Introduction: Short-chain fatty acid (SCFA) production from dietary fiber by the gut microbiome is a crucial component in the prevention and reduction of inflammation. One anaerobic producer of SCFA butyrate is the genus Roseburia, which has been found to be dysbiotically reduced in individuals with IBS, metabolic syndrome and obesity. Another condition in which inflammation plays a major role is COVID-19. In our study, we sought to understand whether dysbiosis was present in individuals with COVID-19, and whether Roseburia was a part of that dysbiosis. Methods: Microbiome profiles of 40 individuals with PCR-confirmed COVID-19 (C19) were compared to those of 11 high-risk healthy control (HRHC) subjects. To obtain these microbiome profiles, DNA was extracted from the fecal samples. DNA was then quantitated and normalized for downstream library fabrication utilizing shotgun methodology. Prepared and indexed libraries were subsequently pooled and sequenced on the Illumina NextSeq 550 System. Sample FASTQ files were analyzed with a computational tool profiling the microbial communities from metagenomic sequencing data with species level resolution. Finally, individual microbiome profiles were analyzed for relative abundance. The C19 subjects were further stratified by disease severity based on NIH criteria. Each severity level was compared to the HRHC, as well as the C19 group as a whole. The study was approved by Advarra IRB and is listed as NCT04359836. Results: When the HRHC relative abundance of Roseburia was compared to C19 it was found that C19 had significantly reduced levels (P< 0.05). Figure 1 illustrates these results with the C19 subjects in shades of blue. Darker represents more severe illness, as described by NIH guidelines. Conclusion: It is impossible to know whether the C19 subjects had lower levels of Roseburia prior to infection or as a result of it. However, these findings pose important questions. If the subjects had a lower level of Roseburia prior to becoming infected with SARS-CoV-2, this dysbiosis could have predisposed these individuals to becoming infected. If the subjects were not dysbiotic prior to infection, the severity of illness could be an indicator of the severity of the resulting dysbiosis. Although much is still unknown about Roseburia, these results indicate it could serve as a biomarker of COVID-19 susceptibility. (Table Presented).
The role of roseburia in COVID-19 pathogenesis