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

Overview

Lichen planus is a chronic inflammatory mucocutaneous disease, which often results in oral manifestations, receiving the name of oral lichen planus (OLP). Its frequency varies from 0,1 to 4% of the general population, with a higher incidence in women, around the 4th and 5th decades of life. Although the pathogenesis of OLP is related to a immune-cellular response, mainly mediated by T lymphocytes, its cause remains unknown. Considering its chronic nature, control of OLP aims to reduce symptoms and improve function, and agents with anti-inflammatory action, especially topical corticosteroids result in some degree of success in most patients, depending on the clinical presentation. However, some cases are resistant to the use of corticosteroids, thus justifying the search for new therapeutic options. The immunomodulation proved to be one of the main functions of probiotic bacteria, and recent studies have shown effect of probiotics on decreasing the expression of inflammatory markers, which enables the study of this therapy as an alternative to the control of OLP. Thus, this project aims to evaluate the effects of therapy with Bifidobacterium animalis subsp. lactis HN019 comparing with clobetasol propionate 0.05% in symptomatic patients with OLP referred for diagnosis and treatment of School of Dentistry of Ribeirão Preto - University of São Paulo (USP). The impact of the topical therapy (probiotic or corticosteroid) on the clinical, histopathological and immunopathological features will be evaluated. This project was previously submitted and approved by the Institutional Review Board of the School of Dentistry of Ribeirão Preto/USP, and all patients must give informed consent to participate in this study.

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.