Polyamine levels in breast milk are associated with mothers’ dietary intake and are higher in preterm than full-term human milk and formulas
M. Atiya Ali, B. Strandvik, K.-G. Sabel, C. Palme Kilander, R. Strömberg, A. Yngve
The polyamines may be a class of organic compounds that many people have either ignored, learned about and forgotten, or simply never have been aware of. A polyamine is an organic compound having two or more primary amino groups. This class of compounds includes many substances that play important roles in both eukaryotic and prokaryotic cells, such as putrescine, cadaverine, spermidine and spermine. The functions of the polyamines are varied, with reports that they modulate permeability of the blood-brain barrier, regulate ion channel activity and play a key role in development. The proliferation of cells appears to be a polyamine-dependent process. In mammals the polyamines are synthesised from ornithine and so are ultimately derived from arginine. Spermine and spermidine appear to be particularly important in development, with reports of a function in maturation of both the intestine and the immune system.
The supply of polyamines in infancy may play a role in establishing immune function, with some indication that high intakes in the first five years of life, provided by human milk are associated with a lower risk of food allergy. It is therefore of some interest to understand the influences on polyamine secretion during lactation. The paper by Atiya Ali sought to explore this by measuring dietary polyamine intake of lactating women and polyamine concentrations in breast milk produced by women at different stages of lactation.
Transitional breast milk was collected from 40 mothers delivering after 24–36 weeks of gestation (1 day after delivery), and from 12 mothers delivering after full term (10 days after delivery). Food intake was assessed in mothers using a 3-day diary. Polyamines were analysed by high-performance liquid chromatography and a further sample of formula milks commonly used in Sweden was analysed for comparison.
The levels of putrescine, spermidine and spermine were all significantly associated with maternal intake of each corresponding polyamine. In addition, the putrescine intake was also associated with the spermidine content in breast milk. Total polyamine level was higher in preterm than term milk and lower in the corresponding formulas. Putrescine and content of preterm milk was higher than in term milk. Formulas designed for full term infants generally contained considerably less polyamines than human milk.
Having established that human milk polyamine concentration is strongly related to maternal dietary intake and is greater than is present in standard infant formulas, the authors stated, “Prospective randomised intervention studies might be important to demonstrate whether the lower polyamine content in term milk might have an impact on the intestinal maturation, which is of relevance when using donor term milk in preterm infants. Recent studies, indicating that polyamine metabolism is under translational control and involved in glucose homeostasis, adipogenesis and different diseases, make it important to study the possible interactions during the neonatal period. Similarly, the impact of lower polyamine contents in formulas rather than in human milk for the development of allergy or other intestinal disorders requires long-term prospective studies, especially in the context of an interaction with the microbial flora.