The gut-liver nexus: exploring gut microbiota dysbiosis in non-alcoholic fatty liver disease and its therapeutic implications

The human gut microbiota (GM) is a diverse ecosystem crucial for health, impacting physiological processes across the host's body. This review highlights the GM's involvement in Non-Alcoholic Fatty Liver Disease (NAFLD) and explores its diagnosis, treatment, and management.

The GM influences gut functionality, digestion, immunity, and more. Short-chain fatty acids (SCFAs), produced by microbial fermentation, regulate metabolism, inflammation, and immune responses. Bile acids (BAs) modulate the microbiome and liver functions, affecting NAFLD progression. Dysbiosis and increased gut permeability contribute to NAFLD through bacterial components and metabolites reaching the liver, causing inflammation and oxidative stress. The microbiome's impact on immune cells further exacerbates liver damage. Symptoms of NAFLD can be subtle or absent, making diagnosis challenging. Imaging techniques assist in diagnosing and staging NAFLD, but liver biopsy remains vital for accurate assessment. Promising treatments include FXR agonists, GLP-1 agonists, and FGF19 and FGF21 mimetics, targeting various pathways associated with NAFLD pathogenesis. Fecal Microbiota Transplantation (FMT) emerges as a potential therapeutic avenue to restore gut microbiota diversity and alleviate NAFLD. Lifestyle interventions, such as dietary modifications, exercise, and probiotics, also play a pivotal role in managing NAFLD and restoring gut health.

Despite significant progress, the complex interplay between the gut microbiome, NAFLD, and potential treatments necessitates further research to unravel underlying mechanisms and develop effective therapeutic strategies.