Total parenteral nutrition: iatrogenic immunosuppression.

It may be necessary for future formulations of TPN to encompass functions other than mere provisions of nutrients. Although current solutions of TPN are well tolerated in most patients for short periods and remain an important adjunct to modern surgical therapy, these solutions have significant room for improvement. Designing the ideal artificial gut for the highly stressed patient may include reproduction of the neurological, endocrine, and immune responses that occur after the oral presentation of foodstuffs.