Effectiveness of probiotic supplementation in reducing halitosis among older adults: a randomized, double-blind, placebo-controlled crossover trial

Abstract

Halitosis is a common oral health condition among older adults and is primarily associated with volatile sulfur compounds (VSCs) produced by oral bacteria. Probiotics have been proposed as a potential approach to modulate oral microbiota and reduce halitosis. This study aimed to evaluate the effectiveness of Lacticaseibacillus paracasei TISTR 2688 in reducing halitosis-related parameters in older adults. A randomized, double-blind, placebo-controlled crossover trial was conducted among 30 older adults with clinically diagnosed halitosis. Participants received either a daily probiotic supplement containing L. paracasei TISTR 2688 or a placebo during two intervention periods. VSC levels, including hydrogen sulfide (H 2 S), methyl mercaptan (CH 3 SH), and dimethyl sulfide ((CH 3 ) 2 S), were measured using Oral Chroma™. Oral health parameters, including plaque index, gingival index, and bleeding index, were assessed at baseline, day 7, and day 14. Data were analyzed using paired statistical tests, with significance set at P < 0.05. All participants ( n = 30; 6 males and 24 females; mean age 70.5 ± 4.3 years) completed the study. Compared with baseline, the probiotic intervention significantly reduced plaque index, gingival index, and bleeding index at day 14 ( P < 0.05). Significant reductions in VSC levels (H 2 S, CH 3 SH, and (CH 3 ) 2 S) were observed in the probiotic group at both day 7 and day 14 ( p < 0.05), whereas no significant changes were found in the placebo group. The reductions in VSC concentrations were substantial, indicating a consistent effect over the intervention period. Supplementation with Lacticaseibacillus paracasei TISTR 2688 was associated with improvements in oral health parameters and reductions in VSC levels in older adults with halitosis. These findings suggest that this probiotic strain may be a useful adjunctive approach for managing halitosis. Further studies with larger sample sizes and longer follow-up are warranted.