A study with the objective of evaluating the effects of chewing gums containing probiotic bacteria on oral malodour.

Twenty-five healthy young adults with self reported malodorous morning breath, who did not suffer from periodontal disease or dry mouth, completed this randomized double-blind placebo-controlled, crossover trial. The design included run-in and washout periods, interspersed by two intervention periods of 14 days each. The subjects were instructed to chew one gum in the morning and one in the evening. The gums contained either two strains of Lactobacillus reuteri (DSM 17938 and ATCC PTA 5289, 2×10^8 CFU/gum) or placebo.

The outcome measures were (i) organoleptic scoring (0–5) by a certified test panel, (ii) concentration of volatile sulphur compounds (VSC) measured using a Halimeter and (iii) concentration of VSC after a cysteine rinse to create a standardized malodour. Registrations were made at baseline and after each intervention period. The median organoleptic score was similar (score 2) in both groups at baseline. After 14 days of treatment the organoleptic scores were significantly lower in the probiotic group compared with the placebo group (p < 0.05). Assessments of the VSC levels displayed no significant differences between the groups, either before or after rinsing with L-cysteine.

Conclusion
Probiotic gum containing Lactobacillus reuteri may have some beneficial effect on oral malodour assessed by organoleptic scores. The results indicate that the probiotic gum may affect bacteria that produce malodourous compounds other than volatile sulphur compounds.