Researchers from the University of Ulsan College of Medicine in Korea discovered that the microbial communities in lung tissues from patients with idiopathic pulmonary fibrosis (IPF) differ from those in normal lung tissues and that they play an important role in the pathogenesis of IPF, according to a study published in Frontiers in Medicine.

There have been conflicting studies on the bacterial population in IPF lung tissues. Hence, the impact of the lung tissue microbiome on IPF clinical outcomes is not clearly defined in the medical literature. This is where Yoon et al come in.

“Our study aimed to identify the diversity and composition of the bacterial microbial communities in lung tissues at the time of diagnosis and determine their association with clinical outcomes, such as survival, disease severity, and progression in patients with IPF,” they wrote.

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They extracted genomic DNA from the lung tissues of patients with IPF (n=20; 10 nonsurvivors). Samples were obtained aseptically at the time of surgical biopsy for the purpose of diagnosis. They also obtained samples from age- and gender-matched lung cancer patients (n=20) from the Bio-Resource Center of Asan Medical Center for the control group. 

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The research team wrote, “The microbial communities in the lung tissues differed between patients with IPF and controls, and between IPF non-survivors and survivors.” Lactobacillus, Paracoccus, and Akkermansia were relatively abundant in IPF, while Caulobacter, Azonexus, and Undibacterium were found to be decreased in patients with IPF compared to controls. In addition, higher relative abundances of Streptococcus, Clostridium, and Sphingomonas were independently associated with mortality in patients with IPF.

Researchers also discovered that decreased relative abundances of the genera Pelomonas and Azonexus were associated with IPF diagnosis. Curvibacter and Thioprofundum abundances were correlated positively with functional volume capacity, while Anoxybacillus and Enterococcus abundances had inverse correlations. In addition, Aquabacterium and Peptoniphilus abundances were positively correlated with distance during the 6-Minute Walking Test, while Fusobacterium and Phycicoccus abundances had inverse correlations.

The research team concluded that the relative abundance of some genera influenced IPF clinical parameters, such as diagnosis, disease severity, and progression, as well as mortality. 


Yoon HY, Moon SJ, Song JW. Lung tissue microbiome is associated with clinical outcomes of idiopathic pulmonary fibrosis. Front Med (Lausanne). 2021;8:744523. doi:10.3389/fmed.2021.744523