Can Yakult probiotics help to treat and prevent dental problems?

Did you know that probiotics are effective at reducing tooth decay risk? Does the probiotics in Yakult work the same way to prevent dental problems?


Dr. Jaclyn Toh

8/9/20213 min read

Oral probiotics (this term could mean orally-ingested probiotics or probiotics with species "optimised" for the maintenance of oral health and prevention of oral diseases such as tooth decay and gum disease) are NOT used as first-line treatment or for first-line prevention.  

The basic principles that have stood the test of time and have research backing for the maintenance of oral health still apply for the vast majority of people. These principles do not contradict general health advice that will benefit your body as a whole:

1. Maintain meticulous oral hygiene: twice daily brushing, daily interdental cleaning (flossing, use of interdental brushes)

2. Maintain a balanced diet high in green vegetables (more on this below) and a wide variety of foods.

3. Reduce refined sugar/carbohydrate intake.

4. Do not consume sweetened beverages frequently.

5. Use fluoridated toothpaste twice daily, especially if you are at high risk for decay. This is something that your dentist can evaluate and advise on.

6. See a dentist regularly for professional cleaning and periodic evaluation of your mouth and teeth. This will ensure that the early signs of dental disease are spotted well in advance and early treatment and prevention can commence. By the time there are symptoms (pain, an abscess etc) the disease process is more advanced and treatment becomes much more complicated with a lower chance for long term success and stability.

These steps should be sufficient to maintain your teeth for life.

If you encounter a localized infection in the mouth, the most effective treatment is removal of the source of infection (either by extracting the infected tooth or starting root canal treatment). Antibiotics can help to prevent the infection from spreading but will not eliminate the infection completely. Probiotics can help to counter the effects of antibiotics on your gut flora (that kill all bacteria indiscriminately, including beneficial species).

At the moment, there is insufficient evidence to routinely recommend oral probiotics. This is because there are many aspects of the oral and even gut microbiome that are still a mystery to us, such as:

1. What is the composition of an "ideal" healthy oral microbiome? Is the oral microbiome variable between individuals?

2. Are there certain beneficial bacterial species that should be present, and in what proportions?

3. Is is possible to reorganize the oral microbiome to eliminate harmful bacterial species?

4. How will the probiotic bacteria be kept alive in the oral cavity to have sustained effects?

5. Does oral probiotic supplementation required prolonged dosing to have a long term benefit, or is a single course sufficient?

Even gut microbiome research which is more advanced than oral microbiome research is still in its infancy. There is much that we do not yet fully understand to be able to recommend routine oral probiotic supplementation with confidence.

There is evidence that green vegetables are essential for the maintenance of beneficial gut bacteria. Without prebiotics (foods that nourish the good bacteria such as green leafy vegetables, asparagus, garlic, onion, leeks, artichoke etc) taking a probiotic on its own will not produce lasting effects.

Interestingly, consumption of green vegetables allows for salivary secretion of nitrate that is converted to nitric acid and nitrous oxide in an acidic environment. These compounds are able to kill harmful bacteria (such as E.Coli that can cause food poisoning) and suppress the growth of decay-causing oral bacteria.

There are 2 questions that I would like a definitive answer to before I feel confident recommending oral probiotics to patients:

1. Is there interaction between the oral and gut microbiome?

2. Is the use of oral probiotics safe in patients with compromised immune systems (young children, the elderly, patients undergoing immunosuppression such as after organ transplantation)?

Until we have more definitive answers to these questions, conventional dental treatment and prevention is still the way to go. I do not think that probiotics are harmful (check with your dentist and doctor before starting any probiotics or supplements) and they may enhance your existing oral hygiene regimen, but I think the effect will be modest at best. This benefit also needs to be balanced from a cost perspective, since most probiotics need to be taken indefinitely.

It will be exciting to see what developments are in store since there is growing interest in the composition and enhancement of our microbiome.

Further reading:

Allaker RP, Stephen AS. Use of Probiotics and Oral Health. Curr Oral Health Rep. 2017;4(4):309-318.

Denise M. Bowen. Probiotics and Oral Health. American Dental Hygienists' Association Feb 2013, 87 (1) 5-9;

Haukioja A. Probiotics and oral health. Eur J Dent. 2010;4(3):348-55.

Laetitia Bonifait, Fatiha Chandad, Daniel Grenier. Probiotics for Oral Health: Myth or Reality? Journal of the Canadian Dental Association. October 2009, Vol. 75, No. 8