STABLE-ISOTOPE BREATH TESTS

There is a need for non-invasive tests of gastrointestinal and nutriti onal function. Clinical problems peculiar to infancy and childhood req uire prompt diagnosis, and methods that are invasive or involve the us e of radioisotopes are often impractical or ethically unacceptable. Wh at the pediatrician and clinical scientist seek are tests that are sim ple, repeatable, and unequivocal in their result for diagnosis, to ass ess the effects of treatment, and to measure the development of gastro intestinal function during early life. Stable isotope breath tests off er a ready and attractive answer to these needs. They involve the inge stion of substrates labeled with the non-radioactive isotope of carbon (C-13), followed by the collection of serial breath samples for analy sis of the enrichment of (CO2)-C-13, the end product of substrate meta bolism. Their non-invasive nature recommends them for use in infancy a nd childhood, and they can be performed in the ward, clinic, laborator y, and home. In this article I discuss to what degree stable isotope b reath tests fulfill the pediatrician's and scientist's needs. I have c hosen two examples from the work of myself and my colleagues to illust rate the principles and use of C-13 breath tests to detect Helicobacte r pylori infection and to measure fat digestion in infancy and childho od. (C) Elsevier Science Inc. 1998.