Probiotic, synbiotic effects on the gut–liver axis: omics-enabled mechanisms and therapeutic windows

The gut-liver axis is a two-way communication network where gut microbes and their metabolites affect liver function, while the liver regulates the intestinal environment through bile acids, immune factors, and antimicrobial substances. Disruption of this balance contributes to various liver diseases, including nonalcoholic fatty liver disease, alcohol-associated liver disease, cirrhosis, and liver cancer. Probiotics and synbiotics are potential therapies that aim to restore microbial balance, strengthen the intestinal barrier, and regulate inflammation and metabolism. Recent omics technologies, such as metagenomics, metabolomics, transcriptomics, and proteomics, have helped uncover how these interventions influence important pathways involving short-chain fatty acids, bile acids, and microbial metabolites. Studies suggest that probiotics and synbiotics may improve liver health through effects on metabolism, immune regulation, and fibrosis, although results vary depending on the specific microbial strains and patient characteristics. Emerging approaches include next-generation probiotics, targeted synbiotic combinations, and personalized microbiome-based treatments. Combining multi-omics data with digital health tools may help identify patients who are most likely to benefit. Overall, microbiota-targeted therapies show promise as personalized strategies for managing liver diseases, but further research is needed to overcome challenges in translating findings into consistent clinical applications.