Fatty acid clustering
We grouped fatty acids according to postnatal level profiles and found several distinct clusters. Some fatty acids clustered according to class; for example, the proportion of the n–3 fatty acids, except DHA, were found in one cluster. The proportion of DHA, on the other hand, shared profile with the long-chain saturates stearic (18:0), behenic (22:0), and lignoceric acid (24:0). The n–6 LCPUFAs AA, adrenic (22:4 n–6), and docosapentaenoic acid (22:5 n–6) clustered together in data based on both relative and absolute concentration, albeit with very different profiles. This analysis highlights the complexity of lipid metabolism during early postnatal life and calls for further studies to determine the origin and fate of circulatory fatty acids.