A study depicted that the link between levels of inflammatory cytokines and markers, and gut microbiota composition in COVID-19 individuals indicate that gut microbiome is implicated in the magnitude of coronavirus infection severity via modulation of the host immune responses.

A two-hospital cohort study was carried to explore whether the gut microbiome is associated with disease severity in patients infected with COVID-19 and whether the alterations in microbiome composition resolve with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) clearance.

From 100 subjects having laboratory-confirmed SARS-CoV-2 infection, the stool, blood, and patient records were procured. After viral clearance, the collection of serial feces samples from 27 of the 100 participants up to 30 days was done. Characterization of the gut microbiome compositions was done by shotgun sequencing total DNA extracted from the feces. The concentrations of blood markers and inflammatory cytokines were estimated from plasma.

The gut microbiome composition was considerably altered in coronavirus-infected subjects in comparison with the non-infected subjects irrespective of whether the subjects had been treated with medications. Various gut commensals with well-known immunomodulatory potential such as Faecalibacterium prausnitzii, Eubacterium rectale, and other bifidobacteria species were found to be underrepresented in the participants and depleted in samples gathered up to 30 days after resolution of the disorder.

Furthermore, this altered composition displayed stratification with disorder severity concordant with the higher concentrations of various inflammatory cytokines and blood markers like gamma-glutamyl transferase, C-reactive protein, aspartate aminotransferase, and lactate dehydrogenase.

Thus, gut microbiome may considerably impact coronavirus infection severity and magnitude of the immune response to SARS-CoV-2 infection. Additionally, the gut microbiota dysbiosis persists after recovery/viral clearance and may contribute to persistent symptoms, highlighting a requisition to elucidate how gut microorganisms are implicated in coronavirus infection and inflammation.