Lung development, health, and diseases

The lungs emerge from the foregut during the embryonic stage, and as they mature, they go through additional morphological and functional changes that extend into the postnatal stage of development. Each developmental stage of the lung is tightly regulated by specific signaling pathways. Nkx2.1 signaling, which is essential for lung specification, is improved by Wnt/β-catenin signaling but necessitates active bone morphogenic protein signaling. Branching morphogenesis of the lungs requires fibroblast growth factor, while vascular endothelial growth factor signaling promotes endothelial cell survival and capillary development. Disruption at any of these developmental stages can result in congenital lung disorders. Although the lungs are quiescent in adulthood, they retain the capacity for regeneration in response to injury caused by infectious and non-infectious agents. Essentially, the lung’s microbiota plays a role in maintaining lung health and disease. Treatment with probiotics has been established in many infectious lung diseases; however, further research is necessary to fully establish their therapeutic potential in treating these conditions.