The respiratory tract, a complex organ system responsible for gas exchange, is inhabited by niche-specific bacterial communities. These microbiota play a crucial role in maintaining respiratory health by acting as gatekeepers, preventing the colonization of respiratory pathogens and maintaining homeostasis. The development and function of the respiratory microbiota are influenced by ecological and environmental factors, and recent studies have highlighted its broader role in human health beyond the gut. The upper respiratory tract (URT) and lower respiratory tract (LRT) have distinct microbial communities, with the URT being more diverse and dominated by bacteria such as *Moraxella*, *Staphylococcus*, and *Corynebacterium*. The LRT, traditionally considered sterile, has been found to harbor a diverse microbial community, primarily derived from the URT. The respiratory microbiota is influenced by host and environmental factors, including birth mode, feeding type, and antibiotic use. Early life is a critical period for the establishment of a stable respiratory microbiota, which is crucial for immune development and respiratory health. The respiratory microbiota interacts with the host immune system, contributing to immune tolerance and resistance to infections. The role of the respiratory microbiota in maintaining respiratory health is still evolving, and further research is needed to understand its precise functions and interactions with the host and environment.The respiratory tract, a complex organ system responsible for gas exchange, is inhabited by niche-specific bacterial communities. These microbiota play a crucial role in maintaining respiratory health by acting as gatekeepers, preventing the colonization of respiratory pathogens and maintaining homeostasis. The development and function of the respiratory microbiota are influenced by ecological and environmental factors, and recent studies have highlighted its broader role in human health beyond the gut. The upper respiratory tract (URT) and lower respiratory tract (LRT) have distinct microbial communities, with the URT being more diverse and dominated by bacteria such as *Moraxella*, *Staphylococcus*, and *Corynebacterium*. The LRT, traditionally considered sterile, has been found to harbor a diverse microbial community, primarily derived from the URT. The respiratory microbiota is influenced by host and environmental factors, including birth mode, feeding type, and antibiotic use. Early life is a critical period for the establishment of a stable respiratory microbiota, which is crucial for immune development and respiratory health. The respiratory microbiota interacts with the host immune system, contributing to immune tolerance and resistance to infections. The role of the respiratory microbiota in maintaining respiratory health is still evolving, and further research is needed to understand its precise functions and interactions with the host and environment.