[Nutrition, microbiota and respiratory infections: key aspects of their interaction]

Introduction: respiratory infections (RI) have experienced a rebound following the lifting of COVID-19 restrictions, constituting a major public health problem. Diet and nutritional status are determining factors in the competence of the immune system, where the gut-lung axis has been identified as a key mechanism in regulating the immune response against these processes. Objectives: to analyze the scientific evidence on the role of diet and microbiota in the prevention and evolution of respiratory infections. Methods: narrative review of recent scientific literature on nutrients, dietary patterns, gut microbiota, and their relationship with respiratory immunity. Results: various nutrients such as fiber, n-3 polyunsaturated fatty acids, vitamins, minerals, and polyphenols, as well as the use of probiotics, modulate the gut microbiota and promote the production of metabolites, especially short-chain fatty acids (SCFAs), with immunomodulatory effects. These mechanisms contribute to improving the pulmonary immune response and reducing the incidence and severity of RI. Conclusions: a balanced and high-nutrient-density diet, rich in prebiotic and probiotic compounds, can contribute to strengthening the immune response and decreasing vulnerability to respiratory infections.