Dietary regulation of genes expressed in the developing intestinal epithelium.

Gene expression is central to the pathogenesis of many disorders. An ability to alter the expression of genes would, if their relation to disease processes were fully understood, constitute a new modality of treatment. This lecture examines the evidence that nutritional factors can regulate genes in the gastrointestinal epithelium and it discusses the physiologic relevance of such alterations in gene expression. Dietary regulation of the genes expressed by the epithelium confers 3 fundamental advantages for mammals. It enables the epithelium to adapt to the luminal environment to better digest and absorb food; it provides the means whereby breast milk can influence the development of the gastrointestinal tract; and, when the proteins expressed by the epithelium act on the immune system, it constitutes a signaling mechanism from the intestinal lumen to the body's defenses. Each of these mechanisms is amenable to manipulation for therapeutic purposes.