Harnessing the oral microbiome in chronic liver disease: Mechanisms, therapeutic modulation and translational...

Advanced chronic liver disease (ACLD) with underlying cirrhosis is increasingly recognised as a condition shaped by the 'oral-gut-liver axis', in which dysbiosis within the oral microbiome contributes to systemic inflammation, infection, decompensation, and acute-on-chronic liver failure. Periodontal disease is highly prevalent in ACLD and is associated with endotoxaemia, immune dysfunction, and hepatic complications. The protected dental biofilm and keystone pathogens are key to the development of local and systemic inflammatory processes. The concept of "oralisation" of the gut microbiome further links oral dysbiosis to microbial translocation and hepatic injury. Recent advances in multi-omics, resistome profiling, and spatially resolved imaging have deepened insights into community function and host-microbial crosstalk, while salivary biomarker panels and microbial signatures across different aetiologies suggest potential tools for non-invasive diagnosis and risk stratification. Clinical priorities now lie along two complementary paths. The first is immediate implementation: embedding routine periodontal assessment and professional plaque removal within hepatology care; consistent advice on oral hygiene, fluoride use, diet, and smoking and alcohol cessation; careful review of proton-pump inhibitor use; and much closer coordination between hepatologists and dentists to facilitate indicated procedures. The second is innovation: development of precision microbiome-based interventional trials powered for hepatic outcomes, including targeted probiotics and postbiotics, biofilm-disrupting and quorum-quenching strategies, and phage or narrow-spectrum antimicrobial therapies supported by rapid diagnostics and robust antimicrobial stewardship. Integrating oral health into hepatology practice may represent a practical opportunity to reduce infection risk, delay decompensation, and improve survival and quality of life in people living with ACLD. This review aims to synthesise current knowledge of the pathobiological mechanisms, analytical innovations, and therapeutic opportunities that underpin this evolving connection, while identifying gaps in the evidence base and proposing future avenues for harnessing the oral-gut-liver axis.