Our daily food intake not only provides the calories and the macro- and micronutrients necessary for survival - nutrients also have a tremendous potential to modulate the actions of the immune system, a fact which has a significant impact on public health and clinical practice. This book presents the latest findings on how nutrient status can modulate immunity and improve health conditions in pediatric patients. Divided into three parts, it covers major aspects of the interplay between nutrients and the regulation of immunity and inflammatory processes. Part one deals with the pharmaceutical value of specific amino acids (arginine and glutamine) and hormones for addressing immune disorders and infant development. The second part revolves around gut function and immunity, and the right balance of probiotics. The final part explores the role of lipid mediators and how their types and proportions can tip the balance in favor of health and disease.