Predicting Hyperoxia-Induced Lung Injury from Associated Intestinal and Lung Dysbiosis in Neonatal Mice
Abstract Background: Newborns with respiratory disorders often require supplemental oxygen. Preclinical studies have demonstrated that hyperoxia disrupts the intestinal barrier, impairs intestinal function, and injures the lungs of newborn animals. The effects of neonatal hyperoxia on intestinal and lung microbiota and the role of the intestinal microbiota in the pathogenesis of hyperoxia-induced lung injury have not been investigated.Results: In this study, we evaluated the effect of neonatal hyperoxia on intestine and lung microbiota alterations in neonatal C57BL/6N mice reared in either room air (RA) or hyperoxia (85% O2) from postnatal days 1 to 7. On postnatal day 7, lung and intestinal microbiota were sampled from the left lung and lower gastrointestinal tract for 16S ribosomal RNA gene sequencing. Tissue from the right lung and terminal ileum were harvested for Western blot and histology analysis. Hyperoxia decreased body weight, induced intestinal injury, decreased intestinal tight junction expression, impaired lung alveolarization and angiogenesis, and increased lung cytokines in neonatal mice. Hyperoxia also altered intestinal and lung microbiota and promoted bacterial translocation from the intestine to the lung as evidenced by the presence of intestinal bacteria in the lungs of hyperoxia-exposed neonatal mice. The relative abundance of these bacterial taxa was significantly positively correlated with lung cytokines. Intestinal and lung microbiota combined with cytokines were incorporated into machine learning algorithms to develop prediction models for the classification of RA- or hyperoxia-reared mice. The experiment results demonstrated that a Bayes network achieved the best predictive performance, attaining accuracy, sensitivity, specificity, and area under the curve values of 94.4%, 88.9%, 100%, and 0.963, respectively. Selected discriminative features included lung cytokines (interleukin-1β, macrophage inflammatory protein-2, and tumor necrosis factor-α), lung microbiota (Ruminococcaceae_UCG-010, CAG-56, and Enterobacter), and intestinal microbiota (Peptococcaceae_ge, Muribaculum, Enterobacter, and Ruminococcaceae_UCG-010). Conclusions: Neonatal hyperoxia exposure during the first week of life induced intestinal and lung dysbiosis and promoted bacterial translocation from the intestine to the lung. These findings suggest that changes in the composition of the intestinal microbiota contribute to hyperoxia-induced lung injury and that the combination of intestinal and lung microbiota may indicate hyperoxia-induced lung injury in neonatal mice.