Hepatocellular carcinoma (HCC) increases cancer-related mortality globally. The disease is diagnosed through imaging and serum biomarkers that lack sensitivity in the early stages of the disease. In this narrative review, a comprehensive literature search was conducted using databases including PubMed, Scopus, and Web of Science to identify relevant studies published during the last five years. The search focused on studies evaluating the relationship between gut microbiota and HCC, including microbial dysbiosis, microbial signatures, metabolites, diagnostic/prognostic potential, and microbiome-based therapeutic approaches. Relevant articles were selected based on predefined inclusion and exclusion criteria, and the findings were qualitatively synthesized to provide an updated overview of the role of the gut microbiome in HCC. The microbial signatures link the gut with HCC by focusing on key taxa like Bacteroidetes, Firmicutes, and Proteobacteria. In addition, further examination focuses on the functional impact of the microbiome, including microbial metabolites that are bile acids, short-chain fatty acids, and lipopolysaccharides that further control inflammation and immune responses, leading to carcinogenesis. Moreover, the review explored microbiome-modulating therapies like prebiotics, probiotics, and fecal microbiota transplantation (FMT) as possible adjuncts to conventional treatments like immunotherapy and chemotherapy. Ultimately, the study highlighted issues in the standardization of microbiome-based interventions and the requirement of a personalized approach for microbiome therapy in the treatment of HCC. The review also highlighted the potential of microbiome-targeted therapies and diagnostics to improve HCC outcomes and offered a unique direction for future research and clinical practice.