Identification of the Variability of Metabolites in Human Milk using Gas Chromatography‐Mass Spectrometry (GC‐MS) Profiling

Abstract

A significant amount of research has been conducted into the macronutrient content of human milk. As such, the variation of milk components such as fat, protein and lactose have been well defined, however, little is known about the metabolites in human milk. Our preliminary investigation has detected approximately 200 metabolites in human milk. In this study we investigated the metabolites present in milk using GC‐MS profiling. Mothers (n=10) of healthy infants (1–18 months) provided approximately 5ml of freshly expressed breastmilk for analysis. Samples were mixed with methanol and snap frozen at −80ºC. Metabolites were extracted and GC‐MS was performed to obtain a metabolite profile for each sample. Data analysis was performed using Analyzer Pro® software. Whilst many of the metabolites in these profiles are yet to be identified, we were able to determine which of the metabolites exhibited the greatest variation. The profiling of these metabolites provides a platform for future research into the metabolic pathways that exhibit the greatest variation in the lactating human breast. These techniques will allow further elucidation of the physiology of the lactating human breast and have the potential to assist in the use of milk samples for the diagnosis of lactation difficulties such as mastitis and inadequate milk supply. Funded by an unrestricted research grant from Medela AG, Switzerland.