This comprehensive review reveals that gut bacteria play a crucial role in atherosclerosis development beyond traditional cholesterol pathways. Researchers found that altered gut microbiota and oral bacteria in the intestines contribute to cardiovascular disease through various mechanisms. Harmful bacterial metabolites like endotoxin and trimethylamine N-oxide promote atherosclerosis, while beneficial compounds like certain tryptophan derivatives may protect against it. The gut microbiota also interacts with lipid metabolism and contributes to vascular aging. Interventions using prebiotics, probiotics, and antibiotics show promise in preclinical studies, suggesting the gut-heart axis represents a new therapeutic frontier for cardiovascular disease prevention.