Abstract Body

Paediatric nutrition is the maintenance of a proper, well-balanced diet, consisting of essential nutrients and adequate caloric intake, appropriate for the stage of development of the child. Changes during the immediate postnatal period are the most significant in terms of future health and well-being, so I will concentrate primarily on milk substitutes, more especially because I think this is an area where most potential exists for improvement. Many studies have shown that growth and development are less optimal in babies fed formula or substitutes than those who are given breast milk. However, it is not always possible to provide breast milk to the infant, and various formulae have been developed, and continue to be developed, to try and provide an acceptable substitute.

Originally, animal milks were used, but the first synthesised milk was invented in 1865 and by 1883 there were 27 patented infant foods. The original substitutes were primarily of animal milk with the addition of various ingredients such as wheat and malt flour and potassium bicarbonate. As time went on, various ingredients were added to improve quality of the food. A good example of this is the development of human milk fat substitutes. The first, up to about the 1920s, provided fats for energy. Between the 20s and the 90s, fatty acids were added and from then to the present, triacylglycerols and complex lipids were added. The structure of lipids in milk is also important. Fat globules consist of a triacyl glycerol core, surrounded by plasma membrane derived from the secretory cells.

Currently, human milk substitute constituents are controlled. The list of required nutrients is given in the Codex Alimentarius. Other ingredients can be added if shown scientifically to be of benefit. Importantly, human milk has many “non-nutritional” components, that perform diverse physiological functions, not all of which are completely understood. These include different cell types, bioactive components, growth factors, hormones and immunological factors. Oligosaccharides function as prebiotics and may also play a role with proteins, to act as “decoy” receptors for pathogens with affinity for the oligosaccharides on the intestinal surface. Human milk also has its own microbiome, which is very varied and which changes during lactation. The function of many of these bacteria remains obscure!

Recent studies have identified many microRNAs which may have important functions, not all of which are understood. MicroRNAs are short, noncoding RNA sequences, which act as post-transcriptional regulators of gene expression. miRNA are taken up across the infant epithelium and transferred to target tissues through the bloodstream. All of these components are important, and approaches to reproduce them and their functions could help in improving milk substitutes.

EFSA has published opinions on nutritional content of infant formula and follow-on foods. The panel concluded that nutrients and other substances should be added only in amounts that serve a nutritional or other benefit. This seems self-evident, and reduces the value of considering novel foods. However, sources of nutrients other than, for example, cow or goat milk, may become more appropriate for sustainability or economic reasons, so that continued research can be of value.

In conclusion, I have considered in some detail the composition of human milk, and how its components may play a function in normal development of the human infant. Although these may not be easy to provide, the differences between breast milk components and substitutes, and the difference in outcome between babies fed breast milk and those given substitutes, makes clear the value of continuing to find novel foods in paediatric nutrition.

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