Respiratory infections heavily burden the healthcare system, particularly in winter. Individuals with a vulnerable immune system, like very young children, the elderly, and those with an immune deficiency, have an increased risk of contracting a respiratory infection. 

Adaptive and innate defense systems are both involved in active antiviral respiratory tract immunity. The initial response to viral airway infections is via identification by the innate immune system of viral components causing activation of adaptive immune cells in the form of cytotoxic T cells, producing neutralizing antibodies and inducing memory T and B cell responses. 

Instead of concentrating solely on treating the symptoms of infectious disease, optimizing immune responsiveness to the pathogens causing these infections may help gain a more favorable outcome. Nutrition may help prevent it via different immune-supporting mechanisms at several levels.

Nutrition helps in the normal functioning of the immune system, with various nutrients acting as energy sources and building blocks during the immune response. Many micronutrients (vitamins and minerals) regulate the molecular responses of immune cells to infection. It is known that chronic undernutrition and specific micronutrient deficiencies impair many aspects of the immune response and make individuals more susceptible to infectious diseases, especially in the respiratory and gastrointestinal tracts. Additionally, other dietary components like proteins, pre-, pro-, and synbiotics, and animal- and plant-derived bioactive components can further reinforce the immune system. 

Nutritional approaches to prevent infections can thus help prevent infections in vulnerable populations.

Govers C, Calder PC, Savelkoul HFJ, Albers R, van Neerven RJJ. Ingestion, Immunity, and Infection: Nutrition and Viral Respiratory Tract Infections. Frontiers in Immunology. 2022;13. DOI: 10.3389/fimmu.2022.841532