Effect of antibiotic-induced intestinal dysbacteriosis on bronchopulmonary dysplasia and related mechanisms.

BACKGROUND

Modification of the gut microbiota by antibiotics may influence the disease susceptibility and immunological responses. Infants in the neonatal intensive care unit (NICU) subjected to frequent antibiotics and oxygen therapies, which may give rise to local and systemic inflammatory reactions and progression of bronchopulmonary dysplasia (BPD). This study aimed to investigate the role of intestinal dysbacteriosis by antibiotic therapy before hyperoxia exposure in the progression of BPD.

METHODS

Mice had been exposed to hyperoxia (85% O) since postnatal day 3 until day 16 for the BPD model establishment, treated with antibiotics from postnatal day 2 until day 8. Treated mice and appropriate controls were harvested on postnatal day 2 or 10 for 16S rRNA gene sequencing, or postnatal day 17 for assessment of alveolar morphometry and macrophages differentiation.

RESULTS

Antibiotic-induced intestinal dysbacteriosis before hyperoxia exposure gave rise to deterioration of BPD evidenced by reduced survival rates and alveolarization. Moreover, antibiotic-induced intestinal dysbacteriosis resulted in increased M1 macrophage maker (iNOS) and decreased M2 macrophage maker (Arg-1) levels in lung homogenates.

CONCLUSION

Broad-spectrum antibiotic-induced intestinal dysbacteriosis may participate in BPD pathogenesis via alteration of the macrophage polarization status. Manipulating the gut microbiota may potentially intervene the therapy of BPD.