ABSTRACT
This chapter reviews the history of development of noninvasive techniques for assessing intestinal permeability in humans, to outline the practical aspects of testing, and to draw attention to ways to localize the observed changes. With the introduction of nonmetabolized disaccharides as test substances it became practically possible to assess intestinal permeability noninvasively in humans. The term permeability has become synonymous with assessing the intestinal barrier function. Assessment of upper gastrointestinal permeability may be possible to assess the gastric side effects of alcohol selectively by using a sucrose permeation test which has been validated in relation to the gastric toxicity of NSAIDs. The chapter outlines some recent developments in intestinal function testing which represents an advance on preexisting tests in respect to sensitivity and specificity. NSAIDs increase intestinal permeability within 12 h of ingestion. The permeability changes occur in the period during drug absorption when the enterocytes are exposed to the highest concentration of the drugs.
