Lacto-N-tetraose

Lacto-N-tetraose (LNT, Galβ1-3GlcNAcβ1-3Galβ1-4Glc) stands as the third most abundant neutral human milk oligosaccharide after 2′-FL and LNnT, constituting 4-10% of total HMOs in mature breast milk and manifesting as a white hygroscopic powder essential for neonatal immune priming and gut barrier maturation. This type 1 chain tetrasaccharide, distinguished from LNnT by its β1-3 Gal-GlcNAc linkage, selectively stimulates Bifidobacterium breve and B. bifidum proliferation (2-4x vs glucose), inhibits rotavirus/ETEC adhesion by 60-85% through type 1 chain mimicry, upregulates mucin-2 and goblet cell differentiation, reduces NEC incidence by 40-60% via TLR4 modulation, and supports cognitive development through ganglioside GM1 mimicry; commercially scalable via engineered E. coli fermentation (>98% purity, GRAS-listed by FDA/EFSA), it exhibits superior gastric stability (pH 2.5-8), Bifidobacterium-selective fermentation yielding propionate/acetate, and 5-year shelf life, making it ideal for infant formula fortification and functional synbiotics.

Appearance

• White to off-white amorphous hygroscopic powder.
• Water solubility >700 g/L at 25°C; clear colorless solutions.

Source

• 4-10% total HMOs in mature human milk; highest in transitional milk.
• Microbial biosynthesis via β3GalT/β3GnT on lactose acceptors.

Molecular Weight and Structure

• 707.63 g/mol, formula C₂₆H₄₅NO₂₁ (CAS 14116-68-8).
• Galβ1-3GlcNAcβ1-3Galβ1-4Glc type 1 chain tetrasaccharide.

Sugar Specificity

• Bifidobacterium β3GalTase/β3GnTase specific; precursor for sialyl-Lewis A.
• Binds DC-SIGN, siglec-5; resists pancreatic α-amylase.

Biological Activity

• Stimulates B. breve/B. bifidum 2-4x growth; inhibits rotavirus 80%.
• Upregulates MUC2, goblet cell differentiation; TLR4 immunomodulation.

Purity and Microbial Contamination

• ≥98% HPLC/NMR; 3′-GL <1%, lactose <0.5%.
• Endotoxins <10 EU/g; total plate count <50 CFU/g.

Identity and Quality Control

• ¹H-NMR confirms β1-3 linkages; [α]D +28° to +35° (c=1, H₂O).
• LC-MS [M+H]+ 708.25; HPAEC Gal:GlcNAc:Glc 2:1:1.

Shelf Life and Storage

• 60 months 25°C/60% RH sealed; indefinite -20°C lyophilized.
• Desiccated storage essential due to hygroscopicity.

Applications

• Infant formula fortification (0.5-2 g/L); synbiotic formulations.
• NEC prophylaxis; gut barrier therapeutics.

Key Characteristics

• Type 1 chain HMO specificity; superior rotavirus inhibition vs LNnT.
• Distal colon-targeted fermentation; MUC2 inducer.

Citation Links

• https://pubchem.ncbi.nlm.nih.gov/compound/440993
• https://en.wikipedia.org/wiki/Lacto-N-tetraose
• https://www.sigmaaldrich.com/BR/en/product/ambeedinc/ambh9884c4c5
• https://www.medchemexpress.com/lacto-n-tetraose.html
• https://hmdb.ca/metabolites/HMDB0006566
• https://pubchem.ncbi.nlm.nih.gov/compound/121853
• https://www.chemicalbook.com/ChemicalProductProperty_EN_CB1418097.htm
• https://glycosmos.org/structure/LNT
• https://www.cd-bioglyco.com/lacto-n-tetraose
• https://www.fda.gov/media/100020/download