Gut Microbiome and Cardiovascular Health: Mechanisms, Therapeutic Potential and Future Directions.

Background: The gut microbiome has a crucial role in host metabolism and immune regulation, and there is growing evidence that dysbiosis may be associated with the pathogenesis of cardiovascular disease (CVD). This narrative review provides an overview of the recent literature on mechanistic connections between the gut and heart, as well as on the therapeutic strategies and research gaps in the gut-heart axis. Methods: We conducted a systematic literature search on PubMed and Embase databases with MeSH and keyword terms: 'gut microbiome', 'cardiovascular disease', 'TMAO', 'short-chain fatty acids', 'probiotics' and 'faecal microbiota transplantation'. We considered human and relevant animal studies focusing on mechanistic pathways or microbiome treatments and excluded editorials, small (less than 10 subjects) case series and articles not published in the English language. Results: Key microbiota-derived metabolites, trimethylamine N-oxide (TMAO) and short-chain fatty acids (SCFAs), contribute to atherogenesis, blood pressure and myocardial inflammation. Dysbiosis-induced barrier dysfunction and disturbed bile acid signalling also serve as the mediators of cardiac remodelling. Dietary fibre, probiotics/prebiotics, postbiotics and faecal microbiota transplantation are emerging interventions for the modulation of CVD risk. Nevertheless, most result from observational studies, whilst such are heterogeneous in sequencing platforms and too small to draw any definitive conclusions. Conclusion: The modulation of gut microbiome might be a new target for CVD prevention and treatment. Large-scale, standardized randomized trials with hard cardiovascular endpoints, as well as integrated multi-omics profiling, will be required to validate microbial biomarkers and to optimize microbiome-based interventions.