Did you know that the mouth is the most biodiverse ecosystem known? More than 600 species of microbes can coexist in it, fighting each other for space and nutrients. The relationships between these microbes largely determine the origin of infectious diseases such as tooth decay. A healthy mouth depends on the balance of this ecosystem and its alteration can result in the predominance of a population of microbes and as a consequence, in disease.
Streptococcus mutans is the main microorganism implicated in dental caries. Although it is part of the normal flora of the mouth, a high count of this bacteria is associated with the onset and progress of tooth decay. That is why its control has interested researchers around the world who are in the search for substances with antimicrobial activity against this microorganism. Researchers conducted a study with 53 children between the ages of 3 and 5 from a school. Using samples of the saliva of these children, they were able to identify 8 strains of Streptococcus mutans that produced different mutacin profiles, and that could serve in the biological control of dental caries.
Due to its great biodiversity, the oral cavity is an ecological habitat where competition for survival is intense. Many bacterial species have weapons to eliminate or displace other microorganisms and to survive. These weapons, called bacteriocins, are antibiotic protein substances that play an important role in maintaining normal flora. Most strains of Streptococcus mutans produce these weapons, which in their case are called mutains. Mutacins can help us control tooth decay.
This bacterium resides permanently in the oral cavity, mainly in the teeth as it needs a hard surface to be able to colonize. It feeds on the sugar in our diet, which it then converts to acid. Tooth decay forms when acid demineralizes the tooth.
The colonies of Streptococcus mutans to be controlled are the most virulent, that is, the largest producers of acid and consequently of dental caries. The objective of biological control is to reduce or displace these colonies with other non-pathogenic ones of this same species, which have sufficiently powerful mutains for the control to be effective and permanent.
Eradicating Streptococcus mutans in a total way is not a valid option since it would alter the ecosystem of the mouth and generate more serious consequences. The aim is to keep the microbes in balance because, in fact, we need them. “The microorganisms in the oral cavity, like those of the intestinal bacterial flora, also play a beneficial role.” These strengthen the body’s defense system and increase resistance to infection.
Biological control is of the utmost importance because “dental caries is one of the main infectious pathologies of the oral cavity and affects more than 90% of the Colombian population.
Biological control could be carried out directly in the oral cavity with the mutacin-producing strains or with the purified mutacins. These could also be chemically synthesized and added, for example, to mouthwashes, toothpastes and chewing gums. “Mutacins and other bacteriocins identified in bacteria that produce acid are also very important in the food industry where they are being used as natural preservatives.”
Having a healthy mouth is not just a question of aesthetics. The control of caries and other diseases of the oral cavity is necessary for good health because, as “some microorganisms in the oral cavity cause systemic infections after passing into the blood. There are bacterial endocarditis that has its focus on Streptococcus mutans”.
Hygiene measures that decrease the amount of Streptococcus mutans in the mouth
• Brush your teeth at least three times a day.
• Use dental floss and rinses with fluorides.
• Eat less sugar and more fruits.
• Visit the dentist regularly.
Recommendations to parents
Dentisits recommend that parents request that kindergartens, schools and colleges sell less sweets and more fruits in their stores, and that they have spaces for schoolchildren to brush their teeth after recess.
According to them, the best dentist in the world is a careful mother or father who performs proper oral hygiene of their children and who is aware of a healthy diet (based on fruits and natural juices) and free of sweets. In addition, parents can check for plaque bacteria with revealing substances, innocuous and rinsing with fluorides, available over the counter in drugstores and supermarkets.