Probiotics and bad breath: odor results are mixed
A meta-analysis found lower volatile sulfur compound levels with probiotics, while quality-of-life results were unclear and smell-test findings differed.
Based on the published abstract. The full paper may contain additional methods, results and limitations.
The 30-second takeaway
Probiotics lowered volatile sulfur compound levels compared with controls in the pooled analysis. However, the abstract reports differing results for assessed breath odor and no statistically significant improvement in oral health-related quality of life. This suggests a possible effect on an odor measure, while leaving the benefit people experience in daily life uncertain.
The authors flag possible publication bias, small samples and differences between trials. The abstract also reports positive and nonsignificant smell-test results without explaining how the analyses differ.
What researchers found
Volatile sulfur compound levels
The -1.01 difference is in standard deviations, units based on variation in compound measurements, indicating lower levels with probiotics versus controls. Assessment timing was not reported.
Measures with different meanings
The review found no clear differences in quality of life, perceived oral health, depression, self-esteem or dental plaque. Lower compound levels alone therefore do not establish an improvement people notice.
An unresolved reporting issue
The abstract describes improved smell-test results using a risk ratio, but a separate analysis of these scores was statistically inconclusive. It does not explain the outcome definitions or study groups well enough to reconcile these results.
The original publication
Efficacy and safety of probiotic therapy for halitosis: a systematic review and meta-analysis of randomized controlled trials.
Yang Y, Ge J, Chen Y et al.
J Breath Res · 2025
- PubMed ID
- 41289613
- Record checked
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