?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.aufirst=Eva&rft.au=Lymberopoulos%2C+Eva&rft.aulast=Lymberopoulos&rft.date=23+August+2022&rft.issn=2235-2988&rft.atitle=COVID-19+severity+is+associated+with+population-level+gut+microbiome+variations&rft.title=Frontiers+in+Cellular+and+Infection+Microbiology&rft.volume=12&rft.genre=article