Researchers dental offer a Darwinian explanation to the effectiveness of the sweet sugar-free gum.

The secret sugar of sugar-free gum sweetened one of the great enigmas of gastronomic this century. Indeed, a team of Ecology Research Group mouth (GREBE) of the Faculty of Dentistry has to lift another part of the veil that obscures the mechanism of action through which the xylitol, this "sugar without sugar, until reduced '85% incidence of tooth decay among people who consume regularly. In the latest issue of the Journal of Dental Research, Luc Trahan, Gene Bourgeau and Richard Breton present data that support the hypothesis that xylitol cause the replacement of a strain of bacteria causing tooth decay by a less pathogenic strain.

"Some bacteria (S. mutans) found in dental plaque of xylitol eat but are unable to deteriorate so their metabolism is running empty," says Luc Trahan. In addition, people who consume xylitol for prolonged periods have a oral flora consisting largely of a mutant strain of S. mutans, insensitive to xylitol, which causes less tooth decay. If the mechanism of action of xylitol based on the selection of resistant strains of bacteria, we were able to recreate the phenomenon in the laboratory. "

Researchers have placed strains of S. mutans, sensitive to xylitol in culture media containing various combinations of sugars in the normal diet. Result? Resistant strains have emerged in almost all environments containing added sugar xylitol. "The mutant strains grow faster than the parent strain and replace, says Luc Trahan. It is not clear why these mutant bacteria cause less tooth decay. Our hypothesis is less well they adhere to the tooth surface. "

The xylitol is a sugar found naturally in the small berries. Scandinavians the extract of the bark of birch to supply industries that use sugar as an additive in chewing gum and some other products. The consumption of 10 to 15 grams of xylitol per day is enough to induce the protective effect against cavities as quickly oral flora comprises 90% of bacteria resistant to xylitol. As against, when a person ceases to consume, the strain that causes tooth decay back in force. "It is not known how long it must consume xylitol for a lasting protective effect, said Luc Trahan. We have undertaken a study, which was attended by students from the university, which should soon provide an answer to this question. "

the School of Dentistry at the University of Minnesota
A chewing gum that prevents tooth decay ... and otitis
Dec 18 2000 - Do not surprise if the industry gum is soon on its packaging highlighted the word "xylitol". This natural sugar found in certain fruit has the property to significantly reduce the number of bacteria Streptococcus mutans that cause tooth decay.

According to a recent study conducted among 151 people easily prone to decay, those who chewed gum sweetened with xylitol for five minutes at the end of the meal had less bacteria than those chewing gum sweetened with sorbitol or not chewing anything. The beauty of the thing is that the effect of xylitol was felt up to three months later.

The principal author of the research, Dr. Gary Hildebrandt, associate professor at the School of Dentistry at the University of Minnesota, says that the bacteria responsible for dental caries are trying to combat the presence of xylitol leaving them with less' energy to reproduce. On the contrary, chewing gum sweetened with sorbitol or with sugar feed the same bacteria.

University of Oulu

Department of Pediatrics, Oulu, Finland.

Xylitol is effective in preventing acute otitis media by inhibiting the growth of Streptococcus pneumoniae. To clarify this inhibition we used fructose, which is known to block similar growth inhibition observed in Streptococcus mutans. In addition, we evaluated the efficacy of sorbitol in inhibiting the growth of pneumococci, as sorbitol is widely used for indications similar to those for which xylitol is used. The addition of 5% xylitol to the growth medium resulted in marked growth inhibition, an effect which was totally eliminated in the presence of 1, 2.5, or 5% fructose but not in the presence of 1 or 5% glucose, galactose 1%, or 1% sucrose. This finding implies that xylitol-induced inhibition of pneumococcal growth is mediated via the fructose phosphotransferase system in a way similar to that in which mutans streptococcal group growth is inhibited. The addition of sorbitol at concentrations of 1, 2.5, or 5% to the growth medium did not affect the growth of pneumococci and neither inhibited nor enhanced the xylitol-induced growth impairment. Thus, it seems that xylitol is the only commercially used sugar substitute proven to have an antimicrobial effect on pneumococci

University of Michigan

Department of Biologic and Materials Sciences, Ann Arbor.

Significant improvement in the dental caries status of children in the United States has been seen in recent decades. The percentage of children who are free from dental caries, however, rapidly decreases with age. By the time young people enter colleges or universities, only a few are caries free. Colleges and universities are places where the young are simultaneously, and perhaps for the last time, reachable as large cohorts before their lives undergo further "individualization." This makes college age a time that is crucial for channeling information about proper oral health practices by organizing mass-directed strategies for prevention of dental caries. It is now clear that dental caries can be prevented effectively. This calls for placing strong emphasis on dietary behavior and on the use of sugar substitutes as part of the strategy. Scientific evidence also suggests that the addition of small daily quantities of xylitol, a natural carbohydrate sweetener, to the diet of children and young adults causes significant reduction in the incidence of dental caries. On the basis of detailed long-term clinical trials carried out during the past 20 years, it appears that a reduction ranging from 30% to more than 85% in dental caries can be achieved simply by using a few xylitol chewing gums daily over a period of 1 to 3 years. In individual cases, virtually total, long-term protection against tooth decay has been observed