Gut Microbiome and Atrial Arrhythmias: A Narrative Review of Emerging Mechanisms

Background: The gut microbiome is increasingly recognized as a key modulator of systemic physiology, including inflammation, metabolism, and autonomic function, all of which are factors implicated in the development of cardiac arrhythmias. Despite this, its specific role in arrhythmogenesis, particularly atrial arrhythmias, remains underexplored. Purpose: This narrative review aims to provide an update on current information about how the gut microbiome may influence cardiac electrophysiology and contribute to the onset of atrial arrhythmias, with a focus on proposed mechanisms and call for further research into potential therapeutic interventions. Methods: Given the emerging nature of this topic and the limited consolidated literature, a narrative review approach was adopted. Sources were identified through targeted database searches using key terms such as gut microbiome, cardiac arrhythmias, atrial arrhythmias, inflammation, and autonomic nervous system. Articles were selected based on relevance and contribution to foundational or novel insights within the field. Results: Key mechanisms that need to be further researched linking the gut microbiome to arrhythmogenesis include systemic inflammation, microbial metabolite production and modulation of the autonomic nervous system. Dysbiosis contributes to an altered gut microbiome environment, allowing inflammatory mediators to affect cardiac function and disrupt electrical signaling. Conclusions: The gut microbiome appears to play a contributory role in arrhythmogenesis through pathways involving inflammation, metabolism, and autonomic regulation. While evidence continues to emerge, further research is needed to clarify the nature of this relationship and establish its relevance to atrial arrhythmia development.