Microbial transfers diversity of bacteria in the lower respiratory tract under ozone exposure

the transferred microbiota enriched BALF was obtained from mice treated with O3 for 14 days in the second cohort. The collected BALF was centrifuged at 10000 rpm for 10 min . Subsequently, the pellet was washed once with PBS. Prior to the intranasal administration, each pellet was suspended in PBS. Instillation of resuspension intranasally per mouse to simulate exogenous resistant microbiota invasion. The O3 exposure conditions remained consistent with those described previously. To eliminate confounding effects from neutrophil PAMP mediated processes and mucosal clearance, the O3 exposure duration was adjusted to 7 days in this experimental phase based on time course experimental results.