Throughout the world, departments of gastroenterology often include a division or section for nutritional care. This is a logical inclusion because of the inextricable nature of gastrointestinal illnesses and impaired nutrient utilization. Despite this intuitive rationale, patients are frequently prescribed the most avant-garde medications, such as the newest cholesterol-lowering drug, without explicit dietary recommendations regarding limiting the intake of cholesterol. This paradoxical approach to treatment is partly due to the lack of formal nutritional training among most physicians caring for patients with gastrointestinal illnesses. In addition, most nutritional scientists are unfamiliar with the pathophysiological effects of gastrointestinal illnesses that impair nutrient utilization. Advances in research are uniting pharmacological and nutritional therapies into a new treatment, termed ‘nutritional pharmacotherapy’. Evidence-based confirmation of this important therapy is included in this issue of Current Opinion in Clinical Nutrition and Metabolic Care. Nutritional pharmacotherapy is defined as the use of nutrients that function more like drugs, sometimes used in combination with drugs to enhance nutrient utilization. Historically, clinical nutritionists have been deeply imbued in the ‘more is better’ ideology. This therapeutic approach led to futile attempts to correct nutrient deficits during the catabolic phases of gastrointestinal illnesses. Controlled clinical trials have shown that it is impossible to reverse gastrointestinal-induced catabolism with the prescription of large amounts of nutrients; moreover, this approach may be harmful, often resulting in liver dysfunction. An improved understanding of the mechanisms of catabolism in gastrointestinal illnesses has shown that increased production of counter-regulatory hormones and upregulation of pro-inflammatory cytokines create a metabolic milieu which in turn inhibits the utilization of large (repletion) amounts of nutrients. Because of their unique properties, nutrients with pharmacological effects (pharmaconutrients) are prescribed in small amounts, and are metabolized efficiently in the patient with altered gut function. Examples of pharmaconutrients include the anti-oxidative effects of micronutrients such as vitamins A, C, and E, selenium and zinc; enterotrophic responses of glutamine in the small intestine and butyrate in the colon; stimulation of the immune response with the omega-3 fatty acids; vasodilatory effects of arginine; and amelioration of components of the stress response with the administration of growth factors such as growth hormone and insulin-like growth factor-1. Escalating costs and precipitous changes in the demographics of healthcare delivery will mandate the prescription of pharmaconutrients in the home setting. This will perhaps be most evident in patients in need of elective gastrointestinal endotherapeutic procedures and surgery. Future preoperative preparations will probably include combinations of enterotrophic nutrients, anti-oxidants and immune stimulants before elective surgery such as total proctocolectomy and ileal-anal pouch for refractory ulcerative colitis. ln summary, pharmaconutrients provide exciting new treatments for patients with gastrointestinal disorders. These nutrients may directly affect the gut or may enhance the response to medications. Alternatively, pharmacological agents may improve the absorption of nutrients. Preliminary work suggests that pharmaconutrients may be useful as singular agents or, more likely, in combination with other nutrients or drugs. Pharmaconutrients will be prescribed in the home setting, and may provide prophylactic benefits for depleted patients in need of major gastrointestinal procedures and surgery. These intriguing nutrient-pharmacological agents may revolutionize the nutritional treatment of selected patients with disorders of the gut. Further investigations are warranted in well-controlled clinical trials.
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