Malnutrition is a major cause of morbidity in a large portion of the population, particularly among people with specific medical conditions-such as lung cancer patients-and vulnerable population groups, such as pregnant women and the elderly. Lung cancer represents one of the most significant health problems in today's society, with an incidence of 1.8 million cases per year (13% of all cancer cases) and an estimated mortality of 1.6 million deaths annually, making it the leading cause of cancer-related death worldwide.

The aim of this study is to collect data from different lung cancer patients in order to establish a precision nutrition recommendation model. The model will be capable of comprehensively characterizing the nutritional and metabolic status of individuals with nutritional impairment and, therefore, provide personalized dietary solutions based on the unique characteristics of each individual.

To date, the number of personalized nutritional approaches to address malnutrition is relatively small; they have only been applied in very specific cases and generally have not addressed nutritional deficiencies as a whole but rather individual deficiencies. Additionally, these initiatives focused more on stratified nutrition (for groups of individuals) rather than precision nutrition (for individual persons), and in almost no case were factors such as genetics and the microbiome-key components of personalized nutrition-taken into account. This highlights the need to generate precision nutrition models that are capable of addressing the complexity of each individual and providing unique solutions for each nutritional and metabolic state. Despite the interest in these initiatives, no precise dietary personalization that considers the singularities of patients has been carried out to date.

The proposed intervention is a prospective study whose main objective is to collect data for the proper and precise characterization of malnutrition status in lung cancer patients and to evaluate the role of major factors related to metabolic health (composition and functionality of genotype and gut microbiota, among others) and the pathogenesis and progression of cancer (tumor characterization, composition and functionality of the lung microbiota, etc.) on the nutritional status, quality of life, and prognosis of these patients. This nutritional study is therefore an exploratory initiative that takes into account several factors contributing to the nutritional and health status of malnourished individuals.

The study will be conducted within the framework of the MENTORINNG project (Project ID: 101162297; Title: Addressing malnutrition and metabolic health in non-communicable diseases through precision Nutrition: impact on quality of life and prognosis of lung cancer patients). Under this umbrella, a multidisciplinary consortium has been created and funded under the "HORIZON-EIC-2023-PATHFINDERCHALLENGES-01; Programme: HORIZON; DG/Agency: EISMEA" call, with a budget of €4,031,666.25 for the development of scientific activities. Several international institutions are part of this consortium.

Inclusion Criteria

• Study population cohort: Patients of both sexes Patients aged between 18 and 85 years Patients diagnosed with lung cancer (non-small cell and small cell) Patients treated with chemotherapy, immunotherapy, combinations of immunotherapy and biological therapy, patients receiving conservative therapy, without active treatment, or any other type of treatment, according to ESMO and NCCN guidelines for the management of metastatic lung cancer (small cell and non-small cell)

• Control population cohort: Volunteers of both sexes Volunteers aged between 18 and 85 years Volunteers free of oncological disease

Exclusion Criteria

• Study population cohort: Patients with uncontrolled chronic diseases Patients with acute gastrointestinal diseases

• Control population cohort: Volunteers with uncontrolled chronic diseases Volunteers with acute gastrointestinal diseases Volunteers who have had any type of oncological condition at any point in their lives Volunteers with diagnosed pulmonary pathology: chronic lung disease, asthma, pulmonary fibrosis, bronchiectasis, interstitial lung disease, recent pneumonia (3-6 months), moderate/severe sleep apnea, latent or previous tuberculosis with sequelae Volunteers with underlying autoimmune diseases: rheumatoid arthritis, systemic lupus erythematosus, multiple sclerosis Volunteers with active or chronic infections: HIV, hepatitis B or C, recurrent chronic infections, tuberculosis

This study aims to include, across the two planned recruitment centers, between 150 and 180 patients with lung cancer (non-small cell and small cell) treated with chemotherapy, immunotherapy, combinations of immunotherapy and biological therapy, patients receiving conservative therapy, without active treatment, or any other type of treatment.

The recruitment centers for lung cancer patients are the Infanta Sofía University Hospital (Madrid, Spain) and the University Hospital of Parma (Parma, Italy). The recruitment center for healthy volunteers is IMDEA Nutrition.