Clinical characteristics of COVID-19 severity and dysbiosis effect [12]
| COVID-19 severity type | Criteria | Dysbiosis effect |
|---|---|---|
| Mild | Clinical symptoms minimal, no imaging consistent for pneumonia | Had viral clearance as evidenced by their fecal samples and these patients showed symptomatic recovery |
| Moderate | Fever, upper respiratory symptoms, and imaging evidence of pneumonia | |
| Severe | (1) Respiratory distress (i.e., RR > 30) (2) SpO2 less than 93% at rest (3) PaO2/FiO2 < 300 mmHg (1 kPa ≈ 7.50 mmHg) | Depletion of beneficial commensals, affecting the breakdown of SCFAs and L-isoleucine biosynthesis, which in turn impaired viral clearance and symptomatic recovery resulting in persistent metabolic dysfunction |
| Critically ill | (1) Respiratory failure requiring intubation and ventilation (2) Shock (3) Organ failure, requiring ICU monitoring and treatment |