Meta-analysis of the lung microbiota in pulmonary tuberculosis

The lung microbiota has received less attention compared to other body sites, in part because its study carries special technological difficulties related to obtaining reliable samples as compared to other body niches. The limited number of studies on the sputum microbiota on TB patients and controls available so far have reported inconsistent, and sometimes, contradictory results. Aiming to clarify if changes in the lung microbiota composition are associated with pulmonary TB, we performed a meta-analysis of available data on microbiota of the lower respiratory tract in TB patients and healthy controls. Re-processing next generation sequencing data under uniform parameters and utilizing state-of-the-art bioinformatics analysis, we obtained distinct clusterings of microbiota between TB cases vs. controls across multiple studies. We identified Tumebacillus ginsengisoli, Propionibacterium acnes, Haemophilus parahaemolyticus as differentially abundant species signature in healthy controls while Caulobacter henricii, Actinomyces graevenitzii, Rothia mucilaginosa, in addition to Mycobacterium tuberculosis as differentially abundant species signature in TB cases, and described R. mucilaginosa as the anchoring species in a network of bacteria co-occurring with Mycobacterium tuberculosis (Mtb) infection.