Alterations in lung and gut microbiota reduce diversity in patients with nontuberculous mycobacterial pulmonary disease

BACKGROUND/AIMS: Although the incidence of nontuberculous mycobacteria pulmonary disease (NTM-PD), a chronic infectious disease, is increasing, lung and gut microbiota dysbiosis in NTM patients has rarely been studied and was therefore the focus of this study. METHODS: We analyzed the microbiota diversity in sputum and stool samples from 10 healthy subjects and 10 patients with NTM-PD through sequencing of the V3 and V4 regions of the 16S rRNA gene. In NTM-PD patients, we comparatively evaluated the microbiota diversity according to the body mass index (BMI), with BMI ≤ 18.5 kg/m(2) defined as “underweight” and BMI > 18.5 kg/m(2) as “others.” RESULTS: The sputum microbiota from NTM-PD patients tended to have lower index values of amplicon sequence variant richness, Shannon evenness, and beta diversity than those from the control group. Furthermore, NTM-PD patients with a low BMI had a lower microbiota diversity than patients with high BMI. Fecal samples from NTM-PD patients also significantly differed in alpha and beta diversity compared with the control group and exhibited a diversity pattern similar to that found in sputum samples. CONCLUSIONS: Our results reveal that the lung and gut microbiota of patients with NTM-PD exhibit an altered distribution and reduced richness and diversity.