title: High levels of anti-inflammatory and pro-resolving lipid mediators lipoxins and resolvins and declining docosahexaenoic acid levels in human milk during the first month of lactation.
abstract: BACKGROUND
  The fatty acid mixture of human milk is ideal for the newborn but little is known about its composition in the first few weeks of lactation. Of special interest are the levels of long-chain PUFAs (LCPUFAs), since these are essential for the newborn's development. Additionally, the LCPUFAs arachidonic acid (AA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are precursors for lipid mediators which regulate inflammation.
  
  
  METHODS
  We determined the composition of 94 human milk samples from 30 mothers over the first month of lactation for fatty acids using GC-MS and quantified lipid mediators using HPLC-MS/MS.
  
  
  RESULTS
  Over the four weeks period, DHA levels decreased, while levels of γC18:3 and αC18:3 steadily increased. Intriguingly, we found high concentrations of lipid mediators and their hydroxy fatty acid precursors in human milk, including pro-inflammatory leukotriene B4 (LTB4) and anti-inflammatory and pro-resolving lipoxin A4 (LXA4), resolvin D1 (RvD1) and resolvin E1 (RvE1). Lipid mediator levels were stable with the exception of two direct precursors.
  
  
  CONCLUSIONS
  Elevated levels of DHA right after birth might represent higher requirements of the newborn and the high content of anti-inflammatory and pro-resolving lipid mediators and their precursors may indicate their role in neonatal immunity and may be one of the reasons for the advantage of human milk over infant formula.
authors.affiliation: Clinical Chemistry and Biochemistry, Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland.
authors.forename: Gisela Adrienne
authors.initials: GA
authors.lastname: Weiss
authors.forename: Heinz
authors.initials: H
authors.lastname: Troxler
authors.forename: Glynis
authors.initials: G
authors.lastname: Klinke
authors.forename: Daniela
authors.initials: D
authors.lastname: Rogler
authors.forename: Christian
authors.initials: C
authors.lastname: Braegger
authors.forename: Martin
authors.initials: M
authors.lastname: Hersberger
mesh_terms: D004281:Docosahexaenoic Acids / Q000096:biosynthesis*; D015777:Eicosanoids / Q000378:metabolism; D015118:Eicosapentaenoic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007249:Inflammation / Q000378:metabolism / Q000473:pathology; D007774:Lactation / Q000378:metabolism*; D050356:Lipid Metabolism; D044045:Lipoxins / Q000096:biosynthesis*; D008895:Milk, Human / Q000737:chemistry / Q000378:metabolism*; D014481:United States
chemical_list: D015777:Eicosanoids; D044045:Lipoxins; C040527:lipoxin A4; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid; C499823:5S,12R,18R-trihydroxy-6Z,8E,10E,14Z,16E-eicosapentaenoic acid