Scientist - News - 09-10-2009:

Yakult may prevent gum inflammation
Beintema, Nienke

Data from a new German study suggest a beneficial effect of Yakult, the probiotic milk product containing Lactobacillus casei strain Shirota, on gum inflammation.

Several studies in the past few years have indicated that probiotics may stimulate oral health. This effect is generally believed to be direct: the probiotics positively affect the oral microflora. A German study published this month in the Journal of Periodontology is one of the first to show an indirect effect, presumably through an improved immune function.

Inflammation markers
The German researchers, from the University of Leipzig and the University Hospital of Jena, conducted a non-blinded study among fifty healthy volunteers. The test group drank one serving of Yakult per day, while the control group did not receive any particular product to drink. After eight weeks, the volunteers were asked to refrain from brushing their teeth for 96 hours. The researchers then checked both groups for plaque formation, gum bleeding, and three inflammation markers in the fluid between gum and teeth — the so-called gingival crevicular fluid. All three markers are positively correlated with inflammation.
Although plaque and bleeding were the same in both groups after the test period, the researchers did find significant differences in the three inflammation markers: polymorphonuclear elastase and matrix metalloproteinase-3 were significantly lower in the probiotic group, while the third marker, myeloperoxidase, was significantly increased in the control group.

Further studies
"The data suggest a beneficial effect of the probiotic milk drink on gingival inflammation", the authors conclude. Addressing whether this effect is direct or indirect, the researchers note that there was indeed a change in oral microflora after the test was started, but this lasted only for two weeks with a test duration of eight weeks. Based on this, they suggest that the effect of the probiotic milk drink could be immunomodulatory.
"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. Further studies are strictly necessary," they state.

More information:
Article in the Journal of Periodontology