Modulation of Gut Microbiota for the Prevention and Treatment of COVID-19

Abstract

The gut microbiota is well known to exert multiple benefits on human health including protection from disease causing pathobiont microbes. It has been recognized that healthy intestinal microbiota is of great importance in the pathogenesis of COVID-19. Gut dysbiosis caused by various reasons is associated with severe COVID-19. Therefore, the modulation of gut microbiota and supplementation of commensal bacterial metabolites could reduce the severity of COVID-19. Many approaches have been studied to improve gut microbiota in COVID-19 including probiotics, bacterial metabolites, and prebiotics, as well as nutraceuticals and trace elements. So far, 19 clinical trials for testing the efficacy of probiotics and synbiotics in COVID-19 prevention and treatment are ongoing. In this narrative review, we summarize the effects of various approaches on the prevention and treatment of COVID-19 and discuss associated mechanisms.

The intestinal microbiota and improving the efficacy of COVID-19 vaccinations

“…In severe disease, IL-6, IL-10, CXCL proteins (such as CXCL8) and TNF-alpha may reduce the T cell pool and number of activated T cells and lead to exhausted or terminally differentiated T cells ( Chen and John Wherry, 2020 ). This can also be supported by recent findings that PD-L1/PD-1 axis were increased, which could result in T cell exhaustion ( Chen and Vitetta, 2021 , Chen and Vitetta, 2021 , Vitte et al, 2020 ). Therefore, T cell responses are also critical in combating SARS-CoV-2 infections.…”

“…In severe COVID-19, pro-inflammatory macrophages are abundant ( Grau and Félez, 1987 ). Hyperinflammation could activate PD-L1, leading to CD8 + T-cell exhaustion, which delays the elimination of the virus ( Chen and Vitetta, 2021 , Chen and Vitetta, 2021 ). Similarly, gut dysbiosis could disturb the appropriate immune responses elicited from vaccinations, which will be discussed in a later section in greater detail.…”

“…This may suggest that nutritional status could be important in COVID-19 vaccine efficacy. Indeed, nutraceuticals such as vitamin C, vitamin D, lactoferrin, omega-3 fatty acids and trace elements such as zinc, selenium and magnesium can improve the gut microbiota and reduce COVID-19 severity ( Chen and Vitetta, 2021 , Chen and Vitetta, 2021 ). Deficiency of these components causes severe COVID-19.…”

Phage therapy in the Covid-19 era: Advantages over antibiotics

“…( Dhar and Mohanty, 2020 ; Li et al, 2018 ). Reports have shown a significant shift in gut microbiota towards opportunistic pathogens in COVID-19 patients with extensive gut dysbiosis ( Chen and Vitetta, 2021 ; Yamamoto et al, 2021a ; Zuo et al, 2020 ).…”

Short- and Long-Term Implications of Human Milk Microbiota on Maternal and Child Health

“…and Bifidobacterium spp.) could be effective in the prevention and treatment of severe COVID-19 [ 115 ]. Interestingly, noting the entero-mammary origin, it is plausible that COVID-19 disease also involves dynamic changes in HM microbiota composition.…”