Lung Microbiota: Its Relationship to Respiratory System Diseases and Approaches for Lung-Targeted Probiotic Bacteria Delivery

Abstract

Microorganisms that make up the local microbiota (suchas Lactobacillus sp. and Bifidobacterium sp.)play a crucial role in the modulation of diseases and health statesby taking place not only in the gut but also in many parts of ourbody. There is also interference between the gut and the lung viathe gut-lung axis. The relationship between respiratory diseasesand lung microbiota, which become more of an issue of particular importancein recent years, shows that probiotics play an essential role in maintainingthe balance of microorganisms in the respiratory tract. However, studieson probiotics' prophylactic or therapeutic application in chroniclung diseases are limited. In this review, the literature between1977 and 2022 was surveyed. General information about human microbiotawas accessed in earlier sources, and especially in the past decade,research on lung microbiota has been reached. The relationship betweenlung microbiota and important respiratory diseases such as bronchopulmonarydysplasia, chronic obstructive pulmonary disease, pneumonia, cysticfibrosis, allergy-asthma, influenza, lung cancer, and COVID-19 infection,was scrutinized after mentioning human microbiota, the gut-lungaxis, and respiratory tract microbiota. The mechanism of action ofprobiotics and the formulation approaches of probiotics in terms ofpharmaceutical technology were reviewed. Finally, future perspectiveson lung-targeted administration of probiotic bacteria with prophylacticor therapeutic potential, or both, were presented.