Two studies find oral probiotic effective in blocking plaque

By Danielle Masterson

- Last updated on GMT

© Getty Images Bernardbodo
© Getty Images Bernardbodo

Related tags Oral health Probiotic

Blis Technologies Limited and distributor Stratum Nutrition announced the publication of two recent studies that investigated the effectiveness of BLIS M18 on black teeth staining.

BLIS M18 contains Streptococcus salivarius ​M18,  a specific strain of bacteria which is found naturally in the mouth and throat. While everyone has Streptococcus salivarius​ bacteria, the specific BLIS M18 strain that blocks bacteria  is less common. 

The effects of BLIS M18 and its cell-free supernatant were found to be effective in controlling the action of chromogenic bacteria that cause black dental stains. 

In vitro study

In a recent in vitro study, BLIS M18 was found to stymie two of the bacterial species that cause the black stains to form on teeth. To evaluate the probiotic’s potential against microorganisms associated with black stains, Streptococcus salivarius M18​ and Lactobacillus reuteri​ were tested against Aggregatibacter actinomycetemcomitans​ and Actinomyces naeslundii​, using their cell-free fermentative broth in a planktonic growth inhibition test.

The researchers found that probiotic cell-free supernatants showed the ability to reduce the pathogenic bacteria growth in a dose-dependent way. Streptococcus salivarius M18​ showed a stronger antimicrobial activity than Lactobacillus reuteri ProDentis​ against the two indicator strains used. A. naeslundi​ was less susceptible to the probiotic activity of both S. salivarius ​and L. reuteri​ compared to A. actinomycetemcomitans.

According to the researchers, the results demonstrate a potent antagonistic ability of probiotics to reduce the growth of microorganisms associated with black tooth stains. They said these these strains could be evaluated for a therapeutic use against dental pigmentations.

Clinical study 

In a companion clinical trial in children, BLIS M18 was shown to discourage the recurrence of the black stains after removal of professional cleaning.

This randomized controlled study evaluated 58 children (aged 4-10 years) with black teeth staining.They were randomly divided into two groups, the first group included 28 children who were given the test product containing SsM18 once a day for 3 months. The second group also included 26 children, but did not receive any treatment. 

Before beginning the study, the stains on all of the children's teeth were removed by dental professionals. Black stains were then assessed after 3 months and again after 6 months.

After 3 months black stains were detected in 6 of the 28 children (21.2%) from the first group who received M18 and in 13 out of the 26 (50%) children from the group who did not take the supplement. After 6 months, black stains were detected in 9 out of the 28 (32.1%) children from in the first treated group and in 14 of the 26 (53.8%) children from the control group.

The researchers concluded that the risk of black stain formation in children could be lessened by administering S. salivarius​ M18.

“Stratum Nutrition’s partner, BLIS Technologies, continues to produce stellar clinical research that shows the many different benefits and mechanisms of action of BLIS M18,” ​said product Manager, Alexis Collins. “In this most recent clinical trial, we can see how the unique bacteriocins and enzymes produced by BLIS M18 not only help prevent the formation of dental plaque, but also help prevent the activity of specific bacteria responsible for black teeth stains. There are undoubtedly more actions of BLIS M18 that benefit dental and gum health, and we are proud to be partnered with BLIS Technologies as they continue to pursue research on this unique oral-colonizing probiotic.”


European Archives of Pediatric Dentistry
“In vitro inhibitory effect of two commercial probiotics on chromogenic actinomycetes”
Authors: E. Gobbi et al

Oral Health and Preventive Dentistry
2020;18(2):161-164. doi: 10.3290/j.ohpd.a43359
“Does Streptococcus Salivarius Strain M18 Assumption Make Black Stains Disappear in Children?”
Authors E. Bardellini et al.

Editor's Note:​ The original version of this article stated a size and CAGR for the oral probiotics market which were inaccurate. We have removed those statements from the article and apologize for any confusion. 

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