The gut-lung axis plays a critical role in the progression of respiratory diseases, with gut microbiota facilitating bidirectional regulation between the respiratory and gastrointestinal systems. Metabolites produced by gut microbiota not only influence gut microbiome composition but also impact respiratory diseases such as asthma, chronic obstructive pulmonary disease (COPD), pulmonary hypertension, and viral pneumonia through direct or indirect mechanisms via the gut-lung axis. This review explores the involvement of gut microbiota-derived metabolites in respiratory disease pathophysiology, aiming to provide new insights into potential mechanisms, preventive strategies, and therapeutic approaches for respiratory conditions.