Unravelling the Links Between Gastroesophageal Reflux and Lung Disease: New Insights.

Gastroesophageal reflux disease (GERD) is a prevalent comorbidity of chronic respiratory diseases including idiopathic pulmonary fibrosis (IPF), non-IPF interstitial lung disease, asthma, chronic obstructive pulmonary disease (COPD) and refractory chronic cough. Prevalence of symptoms of reflux and/ or refractory respiratory symptoms, along with concerns that refluxed gastric contents into the esophagus may micro-aspirate into the lungs causing injury and potentially accelerate disease progression, have resulted in high usage of empirical anti-reflux treatments. However, empirical treatment of reflux (medical or mechanical) is frequently ineffective without obvious explanation for the lack of respiratory improvement. This review provides novel and updated understanding of the pathophysiological mechanisms that link upper gut dysfunction, reflux (both distal and proximal), lung structure, lung mechanics and breathing patterns, including the potential role of the vagally mediated esophageal-bronchial reflex and the bi-directional nature of these interactions in individual respiratory diseases. We also highlight the need for a consensus between gastrointestinal and respiratory communities and propose a framework for diagnosing and managing GERD in respiratory disease.