We evaluated the anti-cariogenic effect of an experimental synbiotic compound containing probioticLacticaseibacillus rhamnosus(NRRL B-442)-based jelly candy supplemented with natural prebiotic grape seed extract (GSE) in a nanoemulsion formula on the colonization and establishment ofStreptococcus mutans(ATCC 25175) andActinomyces viscosus(ATTCC 19246) biofilms through counting colony forming units, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). We were then analysing the remineralizing effect of synbiotic jelly candy on human enamel surface lesions using Vickers microhardness testers, atomic force microscopy (AFM), SEM, energy-dispersive X-ray spectroscopy (EDAX), and confocal laser scanning microscopy (CLSM) at three stages (sound, after demineralization, and after pH cycling). We found after 21 days of treatment of the pH-cycled enamel discs with jelly candy for 10 min twice daily, a 68% decrease inS. mutanscolony formation, reducing biofilm development, trappingS. mutansvisualized in jelly candy under SEM examination, and significantly altering the morphological structure of these bacteria under TEM analysis. For remineralization measurements, statistically significant differences in microhardness integrated mineral loss, and lesion depth through CLSM between demineralization and treatment stages. These findings provide an effective anti-cariogenic synbiotic compound of grape seed extract and probiotic jelly candy with potential remineralizing activity.