This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Chronic idiopathic diarrhea (ICD) is a major health and economic problem in the management of rhesus monkeys in captivity. The pathogenic mechanism(s)underlying this condition have not been well studied beyond histological characterization of the colonic inflammatory cellular infiltrate in the absence of recognized enteric pathogens. The goal of this project is to systematically investigate potential pathogenetic mechanisms, including food hypersensitivity, hypersensitivity to normal gut commensal bacteria, and irregularities in composition of colonic microflora (dysbiosis), in the development of this condition. This project will also investigate the therapeutic potential of dietary supplementation with zinc and/or soluble fiber in the treatment and prevention of ICD.