Lung Microbiome in Lung Cancer: A Systematic Review.

Area of Science:

• Microbiology
• Oncology
• Pulmonology

Background:

• The lung microbiome's role in bronchopulmonary cancer is under investigation.
• Previous studies using 16S rRNA sequencing show variable bacterial taxa abundance in lung cancer.
• A comprehensive summary of the lung microbiome's percentage composition in bronchopulmonary cancer is lacking.

Purpose of the Study:

• To identify predominant bacterial taxa (phylum and genus) in bronchopulmonary cancer.
• To determine if a proportional microbiome pattern exists for diagnosing bronchopulmonary cancer.
• To systematically review existing literature on the lung microbiome in lung cancer.

Main Methods:

• Systematic review of MEDLINE, Embase, and Web of Science databases.
• Inclusion of studies on lung microbiome in bronchopulmonary cancer using bronchoalveolar lavage samples.
• Independent data extraction focusing on percentage composition at phylum and genus levels.

Main Results:

• Nine studies met the inclusion criteria.
• Significant heterogeneity observed in bacterial phyla and genera across studies.
• A consistent percentage of the Firmicutes phylum and the genera Streptococcus and Veillonella were noted, but with variability.
• Differences in participant criteria, sample collection, and data processing contributed to heterogeneity.

Conclusions:

• No consistent percentage pattern of the lung microbiome at the phylum or genus level was identified in bronchopulmonary cancer.
• The predominance of specific bacterial taxa varies across patient cohorts.
• The observed variability prevents the establishment of a reliable diagnostic pattern for bronchopulmonary cancer based on the lung microbiome.