Prevalence of Pediatric Acute-Onset Neuropsychiatric Syndrome and Associated Obsessive-Compulsive Symptoms in Youth with Avoidant/Restrictive Food Intake Disorder.

The brain-lung axis constitutes a bidirectional pathway facilitating dynamic interplay between the central nervous system (CNS) and the respiratory system, whose dysregulation is intricately associated with the pathological progression of numerous diseases. Dysbiosis of the lung microbiome influences the susceptibility to autoimmune inflammation of the brain, participates in CNS autoimmune processes, and is implicated in conditions such as Alzheimer's disease (AD) and multiple sclerosis (MS). Within neural pathways, the autonomic nervous system exerts bidirectional modulatory effects in asthma, neurogenic pulmonary edema (NPE), and chronic obstructive pulmonary disease (COPD) by regulating airway reactivity, propagating inflammatory signals, and mediating neurotransmitter secretion. Regarding metabolite pathways, neuropeptides and extracellular vesicles exacerbate pathological damage in acute respiratory distress syndrome (ARDS) and pneumonia by mediating pulmonary vascular permeability, facilitating the dissemination of inflammatory cytokines, and promoting alveolar microthrombosis. The immune pathway, predominantly orchestrated by microglia, features activation states modulated by the lung microbiome; these activated microglia interact with peripheral immune cells via the release of pro-inflammatory mediators, collectively driving neuroinflammation and the systemic inflammatory response characteristic of brain-lung axis-related disorders (). Schematic diagram of the brain-lung axis interaction network. The communication between the brain and lungs is mediated through direct microbial translocation and metabolite signaling, as well as bidirectional regulation of the autonomic nervous system. HPA: hypothalamic-pituitary-adrenal axis; IL: interleukin; NTs: neurotransmitters; TNF-α: tumor necrosis factor-αpha; Ach: acetylcholine; LPS: lipopolysaccharide; SCFAs: short-chain fatty acids; 5-HT: 5-hydroxytryptamine.