Patients suffering severe COVID-19 show an aggressive and excessive immune response against the SARS-CoV-2 coronavirus, known as a cytokine storm. If left untreated these patients face the risk of tissue damage, multi-organ failure and death. A high relative abundance of Prevotella copri has been reported in patients with newly diagnosed rheumatoid arthritis (RA). On the other hand, it has been observed that Prevotella histicola can modulate the inflammatory manifestations of autoimmune diseases like multiple sclerosis, and it is now being evaluated as a monoclonal microbial treatment in COVID-19. We observed that pre-treatment with P. histicola decreased NF-kB activation, while pre-treatment with P. histicola and P. copri decreased IRF activation in monocytes upon SARS-CoV-2 glycoprotein. Our findings suggest that exposure of blood immune cells, such as monocytes, to commensal species of Prevotella may reduce the inflammatory response to SARS-CoV-2 glycoprotein. Besides treatments targeting the viral infection, other treatments such as immunomodulation by bacteria aiming to reduce or regulate the inflammatory process in COVID-19 to avoid the development of related complications may be considered.