Hong Kong Researchers Establish Likely Connection Between Microbiome & Severity Levels of COVID-19

Hong Kong Researchers Establish Likely Connection Between Microbiome & Severity Levels of COVID-19

Hong Kong-based researchers have established that the gut microbiome is likely associated with the severity of SARS-CoV-2, the virus behind COVID-19, based on a correlation established between gut microbiota composition, inflammatory biomarkers and cytokine levels in COVID-19 patients under study. With findings reported in the peer reviewed journal Gut the study was led by Yun Kit Yeoh, MD, from the department of microbiology at the Chinese University of Hong Kong. The “microbiome” is a field of research growing in prominence as TrialSite showcased in a couple of the pilot “Cure Seekers” episodes.  

The Study

This two-cohort study involved securing not only the patient records but also blood and stool samples from 100 patients that produced laboratory-confirmed COVID-19. The researchers collected the serial stool samples from 27 out of 100 patients during the period of up to 30 days post clearance of the coronavirus infection. “Gut microbiome compositions were then characterized by shotgun sequencing total DNA extracted from stools,” reported Gut. Diagnosing the patients’ plasma, the team were able to assess concentrations of inflammatory cytokines and blood markers. 


The Hong Kong-based team observed gut microbiome composition was materially modified in those patients infected with COVID-19 as compared to those individuals not afflicted with the novel coronavirus., regardless of whether a patient had received medication (P<0.01). They reported in Gut that “several gut commensals with known immunomodulatory potential such as Faecalibacterium prausnitzii, Eubacterium rectale and bifidobacterial were underrepresented in patients and remained low in samples collected up to 30 days after disease resolution.”

The composition of microbiota revealed greater stratification with disease severity concurring with elevated levels of cytokines and blood markers from C reactive protein and lactate dehydrogenase to aspartate aminotransferase and gamma-glutamyl transferase. 


As the authors reported in Gut, the findings link the gut microbiome to the severity of COVID-19. This is potentially associated via modulating host immune responses. Moreover, the authors’ observations touch on the so-called “Long-Haul COVID,” noting that COVID-19 associated “microbiota dysbiosis.” possibly may be a culprit involving longer term symptoms. The authors point out a growing need to better understand how gut microbiomes are connected to inflammation and the novel coronavirus.  

Study author Yun Kit Yeoh shared, “With mounting evidence that gut microorganisms are linked with inflammatory diseases within and beyond the gut, these findings underscore an urgent need to understand the specific roles of gut microorganisms in human immune function and systemic inflammation.”

Lead Research/Investigator

Yun Kit Yeoh, MD, department of microbiology, The Chinese University of Hong Kong, Shatin, Hong Kong

Call to Action: Check out TrialSite Cure Seekers pilot episodes to learn more about microbiome-based research in the United States.