Choline is an essential nutrient needed for proper organ function, and can be found as free choline or as a derivative such as phosphatidylcholine (the most abundant form in food), glycerophosphocholine, phosphocholine and sphingomyelin. Betaine is also a derivative of choline, but unlike other forms of choline, it cannot be converted back to choline, and serves as a methyl donor in one-carbon (1C) metabolism used for methylation reactions. Various substrates are known to be methylated, and among which, methylation of DNA is a well-established type of epigenetic mechanism that regulates gene expression without altering the DNA sequence. A growing interest is in the role of epigenetic variations arising from exposure to 1C nutrients in early life that can shape metabolic phenotypes in later life, supporting the Developmental Origins of Health and Disease hypothesis. Beyond the role of choline (through betaine) in epigenetic modification, choline has received recent attention as a dietary precursor for the gut microbial-generated product trimethylamine that is oxidized in liver to form trimethylamine-N-oxide (TMAO), a marker suggested to increase cardiovascular disease risk. However, TMAO production from dietary precursors is highly variable and appears to be dependent on the gut microbiota composition. The objectives of this presentation are 1) To examine the role of prenatal choline in epigenetic programming of metabolic health; 2) To compare different forms of choline (i.e., free choline versus phosphatidylcholine) in the production of TMAO; and 3) To consider broader implications of choline intake in the context of potential intervention strategies to improve health.
Dr. Clara Cho is an Assistant Professor and CIHR Canada Research Chair in Precision Nutrition (Tier II) in the Department of Human Health and Nutritional Sciences at the University of Guelph as of 2021. She was previously an Assistant Professor in the Department of Nutrition, Dietetics and Food Sciences at Utah State University from 2016-2021. She obtained her BSc in Nutritional Sciences and Physiology at the University of Toronto in 2009, PhD in Nutritional Sciences at the University of Toronto in 2014 and completed her postdoctoral fellowship in the Division of Nutritional Sciences at Cornell University from 2014-2016. Dr. Cho examines the role of methyl nutrients including folic acid and choline in chronic disease risk, with a focus on individual heterogeneity in response to nutrients. Her laboratory provides integrated assessments of the central and peripheral system alterations underlying metabolic phenotypes. Dr. Cho’s work has been supported by the Canadian Institutes of Health Research, Canada Foundation for Innovation, Egg Farmers of Canada, Ontario Research Fund, National Institutes of Health, National Institute of Food and Agriculture and U.S. commodity boards.