Bao Y, et al. - Protracted bacterial bronchitis (PBB) is a chronic purulent bronchitis which could cause recurrent coughing and wheezing in infants. The impacts of main pathogens causing PBB on lung microbiota dysbiosis remain unclear. In this retrospective investigation, it was shown that PBB vs tracheomalacia (TM) infants contained discrepant lung genera and co-occurrence network.