Abstract
COVID-19 is a pandemic infection of the respiratory system caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The viral ribonucleic acid (RNA) was found in many parts of the COVID-19 patients including the stool, suggesting a potential interaction with the host's gut microbiome. The gut microbiome also plays major roles in immunity and inflammation. It also impacts pulmonary functions through the gut-lung axis. There have been recent reports of the importance of the host microbiome in infection and pathogenicity. The understanding of the gut and lung microbiomes would open the gate to new therapeutic approaches.
Highlights
Interdisciplinary Perspectives on Infectious Diseases of the gut-lung axis in the immune response in the context of COVID-19
The number of microorganisms found in the lung is not as high as in the intestine or oral cavity, the lung microbiome is considered as a specific ecosystem where the diversity of different microorganisms composing it is unique for each individual [23, 24]. e lung microbiome is a more dynamic and transient ecosystem; its microorganisms come mainly from the oral sphere and from inhaled air and the digestive tract. e most frequent phyla found in the lung microbiota composition are Proteobacteria, Firmicutes, and Bacteroidetes, while at the genus level, Pseudomonas, Streptococcus, Prevotella, Fusobacteria, Porphyromonas, and Veillonella are the most predominant according to different studies [25,26,27]
Another study investigated the effects of rhinovirus infection on the lung microbiome [36], in which subjects with chronic obstructive pulmonary disease (COPD) and healthy control individuals were infected with rhinovirus and their microbiomes were analyzed at different time points. e results of this study showed a decrease in bacterial diversity in healthy subjects, while in COPD patients, an increase of Haemophilus influenzae which already exists in their lung microbiome has been observed. ese findings explained the impact of viral infections on the respiratory microbiome and its potential implication in secondary bacterial infections [36]
Summary
The lung has been considered a sterile and aseptic organ. Recently, thanks to the development of NextGeneration Sequencing (NGS) techniques, we know that this is not the case and that microorganisms inhabit the lung and form its local microbiome like the gut microbiome [18, 22]. E associations between the lung microbiome composition and asthma have been reported in different studies [29, 30]. The associations between lung microbiome and COPD have been the subject of several studies. A study comparing the microbiome of 9 COPD patients and 9 healthy subjects showed differences in bacterial communities between the two groups [35]. Another study investigated the effects of rhinovirus infection on the lung microbiome [36], in which subjects with COPD and healthy control individuals were infected with rhinovirus and their microbiomes were analyzed at different time points. E results of this study showed a decrease in bacterial diversity in healthy subjects, while in COPD patients, an increase of Haemophilus influenzae which already exists in their lung microbiome has been observed. The associations between lung microbiome and several respiratory diseases have been shown, but the role of the respiratory microbiota is still poorly understood
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
