Immunity and Gut Microbiota in COVID-19: A Review

Authors

Bharti, Mandeep Singh Sibian, Assistant Professor
Department of Nutrition and Dietetics, University Institute of Applied Health Sciences, Chandigarh University, india.

Abstract

The gut microbiome in the coronavirus disease 2019 (COVID-19) pandemic has piqued researchers interest since the outbreak began. The gut microbiome, comprising the bacterial microbiome, mycobiome and virome, is widely changed in COVID-19, according to mounting data. In patients with COVID-19, the gut microbial ecological network inconsiderably attenuated and sparse, along with decrease in gut microbiome diversity. Aside from the presence of the severe acute respiratory syndrome coronavirus type-2(SARS-COV-2), individuals with COVID-19 have an enrichment of opportunistic bacteria, fungi, and eukaryotic viruses in their gut microbiome, which is linked to illness severity and presentation. Meanwhile, the number of symbiotic bacteria and bacteriophages in patients with COVID-19 is decreasing. Even after illness resolution, such gut microbiome traits persist in a significant subset of COVID-19 patients, corresponding with ‘long COVID’ (also known as post-acute sequel of COVID-19). SARS-CoV-2 infection and its downstream negative effects on systemic host immunity and skewed gut microbiota are substantially to blame for the changed gut microbiome. The loss of low abundance beneficial bacteria and blooms of opportunistic fungus like Candida, as well as reduced host immunity and skewed gut microbial ecology, may hinder the gut microbiome’s re-assembly after COVID-19. To completely understand the function of host immunity against SARS-CoV-2 infection, as well as the long-term effect of COVID-19 on the gut microbiota in relation to host health after the pandemic, more research is needed.