Effect of Diet on Immune and Physiological Changes by Infection, Inflammaton, and Allergens
Diet, Genomics and Immunology Lab
2010 Annual Report
1a.Objectives (from AD-416)
ARS is interested in determining the impact of health-promoting components in foods including those containing probiotic bacteria, and how allergens and infections alter intestinal immunity and physiology. Our project plan has two objectives that directly relate to this agreement: Objective 2: To elucidate the mechanisms used by probiotic bacteria to improve respiratory and intestinal mucosal responses to allergens, and correlate intestinal microflora composition of pigs and humans with biomarkers of allergic and intestinal disease, and Objective 3: To elucidate the mechanisms by which micronutrients affect gut physiology and immune competence in response to food-borne illness due to viruses, bacteria, and gastrointestinal parasites. The COOPERATOR directs a laboratory that has supported ARS activities to evaluate mucosal responses to pathogens and allergens. A formal agreement to expand the interaction can facilitate the objectives of the project and support from external funds.
1b.Approach (from AD-416)
Experimental mouse and swine models of viral, bacterial, and parasitic infection as well as exposure to allergens will be evaluated for changes in immune and physiological responses at mucosal surfaces. This information will be used by both ARS and the COOPERATOR to jointly develop new research studies that focus on the evaluation of dietary and probiotic intervention to prevent the onset of inflammation and dysfunction, and enhance healthy mucosal surfaces.
In this project the technology for the use of trans epithelial electronic resistance (TEER) assay has been completed and the assay is now routinely used for all diet-related pig studies involving both the use of the Ossabaw juvenile-obesity pig model in testing of the effects of probiotics on inflammation and the bran-fiber conventional pig model evaluating intestinal response to changing bacterial populations. Mouse models are under study that use molecular, physiological, and histological evaluation assays to examine the role of selenium deficiency in responses to the worm parasite, Heligmosomoides polygyrus, and a foodborne bacterial pathogen model using Citrobacter rodentium. The models have detected differences in intestinal function that are STAT6 and STAT4-dependent, respectively. Activities are monitored by the ARS scientists involved through periodic meetings, email, and conference calls with scientists at the University of Maryland.