ABSTRACT
The gastrointestinal tract contains enough endotoxin and bacteria to kill a man many million times. Man and other mammals have developed a highly evolved mucosal and intestinal immune system whereby potentially hostile microbial components are confined to the gastrointestinal lumen and effectively neutralized. Patients may be uniquely susceptible to gut-derived septic states due to a multitude of modern medical therapies which, in an effort to combat hemodynamic instability, infection, and malnutrition, may inadvertently suppress immune recovery. Clinical and experimental experience with long-term parenteral alimentation has recognized the gastrointestinal alterations inherent with total parenteral nutrition. Lack of enteral stimulation by foodstuffs, despite adequate parenteral nutrition, may be indispensable for gut integrity and function during stress. A comparison of enteral vs. parenteral glutamine-enriched nutrition in experimental methotrexate-induced enterocolitis demonstrated improved gut barrier function and survival in animals treated with enteral glutamine nutrition, compared with an isonitrogenous, isocaloric parenteral glutamine solution.
