Glucagon-like peptide 2: a key link between nutrition and intestinal adaptation in neonates?

This paper reviews the evidence from recent studies in young piglets to examine the hypothesis that glucagon-like peptide 2 (GLP-2) is a physiologically relevant hormonal signal linked to the intestinal adaptation associated with enteral nutrition in neonates. Observations that support the hypothesis include, 1) the GLP-2 secretory response to enteral nutrition is functional as early as late gestation, 2) parallel changes in intestinal growth and circulating GLP-2 occur in response to the quantity and composition of enteral nutrition after birth, and 3) the acute temporal changes in intestinal metabolism and circulating GLP-2 concentrations in response to enteral nutrition are generally coincident. In contrast, however, the lack of intestinal trophic responses to both pharmacological GLP-2 concentrations in the fetus and weanling pigs, and to physiological GLP-2 concentrations in neonates raises doubts concerning the physiological relevance of GLP-2 as a enterally mediated trophic signal. A more definitive test of this hypothesis will require further studies that assess the intestinal metabolic response to enteral nutrition using experimental approaches that block GLP-2 action.