(1) control group who rinsed with 15 mL distilled water; (2) a group who rinsed with 15 mL chlorhexidine, a standard antiplaque mouth rinse; and (3) a group who rinsed with a 15-mL HAEP solution. HAEP decreased the number of colony forming units (CFU) of dental plaque bacteria 84 percent, comparable to chlorhexidine (79-percent inhibition) but significantly better than the control rinse (11-percent inhibition). Both HAEP and chlorhexidine were effective against Staphylococcus, Streptococcus, Klebsiella, and Proteus species, as well as E. coli. The ellagitannin, punicalagin, is thought to be the fraction responsible for pomegranate's antibacterial activity.