Probiotics for the treatment of gingivitis


Probiotics are thought to have beneficial effects on the oral flora which could potentially be useful in the treatment of gingivitis. As a result, a number of difference probiotics including Bifidobacterium animalis, Lactobacillus reuteri (L. reuteri) and Bacillus species have been investigated for their clinical efficacy.

The aim of this review was to evaluate the efficacy of probiotics in the treatment of gingivitis.


Searches were conducted in the Embase, Medline and Cochrane CENTRAL databases supplements by hand searches of the journals; Journal of Periodontal Research, Journal of Clinical Periodontology and Journal of Periodontology. Randomised controlled trials (RCTs) comparing the effectiveness of probiotics with placebo with ≥ 10 patients per group were considered.  The primary outcomes were gingival index and/or bleeding on probing (BOP) with plaque index as a secondary outcome. Two reviewers searched and selected studies for inclusion extracting relevant data. Risk of bias was assessed using the Cochrane domains-based tool. Forest plots were created reporting weighted mean difference (WMD) of outcomes with 95% confidence intervals (CI).


  • 10 RCTs involving a total of 499 patients (261 in probiotic group, 238 in placebo) were included.
  • 2 studies were conducted in Spain, Sweden and Turkey and 1 each in Denmark, Finland, Germany and Italy.
  • 4 studies used probiotic tablets, 3 lozenges, 1 yoghurt, 1 chewing gum and one a combination of toothpaste, mouth rinse and a toothbrush cleaner.
  • Follow up periods ranged from 2 – 8 weeks.
  • The reviewers considered 5 studies to be at high risk of bias and 4 at low risk.
  • All the RCTs showed that probiotic administration was effective in the treatment of gingivitis at follow-up with almost 50% of the studies suggesting significant improvements.
  • The mean percentage of BOP ranged from 11.87% to 21.7% in the probiotics group and from 15% to 33% in the placebo groups at follow-up, respectively.
  • Considering the effects of Lactobacillus reuteri, there was no statistically significant difference between probiotic and placebo groups for
    • gingival index; WMD = -0.48, (95%CI; -1.69 to 0.72) or
    • plaque index;   WMD = 0.18 (95%CI;-0.23 to 0.61).


The authors concluded: –

Within the limitations of this study, the outcomes of this review show weak evidence to support the use of probiotics in mildly reducing inflammatory periodontal parameters in gingivitis. Significant heterogeneity and limited available data may reduce the impact of these conclusions.


The authors registered the protocol for this review in the PROSPERO database although the protocol indicated that the comparison was to be against chlorhexidine and not placebo as reported.  Three major databases have been searched as well as a small selection of periodontal journals. However as only English language studies were included some relevant studies may have been excluded.  %0% of the included studies were considered to be at high risk of bias in additional the studies are relatively small with the longest follow up period being 8 weeks. There is also significant heterogeneity in the delivery format for the probiotics and the two meta-analyses that were performed only included 2 RCTs finding no significant differences between the probiotic and placebo groups.

A 2018 review of the effect on oral health of probiotics in dairy products by Nadelman  et al included 32 studies (Dental Elf – 28th Nov 2018) also suggested a positive impact from probiotics. However, it also suffered from heterogeneity in the range of probiotics and delivery agents as well as small study sizes and short durations.


Primary Paper

Akram Z, Shafqat SS, Aati S, Kujan O, Fawzy A. Clinical efficacy of probiotics in the treatment of gingivitis: A systematic review and meta-analysis [published online ahead of print, 2019 Nov 4]. Aust Dent J. 2019;10.1111/adj.12733. doi:10.1111/adj.12733

Review protocol on PROSPERO

Other references

Dental Elf – 28th Nov 2018

Probiotics for oral health?





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