The efficacy of probiotics in the management of intra-oral halitosis: a systematic review

Objectives To evaluate the efficacy of probiotics in reducing halitosis of dental origin. Methods MEDLINE, EMBASE, and CENTRAL were searched up to and including June 2020. Randomised placebo-controlled, double-blinded clinical trials in systemically healthy adult patients who were given any form of probiotics to manage halitosis of dental origin were included. Primary outcome measures were organoleptic scores and volatile sulphur concentration levels. Secondary outcome measures were microbiologic parameters and quality of life (QOL). Results Of the 301 potentially relevant articles, eight articles were selected for the review. The risk of bias assessment showed that two studies were of low risk of bias, four studies had some concerns, and two studies had a high risk of bias. The beneficial effect of probiotics could neither be confirmed in periodontally treated patients administered with up to 8 weeks of probiotics, nor in periodontitis patients who received both non-surgical periodontal therapy and adjunctive probiotics up to 90 days. Microbiological findings 1 month after probiotics administration and QOL measures showed no significant differences compared to control. Considerable heterogeneity was observed among probiotic administration protocols. Conclusions The available evidence suggests no convincing benefit for the use of probiotics in the management of halitosis. Standardised protocols on recruitment of halitosis subjects and organoleptic measurements are required for future studies on probiotics as an intervention.