The gut starts at the mouth, so it should be no surprise that probiotics, those beneficial bacteria, are a growing presence in the oral health category. But which strains show the most potential, where does the science stand, and how do they work?
There are several different avenues for researchers to explore for probiotics to beneficially impact oral health, ranging from reducing dental plaque-related diseases, such as caries, gingivitis and periodontitis, or even reducing bad breath (halitosis).
One of the best known probiotics for oral health was developed by scientists at the University of Otago in New Zealand: BLIS K12 is a specific strain of Streptococcus salivarius (S. salivarius), which secretes powerful antimicrobial molecules called BLIS: Bacteriocin-Like-Inhibitory Substances.
BLIS K12 is an oral probiotic that is said to support healthy bacteria in the mouth for long-term fresh breath and immune support.
There is plenty of science to support the strain’s oral health benefits. Data about the safety and tolerance of BLIS K12 was reported in Food and Chemical Toxicology (2011, Vol. 49, pp. 2356-2364) with the data indicating that 28 days of daily ingestion of the strain did not produce any adverse effects in humans, thereby supporting its safety in a food-based carrier.
Switzerland-based scientists reported in 2012 that S. salivarius K12 has antimicrobial activity against the bacteria that cause bad breath (Archives of Oral Biology , Vol. 57, pp. 1041-1047). This report added to preliminary data published in the Journal of Applied Microbiology (2006, Vol. 100, pp. 754-764).
The ingredient’s list of potential benefits may also extend to inhibiting the growth of the yeast responsible for oral thrush, or candidiasis (Applied and Environmental Microbiology , Vol. 78, pp. 2190-2199).
"This research represents further evidence that the BLIS K12 probiotic plays an important role in maintaining good oral health and protecting the mouth and throat from the potential of invading pathogens," said Dr Barry Richardson, CEO of BLIS Technologies at the time of the oral thrush publication.
The ingredient forms part of Stratum Nutrition’s portfolio of specialty bioactive ingredients, and has performed “very well” in both the US and European markets, said Heather Thompson, Global Marketing Manager for Stratum Nutrition.
The performance is in part driven by consumer awareness about probiotics and the recognition that probiotics can support a healthy body in other ways than simply contributing good bacteria to the gut, she added.
“Another huge contributor to the success is the growing body of science that provides a unique and specific positioning within ‘oral health’ – ENT immune support. In turn, we see the multiple brands across various sales channels actively searching for how they can expand their probiotic offerings to include BLIS K12,” said Thompson.
“The actual number of SKU across channels is difficult to pinpoint, but currently BLIS K12 can be found in about 2 dozen recognized health products brands within RNH, direct, or professional channels in the US.”
Beyond BLIS, another commercially available probiotic to support oral health is offered by Florida-based Oragenics. The company’s proprietary blend of S. oralis strain KJ3sm, S. uberis strain KJ2sm, and S. rattus strain JH145 is available under the ProBiora3 brand name. The company also has finished products called EvoraPlus and EvoraPro.
The company’s products focus on the concept of inhibiting Streptococcus mutans, the main bacteria associated with tooth decay. S. mutans binds to teeth via aggregation forming dental plaque. The bacteria then convert sugar to acid, which attacks the enamel of the teeth.
Oragenics has funded and published two studies specifically about ProBiora3, one of which was a toxicology study to support the safety of the blend. The other publication detailed results of a pilot study in 20 healthy adult subjects, which found a strong trend towards reducing levels of pathogenic bacteria in the mouth after four weeks of use (Journal of Applied Microbiology , 2009, Vol. 107, pp. 682–690).
The authors stated that the S. rattus strain offers benefits by competing with decay-causing S. mutans, while S. oralis and S. uberis are known to produce hydrogen peroxide, which could inhibit the growth of periodontal pathogens.
An additional study using S. rattus JH145 only found a statistically significant and dose-dependent decrease in S. mutans levels in rats (Journal of Applied Microbiology , 2009, Vol. 107, pp. 1551-1558).
The scientific literature is also peppered with additional examples of beneficial bacterial strains with potential oral health benefits: A study with 42 subjects with moderate gingivitis published in the journal Acta Odontologica Scandinavica showed benefits of L. reuteri prodentis against gingivitis, otherwise known as bleeding or inflamed gums.
Danish researchers used BioGaia’s proprietary probiotic strain and found its interaction with the immune system could boost oral health.
Earlier this year, scientists from the University of Copenhagen reported that chewing gum formulated with L. reuteri DSM 17938 and L. reuteri ATCC PTA 5289 was capable of significantly reduce halitosis (Acta Odontologica Scandinavica, Vol. 70, pp. 246-250).
A pilot study using Yakult’s probiotic milk drink also suggested oral health benefits for the Lactobacillus casei strain Shirota to reduce inflammation and bleeding in the mouth linked to gingivitis and gum disease (periodontitis) based on its influence of the immune system (Journal of Clinical Periodontology, 2009, Vol. 36, pp. 850-856).
Availability of products is one thing, but consumer acceptance of them is another, particularly in a segment dominated by toothbrushes, toothpaste, and mouthwash.
Stratum’s Thompson told us that consumers are slowly beginning to understand that probiotics can do more than support gut health.
“As the number of applications for probiotics grows, consumers begin to look for products based on probiotics that are ‘non-traditional’. That said, there still is quite a bit of catch-up to do in educating consumers in the US on the merits of probiotics and oral health,” she said. “The term ‘oral health’ in a general consumer since translates to a healthy mouth and people tend to think ‘dental’ first, but this is only part of the equation.
“Probiotics are already in the spotlight for FDA so when you have more unique positioning, it can be more difficult to communicate in a regulatory-friendly way. We have extraordinary results in multiple clinical settings for BLIS K12 to support ENT immune health, but in the supplement industry the benefits can be challenging to articulate,” said Thompson.
“A challenge we see with probiotics is that there are still many products on the market that contain strains with no documented benefits and in some cases without strain-specific safety data.
“Cutting through this is a challenge where you have to keep emphasizing the merits (with documented back-up) of your strain – this is something that takes a lot of effort and resources. We continue to build the merits for BLIS probiotics, evaluating the impact on multiple aspects of oral health – beyond ‘the mouth’. Look for more published details on this very soon.”