Oxygen therapy—used for diseases ranging from COPD to COVID-19—can damage the lungs due to oxygen-induced changes to the lung microbiome—the communities of bacteria and other microscopic organisms found the lung—according to a study conducted in mice. The finding could lead to safer, more targeted therapies for patients who are on a ventilator or receiving oxygen therapy, the researchers suggest.
Patients in the intensive care unit with respiratory failure are often exposed to oxygen for prolonged periods, which can damage the lungs. The researchers explored how this prolonged oxygen exposure might affect the lung microbiome and how it might be related to lung injury.
As part of the study, the researchers exposed healthy mice to high concentrations of oxygen and studied its effect on their lung bacteria. They found that high concentrations of oxygen altered the bacterial communities in the lungs of the mice and that damage to the lungs (inflammation) followed shortly after the disruption of the microbiome. By contrast, a genetically identical group of mice that lacked lung bacteria were protected from oxygen-induced lung injury, suggesting that the microbiome somehow plays a role in oxygen-induced lung injury.
"This study provides important insights into the contributions of the microbiome toward inflammation and damage in lungs exposed to varying levels of oxygen, and supports the continued importance of understanding how the microbiome and related factors impact lung disease and clinical outcomes," said James Kiley, Ph.D., director of the NHLBI’s Division of Lung Diseases. He was not involved in the research. The study, partly funded by NHLBI, appeared in Science Translational Medicine.