Gut microbiome dysbiosis & COVID-19


It seems obvious that a better understanding of the factors involved in the pathophysiology of COVID-19 is of crucial importance. Focus on its impact on the intestinal microbiome...

The COVID-19 epidemic is caused by the SARS-CoV-2 virus and affects individuals in a sometimes very heterogeneous way. Gastrointestinal problems are among the most frequently reported symptoms of this disease. Moreover, it is now known that microbiome alterations persist in patients with long-term complications due to COVID-19, and the dysregulations of the intestinal flora were increased in patients who had received antibiotic treatment during their hospitalization. However, the causal link between these different elements had not been proven until a publication at the beginning of November in Nature Communications.
Indeed, an American team has demonstrated in mice and humans that intestinal dysbiosis resulting from COVID-19 could be the cause of secondary bacterial infections (12 to 14% of patients), which can sometimes be deadly. These infections would be due to the passage of bacteria from the intestinal microbiome into the bloodstream of their host, probably as a result of cellular alteration of the intestinal barrier. In addition, a decrease in lymphocytes is frequently noted in patients with COVID-19, which also facilitates secondary infections. This effect on the microbiome would also be amplified by the well-known impact of antibiotics administered during hospital stays to avoid nosocomial infections.
This phenomenon of intestinal bacteria passing from the gut to the bloodstream is also observed in immunocompromised patients, cancer patients, patients with acute respiratory distress syndrome, and those in intensive care receiving probiotics. Therefore, a better understanding of this phenomenon would be beneficial not only for the treatment of patients infected with SARS-CoV-2, but also for immunocompromised patients.