Role of Brain-Gut-Microbiome Axis in Depression Comorbid with Asthma

Asthma (ATA) is a long term inflammatory condition of the respiratory tract (RT) where stress and psychological factors play a significant role. A high rate of comorbidity of ATA and depression or major depressive disorder (MDD) is observed in many patients. The proposed correlations between ATA and depression include a vulnerability (trait) and state connection. Vulnerability for both ATA and depression may utilize genetic and early development causes. In addition, some other factors are common in both the conditions, such as obstructive factors, factors associated with inflammation, insomnia, psychological reactions to long term medical illness. The recent research advocates the participation of the central nervous system (CNS) in ATA. Recently, the role of the brain-gut-microbiome (BGM) and gut-lung-microbiome (GLM) axis is studied, and both the pathways have exhibited strong interconnection with each other. Commensal microbes are crucial for the formation of a proper immune system. The role of commensal bacteria in both the respiratory and gastrointestinal tracts can be a crucial factor in treating ATA. Similarly, human gut microbiota (GM) exhibits a marked role in the pathophysiology of depression. Recent studies suggest correlations between the altered GM and major depressive disorders (MDD). Further characterization of clinical, psychological, cellular, and molecular associations between ATA and depression is required to evaluate and treat these patients in a better way. The present book chapter mainly focuses on the influence of the brain-gut-microbiome axis with the involvement of lungs in the pathophysiology and treatment of depression comorbid with ATA.