RT Journal Article SR Electronic T1 Streptococcus salivarius - a potential salivary biomarker for orofacial granulomatosis and Crohn’s disease? JF bioRxiv FD Cold Spring Harbor Laboratory SP 422865 DO 10.1101/422865 A1 Rishi M. Goel A1 Erica M. Prosdocimi A1 Ariella Amar A1 Yasmin Omar A1 Michael P. Escudier A1 Jeremy D. Sanderson A1 William G. Wade A1 Natalie J. Prescott YR 2018 UL http://biorxiv.org/content/early/2018/09/23/422865.abstract AB Objective Orofacial granulomatosis (OFG) is a rare disease characterised by chronic, non-caseating, granulomatous inflammation primarily affecting the oral cavity. Histologically, it is similar to Crohn’s disease (CD) and a proportion of patients have both OFG and CD. The cause of OFG remains elusive but it has been suggested that microbial interactions may be involved. The aim of this study was to compare the salivary microbial composition of subjects with OFG and/or CD and healthy controls.Design 261 subjects were recruited, of whom 78 had OFG only, 40 had both OFG and CD, 97 had CD only with no oral symptoms and 46 were healthy controls. Bacterial community profiles were obtained by sequencing the V1-V3 region of the 16S rRNA gene.Results There were no differences in richness or diversity of the salivary bacterial communities between patient groups and controls. The relative abundance of the Streptococcus salivarius-group were raised in patients with OFG or CD only compared to controls while that of the Streptococcus mitis -group was lower in CD compared to both OFG and controls. One S. salivarius oligotype made the major contribution to the increased proportions seen in patients with OFG and CD.Conclusion The salivary microbiome of individuals with OFG and CD was similar to that found in health although the proportions of S. salivarius, a common oral Streptococcus were raised. One specific strain-level oligotype was found to be primarily responsible for the increased levels seen.