People often ask whether oral probiotics do anything for breath. Researchers have asked the same question. Below are three published reviews, each pooling several clinical trials, summarized in plain words.
The short version: the research is still early and the results are mixed.
The Effect of Probiotics on Halitosis: a Systematic Review and Meta-analysis
Systematic review and meta-analysis, 2019. Yoo JI, Shin IS, Jeon JG, Yang YM, Kim JG, Lee DW. Probiotics and Antimicrobial Proteins.
Pooled three randomized trials. Probiotics lowered odor scores compared with placebo, with no significant change in volatile sulfur compound levels. The authors judged the evidence too limited for firm conclusions.
doi.org/10.1007/s12602-017-9351-1
Role of Probiotics in Halitosis of Oral Origin: A Systematic Review and Meta-Analysis of Randomized Clinical Studies
Systematic review and meta-analysis, 2022. López-Valverde N, López-Valverde A, Macedo de Sousa B, Rodríguez C, Suárez A, Aragoneses JM. Frontiers in Nutrition.
Four randomized trials, 283 participants, using a range of strains. The pooled analysis found no statistically significant difference between probiotic and control groups. The authors called for larger trials.
doi.org/10.3389/fnut.2021.787908
Efficacy and safety of probiotic therapy for halitosis: a systematic review and meta-analysis of randomized controlled trials
Systematic review and meta-analysis, 2025. Yang Y, Ge J, Chen Y, Liu H. Journal of Breath Research.
Ten randomized trials. Pooled results showed lower volatile sulfur compound levels with probiotics than with controls; several other outcomes showed no significant difference. Small samples and possible publication bias are listed as limits.
doi.org/10.1088/1752-7163/ae23f0
How to read this
These summaries describe published research on probiotics in general. The trials used a range of strains and products. None of them tested a Kiss Me Clean product, and nothing here is a claim about what any product does.
If bad breath is persistent or unexplained, see a dentist or doctor.