Impact of Early Enteral vs. Parenteral Nutrition on Preservation of Gut Mucosa Integrity in Patients Requiring Mechanical Ventilation and Catecholamine

Published data suggest that enteral nutrition may be associated with improved preservation of the gut lymphoid tissues and gut immune function, as well as with decreased gut mucosa permeability, thereby diminishing the risk of organ failure. Citrulline is an amino acid produced from glutamine by small-bowel enterocytes. Plasma citrulline levels reflect functional enterocyte mass. Intestinal fatty acid-binding protein (I-FABP, also known as FABP2) is a small protein found in the cytosol of small-bowel enterocytes. Plasma I-FABP is normally undetectable and, when elevated, constitutes a reliable marker for enterocyte damage. The hypothesis underlying this ancillary study is that first-line enteral nutrition is associated with improved gut mucosa integrity and function compared to parenteral nutrition.