Impact of COVID-19 on the Microbiome and Inflammatory Status of Type 2 Diabetes Patients

The severe acute respiratory syndrome–related coronavirus 2 (SARS-CoV-2) pandemic has advanced our understanding of the host–microbiome–virus interplay. Several studies in various geographical regions report that SARS-CoV-2 infection disrupts the intestinal microbiota, allowing pathogenic bacteria such as Enterobacteriaceae to thrive, and triggering more severe disease outcomes. Here, we profile the microbiota of 30 individuals, 15 healthy controls and 15 type 2 diabetes (T2D) patients, before and after coronavirus disease 2019 (COVID-19). Despite similar viral loads in both patients and controls, SARS-CoV-2 infection led to exacerbated microbiome changes in T2D patients, characterized by higher levels of Enterobacteriaceae, loss of butyrate producers and an enrichment in fungi such as Candida spp. and Aspergillus spp. Several members of the microbiota were associated with more severe clinical and inflammatory (IL-8 and IL-17) parameters. Future studies to delineate the connection between cytokine release and microbiota disturbances will enhance our understanding of whether these microbial shifts directly impact the cytokine storm in COVID-19 patients or whether they are consecutive to the critical disease.