Urinary prostaglandin D metabolite excretion during the first six months of life was significantly lower in breast-fed than formula-fed infants.

Aim: The metabolic changes that occur during the postnatal weaning period appear to be particularly important for future health, and breast milk is considered to provide the optimal source of infant nutrition. This pilot study from September 2013 to May 2015 examined the effect of breastfeeding on prostaglandin metabolism in healthy term infants.

Methods: Urine samples were collected from 19 infants at one month of age in the Juntendo University Hospital, Tokyo, Japan. The 13 infants in the breast-fed group received less than 540 mL/week of their intake from formula, and the other six were exclusively fed on formula. At six months, we sampled 14 infants: nine breast-fed and five receiving formula. The infants were from normal single pregnancies and free from perinatal complications. We analysed urinary prostaglandin metabolites-tetranor prostaglandin E metabolite (t-PGEM) and tetranor prostaglandin D metabolite (t-PGDM)-using liquid chromatography tandem-mass spectrometry.

Results: Urinary t-PGDM excretion at one and six months was significantly lower in breast-fed infants than formula-fed infants. However, urinary t-PGEM excretion at one and six months was not significantly different between the groups.

Conclusion: Our study showed that the type of feeding in early infancy affected prostaglandin metabolism in healthy term infants.