Pharyngeal Microbiota in Pre-COPD and COPD: Associations with Clinical Pattern and Respiratory Infection

Area of Science:

• Microbiome research
• Respiratory medicine
• Microbial ecology

Background:

• The pharyngeal microbiota is crucial for respiratory health, influencing immunity and preventing pathogen colonization.
• Dysbiosis of the pharyngeal microbiota is linked to respiratory diseases like COPD.
• Current diagnostics often miss the broader microbial dynamics by focusing on individual pathogens.

Purpose of the Study:

• To investigate the pharyngeal microbiota composition and diversity in individuals with pre-COPD and stable COPD.
• To compare microbial profiles between pre-COPD (with/without acute respiratory infection [ARI]) and stable COPD populations.
• To assess the functional capacity of the pharyngeal microbiota in these groups.

Main Methods:

• 16S rDNA sequencing on the Illumina MiSeq platform was used for pharyngeal swab analysis.
• Taxonomic and functional profiles were generated using MicrobAT®.
• Microbial diversity was assessed using the Shannon index and PERMANOVA; composition differences were analyzed with Kruskal-Wallis tests and robust PCA.

Main Results:

• Microbial diversity was preserved in pre-COPD (PC) individuals but significantly reduced in ARI and COPD patients.
• Pharyngeal microbiota composition differed significantly across the three groups (p=0.001).
• Functional analysis showed minimal deficits in PC (<10%) but major impairments in ARI (81%) and COPD (56%).

Conclusions:

• Broad-spectrum analysis of the pharyngeal microbiota is essential for understanding respiratory health.
• Findings suggest potential for novel diagnostic and therapeutic strategies targeting the overall microbial ecosystem.
• Assessing microbiota beyond individual pathogen detection offers new insights into pre-COPD and COPD pathogenesis.