Diversité physiopathologique du microbiote respiratoire

Healthy airway microbiota of intestinal and environmental origins changes qualitatively and quantitatively throughout the respiratory tract. Some factors related to the host or of exogenous origin, could generate an imbalance of the microbiota, called dysbiosis. Acute infections of upper and lower respiratory tract, facilitated by these factors, could be associated to dysbiosis contributing to the emergence of opportunistic pathogenic bacteria belonging to the microbiota. In chronic respiratory tract diseases, especially cystic fibrosis, quantitative but also qualitative changes of airway microbiota were observed including a reduction in the bacterial diversity. The contribution of novel culture-independent methods for studying airway microbiota allows today to consider these diseases as polymicrobial involving complex dysbiotic microbial communities. This allowed the development of novel therapeutic approaches aiming at reequilibriate a dysbiotic microbiota. Advances toward the description of airway microbiota in heath and diseases and the explanation of its role will allow a better understanding of the pathophysiological mechanisms underlying respiratory tract diseases and to explore new therapeutic strategies.