Insufficient evidence that probiotics can prevent caries, but they can reduce the mutans streptococci counts in the short term


Probiotics have been used in the management of a wide range of conditions and have been shown to have a beneficial effect in gastrointestinal disease for example. A potential role in the prevention of caries has been suggested and the aim of this review was to evaluate the caries preventive effect of probiotics.

Searches were conducted in Medline, ISS Web of Knowledge and the Cochrane databases for English language studies comparing a probiotic versus a placebo or no probiotic. Only controlled clinical trials with at least 15 participants for each group were included.  The main outcome of interest was caries with mutans streptococci and lactobacilli counts as surrogate outcomes. Two authors conducted study selection data abstraction and quality assessment independently.

  • 19 studies (12 randomised controlled trials 7 cross-over trials) were included.
  • 2 studies were considered to be at low risk of bias, 10 at moderate risk and 7 at high risk.
  • Only two studies reported caries as an outcome
  • 12 studies contributed to the meta-analysis
    • when comparing the probiotic and control group after treatment, significantly more patients in the probiotic group had low mutans streptococci (<105 CFU/ml) counts and significantly less patients had high (>106 CFU/ml) counts.
    • No significant differences were noted in Lactobacillus counts,

The authors concluded

Within the limitations of the available data, it may be concluded that probiotics decrease the mutans streptococci counts. This suggests that probiotics could have a positive effect in the prevention of caries.


We have previously highlighted another review of this topic by Cagetti et al (Dental Elf 6th Nov 2013) which included 23 studies and also found that the majority of studies showed significant reductions in relevant bacterial species.  This new review has also been restricted articles to those in English and has searched different databases, which may explain the slight difference in the number of included studies.  This review as with the previous review has focused on the surrogate endpoints of mutans streptococci and lactobacilli counts and as the authors note their use as a predictor if caries is controversial.  The majority of the studies included in the review are of short duration and there are also issues with the quality of the studies that could be included so this should be taken into account when considering the findings.


Laleman I, Detailleur V, Slot DE, Slomka V, Quirynen M, Teughels W. Probiotics reduce mutans streptococci counts in humans: a systematic review and meta-analysis. Clin Oral Investig. 2014 Mar 25. [Epub ahead of print] PubMed PMID: 24663813.

 Dental Elf 6th Nov 2013- Only poor quality evidence available to assess the effect of probiotics on caries



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