Pre-Existing Microbiome Signature in a SARS-CoV-2 Discordant Family

Our index patient is a 19-year-old man with Crohn's disease. After developing symptoms consistent with COVID-19, he, his 62-year-old father, and 14-year-old sister tested positive for SARS-CoV-2 in May 2020. Despite a shared household, his 50-year-old mother with a history of asthma and his healthy brother and sister-in-law (a married couple) remained negative. The index patient and his mother had undergone microbiome analysis in May 2019, following his brother and his sister-in-law in November 2020. We observed significant differences between the fecal microbiota of the SARS-CoV-2-positive son and those of his healthy family. There were differences in the bacterial phylum, class, order, family, and genus level with the increased relative abundance of Bacteroidetes and reductions or deletions in bacterial diversity, particularly of the Bifidobacterium family. This unique study may signal a new exploratory avenue for the prevention or treatment of SARS-CoV-2 infections.