“…58,68 In studies with repeated sampling, the dominance of one taxon was maintained over time, and its relative abundance increased throughout the pneumonia episode, particularly if the patient was intubated. 51 Intubation was consistently a risk factor for bacterial disturbance in the lower respiratory tract (low diversity and evenness) supporting the hypothesis of a lung microbiota resulting from the equilibrium between microaspirations from the upper respiratory tract and clearance mechanisms. 34,51,58,63 Antibiotic administration seemed to have less effect on bacterial diversity than intubation, 58 and this effect was transitory, with recovery of a similar oropharyngeal microbiota a few days after antibiotic treatment compared to the microbiota before antibiotic administration.…”