Enterocyte Injury and Acute Gastrointestinal Dysfunction in Critical Illness

Acute gastrointestinal injury (AGI) is a common but not fully understood organ dysfunction in critically ill patients. Current AGI grading systems rely primarily on clinical presentation and feeding tolerance, which are inherently subjective and may not accurately reflect the underlying biological severity of intestinal damage. Intestinal fatty acid-binding protein (I-FABP) is a protein expressed almost exclusively in the cytoplasm of mature small intestinal epithelial cells. In cases of ischemia, inflammation, or mechanical injury, I-FABP is rapidly released into the bloodstream and subsequently excreted in the urine. These characteristics make I-FABP a highly specific biomarker for intestinal epithelial cell injury and intestinal ischemia. A prospective study combining paired blood and urine I-FABP measurements, standardized AGI assessment, and careful consideration of surgical status was conducted to elucidate the role of intestinal epithelial cell injury in acute gastrointestinal dysfunction.