Nutrition in early life, immune-programming and allergies: the role of epigenetics.

Early life nutritional exposures are significant determinants of the development and future health of all organ systems. The dramatic rise in infant immune diseases, most notably allergy, indicates the specific vulnerability of the immune system to early environmental changes. The associated parallel rise in metabolic diseases including obesity, childhood type 2-diabetes and non-alcoholic fatty liver disease highlights the interplay between modern dietary patterns and increasing abnormalities of both immune and metabolic health. The low-grade inflammation that characterize these non-communicable diseases (NCDs) suggests a central role of the immune system in the pathogenesis of these conditions. Understanding how environmental influences disrupt the finely balanced development of immune and metabolic programing is of critical importance. Diet-sensitive pathways are likely to be crucial in these processes. While epigenetic mechanism provides a strong explanation of how nutritional exposures can affect the fetal gene expression and subsequent disease risk, other diet-induced tissue compositional changes may also contribute directly to altered immune and metabolic function. Although modern dietary changes are complex and involve changing patterns of many nutrients, there is also interest in the developmental effects of specific nutrients such as folic acid levels, which have clear epigenetic effects on programming. Here we examine the current knowledge of the nutritional-programming of immune health and how research into nutritional-epigenetics in the context of allergic disease as one of the earliest onset NCDs can expand our knowledge to discover the biological processes sensitive to nutritional exposures in early life to prevent later disease risk.