at ambient or -18°C.
• Cool, dry; desiccated to prevent hydrolysis.​

Applications

• Infant formula enrichment; prebiotic supplements; functional foods.​
• NEC therapeutics; microbiota research; vaccine adjuvants.​

Key Characteristics

• Distal gut-targeted fermentation; high fucose yield SCFAs; strain-specific utilization.​

Citation Links

• https://pubs.acs.org/doi/10.1021/acs.jafc.3c09742​
• https://pmc.ncbi.nlm.nih.gov/articles/PMC7258437/​
• https://www.elicityl-oligotech.com/human-milk-oligosaccharides-hmo/419-lactodifucotetraose–difucosyllactose–df-l-90-nmr.html​
• https://pubchem.ncbi.nlm.nih.gov/compound/91850278​
• https://www.nature.com/articles/s41598-020-72792-z​
• https://pubmed.ncbi.nlm.nih.gov/38374607/​
• https://pmc.ncbi.nlm.nih.gov/articles/PMC10907138/​
• https://efsa.onlinelibrary.wiley.com/doi/10.2903/j.efsa.2023.8333​
• https://pubmed.ncbi.nlm.nih.gov/33382612/​
• https://www.dsm-firmenich.com/…GlyCare%20DFL_info…