Clinical nutrition for the gastroenterologist: the physiologic rationale for providing early nutritional therapy to the hospitalized patient.
Conflicting reports in the literature have been misinterpreted by clinicians, who conclude that nutritional therapy for the hospitalized patient is of marginal value. The true benefit of such therapy is derived from the provision of early enteral nutrition. This article describes the physiologic response to enteral feeding, which accounts for the outcome benefits, and illustrates how use of the gut alters immune responses and the intestinal microbiota.The provision of early enteral nutrition has been shown to reduce infection and mortality in high-risk hospitalized patients (compared with not providing such therapy). Early feeding maintains gut integrity, reduces permeability, promotes tolerance and appropriate immune responses, and supports commensalism of the intestinal microbiota. Early enteral nutrition influences cross-talk signaling between luminal bacteria and the intestinal epithelium. Failure to utilize the gut in acute illness can amplify the systemic inflammatory response syndrome and worsen disease severity, while at the same time promoting antibiotic resistance and increased septic morbidity.Appropriate nutritional therapy does change outcomes in the hospitalized patient, especially for those who are at risk on the basis of disease severity and/or poor nutritional status. Greatest benefit is seen from those therapeutic regimens that specifically target gut defenses and the intestinal microbiome.