Any ideas why cinnamon helps kill oral bacteria?

Phytochemicals. "essential oils are the main antimicrobial agents in spices. Most of these oils seem to derive their antimicrobial properties from a benzene functional group. The presence of sulfur may also be an important part in the antimicrobial mechanisms of some spices." http://www. Drew. Edu/wp-content/uploads/sites/99/team3sandler12.Pdf.