Cardiovascular disease (CVD) remains a global health burden despite advances in prevention and treatment. Conventional biomarkers, while effective for a number of patient groups, fail to provide personalized diagnosis and prognosis, necessitating the exploration of novel markers. Advancements in sequencing technology have unveiled the role of cell-free DNA (cfDNA) as a reservoir of genetic information from all cells within the body, and associations between elevated cfDNA levels and CVD risk factors and status have been reported. Recent attention has turned to a subset of cfDNA, circulating bacterial DNA (cbDNA), derived from gut microbiota, as a potential biomarker. Investigations into microbial translocation from the gut, particularly the phenomenon of ‘leaky gut,’ reveal its association with CVD and provide a potential source for cbDNA. Here, we review the existing literature on cbDNA in CVD, highlighting its potential diagnostic and prognostic value. Current studies have largely been carried out in small, disparate cohorts, using different sample types and a range of methodologies. While cbDNA shows potential as a diagnostic and prognostic biomarker, the lack of consensus in methodologies and populations studied calls for standardized approaches and large cohorts to establish cbDNA as a reliable CVD biomarker. Future research should focus on identifying the source of cbDNA and its pathological relevance, utilizing advanced sequencing techniques and standardized cohorts for conclusive findings.