The Salivary and Faecal Microbiome of Recurrent Aphthous Stomatitis Patients Before and After Treatment With Probiotics

Recurrent aphthous stomatitis (RAS) is one of the most common ulcerative diseases affecting the oral mucosa. The aetiology remains unknown, but several local, systemic, immunologic, genetic, allergic, nutritional, and microbial factors have been proposed as causative agents. Clinically, RAS is characterised by recurrent bouts of one or several rounded, shallow, painful oral ulcers at intervals of a few months or days. The aim of this study is to characterise the salivary and faecal microbiome in 20 patients with RAS and compare the findings with those of 20 healthy controls. The study also includes a double-blind randomized placebo-controlled intervention with probiotics (Lactobacillus reuteri-containing lozenges 2 tablets daily for 3 months) or placebo. The salivary and faecal microbiome in RAS patients is compared before and after treatment. This study will improve our understanding of the pathogenesis in RAS and provide us with knowledge on potential future therapeutic approaches.