Clinical Efficacy of the Probiotic <i>Weissella cibaria</i> CMU in Adults with Gingivitis: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

Periodontal disease results from dysbiotic oral biofilms and the host's inflammatory response. Given the limitations of conventional therapies, this study aimed to evaluate the efficacy and safety of <i>Weissella cibaria</i> CMU (OraCMU) in improving gingival inflammation in individuals with gingivitis and incipient periodontitis. In this randomized, double-blind, placebo-controlled trial, 80 participants received either OraCMU tablets (2.0 × 10⁸ CFU/g; <i>n</i> = 40) or placebo (<i>n</i> = 40) twice daily for 8 weeks. The primary outcome was the gingival index (GI), and secondary outcomes included bleeding on probing (BOP), probing depth, clinical attachment level, gingival recession, plaque index, inflammation-related proteins, and oral microbiota. Clinical parameters were assessed at six preselected index teeth (#16, 12, 24, 32, 36, and 44). At week 8, the probiotic group showed significantly greater reductions in GI (-0.19 ± 0.03 vs. -0.08 ± 0.04; <i>P</i> = .035) and BOP (-7.74 ± 1.54 vs. -2.82 ± 1.60; <i>P</i> = .030) compared with the placebo group. Inflammatory markers, including fibroblast growth factor-5 (<i>P</i> = .003), thymic stromal lymphopoietin (<i>P</i> = .017), and the receptor activator of nuclear factor κB ligand/osteoprotegerin ratio (<i>P</i> = .021), were significantly decreased. The levels of <i>Porphyromonas gingivalis</i> (<i>P</i> = .001), <i>Treponema denticola</i> (<i>P</i> = .005), and <i>Prevotella intermedia</i> (<i>P</i> = .046) were also significantly reduced, while <i>Weissella</i> increased (<i>P</i> < .001) in the probiotic group. Eight-week supplementation with OraCMU improved gingival health and modulated the oral microbiota and inflammatory response. No serious adverse events were reported during the study period. These findings support the potential clinical utility of OraCMU as a probiotic adjunct for managing gingivitis.