The brain-lung axis: Bridging neurological and respiratory disorders via neural-immune-microbial dialogue

The human brain maintains intricate interconnections with various peripheral organs. Recent scientific inquiry has substantiated the existence of the gut-brain axis; nevertheless, emerging evidence suggests that the brain and lungs engage in bidirectional communication through multiple pathways, thereby giving rise to the conceptualization of a brain-lung axis. Studies indicate the presence of crosstalk between the central nervous system and the lungs, mediated by the lung microbiome, neural pathways, metabolite signaling, and immune pathways. This bidirectional communication between the brain and lungs is further implicated in the pathogenesis of several diseases: traumatic brain injury, stroke, and other cerebral disorders can precipitate pulmonary injury; conversely, severe pulmonary conditions, such as acute respiratory distress syndrome and chronic obstructive pulmonary disease, can exacerbate neuroinflammation, intensify brain damage, impair neurological function, and contribute to adverse prognoses. Exploring the brain-lung axis not only facilitates a multifaceted understanding of disease progression, but also unveils critical targets for therapeutic intervention. Research into the brain-lung axis provides novel perspectives for deciphering underlying pathological mechanisms, developing diagnostic methodologies, and formulating treatment strategies. It further establishes a theoretical foundation for cross-organ targeted therapies, holding promise for ameliorating patient outcomes and promoting the advancement of integrated diagnostic and therapeutic approaches for respiratory and neurological disorders.