The study of the microbiome has changed our overall perspective on health and disease. Although studies of the lung microbiome have lagged behind those on the gastrointestinal microbiome, there is now evidence that the lung microbiome is a rich, dynamic ecosystem. Tuberculosis is one of the oldest human diseases, it is primarily a respiratory infectious disease caused by strains from the Mycobacterium tuberculosis Complex. Even today, during the COVID-19 pandemic, it remains one of the principal causes of morbidity and mortality worldwide. Tuberculosis disease manifests itself as a dynamic spectrum that ranges from asymptomatic latent infection to life-threatening active disease. The review aims to provide an overview of the microbiome in the tuberculosis setting, both in patients’ and animal models. We discuss the relevance of the microbiome and its dysbiosis, and how, probably through its interaction with the immune system, it is a significant factor in tuberculosis’s susceptibility, establishment, and severity.

The respiratory tract harbors a variety of microbiota, whose composition and abundance depend on specific site factors, interaction with external factors, and disease. The aim of this study was to investigate the relationship between COVID-19 severity and the nasopharyngeal microbiome. We conducted a prospective cohort study in Mexico City, collecting nasopharyngeal swabs from 30 COVID-19 patients and 14 healthy volunteers. Microbiome profiling was performed using 16S rRNA gene analysis. Taxonomic assignment, classification, diversity analysis, core microbiome analysis, and statistical analysis were conducted using R packages. The microbiome data analysis revealed taxonomic shifts within the nasopharyngeal microbiome in severe COVID-19. Particularly, we observed a significant reduction in the relative abundance of Lawsonella and Cutibacterium genera in critically ill COVID-19 patients (p < 0.001). In contrast, these patients exhibited a marked enrichment of Streptococcus, Actinomyces, Peptostreptococcus, Atopobium, Granulicatella, Mogibacterium, Veillonella, Prevotella_7, Rothia, Gemella, Alloprevotella, and Solobacterium genera (p < 0.01). Analysis of the core microbiome across all samples consistently identified the presence of Staphylococcus, Corynebacterium, and Streptococcus. Our study suggests that the disruption of physicochemical conditions and barriers resulting from inflammatory processes and the intubation procedure in critically ill COVID-19 patients may facilitate the colonization and invasion of the nasopharynx by oral microorganisms.

Background: Hyperuricemia and gout are closely associated with alterations in gut microbiota function. Short-chain fatty acids (SCFAs) produced by intestinal microorganisms may modulate immune responses and inflammation relevant to gout pathophysiology. This study evaluated fecal SCFA concentrations, their associations with dietary purine intake, and the relationship between Akkermansia spp. and Prevotella spp. abundance and fecal SCFA profiles across the clinical spectrum of hyperuricemia. Methods: This cross-sectional study included 380 Mexican adults: normouricemic controls (n = 141), individuals with asymptomatic hyperuricemia (AH; n = 98), and patients with gout (n = 141). Fecal SCFAs were quantified by GC-FID and bacterial abundance by qPCR. Dietary intake was assessed by semi-quantitative food frequency questionnaire and classified by purine content. Between-group differences were evaluated by the Kruskal–Wallis test (Benjamini–Hochberg correction); multivariable linear regression adjusted for age, sex, and BMI was used to assess associations, including a pre-specified dietary purine intake per clinical group interaction term. Results: Fecal acetate and propionate were significantly higher in gout patients than controls, whereas AH individuals had significantly higher butyrate. Moderate-purine food intake showed opposing associations with fecal acetate in controls (β = +3.61, p = 0.019) and gout patients (β = −4.59, p = 0.036), with a significant interaction (p = 0.004). Exploratory analyses revealed a positive association between Prevotella spp. abundance and fecal acetate exclusively in the gout group (β = 0.085, p = 0.020). Conclusion: These findings suggest distinct fecal SCFA profiles across stages of urate-related disease, with a disease-specific gut metabolic response to dietary purine intake potentially contributing to the inflammatory environment of established gout. Longitudinal studies with whole-microbiome profiling are needed to establish causality.

Objective: To evaluate the effect of the synthetic C4-HSL and 3O-C12-HSL molecules produced by wild strains of P. aeruginosa as promoters of the root system of Solanum lycopersicum L in vitro. Design/methodology/approach: Wild and control strains were studied, in which crude extraction in ethyl acetate and quantification of both molecules were performed. Different concentrations of synthetic 3O-C12-HSL and C4-HSL (10, 12, 24, 48, 96, and 192 μM) were used. The ability to elongate the primary root, as well as the length and density of root hairs under conditions were evaluated. Laboratory-controlled studies. Results: The results obtained showed no beneficial effect on PAO1 in the crude extracts. However, a positive effect was observed when using the synthetic molecules 3O-C12-HSL and C4-HSL on primary root elongation at a concentration of 24 µM and on root hair density at a concentration of 96 µM, respectively, with a statistically significant difference (p <0.05) compared to the controls. Findings/Conclusions: This study reports positive effects on primary root elongation and root hair density using the synthetic molecules C4-HSL and 3O-C12-HSL in S. lycopersicum.