The immune system composed of cells that are sensitive to a series of surrounding factors and forming an integrated network. During the last decade a significant increase in the number of studies demonstrated that diet components released from adipocytes and metabolic pathways, affected the immune system and highly contributed to the human health. T-cells are significantly affected by nutrition. Decrease in glucose uptake and metabolism, cytokine synthesis, T-cell proliferation and survival in addition to decrease in circulating leptin level have been observed in cases of heavy malnutritions. It has also been shown that leptin represents an important link between nutrition and immunity. Additionally, the effects of diet components on epigenetic mechanisms were also found essential in regulation of the immunity-related genes. The microbiota has also been showen to be a significant factor in the formation and protection of the human immunity. In addition to supply adequate energy and protein requirements for immune system, supporting the immune system with specific nutrients (omega-3 fatty acids, vitamins, trace elements, flavonoids, etc.) is also important. Because they are also required to combat with local or systemic inflammation by strengthening the mucosal, cellular, and humoral immunity. Recently, the concept of immuno-nutrition has been applied with considerable interest. Nutritional Immunology, as a discipline, aims to understand nutritional factors influencing on immune responses.

Introduction

The natural immune system composed of different cells including neutrophils, eosinophils, monocytes, macrophages, basophils, dendritic cells, and natural killer cells (NK). The complement system is activated and numerous cytokines are secreted as an inflammatory response to infection and inflammation. Immunity consists of extremely integrated cells susceptible to surrounding factors.1 The lymphoid system is widely localised in the gut and those cells are particularly sensitive to metabolites induced from nutrients and products induced from microbiota and they also modulate the activation and function of the cells. Approximately 70% of the cells in the immune system and over 90% of the Ig producing cells in human body are localised in the intestines. 2.5
۱۰۱۰ lymphoid cells are seen in bone marrow, spleen and lymph nodes while 8.5
۱۰۱۰ Ig producing cells were described in the gut-related lymphoid tissue. For these reason gut is the largest immune organ where nutrients have the first contact with immune cell receptors and their effects occurred on the immune system.2 Nutritional immunology was identified for the first time in the early 19th century by the identification of an atrophy of the thymus in a malnourished patient. Progressive developments in molecular studies in the field of nutritional immunity or immunonutritional discipline have been observed during the last decade.1 , 3 (Table 1).