The balance of current clinical data suggests that the route by which patients are fed during the postinjury phase may influence immunologic and metabolic responses to subsequent insults. The mechanisms underlying such amplification processes are presumed to be generated by loss of intestinal barrier function. The resulting host exposure to toxins is hypothesized to induce regional production of inflammatory mediators which serve to alter organ-specific and systemic responses. The cytokine class of mediators appears capable of altering splanchnic tissue function in a manner consistent with observed clinical responses. The breadth of tissue activity influenced by the cytokines spans those benefitting tissue homeostasis and repair to an exaggerated response which may induce tissue injury and organ failure. Data are presented from both clinical and experimental studies to suggest that a lack of intestinal nutrient provision, such as that induced by parenteral feeding, appears to predispose to enhanced cytokine mediator production in hepatic tissues. Thus alterations in the route of antecedent feeding may influence immunologic and metabolic function in a manner which will amplify responses to a subsequent inflammatory challenge.