The Athlete's Breath: Strain-Specific Probiotic Evidence for Managing Intra-Oral Halitosis in Adults — A Critical Narrative Review

Abstract

Probiotics have been proposed as adjuncts for intra-oral halitosis, while exercise-related oral dryness, sports nutrition, and a substantial burden of oral disease make oral health relevant to sports medicine. Aim. To critically review strain-specific clinical evidence for probiotics in adult intra-oral halitosis and consider implications for sports dentistry. Material and methods. A targeted, non-systematic PubMed/MEDLINE update, recent systematic reviews, citation tracing, and a contextual search of athlete oral-health literature were used through 6 September 2026. Randomized between-group effects were prioritized. Results. Fifteen placebo- or matched-control randomized trials (844 participants) and one 117-participant active-comparator trial were examined. Selected strains improved some VSC or organoleptic outcomes, whereas other trials were null, transient, or analytically uncertain. No athlete-specific efficacy trial was identified. Conclusions. Evidence does not support a uniform probiotic class effect or routine recommendation. In sports dentistry, probiotics should be regarded only as evidence-limited, strain-specific adjuncts to cause-directed oral care.