Effect of intestinal resections on arginine metabolism: practical implications for nutrition support

Purpose of review The present review relates recent developments in the understanding of arginine and citrulline metabolism and complementation after intestinal resection. Recent findings Arginine metabolism is disturbed after significant intestinal resection, with reduced fluxes and circulating and tissue concentrations. There is also a reduction in citrulline production, a major source of endogenous arginine by enterocyte metabolism. There is evidence to suggest that arginine or citrulline supplementation may be important in this situation. Summary In experimental intestinal resection, arginine availability decreases as intestinal citrulline synthesis decreases. In this setting, there is debate over the efficiency of arginine supplementation on intestinal adaptation, perhaps due to different doses used. In contrast, citrulline, a precursor for arginine synthesis, whether provided enterally or parenterally, is more efficient at 1 g/kg/day than complementation with arginine (at the same dose) in sustaining arginine pools. In addition, citrulline is more effective than arginine in maintaining nitrogen homeostasis. Clinical studies are vital in order to establish the value of citrulline supplementation in short bowel patients.