Characterization of the lung microbiome and inflammatory cytokine levels in women exposed to environmental risk factors: A pilot study

Introduction: Lung microbiome dysbiosis affects the immune system balance and promotes lung inflammation. We aimed to characterize and compare the lung bacteriome composition and the cytokine profile in women with normal lung function exposed to risk factors for chronic lung diseases (tobacco smoking and biomass-burning smoke exposure). Methods: We included women with biomass-burning smoke exposure (BE, n = 11) and current smokers women (TS, n = 10). The bacteriome composition was performed in induced sputum, sequencing the 16 rRNA gene. Cytokine levels were measured using enzyme-linked immunosorbent assay multiplex assay in the supernatant of induced sputum. For quantitative variables, we used medians and minimum and maxim values. For the amplicon sequence variants (ASV) differential abundance testing between groups. Results: At the taxa level, the phylum Proteobacteria was found in a higher proportion in the TS group concerning BE (p =.045); however, after the false discovery rate adjustment, this difference was not retained (p =.288). We found a higher concentration of IL-1β in the TS group than in the BE group (248.6 vs. 177.9 pg/mL, p =.010). Women with high biomass-burning smoke exposure in an hour per day had a positive correlation with the abundance of Bacteroidota (ρ = 0.71, p =.014) and Fusobacteriota (ρ = 0.73, p =.011). FEV1/FVC had a positive correlation with an abundance of Bacteroidota, Proteobacteria, and Fusobacteria (ρ = 0.74, p =.009, ρ = 0.85, p =.001, and ρ = 0.83, p =.001, respectively). In tobacco smoking, women had a positive correlation (ρ = 0.77, p =.009) between cigarettes per day and Firmicutes' abundance. Conclusion: Compared to biomass-burning smoke-exposed women, current smokers have poor lung function and high levels of IL-1β in sputum. Women with biomass-burning smoke exposure present an increased abundance of Bacteroidota and Fusobacteriota.