The relevance of microbiota-induced antibody responses in COVID-19 pathogenesis

This study addressed the role of microbiota in the protection from severe COVID-19 disease. To this end, oropharynx and fecal samples of healthy donors and COVID-19 patients were collected and their bacterial diversity was analysed by 16S rRNA sequencing. Additionally, IgA-bound fractions of microbiota from healthy donors was sorted using BD Influx and its bacterial diversity was determined using 16S rRNA sequencing. Finally, fecal microbiota from healthy donors was stained with anti-RBD-S-SARS-CoV-2 antibodies and antibody-bound fractions were sorted using BD Influx and their diversity was analysed. Altogether, these data suggest that healthy microbiota is targeted by anti-RBD antibodies.