Figure 1.

Study flow diagram with information on the methods used. We used two types of biological material from patients with COVID-19: stool samples and blood. The microbiota was studied using culture-based method (to calculate alpha-diversity indices) and molecular genetic testing (to calculate the Firmicutes/Bacteroidetes (F/B) ratio). The determination of the relative normalized expression of the studied genes was carried out by the method of polymerase chain reaction with reverse transcription.