Probiotic in chewing gum could help fight cavities

Brazilian researchers find a way to use Lactobacillus acidophilus against cavity-causing microorganisms.

By Noêmia Lopes

Agência FAPESP – A chewing gum made with microencapsulated probiotics that are released by chewing produces compounds that inhibit the action of cariogenic microorganisms. This discovery is the result of studies carried out over the last three years at the Universidade Estadual Paulista Araraquara’s (Unesp Araraquara) School of Pharmaceutical Sciences.

In vitro experiments identified Lactobacillus acidophilus as the most appropriate species for the development of the new gum. As a result of the applied technology, these bacteria can survive the processing conditions, stay alive inside the gum (without refrigeration), maintain the longest possible shelf life, meet certain sensory requirements (taste, texture, color and smell) and, finally, be released by chewing in the oral cavity, producing compounds that combat Streptococcus mutans, one of the main pathogens that cause cavities.

In vivo studies conducted with 65 volunteers showed that chewing gum made with probiotic microorganisms increases the presence of Lactobacillus acidophilus in saliva. “This indicates that its use could be beneficial in cavity treatment,” said Elizeu Antonio Rossi, a professor at FCFAR/Unesp.

Rossi served as an adviser to Nadiége Dourado Pauly-Silveira, whose doctoral thesis led to the development of the new gum, and coordinated a Regular Research program linked to the study.

According to the researcher, FCFAR/Unesp has studied and developed products with probiotic microorganisms, pursuing specific treatments for coronary diseases, colon cancer, breast cancer, osteoporosis and diabetes.

“One interesting distinction of this new study on the oral cavity is that the probiotic action is local. Or rather, it is probably not a systemic action that would necessarily involve the effects of probiotic microorganisms in the intestine,” he explained.

Previous scientific research has indicated that the use of probiotics to alter the oral microbiota is feasible: probiotics can compete with pathogens like Streptococcus mutans for adhesion receptors and nutrients, not to mention produce compounds that are capable of inhibiting the development of pathogens, a property that Rossi and Pauly-Silveira worked hard to harness.

Stages and challenges

Once the in vitro experiments proved the efficacy of Lactobacillus acidophilus in inhibiting Streptococcus mutans, the researchers tested various known methodologies of probiotic microencapsulation. The study involved adaptations and combinations of techniques that resulted in a patent request, which is currently in the analysis stages.

“Adequately coating the probiotics allowed us to overcome a series of obstacles, such as how to keep these microorganisms alive inside the gum – given the heat used during product procession and storage at room temperature – for the greatest possible shelf life without altering the taste, texture, color or smell,” explained Rossi.

The next challenge was to ensure that the microencapsulation was not too hermetic, i.e., did not prevent the release of the probiotics during chewing, as well as to analyze market acceptance. To this end, 65 volunteers tried the new gum.

Determining the quantity of probiotics available in the gum required that scientists collect saliva samples ten minutes before and after chewing and count the bacteria that grew from cultures of the samples.

“We found that the quantity of Lactobacillus acidophilus in the saliva increased up to 1,000 times. With regard to acceptance, the new gum received an average of around seven on a scale of one to nine, similar to standard products, which led us to believe that introducing probiotics does not negatively affect sensorial perceptions,” affirmed Rossi.

The Lactobacillus acidophilus remained viable inside the gum for 154 days without refrigeration. According to researchers, “it was the best brand among the other probiotics tested, which lasted only 56 days.”

Scientists chose the chewing gum for probiotics use based on taste tests with children and adults. Mouth washes and chewable tablets were also considered but were not within the research group’s scope of study, which focused on food.

The next step will be to begin clinical trials. To this end, Rossi’s team has already contacted orthodontists who can monitor two groups of children for at least a year: one that has been instructed to chew probiotic gum and one that will serve as a control group and will receive a placebo.

“Everything indicates that we will see beneficial results. Furthermore, the gum that we developed is sugar free, like many others on the market, and it does not cause cavities – the difference is that in addition to not causing cavities, the product also attacks the problem.”