He obtained his Ph.D. in Molecular Biology from New Mexico State University. Dr. Yu is interested in ecological studies of microorganisms inside (mainly the gastrointestinal track) and outside (the surrounding environments) of food-producing animals that are important to animal nutrition and health. Another thrust of his research is ecological studies of antibiotic resistance originating from food-animal production. In recent years, concern has increased on the impact of agricultural use of antibiotics, especially in food animals, on human health.