<p>Healthcare training programs that require coursework in microbiology and immunology typically focus on diseases and maladies affecting the adult population, but many such issues can be traced to events in the critical window of development, the period from conception to puberty. Yet, nutrition is less often adequately discussed, even though it is a cornerstone of health during the critical window. This text fills these coverage gaps with an emphasis on nutrition, genetics, immunology, and the microbiome. The text also highlights events in the critical window, the importance of the interdependence of lifeforms, and major concepts that link the medical disciplines and basic biology.</p><p></p><p>The initial six chapters focus on events within the critical window, including fetal and neonatal development, nutrition, and the role of the microbiome in health. It also discusses the impact of antibodies, regulatory factors, pathogens, pharmaceuticals, and environmental contaminants that are transferred to the fetus <em>in utero</em> or the infant through breast feeding. Special attention is given to internal protection provided by the innate and adaptive immune systems. An additional chapter is devoted to evaluating medical evidence (including drug and vaccine trials) and a concluding chapter discusses the myths, misconceptions, and controversies in healthcare.</p><p></p><p>Appendix I is included for the student seeking more in-depth coverage of the underlying basic science such as molecular genetics, the role of meiosis and horizontal gene transfer in creating genetic diversity, and the genetics of adaptive immunity. Appendix I also describes the tools of biotechnology, while discussing bioengineering and modern vaccine development. Appendix II describes mammalian diversity and the value of animal models. Reflecting recent medical events, another appendix reviews the immuno-virology of COVID-19. Numerous figures and tables illustrate and extend the text, and a glossary helps the student navigate the thicket of common acronyms in these fields.</p><p></p><p><em>Nutrition, Immunology, and Microbiology: The Critical Window of Development </em>is an ideal textbook for professional healthcare training programs. </p><p></p><p><strong>J.E. Butler </strong>is professor emeritus of microbiology and immunology at the University of Iowa Carver College of Medicine with cross-over experience in comparative immunology.</p><p></p><p><strong>Kirsten Bennett </strong>is a pediatrics registered dietitian currently in private practice with clinical and teaching experience as part of the Pediatrics Department of the University of New Mexico School of Medicine and the Nutrition and Dietetics Program at the University of New Mexico.</p><p></p><p><strong>Larry Williams </strong>served as Associate Professor of Pediatrics at Duke University and recently retired as medical director at Abbott Nutrition Research and Development. He currently consults on scientific, medical, and nutritional issues.</p><p></p><p><strong>Ekhard Ziegler </strong>is professor emeritus in the Department of Pediatrics, Carver College of Medicine, and former Director of the Foman Infant Nutrition Unit.</p>