Human colostrum (HC) is essential for oral health as it is rich in probiotics that could affect the growth of the cariogenic S. mutans and its biofilm formation; hindering dental caries in advance. In this study, HC was collected from 36 healthy mothers 1-3 days postpartum. The effect of HC on oral health was carried out by assessing the impact of HC and its derived probiotics' cell-free supernatants (CFS) on the growth of S. mutans (using modified well diffusion) and its biofilm formation (using microtiter plate assay). Moreover, the effect of whole HC on L. rhamnosus, a probiotic oral bacterium, was examined. Probiotics were isolated and identified phenotypically by API 50 CH carbohydrate fermentation and genotypically by 16S rRNA amplification. The in vitro study revealed that HC has cariogenic activity and is associated with biofilm formation. Biofilm strength was inversely proportional to HC dilution (p-value < 0.0001). Nevertheless, HC and colostrum-derived probiotics improve oral health by inhibiting the growth of caries-inducing S. mutans with lower inhibition to L. rhamnosus probiotics. The CFS of isolated probiotics reduced the biofilm formation via the cariogenic S. mutans. These results are not only promising for caries eradication, but they also highlight the importance of breastfeeding infants from their first hours to shape healthy oral microbiota, protecting them from various diseases including dental caries.
Keywords: L. rhamnosus; S. mutans; biofilm; breast feeding; cell-free supernatant; dental caries; human colostrum; oral microbiota; probiotics; teeth decay.