Potential Association Between Changes in Microbiota Level and Lung Diseases: A Meta-Analysis.

Area of Science:

• Pulmonary Medicine
• Microbiology
• Genomics

Background:

• The lung microbiota's role in respiratory diseases is increasingly recognized, yet its precise association with various lung conditions remains unclear.
• Existing studies have yielded inconsistent conclusions regarding the relationship between microbial community alterations and lung disease pathogenesis.

Approach:

• A comprehensive meta-analysis was conducted, synthesizing data from six studies involving 695 lung disease patients and 176 healthy controls.
• Standard mean deviation (SMD) and 95% confidence intervals (CIs) were calculated using a random-effects model.
• Subgroup, sensitivity, and publication bias analyses were performed to ensure robustness of findings.

Key Points:

• Overall, lung microbiota levels were significantly higher in patients with lung diseases compared to healthy individuals (SMD = 0.39).
• Elevated microbiota levels were observed in specific conditions including idiopathic pulmonary fibrosis (IPF), chronic obstructive pulmonary disease (COPD), and asthma.
• Conversely, a lower microbiota level was noted in patients with chronic hypersensitivity pneumonitis (CHP).
• The abundance of specific bacteria, namely *Acinetobacter baumannii* and *Pseudomonas aeruginosa*, was significantly increased in COPD and asthma patients.

Conclusions:

• This meta-analysis confirms a significant association between altered lung microbiota levels and various lung diseases.
• Elevated levels of *A. baumannii* and *P. aeruginosa* in COPD and asthma suggest their potential as diagnostic or therapeutic biomarkers.
• Further research is warranted to elucidate the causal mechanisms and clinical utility of these microbial signatures in lung disease management.