Researchers from Yonsei University in South Korea have found that certain commensal bacteria that reside in the human intestine produce compounds that inhibit SARS-CoV-2. The research was presented at the World Microbe Forum, an online meeting of the American Society for Microbiology (ASM), the Federation of European Microbiological Societies (FEMS), and several other societies that will take place online 20-24 June 2021.


  1. Previous clinical findings have shown that some patients with moderate to severe COVID-19 have gastrointestinal symptoms, while others showed signs of infection solely in the lungs.
  2. We wondered whether gut resident bacteria could protect the intestine from the invasion of the virus, the researchers said.
  3. To investigate this hypothesis, the researchers screened dominant bacteria inhabiting the gut for activity against SARS-CoV-2. Their search revealed that Bifidobacteria, which have previously been shown to suppress other bacteria such as H. pylori and have proven active against irritable bowel syndrome, had such activity.
  4. The investigators also used machine learning to search for potential illness-fighting compounds in databases containing microbially produced molecules, discovering some that might also prove useful against SARS-CoV-2.