A systematic review of TMAO, microRNAs, and the oral/gut microbiomes in atherosclerosis and myocardial infarction: mechanistic insights and translational opportunities

Cardiovascular disease (CVD) is the leading cause of death worldwide, driven by complex interactions among atherosclerosis, inflammation, and metabolic dysregulation. Recent studies have identified the gut and oral microbiomes-through their metabolism of dietary precursors into trimethylamine (TMA) and its hepatic conversion to trimethylamine-N-oxide (TMAO)-as pivotal contributors to CVD risk. In parallel, microRNAs (miRNAs) have emerged as crucial regulators of inflammatory and metabolic pathways that further modulate these processes. This review examines recent human studies (2020-2025) to explore how microbiota-derived TMAO, miRNA regulatory networks, and changes in the oral microbiome contribute to the development of atherosclerosis and myocardial infarction. It also highlights potential therapeutic strategies targeting these pathways, providing insights for precision medicine in cardiovascular disease management.