Discovering the oral microbiota

The human body is populated by trillions of microorganisms (bacteria, viruses, fungi and protozoa) which together are defined as microbiota .

The microbiota has a different composition in the various areas of the body where it is hosted, depending on the availability of oxygen, the presence of nutrients and the pH. Most of the microorganisms that make it up are found in the gastrointestinal tract . The other areas that are colonized by the microbiota are the skin , the genitals and the oral cavity .

What is the oral microbiota

The term oral microbiota identifies the set of microorganisms present in the mouth and in the anatomically close areas, such as the nasal cavities , the pharynx and the respiratory tract . Inside it, about 700 different microbial species can be distinguished , mainly represented by bacteria and in particular by Streptococcus salivarius .

How is the oral microbiota formed?

At birth, the oral cavity is sterile. The microbiota is acquired by newborns at the time of birth : if this has been natural , the microorganisms of the maternal vaginal tract will mainly be present , while in the case of a cesarean section there will be a composition similar to that of the mother ‘s skin and that of the health workers who have take care of the baby in the first days of life.

The breastfeeding method adopted in the first months of life affects the composition of the oral microbiota. Furthermore, at the time of weaning , there is a rapid and progressive change in the microbiota, which around the age of 3 becomes similar to that of the adult .

What role does the oral microbiota play?

The “friendly” microorganisms that make up the microbiota are able to adhere to the surface of the mucous membranes of the oral cavity, the upper respiratory tract and the teeth, and form a film (called biofilm) which exerts a protective action against the proliferation and the penetration of potentially harmful (i.e. pathogenic) bacteria and viruses.

In this regard, it is essential to underline that the oral microbiota is the first defender of the digestive and respiratory tract  and for this reason it is important that it is in a state of balance (eubiosis) .

In fact, when the “good” microorganisms (such as Stretococcus salivarius ) are more numerous than the pathogenic bacteria, the microbiota adequately performs its role of guardian of the health of the mouth and respiratory tract, acting as a barrier against harmful microorganisms and protecting thus the integrity of the enamel of the teeth and of the mucous membranes of the mouth and respiratory tract.

On the other hand, when the balance of the composition of the oral microbiota is altered, there is a greater proliferation of “bad” microorganisms to the detriment of the “good” ones, a situation which is defined as dysbiosis of the oral cavity .

Oral microbiota and child health

The state of eubiosis of the oral microbiota is particularly important in the first years of life , when the immune system is not yet fully mature and children are particularly prone to recurring respiratory tract infections.

A state of dysbiosis , in fact, can pave the way for disturbances such as halitosis and very frequent pathologies in children, such as mouth ulcers, stomatitis, gingivitis, pharyngitis, tonsillitis, otitis and dental caries .

What to do to prevent these problems?

There are some basic measures to maintain (or restore) the state of eubiosis of the microflora of the oral cavity , which can help prevent the disorders listed above.

In fact, we know that the good balance of the oral microbiota depends above all on a healthy and balanced diet , on the action of saliva (which by keeping the pH between 6.5 and 7.5 favors the transfer of some nutrients to the microorganisms present) and on a proper oral hygiene . 

On the contrary, an unbalanced diet too rich in simple sugars , poor oral hygiene , a prolonged inflammatory state of the respiratory tract due to the presence of fine dust in the air and the frequent use of antibiotics  can induce a state of dysbiosis of the oral cavity . with all the associated consequences.

Consequently, we can say that a balanced diet and constant and correct oral hygiene can help protect the child from the most common “colds” , as well as preserve the health of teeth and gums.

In addition, in the case of dysbiosis, the use of probiotics for sufficiently prolonged periods is able to positively and effectively modify the microbiota of the oral cavity, with a very significant reduction of the aforementioned pathologies and disorders .