Lung Microbiome Participation in Local Immune Response Regulation in Respiratory Diseases

Abstract

The lung microbiome composition has critical implications in the regulation of innate and adaptive immune responses. Next-generation sequencing techniques have revolutionized the understanding of pulmonary physiology and pathology. Currently, it is clear that the lung is not a sterile place; therefore, the investigation of the participation of the pulmonary microbiome in the presentation, severity, and prognosis of multiple pathologies, such as asthma, chronic obstructive pulmonary disease, and interstitial lung diseases, contributes to a better understanding of the pathophysiology. Dysregulation of microbiota components in the microbiome–host interaction is associated with multiple lung pathologies, severity, and prognosis, making microbiome study a useful tool for the identification of potential therapeutic strategies. This review integrates the findings regarding the activation and regulation of the innate and adaptive immune response pathways according to the microbiome, including microbial patterns that could be characteristic of certain diseases. Further studies are required to verify whether the microbial profile and its metabolites can be used as biomarkers of disease progression or poor prognosis and to identify new therapeutic targets that restore lung dysbiosis safely and effectively.

Nasal Bacteriomes of Patients with Asthma and Allergic Rhinitis Show Unique Composition, Structure, Function and Interactions

“…Asthma and allergic rhinitis are two conditions that, either when occurring together or separately, impart a health and economic burden to persons and society [ 6 , 7 , 15 , 95 , 96 , 97 ]. Emerging evidence has suggested that both airway diseases are intimately linked to alterations of the nasal bacteriome [ 45 , 52 , 56 , 93 , 98 , 99 , 100 , 101 , 102 ]. In this cross-sectional study, we apply 16S rRNA amplicon HTS to a large cohort of individuals from northern Portugal with asthma or allergic rhinitis (with and without comorbid asthma) and healthy controls to characterize their nasal bacteriotas.…”

“…The airway microbiota can influence host metabolism and homeostasis, including epithelial cell growth and repair, and inflammatory and immune responses, thereby impacting chronic disease onset and progression [ 34 , 39 , 45 , 99 , 100 , 101 , 102 , 109 , 117 , 118 , 119 ]. Compared to healthy controls, our PICRUSt2 analyses predicted 50–55 pathways upregulated in rhinitic patients ( Figure S3 ).…”

Temporal changes of the respiratory microbiota as cats transition from health to experimental acute and chronic allergic asthma

“…Sequencing bacterial 16S rRNA amplicons, even in low biomass samples such as bronchoalveolar lavage fluid (BALF), represents a powerful tool to overcome a critical barrier to progress in understanding the role of complex microbial communities in the respiratory tract. Recent data suggest the endogenous airway microbiota play a fundamental role in establishing health vs. diseased states with the microbiota having a symbiotic relationship with the host, by providing a barrier function against pathogenic species, regulating cell growth, promoting healing, and modulating immune responses ( 11 , 12 ). While lower airways of healthy individuals have traditionally been considered sterile because of negative culture results, sequencing of microbial 16S rRNA amplicons has revealed a rich and diverse population of bacterial species previously missed ( 13 , 14 ).…”

Divergent airway microbiomes in lung transplant recipients with or without pulmonary infection

“…The lung microbiome of healthy individuals is characterized by a low bacterial load and a high species diversity, with the most common genera being Prevotella , Streptococcus , Veillonella , Neisseria , Haemophilus , and Fusobacterium [ 28 , 29 ]. In this study, Prevotella was found among the under-represented species during infection and inflammation.…”