Dysrupted microbial tryptophan metabolism associates with SARS-CoV-2 acute inflammatory responses and long COVID

Protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and risk of long COVID has been associated with the depletion or over-abundance of specific taxa within the gut microbiome. However, the microbial mechanisms mediating these effects are not yet known. We hypothesized that altered microbial production of tryptophan and its downstream derivatives might contribute to inappropriate immune responses to viral infection. In patients hospitalized with COVID-19 (