Increasing severity of COPD is associated with a greater inflammatory response, in part coming from the use of corticosteroids and in greater part coming from the lung microbiome makeup.
Chronic obstructive pulmonary disease (COPD) is associated with continuous airflow inflammation and obstruction.And this is typically the result of airway bacterial dysbiosis.
Mohammadali Yavari Ramsheh and colleagues from the Department of Respiratory Sciences, Institute for Lung Health, University of Leicester, England took brush samples from individuals between 2009 and 2012; 207 from healthy individuals and 339 from patients with COPD. Of the latter group, 192 used inhalers of corticosteroids.
Of the bacteria in the lung microbiome, the commensal (good) bacterial species, Prevotella, were found to have declined from 47.7 per cent in healthy individuals to 33.5 per cent in COPD patients. On the other hand, pathogens such as Streptococcus had increased from 5.3 per cent in the healthy to 8.6 per cent in those with COPD, and Moraxella had increased from 0.02 per cent in the healthy to 0.05% in the sick.
The decline in Prevotella was directly linked to the severity in illness symptoms, particularly to exercise capacity and lung function.
The differences were far less marked where patients did not use inhalers. However where inhalers were used, good levels of Prevotella were linked to positive expression of the lining epithelial genes, while higher levels of Moraxella were linked with greater inflammation, particularly with the expression of the IL-17 and TNF inflammatory pathways.
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- Lancet Microbe; Lung Microbe Composition and bronchial epithelial composition; April 23, 2021. Lung microbiome composition and bronchial epithelial gene expression in patients with COPD versus healthy individuals: a bacterial 16S rRNA gene sequencing and host transcriptomic analysis