Professor Allan Walker
Winner of the Macy-Gyorgy Award
for Research in Human Milk and Lactation

The International Society for Research in Human Milk and Lactation (ISRHML) Meeting in Perth, Australia has selected the 8th Recipient of the Macy-Gyorgy Award – Professor Allan Walker of Harvard Medical School. This award, given every other year at the international meeting, honors senior scientists who have made outstanding original scientific contributions to the study of human milk and lactation and whose work has been recognized internationally and whose papers have appeared in excellent peer-review journals.

Dr. Walker is widely recognized as one of the pioneers in mucosal immunology, and particularly on the mechanisms whereby human milk influences maturation of the human gut and affords immune protection to the breastfeeding infant. He made several research observations on the role of human milk on the mucosal barrier in infants, and has continued to be in the forefront of research on the interaction of human milk with development of the infant’s mucosal immune system.

Dr. Walker is currently the Conrad Taff Professor of Nutrition and Pediatrics at Harvard Medical School. He grew up in Chicago and graduated from DePauw University (magna cum laude) with a major concentration in English. He received his medical degree at Washington University (cum laude) and did residency training in Minnesota in Pediatrics, where he pursued his immunology interests under Dr. Robert Good. He then became a Research Fellow in Medicine (Gastroenterology) at the Massachusetts General Hospital under Drs. Kurt Isselbacher and Kurt Bloch. When he came to the Department of Medicine at MGH, there was no specialty of gastroenterology in pediatrics. Dr. Walker was asked to develop this specialty. From the outset, he recognized that human milk interactions were essential components of development of the intestinal immune system. His focus on human milk has become central to the teaching and practice of pediatric gastroenterology and neonatology to this day.

From the beginning of this program Dr. Walker focused on attracting and training highly talented and motivated pediatricians into the field of gastroenterology and nutrition. His program was so successful at Massachusetts General Hospital that he was invited to develop a similar program at Boston Children’s Hospital. The resulting Combined Program in Pediatric Gastroenterology and Nutrition served as a model of excellence for the rest of the world, training large numbers of fellows in research on clinical nutrition and developmental gastroenterology, many of whom are today leaders in the field. Research in human milk and intestinal mucosal development is the underlying thrust of each of the programs he has developed.

In addition, identifying factors in breast milk that function locally within the intestine such as secretory IgA has cemented the concept that this is an essential component of milk and of our current understanding of how human milk mediates the transfer of passive immunity from mother to infant. He also reported on how breast milk helps the mucosal barrier develop in the premature and term infant gut. Furthermore, his was some of the first research on the relationship between consumption of human milk and reduced incidence of necrotizing enterocolitis in premature infants. This has led to his pioneering studies on the development of innate immunity in the infant gut, the role of Toll-like receptors and their signal transduction pathways on early inflammatory responses by infants, and how this system is modulated by human milk factors. Indicative of Dr. Walker’s contribution to this field is that he has had continuous NIH support for twenty-five years for a grant entitled “The Effect of Colostrum on Gut Maturity and Host Defense” and as a MERIT Award for the last ten years. He has also defined the mechanisms of other protective nutrients in breast milk (nucleotides, prebiotics, etc.) and has a number of publications on this issue.

Dr. Walker has been in the forefront of transforming our understanding of human milk from an ideal nutrient for the infant to a maternal secretion that plays a major role in providing maternal protection to the nursing infant through the acquired and innate immune systems. His work has been recognized internationally, and, as is apparent by the attached CV, he has published an outstanding number of seminal primary observations in major peer reviewed journals. He has also written extensive reviews and books to disseminate what is known about the protective effects of breastfeeding both to medical professionals and to the general public.