EC Microbiology

Background: The gut-liver axis is a vital bidirectional communication network connecting the gastrointestinal tract and the liver through the portal vein, bile acids, and systemic circulation. This interaction regulates metabolic, immunological, and barrier functions essential for systemic homeostasis. Dysbiosis, or imbalance in gut microbiota, disrupts this axis, contributing to liver diseases via mechanisms like increased intestinal permeability, microbial translocation, and altered metabolite production.

Purpose: This review explores the mechanistic links between gut dysbiosis and liver diseases, focusing on bacterial translocation, pathogenic bacteria, microbiota-derived metabolites, and immune-mediated liver injury. It also highlights emerging microbiome-targeted therapeutic strategies and their potential to restore gut-liver homeostasis.

Main Body: Gut dysbiosis compromises intestinal barrier integrity, allowing microbial products like lipopolysaccharides (LPS) to translocate to the liver, triggering inflammation and fibrosis. Pathogenic bacteria (Enterococcus faecalis, Escherichia coli, and Klebsiella pneumoniae) exacerbate liver diseases through cytolysin production, endotoxin release, and ethanol metabolism. Altered gut metabolites, such as bile acids and short-chain fatty acids (SCFAs), further impair liver metabolism and immunity. Dysbiosis is implicated in metabolic dysfunction-associated steatotic liver disease (MASLD), alcoholic liver disease (ALD), cirrhosis, and hepatocellular carcinoma (HCC). Emerging therapies like probiotics, fecal microbiota transplantation (FMT), and bacteriophage therapy show promise in restoring gut-liver axis balance, though challenges related to safety, efficacy, and individual variability persist.

Conclusion: Understanding the gut-liver axis and its dysregulation is critical for the development of targeted microbiome-based interventions. Future research must focus on personalized therapies, long-term efficacy, and scaling interventions to address the global burden of liver diseases.

 Keywords: Gut-Liver Axis; Dysbiosis; Liver Diseases; Microbiota-Derived Metabolites; Microbiome-Targeted Therapies

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