Chewing Gum with Beneficial Bacteria Touted as Cavity Fighter

LUDWIGSHAFEN, Germany, Aug. 24 -- Here's one to chew on.

A giant German chemical company says it is nearly ready to market a chewing gun laden with newly discovered bacteria called Lactobacillus anti-caries. The gum, according to a press release, can halve the number of tooth decay-causing Strepptococcus mutans bacteria in the mouth.

The company, however, is closed-mouthed with details about this purported cavity-fighting bacteria and their sticky vector. Proof that the bacteria exist? Double-blind randomized clinical trials to prove the anti-cavity claims? Peer-reviewed studies? Go blow a bubble.

No studies have been published or reported on L. anti-caries against oral bacteria or the efficacy in preventing caries. So with the lack of any supporting scientific evidence, there was no lack of skepticism.

"Any prudent practitioner has to be skeptical about claims like this," said Tim Iafolla, D.M.D., M.P.H., of the National Institute of Dental Research.

"It's one thing for them to make the claim, but they have to show some research before they can actually claim that it can reduce tooth decay," Dr. Iafolla said.

"It probably won't hurt patients to try it," said Amid I. Ismail, D.D.S, M.P.H., Dr.P.H., of the University of Michigan in Ann Arbor, "but we just don't know if it's going to be effective until we see studies."

L. anti-caries, according to the company, causes S. mutans to clump together rather than becoming attached to the tooth surface where it ferments sugars to produce an acid that breaks down the enamel and over time produces caries, or cavities.

"Part of the problem is that dental decay takes years to develop," commented Robert A. Bagramian, D.D.S., M.P.H., Ph.D., also of the University of Michigan in Ann Arbor. "The fact that they have been able to show that this chewing gum reduces certain bacteria in the mouth is not really showing that it prevents decay, and that is the ultimate test."

All chewing gum increases saliva production that helps rinse away bacteria, neutralize acid produced by harmful bacteria, and remineralize weak enamel, though many gums contain sweeteners promote bacterial growth.

While some gum containing xylitol, a sugar bacteria cannot use, has been shown to reduce cavities, this requires consistent use over a period of years. Casual use likely will not produce effects for the L. anti-caries gum either.

While the gum may reduce bacteria temporarily by displacing S. mutans, there is no lack of opportunistic "bad" bacteria to move in afterward.

"It's a very complex jungle in our mouth," said Dr. Ismail. "There are other ones that will remerge and occupy the space."

There are more than 700 species of bacteria that inhabit the mouth and at least seven are known to cause dental caries. The report did not say whether the gum affects these other species.

The L. anti-caries type of Lactobacillus, lactic acid bacteria, is reportedly found in live yogurt. Sugarless yogurt can be good for bad breath by significantly reducing plaque and gingivitis though not reducing oral bacteria levels, according to one study. Another reported that yogurt cultured with L. reuteri did reduce the number of S. mutans.

Adding healthy bacteria to chewing gum is a harmless, natural way of reducing cavity-producing bacteria and will likely be appropriate for children, said Dr. Iafolla.

The gum, if it does anything, actually may be most practical for use in children, who chew gum more frequently and have a high caries burden, as well as adults with reduced salivary flow due to radiotherapy or medication use.

"For children or adults who like chewing gum or those special populations this fits their lifestyle and may be very helpful," Dr. Ismail said.

However, L. anti-caries and even xylitol products are not effective against the gum disease caused by smoking or chewing tobacco.

He encouraged maintaining a good oral care routine as the primary defense against dental caries and the bacteria that cause them.

BASF, the German chemical company, reported that the chewing gum and a line of similar oral hygiene products may start to appear on the market in 2007. The report stated that the company is also developing a line of probiotic products including a deodorant based on L. ala-odoris, which can inhibit odor-producing bacteria in the armpit, and foot sprays or lotions based on L. pes-odoris.