Popular Chewing Gum Eliminates Bacteria That Cause Bad Breath

The finding was presented at the recent annual meeting of the International Association for Dental Research.

Given that the gum contains cinnamic aldehyde, a plant essential oil used for flavoring, the result was not surprising, said Christine Wu, professor of periodontics and associate dean for research at the UIC College of Dentistry. Wu, who searches for natural antibacterial agents from plant sources that suppress oral pathogens, had tested several plant essential oils and found that they inhibited the growth of bacteria responsible for cavities and periodontal infections.

"In laboratory tests, some of these oils also prevented the growth of three species of oral bacteria associated with bad breath and the production of volatile compounds that cause the unpleasant smell," Wu said.

The laboratory findings and interest from the Wrigley Company in Chicago prompted Wu to launch a clinical trial of the effects of chewing gum on oral bacteria.

In the study, 15 subjects chewed one of three gums for 20 minutes: Big Red, the same gum with natural flavors but no cinnamic aldehyde, or a gum base with neither flavors or oil.

Twenty minutes after the subjects stopped chewing the gum, their saliva was tested and compared with samples collected before chewing began.

Microbiological analysis showed that Big Red reduced by more than 50 percent the concentration of anaerobic bacteria in the saliva. It was particularly effective against anaerobic bacteria residing at the back of the tongue, reducing the population by 43 percent. These bacteria produce volatile sulfur compounds through the putrefaction of proteins and are considered the major contributors to halitosis, or bad breath.

The gum that contained natural flavors but no cinnamic aldehyde also reduced the number of bacteria by about 40 percent.

"The result was puzzling at first, but after compiling our data, we were informed that the natural flavors included a small amount of a plant extract," Wu said. "We had already shown in previous lab studies that this extract suppresses the growth of oral pathogens."

The gum base without flavors or cinnamic aldehyde produced no significant reduction in oral bacteria.

"Our study shows that chewing gum can be a functional food, having a significant impact on oral hygiene over the short term, if it contains antimicrobial agents such as cinnamic aldehyde or other natural active compounds," Wu said. "The product doesn't just mask foul mouth odor; it eliminates the bacteria that cause it, at least temporarily."

Min Zhu, research associate in Wu's laboratory, collaborated in the study, which was funded by the Wm. Wrigley Jr. Company.

For more information about the UIC College of Dentistry, visit http://dentistry.uic.edu.