Location: Children's Nutrition Research Center2020 Annual Report
The overall goal of our research is to better understand the impact of specific components of plant-based foods have on nutritional health and dietary outcomes. Research will be undertaken that aims to increase our understanding of the negative impact of dietary oxalic acid on human health and the mechanisms regulating its concentration in plant foods. Additionally we aim to increase our understanding of the role of carotenoids to improve the health and quality of life for mothers and infants. To accomplish this the following objectives will be undertaken: 1) characterize oxalate catabolic activity in low and high oxalate plants of dietary importance such as leafy greens harvested at different stages of development; 2) identify and characterize in a model plant system the genes and encoded proteins responsible for each step in a novel pathway of oxalate catabolism; 3) determine the influence of the newly identified oxalate catabolism pathway on the nutritional composition, phytochemical profile, and production characteristics in plants of dietary importance such as leafy greens grown to different stages of maturity (microgreens to mature greens); 4) to define the effect of pregnancy and lactation on carotenoid and vitamin A status and markers of bioactivity in diverse healthy weight and obese women; 5) to determine the pharmacokinetic basis for why adiposity affects breast milk carotenoid composition; 6) determine the interaction between antinutrients calcium oxalate and phytate in plant foods and the gut microbiome; and to 7)utilize a germ-free murine model to determine the inter-relationships between microbial gut ecology, plant calcium oxalate content or phytate content and host calcium, zinc and iron bioavailability.
These research studies will use various techniques to accomplish the research to be undertaken. We will assess the oxalate catabolic activity in low and high oxalate plants of dietary importance at different stages of development. Various analyses will be utilized (mineral, bioavailability, statistical and microscopic analysis of calcium oxalate crystal deposition) to address these research objectives. Further, carotenoid and vitamin A status of the mother during pregnancy and lactation are important to assure optimal health of the mother and adequate transfer of these components to the fetus and infant, respectively. A quasi-experimental (observational) study of a diverse group of U.S. mothers during pregnancy and early lactation will be conducted to define the key determinants of changes in carotenoid and vitamin A status across pregnancy and to explore the implications of these changes for markers of inflammation and cognitive function. Researchers will also examine the nutritional composition of food and explore how these components regulate metabolism. Mice fed plant diets differing in antinutrient content along with in vitro phenotyping will provide insight into the impact of antinutrients on microbial composition. Mice colonized with microbiomes associated with either an antinutrient replete or antinutrient deficient plant-based diet will be used in feeding studies to address alterations in Ca, Zn, and Fe absorption.
To review the progress made during the year, please refer to the following projects: 3092-51000-061-01S (Project #1), 3092-51000-061-02S (Project #2), and 3092-51000-061-03S (Project #3).
Yang, J., Hirschi, K.D., Vivekanudeep, K., Spinler, J.K. 2020. Dietary modulation of the gut microbiome - Probing the role of small RNAs. Reference Module in Life Sciences. https://doi.org/10.1016/B978-0-08-100596-5.22722-4.
Cheng, N., Yu, H., Rao, X., Park, S., Connolly, E.L., Hirschi, K.D., Nakata, P.A. 2020. Alteration of iron responsive gene expression in Arabidopsis glutaredoxin S17 loss of function plants with or without iron stress. Plant Signaling and Behavior. https://doi.org/10.1080/15592324.2020.1758455.
Raber, M., Basen-Engquist, K., Moran, N.E., Chandra, J. 2020. The Healthy Cooking Index does not predict the carotenoid content of home-cooked meals. Nutrients. 12(2): 524. https://doi.org/10.3390/nu12020524.
Ross, C.A., Moran, N.E. 2020. Our current Dietary Reference Intakes for Vitamin A — Now 20 years old. Current Developments in Nutrition. https://doi.org/10.1093/cdn/nzaa096.
Kakeshpour, T., Tamang, T., Park, W.D., Manohar, M., Yang, J., Hirschi, K.D., Park, S. 2020. Expression of small interfering RNAs in lettuce using artificial microRNA technology. Biotechniques. 68(4). https://doi.org/10.2144/btn-2019-0139.
Hirschi, K.D. 2020. Genetically modified plants: Nutritious, sustainable, yet underrated. Journal of Nutrition. https://doi.org/10.1093/jn/nxaa220.