The impact of a bacterial lysate on composition of the lung microbiota in a mouse model of asthma exposed to titanium dioxide as one of air pollutants.

Abstract

Environmental microbes have been linked to both beneficial and harmful effects on the lungs in relation to asthma. The aim of our study was to characterize the bacterial microbiome in lung samples from a mouse model of asthma exposed to titanium dioxide (TiO2) particles, and the effect of OM-85 Broncho-Vaxom®, a bacterial lysate on lung microbiome in mice. The mice were divided randomly into four groups of 6-8 mice per group. To identify the microbial communities in lung samples the upper right lung of all groups, we amplified and sequenced the rRNA gene regions from bacterial DNA (16S). The amplified 16S region was sequenced using the Roche-454 Life Sciences Titanium pyrosequencing platform. In the OVA + TiO2 + OM-85 group, airway hyperresponsiveness and inflammatory cells in bronchoalveolar lavage fluid (BALF) decreased compared to the OVA + TiO2 group. Inflammatory cytokine levels were lower in the OVA + TiO2 + OM-85 group. Certain bacteria, and Collinsella aerofaciens, decreased in the OVA + TiO2 + OM-85 group, while Neisseria perflava and Fusobacterium periodonticum increased. Lactic acid bacteria groups decreased in the OVA + TiO2 + OM-85 group. TiO2 particles exposure changed lung microbial taxa, and modified by a bacterial lysate, suggesting that a probiotic can be helpful in reducing exacerbation of airway disease exposed to air pollutants.