Location: Children's Nutrition Research Center2020 Annual Report
Objective 1: Determine if antinutrients in plant foods impact the gut microbiome. Subobjective 1A: Using mice feeding studies, analyze the interaction between antinutrient content in plant-based diets and gut microbiota. Subobjective 1B: Assess the impact of plant-based antinutrient content on animal and human microbiomes using in vitro systems. Objective 2: Utilize a germ-free murine model to determine the inter-relationships between microbial gut ecology, plant anti-nutrients and host mineral bioavailability.
Unique plant diets differing in antinutrient content can be used along with 16S ribosomal RNA sequencing to determine how bacterial populations fluctuate as a function of antinutrients. Calcium (Ca) is often sequestered as an oxalate salt making it an 'antinutrient' and bio-unavailable. Medicago truncatula contains insoluble calcium oxalate crystals making it a poor source of dietary Ca. However, a M. truncatula mutant lacking oxalate crystals in the leaf tissue is an excellent source of Ca and allows the preparation of diets that differ in a single plant mutation to be used to analyze the impact of oxalate on the microbiome. Using primary cell culture models from both humans and mice will provide further insights into the impact of antinutrients on microbial composition. Meanwhile, mice reconstituted with either a microbiome associated with an antinutrient replete or antinutrient deficient diet, but consuming equivalent diets, will be analyzed for differences in calcium, iron, and zinc absorption.
Although our project was approved for only a few months, our initial goals for fiscal year 2020 were to grow plants to prepare diets and then perform mouse feeding studies. All animal, radioactive, and recombinant DNA protocols have now been approved; however, due to COVID-19, we were required to scale back greenhouse activities and all animal feeding studies were halted. At the time of submission of this report we still are unable to order animals to initiate feeding studies. As of mid-May, we initiated growing some of the plant material for future feeding studies. We have analyzed some preliminary data from work done in early 2020 and are ready to initiate feeding studies when such work is allowed to continue.