Microbiota of Oral Soft Tissues and Saliva in Sjogren's Subjects

Objectives: To compare the microbiota of the oral soft tissues and saliva in Sjogren's subjects and subjects with normal salivary flow. Methods: Soft tissue samples were taken in 24 Sjogren's subjects and 11 controls at baseline. The samples were taken using a buccal brush from the tongue dorsum (TD), lateral (TL) ventral (TL), floor of mouth (FOM), buccal (B), hard palate (HP), vestibule/lip (VL) and attached gingiva (AG). These samples as well as an un-stimulated saliva sample (S) were individually analyzed for their content of 41 bacterial species using checkerboard DNA-DNA hybridization. Levels and % DNA probe counts of each species were determined for each sampled site and averaged across subjects in the 2 clinical groups. Significance of difference between clinical groups for each species at each sample location was determined using the Mann-Whitney test. The similarity among mean microbial profiles expressed as proportions for the different sample locations in the 2 clinical groups was determined using the minimum similarity coefficient and clustered using an average unweighted linkage sort. Results: There were significantly lower mean total DNA probe counts for Sjogren's subjects compared with controls in the samples from the TD (46.6±10.1 vs 97.5±21.7), B (6.2±1.2 vs 14.8±4.2) and HP (7.6±1.9 vs. 32.5±15.1). For these locations, species that were significantly elevated were S. oralis, E. corrodens, N. mucosa, P. acnes and P. melaninogenica in the control subjects. Using cluster analysis, the mean microbial profiles for Sjogren's and control subjects clustered separately. Further, in each clinical group, two clusters were formed consisting of saliva TD, TL versus the remaining surfaces. Conclusions: The microbial species on the soft tissues and in saliva of Sjogren's subjects differs in quantity and proportions from that detected in control subjects. Supported by NIDCR grant DE14368.