Comparison of the phospholipid classes in human milk in Japanese mothers of term and preterm infants

BACKGROUND

Phospholipids (PLs) play an essential role in the growth and brain development of infants.

AIM

To investigate PL composition in human milk (HM), including lysophosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine, phosphatidylcholine (PC) and sphingomyelin (SM), from healthy Japanese mothers. Analyses were performed on colostrum, transitional milk and mature milk from mothers of preterm and term infants.

METHODS

HM samples were collected from mothers of 15 term infants (term group) and of 19 preterm infants (preterm group). PL composition was determined by two-dimensional thin-layer chromatography in conjunction with phosphorus analysis.

RESULTS

In both groups, the PL content (% of total lipid) of mature milk was significantly lower than in colostrum. SM and PC were the main PLs in HM, but in the preterm group, the percentage of SM in mature milk was significantly higher and PC in mature milk was significantly lower than in the term group.

CONCLUSION

The transition from colostrum to mature milk leads to an increase in SM and a decrease in PC in the HM of preterm infants, along with a decrease in PL content. This is the first report to demonstrate the differences in PL composition in HM between mothers of preterm and term infants.

Characterization of caldarchaetidylglycerol analogs, dialkyl-type and trialkyl-type, from Thermoplasma acidophilum

The structures of three kinds of phospholipids (PL-X, PL-Y, and PL-T) isolated from Thermoplasma acidophilum have been characterized. The core lipid of PL-Y was caldarchaeol, and that of PL-X was archaeol. The composition of the hydrocarbon chains of the PL-T core lipid was C20 phytane and C40 isoprenoid in a molar ratio of 2 to 1. The major molecular species of the C40 isoprenoid was acyclic without the cyclopentane ring. These three kinds of intact phospholipids commonly had glycerophosphate residues as polar head groups. The structure of PL-T was characterized as trialkyl-type caldarchaetidylglycerol, PL-Y as caldarchaetidylglycerol, and PL-X as archaetidylglycerol.