Effect of Bifidobacterium Animalis Subsp. Lactis HN019 on Oral Lichen Planus

This is a randomized double-blind clinical trial with symptomatic patients presenting OLP, which will be randomly assigned to either topical Bifidobacterium animalis subsp lactis HN019 or clobetasol propionate 0.05%. The selected patients will receive capsules to be diluted in 15 ml of water containing 6 x 109 CFUs of Bifidobacterium subsp. lactis HN019 (experimental group) or 0.05% clobetasol propionate (control group) for mouth washing, twice a day for 4 weeks. Patients will be instructed to maintain normal brushing and not to use or consume another corticosteroid and /or probiotic during the study. Outcomes measures will be symptoms (VAS and Likert-like scale), quality of life (SF-36 form), and clinical changes (erythema, reticulation, erosion/ulcer based on clinical photographs), which will be performed at baseline, 15 days (only VAS, Likert-like scale and photographs) and and at one month of treatment. All patients will undergo biopsies for the diagnosis of OLP, and those who consent will be submitted to an optional biopsy at the end of the topical treatment for histopathological and immunopathological characterization.