AUTHOR=Liu Bin , Yu Ying , Zhao Min , Xiao Kun , Yan Peng , Duan Zhimei , Wang Kaifei , Zhao Na , Cao Jiabao , Wang Jun , Xie Lixin 

TITLE=Correlation Analysis of the Microbiome and Immune Function in the Lung-Gut Axis of Critically Ill Patients in the ICU

JOURNAL=Frontiers in Medicine

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2022.808302

DOI=10.3389/fmed.2022.808302

ISSN=2296-858X

ABSTRACT=<sec><title>Objective</title><p>Critical illnesses in the intensive care unit (ICU) have been a global burden. We aimed to determine the correlation between the lung and gut in critically ill patients to find novel evidence of the lung-gut axis, which may be a new treatment for patients with critical illness in the ICU.</p></sec><sec><title>Methods</title><p>We collected bronchoalveolar lavage specimens and fecal samples of 31 patients with critical illness within 24 h after admission. Metagenomics was used to detect lung and intestinal samples. Immune cells were detected by flow cytometry.</p></sec><sec><title>Results</title><p>There are 86 common species in both lung and gut. The abundance of <italic>Enterococcus faecium</italic> is high in both the lung and gut of patients with critical illness in the respiratory intensive care unit (RICU). <italic>Corynebacterium striatum</italic> in the lung and gut is correlated with different immune cells. In addition, <italic>C. striatum</italic> in the lung and gut might share the same source, supporting the concept of a gut-lung axis in humans.</p></sec><sec><title>Conclusions</title><p>The microbiome in the lung and gut showed a correlation to some extent, and <italic>C. striatum</italic> in the lung and gut might share the same source. In addition, the microbiome showed a correlation with immunity, indicating a potential therapeutic target in patients with critical illness. The lung-gut axis might play an important role in patients with critical illness in the RICU.</p></sec>