SUMMARY
Small intestinal bacterial overgrowth (SIBO) is a distinct but interconnected form of gut dysbiosis and often coexists with broader alterations in gut microbiota diversity, particularly in patients with chronic liver disease. Excessive colonization of the small intestine with pathogenic or opportunistic bacteria contributes to increased intestinal permeability, endotoxemia, and systemic inflammation, which exacerbates liver damage. The intestine and liver are closely interconnected, and disturbances in the composition of the gut microbiota can significantly impact liver health (the gut-liver axis). In this review, the authors highlight the main mechanisms of liver damage in SIBO and the risk factors associated with this condition, which influence the clinical severity of viral hepatitis.
Keywords: small intestinal bacterial overgrowth syndrome, chronic liver disease, viral hepatitis, liver fibrosis, diagnostic methods

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