Mucosal and salivary microbiota associated with recurrent aphthous stomatitis

Abstract

BackgroundRecurrent aphthous stomatitis (RAS) is a common oral mucosal disorder of unclear etiopathogenesis. Although recent studies of the oral microbiota by high-throughput sequencing of 16S rRNA genes have suggested that imbalances in the oral microbiota may contribute to the etiopathogenesis of RAS, no specific bacterial species associated with RAS have been identified. The present study aimed to characterize the microbiota in the oral mucosa and saliva of RAS patients in comparison with control subjects at the species level.ResultsThe bacterial communities of the oral mucosa and saliva from RAS patients with active lesions (RAS, n = 18 for mucosa and n = 8 for saliva) and control subjects (n = 18 for mucosa and n = 7 for saliva) were analyzed by pyrosequencing of the 16S rRNA genes. There were no significant differences in the alpha diversity between the controls and the RAS, but the mucosal microbiota of the RAS patients showed increased inter-subject variability. A comparison of the relative abundance of each taxon revealed decreases in the members of healthy core microbiota but increases of rare species in the mucosal and salivary microbiota of RAS patients. Particularly, decreased Streptococcus salivarius and increased Acinetobacter johnsonii in the mucosa were associated with RAS risk. A dysbiosis index, which was developed using the relative abundance of A. johnsonii and S. salivarius and the regression coefficients, correctly predicted 83 % of the total cases for the absence or presence of RAS. Interestingly, A. johnsonii substantially inhibited the proliferation of gingival epithelial cells and showed greater cytotoxicity against the gingival epithelial cells than S. salivarius.ConclusionRAS is associated with dysbiosis of the mucosal and salivary microbiota, and two species associated with RAS have been identified. This knowledge may provide a diagnostic tool and new targets for therapeutics for RAS.Electronic supplementary materialThe online version of this article (doi:10.1186/s12866-016-0673-z) contains supplementary material, which is available to authorized users.

Oral Microbiota Composition and Antimicrobial Antibody Response in Patients with Recurrent Aphthous Stomatitis

“…Streptococcus populations may fluctuate in response to a disturbed environment, which is in line with earlier observations [7,26]. A lower abundance of Streptococcus, together with a higher abundance of Acinetobacter johnsonii, has been recently linked to a higher risk of RAS [7]. In agreement with this study, we also found a higher abundance of A. johnsonii in RAS patients over healthy controls (0.031% in the Active cohort; 0.002% in the Passive cohort; and 0.001% in healthy controls), although not significantly so.…”

“…To date, only a few studies have examined the specifics of microbiota composition in patients with recurrent aphthous stomatitis [6,7,24]. In agreement with these previous studies, we observed that microbiota in RAS patients differs from microbiota found in healthy individuals.…”

“…Furthermore, the abundance of S. oralis was slightly higher in healthy controls (69.8%) over RAS patients (42.6% in the Active cohort and 50.9% in the Passive cohort). Streptococcus populations may fluctuate in response to a disturbed environment, which is in line with earlier observations [7,26]. A lower abundance of Streptococcus, together with a higher abundance of Acinetobacter johnsonii, has been recently linked to a higher risk of RAS [7].…”

Characterization of intratissue bacterial communities and isolation of Escherichia coli from oral lichen planus lesions

“…E. coli are usually known as gut commensals of humans and animals but also include diverse pathogens that cause diseases in intestinal or urinary tracts 14 . The presence of E. coli in the buccal mucosa, supragingival plaque, and tongue dorsum of healthy individuals has been reported in several oral microbiome studies 6,15,16 . As E. coli was detected in our negative control sample at an abundance of 0.01% ( Supplementary Fig.…”

Salivary microbiome of an urban Indian cohort and patterns linked to subclinical inflammation

“…Acinetobacter, implicated in recurrent aphthous stomatitis, periodontitis, nosocomial, and opportunistic infections particularly in tropical regions including India and Haemophilus, another genus linked to dysbiosis and invasive infections were more abundant in Indians' saliva (AlAtrouni et al, 2016;Chu et al, 1999;Patil & Chopade, 2001;Souto, Silva-Boghossian & Colombo, 2014;Kim et al, 2016;Said et al, 2014). The relevance of oral reservoirs of potential medical pathogens relevance merits further study.…”