Longitudinal evolution of the concentration of gangliosides GM3 and GD3 in human milk
Giuffrida F, Elmelegy IM, Thakkar SK, Marmet C, Destaillats F
Gangliosides are glycosphingolipids formed by a ceramide and an oligosaccharide chain; they are distributed in most human tissues with the highest amount found in neural tissue, lung, spleen and gut. During early life dietary gangliosides may be have an important role on brain development, modification of the intestinal microflora and promotion of intestinal immunity. While their presence in human milk is known, quantitative data on their concentration is still scarce.
The diverse structures in the lipid moiety and in the oligosaccharide originate different gangliosides, and this work describes a validated procedure to quantify the two major classes: GD3 and GM3. Previously existing methods had either low sensitivity or were very time consuming limiting the amount of samples that could be analyzed. The method described in this paper uses liquid chromatography coupled with electrospray ionization high-resolution mass spectrometer and it has several advantages including: more selectiveness and robustness, allows the identification of molecular species of GD3 and GM3 and it is feasible to use in large sample sets.
The authors were able to provide the first report of longitudinal ganglioside concentrations in human milk. They analyzed a large cohort with samples at 0-11, 30, 60 and 120 days after birth. The content of GD3 and GM3 in human milk ranged between 0.9 to 3.8 µg/ml and 4.3 to 9.8 µg/ml, respectively. At the beginning of the lactation period (0-11 days) the amounts of GD3 and GM3 were comparable and the ratio GM3:GD3 was 1:1. Thereafter GM3 concentration increased and GD3 decreased, and the ratio GM3:GD3 was 10:1 at 60 and 120 days. Assuming a mean volume of breast milk consumption of 600, 700 and 800 ml, the estimated intake of ganglioside in infants is 5.5, 7.0 and 8.6 mg/d at 30, 60 and 120 d postpartum. Further investigations are needed to determine the biological function of gangliosides in milk.
Lipids. 2014;49(10):997-1004. doi: 10.1007/s11745-014-3943-2.