Study on the Distribution of Respiratory Bacterial Communities in Patients with Pulmonary Tuberculosis

Objective: This study aims to reveal the changes in the lower respiratory tract bacterial community of tuberculosis patients compared to healthy individuals. It initially explores the correlation between the lower respiratory tract microbiota and the occurrence and development of pulmonary tuberculosis, aiming to provide new reference ideas for the treatment of pulmonary tuberculosis. Methods: This research methodology is based on second-generation sequencing, targeting the V3-V4 variable region of bacterial 16S rDNA for high-throughput sequencing. The study collected bronchial epithelial brush-off samples from 11 healthy volunteers and 20 confirmed pulmonary tuberculosis patients in Yunnan Province for sequencing. Subsequently, a comparative analysis of the sequenced bacterial community results was conducted to explore the association between tuberculosis and human microecology. Results: In this experiment, 40 samples of bronchial epithelial brush-off and throat swab were collected from 20 smear-positive pulmonary tuberculosis patients. For the healthy control group, 55 samples of bronchial epithelial brush-offs were collected from five different lung segments of 11 healthy volunteers in Yunnan Province. High-throughput sequencing was performed on these samples. The results showed that the colonized flora present in the lower respiratory tract of healthy people in our province mainly includes Bacillus, Lactococcus, Enterococcus, and Streptococcus at the genus level. The results from 20 tuberculosis patients revealed that the number of lower respiratory tract flora in tuberculosis patients is richer than that of healthy people. Besides Mycobacterium tuberculosis, the dominant bacteria mainly include Prevotella, Veillonella, Pseudomonas, and Streptococcus. Although Prevotella is the dominant flora in the samples of tuberculosis patients, its abundance varies significantly among samples. Conclusion: Comparing the respiratory flora of healthy people and tuberculosis patients revealed significant differences. Not only have the types and abundance of bacteria increased significantly, but there are also unique bacterial species in the patient’s respiratory tract. This suggests that these unique bacteria are likely closely related to the occurrence and development of pulmonary tuberculosis. Furthermore, bacterial abundance may also be related to antibiotic use, providing a new direction for further research.