Saliva as a non-invasive specimen for COPD assessment

Abstract

Background People with COPD have been reported to bear a distinct airway microbiota from healthy individuals based on bronchoalveolar lavage (BAL) and sputum samples. Unfortunately, the collection of these samples involves relatively invasive procedures and is resource-demanding, limiting its regular use. Non-invasive samples from the upper airways could constitute an interesting alternative, but its relationship with COPD is still underexplored. We examined the merits of saliva to identify the typical profile of COPD oral bacteria and test its association with the disease. Methods Outpatients with COPD and age-sex matched healthy controls were recruited and characterised based on clinical parameters and 16S rRNA profiling of oral bacteria. A clustering analysis based on patients’ oral bacteria beta-diversity and logistic regressions were performed to evaluate the association between oral bacteria composition and COPD. Results 128 individuals participated (70 patients and 58 controls). Differential abundance analyses showed differences in patients comparable to the ones previously observed in samples from the lower respiratory tract, i.e., an increase in Proteobacteria (particularly Haemophilus) and loss of microbiota diversity. An unsupervised clustering analysis separated patients in two groups based on microbiota composition differing significantly in the frequency of patients hospitalized due to severe acute exacerbation of COPD (AECOPD) and in the frequency of GOLD D patients. Furthermore, a low frequency of Prevotella was associated with a significantly higher risk of recent severe AECOPD and of being GOLD D. Conclusion Salivary bacteria showed an association with COPD, particularly with severe exacerbations, supporting the use of this non-invasive specimen for future studies of heterogeneous respiratory diseases like COPD.

A novel non-invasive biomarker based on oral microbiome dysbiosis for detection of Community-Acquired Pneumonia

“…This can greatly reduce the interference of confounding factors on the oral flora and ensure the accuracy of the results. The oral bacteria composition of patients with COPD also found the loss of microbiota diversity (23). We also found that CAP group had a lower diversity than healthy controls.…”

A Novel Non-Invasive Biomarker Based on Oral Microbiome Dysbiosis for Detection of Community-Acquired Pneumonia

“…The oral bacteria composition of patients with COPD also found the loss of microbiota diversity [23]. We also found that CAP group had a lower diversity than healthy controls.…”

The Role of Oral Microbiota in Chronic Obstructive Pulmonary Disease

“…It is a consensus that a negative correlation between disease severity and DOI: 10.1159/000525605 microbiota diversity. Oral bacteria of people with COPD were significantly less diverse (phylogenetic diversityalpha diversity, i.e., within individual diversity) than that of healthy individuals (Mann-Whitney U test, U = 1,275, p = 0.0013) [44]. Interestingly, although no significant differences in the bacterial load of the lung microbiota were found between healthy and COPD patients, the proportion of pathogenic bacteria gradually increased as COPD progressed [45,46].…”