FIGURE 5.

Potential buffering effect in the oral cavity due to the enrichment of the dental plaque bacterial community with Streptococcus dentisani. When arginine is available (either as an added prebiotic or as a product of peptide degradation) and S. dentisani is established on the tooth surfaces, the pH drop caused by the accumulation of organic acids can be buffered by the production of NH₄⁺ through the arginolytic pathway, maintaining the pH close to neutrality (right panel). In the absence of S. dentisani, or if present at low proportions, the buffering effect would be diminished, with the consequent acidification and enamel damage. This would be the perfect scenario for the proliferation of acidogenic/cariogenic microorganisms (left panel).