Disorders of gut microbiota and fecal-serum metabolic patterns are associated with pulmonary tuberculosis and pulmonary tuberculosis co-morbid type 2 diabetes mellitus

BACKGROUND: Pulmonary tuberculosis (PTB) and diabetes mellitus (DM) are prevalent chronic diseases with substantial implications for human health. DM patients are more susceptible to PTB, which exacerbates diabetes-related complications. However, the complex molecular mechanisms underlying the enhanced susceptibility of DM patients to PTB infection remain poorly understood.
RESULTS: α-and β-diversity of gut microbiota were significantly reduced in PTB patients and PTB-DM patients. In addition, the abundances of families Lachnospiraceae and Ruminococcaceae in Firmicutes phylum were downregulated in PTB patients and further diminished in PTB-DM patients. On the other hand, untargeted metabolomics in frozen serum and stool samples indicated that such as Phenylalanine, tyrosine and tryptophan biosynthesis, Arginine and proline metabolism, Tryptophan metabolism and Histidine metabolism et al were consistently and significantly altered in PTB patients and PTB-DM patients, with the significant upregulation of most metabolites. Amino acids like serine, proline, histidine et al were both remarkably elevated in PTB and PTB-DM patients. The correlation network analysis reveals the relationships between the shared microbial biomarkers and the shared metabolic pathways.
CONCLUSIONS: This research contributes to the exploration of pivotal diagnostic biomarkers for both patients with PTB and PTB accompanied by diabetes. Specifically, shared reductions were identified in the genera g-Roseburia, g-Ruminococcaceae_UCG.013, g-Ruminococcaceae_NK4A214, g-Lachnospiraceae_unclassified and g-Firmicutes_unclassified, in addition to notable regulation of amino acids like glycine, serine and histine in patients with PTB and PTB-DM. Our study expands the comprehension of the intricate connections linking gut microbiota, fecal metabolites and serum metabolites in PTB and PTB-DM patients.