Table 1

Characteristics of the included studies

StudyTypeHalitosis criterionSubject ageClinical parametersProbiotics administration
(vehicle, strains and frequency)
Follow-up
Mousquer et al61RCT
Placebo double-masked parallel
OLP score ≥129
≥18
OLP
VSC
TCS
Gum including 1 billion CFU Lactobacillus salivarius G60 taken twice per dayBaseline
2 weeks
Lee et al60RCT
Placebo double-blind parallel
VSC ≥1.5 ng/10 mL68
20–39
OLP
VSC (H2S, CH3SH, C2H6S)
800 mg tablet containing 1.0×108 CFU/g Weissella cibaria taken once per dayBaseline
4 weeks
8 weeks
He et al42RCT
Placebo double-blind parallel
OLP score ≥2
VSC ≥150 ppb
28
23–44
OLP
VSC
TCS
PI
Tablet containing 1×109 CFU Streptococcus salivarius K12 taken twice per dayBaseline
4 weeks
Keller et al58RCT
Placebo double-blind crossover
OLP score >125
19–25
OLP
VSC
Chewing gum containing Lactobacillus reuteri DSM 17938 and Lactobacillus reuteri ATCC PTA 5289, both with a concentration of 1×108 CFU taken twice per dayBaseline
2 weeks
Suzuki et al57RCT
Double-blind placebo-controlled crossover
OLP score ≥1.523
22–67
OLP
VSC (H2S, CH3SH, C2H6S)
PI
TCS
Tablet containing 6.7×108 CFU Lactobacillus salivarius WB21 and 280 mg xylitol taken three times per dayBaseline
2 weeks
Penala et al59RCT
Placebo double-blind parallel
OLP score >229
25–59
OLP
PI
Capsule mixture including Lactobacillus salivarius (2×109 CFU) and Lactobacillus reuteri (2×109 CFU) dissolved in 10 mL distilled water to rinse for 1 min twice dailyBaseline
4 weeks
12 weeks
Kim et al49RCT
Placebo double-blind parallel
OLP score ≥2
VSC ≥0.15 ng/mL
58
20–70
VSC (H2S, CH3SH, C2H6S)
OLP
Bag of powder mixture including Weissella cibaria CMU (1.0×108 CFU) melted in the mouth once per dayBaseline
2 weeks
4 weeks
8 weeks
  • CFU, colony forming units; C2H6S, dimethyl sulfide; CH3SH, methyl mercaptan; H2S, hydrogen sulfide; OLP, organoleptic; PI, plaque index; RCT, randomised controlled trial; TCS, tongue coating score; VSC, volatile sulfur compound.