134 Ingredients That Modify the Immune System

Abstract

Abstract Companion animal diets have moved beyond providing complete nutrition for growth or maintenance and into functional outcomes that maintain and improve health and longevity. Select dietary ingredients have additional effects, intended or not, on animal physiology and immune function. Many immune-altering nutrients are fats or fat-soluble, including omega-3 fatty acids, essential oils, phytogenic compounds, and Vitamins A, E, and D. Examples of other related ingredients to which the immune system is responsive include phytogenic compounds, zinc, and probiotics. Because composition and inclusion rate of these nutrients impact immune function and physiology, a focused and intentional selection of specific ingredients is one method to alter inflammatory cascades in animals consuming the diet. While work in human, livestock, and companion animal models is working to identify therapeutic inclusion rates for these nutrients and ingredients, it should be noted that physiological alterations are nutrient-specific and are seen in both over and under-inclusion. For example, inclusion above currently recommended levels may optimize immune function and reduce inflammation in the case of vitamin D or omega-3 PUFA, while for zinc, additional pharmacological supplementation above requirements may inhibit immune function. Probiotics need to be specifically selected and included continuously for maximal benefit. When choosing to formulate an anti-inflammatory diet for long-lived animals, it must also be considered that important “background” functions of the immune system, including monitoring for and clearing pathogenic microbial populations, may be downregulated due to a general reduction in immune reactivity. Continued work to understand how diet and nutrition impact immunity, and how to balance inflammation through nutrition, is an area of active research and will inform downstream users how to best use data to impact consumers of that feed in desirable ways.