Microbiological oropharyngeal patterns in patients with different phenotypes of chronic obstructive pulmonary disease

Persistent bronchial inflammation in chronic obstructive pulmonary disease (COPD) is considered the cause of ventilation disorders and related contamination with conditionally pathogenic microorganisms; the latter can proceed and transform into a full infection, which can aggravate and exacerbate COPD. The aim of the study was to evaluate the relations between the oropharyngeal microbiota in patients with COPD and the clinical, functional, and prognostic parameters of the disease. Materials and Methods. 64 patients with COPD were included in the study; the participants were scheduled to visit our clinic on two occasions. In the first visit, their medical history was studied in detail and the major examination procedures were conducted. Those included an assessment of the respiratory function, the 6-minute walk test, the degree of dyspnea by the Medical Research Council scale, body plethysmography, the diffusion capacity of the lungs, and a chest CT scan. The second visit took place 12 months after the first one to assess the changes in the course of the disease. The result was considered negative if, in the second examination, the patient‘s condition was found more severe. Oropharyngeal samples of all patients were sequenced to identify the V3–V4 variable sites of the 16S rRNA gene. Results. It is found that the microbiological oropharyngeal patterns in COPD patients depend on the source of micro-aspiration. In addition, the changes in the oropharyngeal microbiota correlate with the severity and prognosis of the disease, as well as the patient phenotype. Based on the data obtained by sequencing parts of the 16S rRNA gene, the role of oropharyngeal microbiota in determining the course and prognosis of COPD has been elucidated. Conclusion. The presented clinical and functional characteristics associated with oropharyngeal microbiota indicate that microaspirations from other body compartments not only affect the composition of oropharyngeal microbiota in patients with COPD but also have an important prognostic significance. © 2018, Nizhny Novgorod State Medical Academy. All rights reserved.