New research shows that drinking wine and eating cranberries can help ward off cavity-causing bacteria. Dental researchers from the University of Rochester say that cranberry and wine can fight against Streptococcus mutans, which invades mouths after meals. S. mutans prey on sugar residue left on teeth from desserts and sweets, and emit acid that eats away at tooth enamel. "Natural substances offer tremendous possibilities for stopping tooth decay," says Dr. Hyun Koo, a dentist and microbiologist. Cranberries and wine are two that combat bad bacteria growth in our mouths.