Results published in the Journal of Clinical Periodontology indicated that the Lactobacillus casei strain Shirota may improve oral health based on its influence of the immune system.
The pilot study was partially sponsored by Yakult and used the company’s probiotic milk drink, and involved 50 healthy people free of gum disease (periodontitis).
“From our point of view, the effect of the probiotic milk drink could be immunomodulatory,” wrote the researchers, from the University of Leipzig and University Hospital Jena.
“It has to be considered that this is an explanation of the results of a pilot study and based especially on the results of the gingival crevicular fluid,” they added. “Further studies are strictly necessary.”
Commenting on the study, Dr Jia Zhao, science manager for Yakult Europe told NutraIngredients-USA that, being a pilot trial, “interpretation of the data has to be done with caution”.
“However, what has been suggested by the authors is quite interesting that the probiotics may be immunomodulatory rather than direct effects on the microbiota of the oral cavity,” said Dr Zhao.
“As we tried to address at the recent 5th International Yakult Symposium in Amsterdam, the gut, the largest immune organ of our body, seems to stand in the center of many physiological events to form a co-ordinated body's natural defense.
“Such 'beyond the gut' areas would be of great interest of future research for the possible application of probiotics to the health maintenance,” she added.
Decades of study
Yakult’s L. casei strain Shirota is one of the most studied probiotic strains. It was successfully cultured first by Yakult’s founding father Dr Minoru Shirota while he was working at the Kyoto Imperial University's School of Medicine.
According to the company, Yakult is consumed by 25 million consumers every day around the world. The company now operates in 31 countries across five continents.
While the majority of science supports the strain’s gut health benefits, the new study looked at the effect of the probiotic milk drink on gum health and the development of experimental gingivitis, otherwise known as bleeding and inflamed gums.
Study details
Fifty volunteer students were recruited to participate in the parallel-designed non-blinded study. All 50 completed the study. One group was required to drink 65 ml of Yakult daily, giving a daily probiotic dose of 100 billion bacteria per 100 ml. The other group was given no product to consume at all.
After eight weeks of drinking the probiotic milk, the researchers did not note any differences between the groups with respect to bleeding or plaque levels.
However, analysis of the fluid between the gum and the tooth (gingival crevicular fluid) showed that the probiotic was associated with reductions were in elastase activity, and enzyme linked to inflammation, and matrix metalloproteinase-3 (MMP-3), an enzyme that is responsible for the degradation of extracellular matrix components and known to have increased activity during inflammation.
Furthermore, myeloperoxidase (MPO), a marker of oxidation, was also significantly increased in the control group, compared to the probiotic group.
“Within the limits of this pilot study (e.g. no blinding, number of volunteers), one may conclude that the results of our study reveal a beneficial effect of a probiotic milk drink on the periodontal health in non-immunocompromised subjects,” wrote the researchers.
“Probiotics may have a reversible immunomodulating effect on plaque-induced inflammation of the gingival,” they added.
Feeding a hungry market
Oral health is being tipped to be a big area for probiotics, but mainly in gum formulations. Euromonitor stated in a recent comment article: “Probiotics are in line to become the next blockbuster functional ingredients in gum and mints.”
Indeed, a study with 42 subjects with moderate gingivitis published recently in the journal Acta Odontologica Scandinavica showed benefits of Lactobacillus reuteri prodentis bacteria in a gum.
Danish researchers used BioGaia’s proprietary probiotic strain and found its interaction with the immune system could boost oral health.
Source: Journal of Clinical Periodontology
October 2009, Volume 36, Issue 10, Pages: 850-856
"The influence of a probiotic milk drink on the development of gingivitis: a pilot study"
Authors: B. Staab, S. Eick, G. Knofler, H. Jentsch