The oral cavity is colonized by several hundred bacteria. These microorganisms tightly aggregate to the teeth surface to form a biofilm known as dental plaque. Following fermentation of dietary sugars, this bacterial biofilm produces elevated levels of organic acids that demineralize the teeth surface thereby causing dental caries.

According to Victoria Moreno-Arribas, Instituto de Investigación en Ciencias de la Alimentación (CIAL), CSIC-UAM, Madrid, Spain, and co-workers red wine may prevent dental caries from arising. The researchers grew oral cavity pathogens as biofilms. Next, they dipped the biofilms into red wine, dealcoholized red wine, or red wine extract solutions spiked with grape seeds. Remarkably, the three experimental conditions inhibited the bacterial growth. These antimicrobial effects seem to be attributable to flavan-3-ol precursors such as (+)-catechin and procyanidin B2, namely polyphenols contained in red wines in elevated amounts.

• Red Wine and Oenological Extracts Display Antimicrobial Effects in an Oral Bacteria Biofilm Model,
  Irene Muñoz-González, Thomas Thurnheer, Begoña Bartolomé, M. Victoria Moreno-Arribas,
  J. Agric. Food Chem. 2014.
  DOI: 10.1021/jf501768p