Effect of probiotic Lactbacillus salivarius WB21 on oral malodor

Objective: Lactobacilli are used frequently as probiotics to induce a beneficial effect for human health, but little is known about the effect of probiotics on oral malodor. This study evaluated whether oral administration of lactobacilli alters the degree of oral malodor or the clinical conditions associated with halitosis. Methods: Twenty patients with genuine halitosis (6 male and 14 female; mean age, 50.9 ± 12.1 years; range, 30-66 years) were treated daily with a tablet containing 2.0 × 10⁹ Lactobacillus salivarius WB21 and xylitol. After 2 and 4 weeks, oral malodor and clinical parameters were evaluated at the same time of day, at least 5 hours after eating and mouth cleaning, in each patient. The severity of oral malodor in each individual was determined using an organoleptic test (OLT) and gas chromatography. Results: All 20 patients were positive for L. salivarius DNA in their saliva at 2 weeks, even though 12 patients were negative for this organism at baseline. In subjects with physiologic halitosis, who received the probiotic tablets containing L. salivarius WB21, the OLT score and hydrogen sulfide, methyl mercaptan, and total volatile sulfur compound concentrations were decreased significantly after treatment. In subjects with oral pathologic halitosis, the hydrogen sulfide concentration and percentage of bleeding on probing were decreased at 2 weeks. In addition, at 4 weeks, the OLT score was significantly lower and stimulated salivary flow significantly higher than baseline in subjects with oral pathologic halitosis. Conclusion: Oral administration of L. salivarius WB21 successfully reduced oral malodor and may have beneficial effects on periodontal inflammation and salivary flow. Using these probiotic bacteria as an adjunct to mechanical debridement may be an effective approach for the treatment of periodontitis as well as oral malodor.