Oral-heart axis from pregnancy and postpartum: maternal oral microbiota relates with cardiac reverse remodeling

Background Emerging evidence links the oral microbiota to cardiovascular health, but this relationship remains poorly understood during pregnancy. Here, we investigated associations between the oral microbiota, cardiovascular physiology, and diet during and after pregnancy.Materials and methods Salivary microbiota from 65 women in the 3rd trimester and 6 months postpartum were analyzed by 16S rRNA gene sequencing. Cardiovascular function was assessed via echocardiography, endothelial function by EndoPATTM, nitric oxide levels by plasma nitrate/nitrite levels, and diet through the Food Frequency Questionnaire.Results Left ventricular end-diastolic volume (LVEDV) was negatively associated with nitrite-reducing bacteria, namely, Prevotella, at both time points. Cluster analysis identified two reverse-remodeling profiles, one with poorer remodeling, greater postpartum weight retention and higher pregnancy microbial richness enriched with inflammation-associated genera that persisted postpartum. Higher Porphyromonas abundance during pregnancy predicted smaller postpartum LVEDV reductions. At postpartum, in the healthier cluster, Neisseria correlated with left ventricular mass changes and Parvimonas correlated with ΔLVEDV. Multivariate models confirmed independent microbiota–cardiac associations, while regression analyses did not support a clear diet–microbiota–cardiac axis.Conclusion In conclusion, the salivary microbiota profile was associated with cardiovascular physiology during pregnancy and with postpartum cardiovascular recovery. These findings warrant confirmation in larger cohorts to clarify their clinical relevance.