Although TPN has major beneficial effects to the patient and specific organ systems, TPN has a downside which is related to intestinal disuse. Which of the following statement(s) is/are true concerning the effects of TPN on the GI tract?

a. Patients receiving TPN have an accentuated systemic response to endotoxin challenge compared to enterally fed volunteers

b. TPN can result in disruption of intestinal microflora

c. In experimental models, bacterial translocation from the gut is increased

d. Effects of TPN on the gut may lead to multiple organ failure

A number of studies have examined the effects of TPN on intestinal function and immunity. Although most of these studies have been done in animal models, TPN has consistently been shown to have some detrimental effects. In rats, TPN results in significant disruption of the intestinal microflora and bacterial translocation of the gut to the mesenteric lymph nodes. In addition, when stresses such as a burn injury, chemotherapy, or radiation are introduced into these models, animals on TPN have a much higher mortality. The body of literature suggests that TPN under certain circumstances may predispose patients to an increase in gut-derived infectious complications. In a study in human volunteers, individuals receiving TPN had an accentuated systemic response to endotoxin challenge compared to enterally fed volunteers. This study is consistent with impairment of gut barrier function during parenteral feedings which may promote the release of bacteria and/or cytokines leading to pronounced systemic responses and possibly multiple organ failure.