Influence of Postoperative Enteral Nutrition on Cellular Immunity: Investigative Procedures, Tests and Analysis

“Postoperative enteral nutrition and cellular immunity” is mostly described in the literature on research into surgical complications. The intention is to show whether a given treatment can be identified as having a beneficial clinical effect and to demonstrate this by the effect on, among other factors, cellular immunity. In order to show that the inclusion of a particular nutrient would have a beneficial effect on cellular immunity, and thus the postoperative course, the research is often related to various types of postoperative immuno-nutrition. This chapter will briefly describe various types of immuno-nutrition and the influence of the added nutrients on cellular immunity. In describing cellular immunity, many different lymphocyte subpopulations have been used, along with markers to describe their activity. As all the different subpopulations can be difficult to remember and understand, the aim of this chapter is to give the reader a short overview of the cellular immunity aspects. It will also give a brief overview of the two types of cells most often described in the literature and their function in the immune response. Many articles indicate the subpopulations of different lymphocyte groups in percentages, making it difficult to understand the comparisons between the different phases of, for example, a postoperative course. This chapter will provide a summary of the investigative procedures described in the literature and explain how to proceed with tests and analyses and how to specify the results so that they can be used to compare the results obtained at different times during the test period. A brief description of the flow cytometric method has therefore been included to give the reader an understanding of how the number of subpopulation percentages is indicated.