Dental Probiotics: What Are They & How Do They Benefit Oral Health?

The human microbiome has become the centre of many discussions related to health issues. This makes sense, considering that we are made up of more non-human microorganisms than human cells. And if we broaden our view of what the human body is, we quickly understand that we cannot exclude the trillions of microorganisms living in and on our bodies, including the ones that live in our mouths.

Just like other microbiomes in the body, our oral microbiome comprises many types of bacteria. For too long most dentists and clinicians have focused only on pathogenic bacteria that are responsible for oral diseases such as dental caries or periodontal disease, rather than looking at the oral microbiota in its entirety. But in recent years, we have gained a better understanding of what types of bacteria live in the mouth and what role they play in their microbial community.

Importance of the Oral Microbiome

With the rise of information on the human microbiome and its importance to overall health, probiotics have become a popular addition to daily supplement routines. And, many probiotics on the market help improve the microbiome of the gastrointestinal tract (popularly called the “gut”), especially since it is the centre of our body’s defence against antigens and outside environmental factors.

However, the second largest and most diverse microbiome lives in the oral cavity and considering its anatomical connection to the gastrointestinal tract, it deserves much more attention than it currently receives. Sadly, our oral microbiomes are often in dysbiosis, largely due to the diet we eat, the medicines we take, as well as chronic stress, and other environmental factors. This dysbiosis manifests as oral diseases like dental caries (cavities) and periodontal (gum) disease, which are among some of the most common chronic diseases in the world.

Such poor oral health is sometimes labeled as the “silent epidemic” and the following statistics reflect its magnitude:

1. More than 1 in 4 adults  have untreated tooth decay.
2. About 1 of 5 children aged 5 to 11 years have at least one untreated decayed tooth. 
3. Nearly half of all adults aged 30 years or older show signs of gum disease.

Which begs the question: If cavities and gum disease reflect oral microbiome dysbiosis, why aren’t dental probiotics a more commonly used approach to prevention and co-treatment?

Beneficial Bacteria for Optimal Oral Health

Certain bacteria strains have been scientifically and clinically proven to improve oral health and restore oral microbiome balance. Some of these include Streptococcus salivarius M18, Lactobacillus reuteri, and Lactobacillus paracasei. When taken consistently, these bacteria colonise the oral cavity and crowd out pathogenic bacteria, limiting their growth and subsequently reducing the overall toxic bacterial load in the mouth.

Lactobacillus reuteri and Lactobacillus paracasei naturally reside in the gastrointestinal tract but have beneficial qualities for the mouth as well. Culture analyses of saliva from clinical study volunteers have shown that colonisation of Lactobacillus bacteria within the oral cavitary result in a statistically significant reduction in the number of Stretpococcus mutans (pathogenic, cavity-causing bacteria) present in the saliva. But because these bacteria also have numerous benefits for the gut (including improving the function of our immune system and strengthening the intestinal barrier) they are often found in digestive probiotics that are swallowed and delivered straight to the gastrointestinal tract, and a supplement that is swallowed won’t benefit the oral cavity. So, to colonise the mouth with these bacteria it is essential to deliver them via a dissolvable substrate, allowing bacteria to make their home directly on the teeth and gums.

Uniquely, Streptococcus salivarius M18 inhabits the oral cavity with functions specific to the oral microbiome.

Streptococcus salivarius M18 (“S. salivarius M18”) produces four potent antimicrobial proteins. The most significant is salivaricin M which can inhibit the growth of Streptococcus  (the pathogenic bacteria primarily responsible for dental caries). Additionally, S. salivarius M18 produces two enzymes called dextranase and urease. Dextranase reduces plaque accumulation on the teeth by breaking down dextran, which is a component of plaque. Urease interacts with the urea in saliva to help neutralise the acidic pH level of the mouth caused by Streptococcus or acidic foods and drinks. Since Streptococcus thrive in an acidic environment, S. salivarius M18 is key for reducing the risk of cavities through its interaction with urease.

Creating new habits, are key to successful integration of dental probiotics.

Brushing and flossing are the daily accepted standards of good oral health habits, but more steps must be taken to treat chronic microbiome dysbiosis. Dentists and functional health practitioners are in an ideal position to act as educational guides for patients and should proactively help them tackle modifiable factors that affect oral dysbiosis including diet, stress management, and probiotic supplementation. Our tagline, “Floss. Brush. Take one of us.” helps introduce the concept of dental probiotics  as a new addition to the daily oral hygiene routine. It is our mission to help individuals and families achieve optimal oral health by creating quality holistic oral care products.