Correlation Between Dysbiosis and Atrial Fibrillation: What’s New?

Atrial fibrillation (AF), one of the most prevalent and widespread arrhythmias, has remained a heavy global burden in the past decade and directly influences the quality of human life. It is estimated that AF affects 2–4% of the world’s adult population, and it is predicted to double due to (i) life expectancy increasing and (ii) the rising frequency of undiagnosed cases. Recent studies suggest that the alteration of gut microbiota (GM), known as dysbiosis, could increase the AF risk. Since dysbiosis is a modifiable risk factor, interventions aimed at restabilizing gut eubiosis by diet, probiotics, or prebiotic supplements may represent a promising strategy for AF prevention and/or treatment, although current clinical evidence remains limited. In this scenario, it is very critical to understand which types of GM alterations or metabolites may be involved in the development of atrial AF, as this could open new strategies for managing the pathology. However, many gaps still need to be filled, as it remains unclear how dysbiosis contributes to AF across different populations and no fine characterization of the underlying pathogenic mechanisms is available yet. This review summarizes the last evidence on the association between GM dysbiosis and AF, highlighting the main proposed mechanisms, key microbial genes and metabolites involved, clinical implications and the need for further prospective studies.