Robert Bertolo has been with the Department of Biochemistry at Memorial University of Newfoundland since 2002. He trained at Guelph and Alberta studying nutrition and metabolism during development with a focus on amino acid and protein nutrition. As a Professor of Nutrition and Metabolism and Canada Research Chair in Human Nutrition (2002-2013), his current research involves the neonatal use of amino acids for growth and non-growth requirements. From a nutritional perspective, he is interested in how much methionine is needed to maintain growth and methylation demands and which pathways take priority when nutrition is inadequate. Dr. Bertolo also has research programs on amino acid requirements during intestinal stress such as in parenteral feeding. More recently, he has developed a model to study neonatal parenteral nutrition feeding and programming of adult diseases. His research is funded by CIHR, NSERC, CFI, hospital foundations and industry to support this research and has served on several grants review panels in Canada and USA. Dr. Bertolo is also actively engaged in nutrition outreach and student development, was the President of the Canadian Nutrition Society and serves in leadership roles in American Society for Nutrition and Institute for the Advancement of Food and Nutrition Sciences.
Methionine is an essential amino acid required not only for protein synthesis, but also as the primary source of one-carbon or methyl groups. These methyl groups are primarily used for methylation to creatine, phosphatidylcholine and for regulating gene expression via DNA methylation. Imbalances in methyl supply early in life can program gene expression and increase risk for diseases later in life. Because neonates have particularly high demands for methyl groups, dietary methyl supply is key to meeting all these demands. This presentation will highlight particularly vulnerable populations to dietary methyl imbalances. For example, parenteral nutrition (PN) is an essential part of the management of preterm and intrauterine growth-restricted (IUGR) infants. And we know that substantial one-carbon and methionine metabolism occurs in the small intestine, which is bypassed and atrophied with PN feeding. Moreover, PN products typically provide few one-carbon nutrients, which can not only limit methionine for short term growth, but also limit methyl groups, which can lead to long term programming of diseases.