Feeding the immune system

Abstract

A well-functioning immune system is key to providing good defence against pathogenic organisms and to providing tolerance to non-threatening organisms, to food components and to self. The immune system works by providing an exclusion barrier, by identifying and eliminating pathogens and by identifying and tolerating non-threatening sources of antigens, and by maintaining a memory of immunological encounters. The immune system is complex involving many different cell types distributed throughout the body and many different chemical mediators some of which are involved directly in defence while others have a regulatory role. Babies are born with an immature immune system that fully develops in the first few years of life. Immune competence can decline with ageing. The sub-optimal immune competence that occurs early and late in life increases susceptibility to infection. Undernutrition decreases immune defences, making an individual more susceptible to infection. However, the immune response to an infection can itself impair nutritional status and alter body composition. Practically all forms of immunity are affected by protein-energy malnutrition, but non-specific defences and cell-mediated immunity are most severely affected. Micronutrient deficiencies impair immune function. Here, vitamins A, D and E, and Zn, Fe and Se are discussed. The gutassociated lymphoid tissue is especially important in health and well-being because of its close proximity to a large and diverse population of organisms in the gastrointestinal tract and its exposure to food constituents. Certain probiotic bacteria which modify the gut microbiota enhance immune function in laboratory animals and may do so in human subjects.

n-3 Polyunsaturated Fatty Acids and Mechanisms to Mitigate Inflammatory Paracrine Signaling in Obesity-Associated Breast Cancer

“…Additionally, EPA and DHA exert anti-inflammatory effects following their selective incorporation into the phospholipid fraction of cell membranes where they can act to decrease the signaling efficiency of protein complexes in lipid rafts [70], or serve as substrates for the synthesis of anti-inflammatory bioactive lipid mediators ( i.e. , eicosanoids) [71,72]. Taken together, n -3 PUFA may beneficially modulate obesity-associated pro-inflammatory paracrine interactions between the different cell types within AT.…”

Protein Malnutrition Alters Spleen Cell Proliferation and IL-2 and IL-10 Production by Affecting the STAT-1 and STAT-3 Balance

“…Several studies have shown that malnourished individuals are frequently more susceptible to infections and present an increased mortality rate [1,2]. Considerable evidence suggests that PM impairs immune functions and affects hematopoiesis, thymic development, and the blood cell count as well as many other immunological parameters [1][2][3][4][5][6]. PM induces structural changes in the lymphoid organs, resulting in the involution of the thymus, lymph nodes, and the spleen.…”

Follow-up Formula Consumption in 3- to 4-Year-Olds and Respiratory Infections: An RCT

“…1,2 The transition from a diet of human milk and/or infant formula to a diet consisting of cow' s milk, nonmilk beverages, and solid foods may compromise a child' s nutritional status. 3 Much of the current understanding of nutritional impact on immune outcomes derives from animal studies, which are easily controlled for specific dietary components or from populations whose nutrient deficiencies are endemic.…”