Sputum microbiota profiles of patients with rifampicin-resistant tuberculosis during the intensive-phase treatmentOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
This study examined how the sputum microbiota of rifampicin-resistant tuberculosis patients changes during six months of intensive-phase treatment. Sputum was analyzed with 16S rRNA gene sequencing targeting the V1 to V3 region. The team compared patients before treatment, after treatment, and against healthy controls. They assessed alpha and beta diversity, LEfSe biomarkers, ROC diagnostic models, and PICRUSt2 predicted metabolic pathways. The goal was to see whether second-line drugs reshape the respiratory microbiota.
Who was studied?
The cohort was 28 adults in Guangzhou, China: 14 patients with confirmed rifampicin-resistant tuberculosis and 14 healthy hospital-staff controls. Patients were aged 18 to 65, with a mean of 43.4 years, and were over 75 percent male. Controls averaged 32.5 years, with 42.9 percent female and negative interferon-gamma release assays. Sputum was sampled at baseline and after six months of intensive treatment. All patients received WHO-guided second-line regimens; nine were retreatment cases and five newly diagnosed.
What were the most important findings?
Rifampicin-resistant patients had significantly lower alpha diversity than healthy controls at both baseline and six months, with no significant change across treatment. Beta diversity separated patients from controls (PERMANOVA R2 = 0.20, p = 0.001), with the first two PCoA axes explaining 29.1 and 19.5 percent of variation. LEfSe flagged 25 discriminative taxa, spanning 2 phyla down to 1 species. A five-genus ROC model separated patients from controls with an area under the curve of 0.94, reaching 92.86 percent sensitivity and specificity. PICRUSt2 found 12 differential pathways; pyruvate fermentation and lysine and glutamate metabolism were reduced in patients.
What are the greatest implications of this study?
The results suggest respiratory ecological imbalance may play a role in rifampicin-resistant tuberculosis, and that six-month intensive treatment does not restore microbial diversity. Disease state appeared to shape the sputum microbiota more than the second-line drugs did. The five-genus signature points to possible sputum-based diagnostic markers, though it needs validation in larger, multicenter cohorts. Findings are limited by 14 patients from one hospital, sputum-only sampling, and bacteria-only sequencing, so causation cannot be inferred.