Gut microbiota alterations are linked to COVID-19 severity in North African and European populations.

Although COVID-19 primarily affects the respiratory system, many patients experience gastrointestinal symptoms, suggesting a role for the gut microbiota in disease pathogenesis. To explore this, we performed shotgun metagenomic sequencing on stool samples from 200 COVID-19 patients and 102 healthy controls in Morocco and France. Despite geographic differences in microbiota composition, patients with COVID-19 in both continents exhibited significant gut microbiota alterations, which were more pronounced in severe cases, with similar features compared with controls. Functional pathways, including L-Tryptophan biosynthesis, were disrupted, particularly in patients with severe disease. Machine learning models accurately predicted disease severity based on gut microbial profiles in the Moroccan cohort, though not in the French cohort. These results highlight consistent microbiota changes associated with COVID-19 and support a potential link between gut dysbiosis and disease severity.