Lung CT Changes in COPD Patients Affects the Human Lung Microbiome

There is an association between computed tomography (CT) detectable structural changes in the lungs of patients with chronic obstructive pulmonary disease (COPD) and changes in bacterial communities that influence alterations in the relationship between microbes and host cells, according to a new study published in PLOS One.

The study included 16 patients with COPD between the ages of 48 and 74, and 9 control participants. Researchers collected brush samples from the lungs of the COPD patients from different CT subtypes of COPD in order to analyze the composition of the lung microbiome. The control patients were analyzed through an independent barcoding approach by applying 454-pyrosequencing of 16S rRNA gene fragment amplicons.

“This allowed us to show that the composition of the bacterial community in the lungs of COPD patients without structural changes is very similar to that of healthy subjects,” Dr Marion Engel, the study’s first author and a scientist in the Complex Systems Research Group at Helmholtz Zentrum München, a German research center, said in a press release. “On the other hand, the bacterial composition in the lungs of ill subjects with structural changes differ significantly from those of the other two groups, regardless of the severity of the disease.”

The study results revealed that changes in different CT subtypes differ from the community composition in the lungs of patients without changes in CT. The results indicated a greater presence of the bacteria Prevotella in those with the mild COPD subtype and from controls, while Streptococcus was seen in a higher abundance in severe cases.

Furthermore, 58% of severe subtype COPD patients and 50% of the mild subtype COPD patients were given Glucocorticoid/LABA medication. The researchers hypothesized that the medication would produce an effect on the bacterial community composition, but no effects or changes were detected.

“Our results suggest the presence of networks of associated bacteria, which are shifting, depending on changes in the lung,” Engel said. “These shifts might lead to a dysbiosis in the lung with increasing severity of the disease which, at the end, might then result in altered susceptibility to exacerbation events, as well as responsiveness towards medical treatment.”