Immunonutrition, a topic of interest

Outbreaks of avian and swine influenza, as well as African swine fever in Asia, are forcing scientists to reevaluate and redirect their research towards a stronger strengthening of the immune system through nutrition.

Immunonutrition is the study of the relationship between food and the immune system. It evolved with the study of immunodeficiencies caused by malnutrition, human immunodeficiency virus (HIV), animal infectious anemia. However, due to technological advances made in recent decades, malnutrition is no longer the main cause of decreased immune status in healthy people/animals. Rather, the stage of life (newborn or old age) and natural stressors have become the main cause of immunodeficiency. Unlike malnutrition, immunodeficiency due to the stage of life or natural stress cannot be addressed by correcting the underlying nutritional problems. The decreased immune status due to the stage of life or natural stress is characterized by a reduced ability to process and present foreign antigens to immune cells, resulting in a less efficient or altered immune response that leads to increased susceptibility to infections and an increase in autoimmunity and cancers. Beyond providing essential nutrients, diet can actively influence the immune system. More than 65% of the immune cells in the body are present in the intestine, which makes the intestine the "largest immune organ." The receptors present in the immune cells in the intestine are the main targets for immunomodulation through diet. The diet interacts with the immune system at multiple levels, starting with providing basic nutrients, then going on to provide higher levels of key nutrients such as proteins, vitamins and minerals, and leading to a more focused modulation of the immune system.

Nutrients such as copper, zinc, iron, selenium, vitamin A, vitamin B6, folic acid (vitamin B9), vitamin B12, vitamin C and vitamin D are related to the normal functioning of the immune system.

The nutritional requirements of an animal depend on its sanitary conditions (healthy or sick) and stress.

Immunonutrition “is precisely responsible for providing the necessary nutrients to strengthen the immune system, curative or preventive".

Arginine, glutamine, nucleotides and fatty acids (omega-3), are among some of the so-called immunonutrients, compounds that are contained in certain foods, but also exist in food supplements, which lately are gaining popularity, through products or nutritional formulas.

Metabolic requirements for the proper functioning of macrophages, neutrophils and T cells.

When an animal is challenged by a pathogen, it decreases food consumption and to compensate for the negative balance of nitrogen (N) and energy (ATP), the catabolism of body tissues (muscles and fats) begins, to nourish the immune system, this increases. The demand for arginine, glutamine, threonine, methionine + cystine, branched amino acids (Leucine, isoleucine and valine) also uses polyunsaturated fatty acids (muscle glycogens), replacing the glucose in the food. Amino acids are deaminated and used as energy sources too.

- The nutritionist must formulate for maintenance, growth, production and a strengthened immune system of animals.

- The nutritional requirements of an animal depend on its sanitary conditions (healthy or sick) and the level of stress.

- The order of nutrient needs may vary between a healthy, sick and stressed animal, also by the route that is challenged (intestinal, respiratory, urinary, etc).