The impact of human breast milk components on the infant metabolism

PLoS One. 2018 Jun 1;13(6):e0197713. doi: 10.1371/journal.pone.0197713. eCollection 2018.

Abstract

Background & aims: Breastfeeding is beneficial for mothers and infants. Underlying mechanisms and biochemical mediators thus need to be investigated to develop and support improved infant nutrition practices promoting the child health. We analysed the relation between maternal breast milk composition and infant metabolism.

Methods: 196 pairs of mothers and infants from a European research project (PreventCD) were studied. Maternal milk samples collected at month 1 and month 4 after birth were analysed for macronutrient classes, hormone, and fatty acid (FA) content. Phospholipids, acylcarnitines, and amino acids were measured in serum samples of 4-month old infants. Associations between milk components and infant metabolites were analysed with spearman correlation and linear mixed effect models (LME). P-values were corrected for multiple testing (PLME).

Results: Month 1 milk protein content was strongly associated with infant serum lyso-phosphatidylcholine (LPC) 14:0 (PLME = 0.009). Month 1 milk insulin was associated to infant acetylcarnitine (PLME = 0.01). There were no associations between milk protein content and serum amino acids and milk total fat content and serum polar lipids. Middle- and odd-chain FA% in breast milk at both ages were significantly related to serum LPC and sphingomyelins (SM) species in infant serum (all PLME<0.05), while FA% 20:5n-3 and 22:6n-3 percentages were significantly associated to serum LPC 22:6 (PLME = 1.91×10-4/7.93×10-5) in milk only at month 4. Other polyunsaturated fatty acids and hormones in milk showed only weak associations with infant serum metabolites.

Conclusions: Infant serum LPC are influenced by breast milk FA composition and, intriguingly, milk protein content in early but not late lactation. LPC 14:0, previously found positively associated with obesity risk, was the serum metabolite which was the most strongly associated to milk protein content. Thus, LPC 14:0 might be a key metabolite not only reflecting milk protein intake in infants, but also relating high protein content in milk or infant formula to childhood obesity risk.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Breast Feeding*
  • Child
  • Fatty Acids, Omega-3 / blood*
  • Fatty Acids, Omega-6 / blood*
  • Female
  • Humans
  • Infant
  • Infant Formula / chemistry
  • Infant Nutritional Physiological Phenomena
  • Infant, Newborn
  • Lactation / blood
  • Lysophosphatidylcholines / blood
  • Milk Proteins / blood
  • Milk, Human / chemistry*
  • Milk, Human / metabolism
  • Mothers

Substances

  • Fatty Acids, Omega-3
  • Fatty Acids, Omega-6
  • Lysophosphatidylcholines
  • Milk Proteins

Grants and funding

This work was financially supported by the Commission of the European Communities, the 6th Framework Programme, contract FP6-2005-FOOD-4B-36383–PREVENTCD, the 7th Framework Programme, contract FP7-289346-EARLY NUTRITION, the European Research Council Advanced Grant ERC-2012-AdG – no.322605 META-GROWTH, the Azrieli Foundation, Deutsche Zöliakie Gesellschaft, Eurospital, Fondazione Celiachia, Fria Bröd, Instituto de Salud Carlos III, Spanish Society for Pediatric Gastroenterology, Hepatology, and Nutrition, Komitet Badań Naukowych (1715/B/P01/2008/34), Fundacja Nutricia (1W44/FNUT3/2013), Hungarian Scientific Research Funds (OTKA101788, NKFI120392 and TAMOP 2.2.11/1/KONV-2012-0023), Stichting Coeliakie Onderzoek Nederland, Thermo Fisher Scientific, and the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition. This manuscript does not necessarily reflect the views of the Commission and in no way anticipates the future policy in this area. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The authors declare to have no conflict of interest.