Oral bacterial diversity is inversely correlated with mucosal inflammation

Abstract

Objective We investigated the relationship amongst the oral mucosal bacterial community, clinical severity and inflammatory markers in the two most common immune‐mediated oral mucosal diseases, namely recurrent aphthous stomatitis (RAS) and oral lichen planus (LP). Methods Patients with RAS (n = 15) and LP (n = 18) and healthy controls (n = 13) were recruited using criteria to reduce the effect of factors that influence the microbiota structure independently of oral mucosal disease. Clinical severity was quantified using validated scoring methods. DNA was extracted from oral mucosal swabs for 16S rRNA gene high‐throughput sequencing. Salivary cytokines were measured using cytometric bead assays. Correlation studies were conducted amongst microbial diversity, clinical scores and cytokine concentrations. Results We observed a significant reduction of bacterial diversity in LP and RAS patients compared to controls (p = .021 and .044, respectively). Reduced bacterial diversity in LP and RAS correlated with increased clinical scores of the two conditions (⍴ = −0.551 to −0.714). A negative correlation was observed between microbial diversity and salivary interferon‐γ, interleukin‐17A and interleukin‐1β (⍴ = −0.325 to −0.449). Conclusions This study reports reduced oral microbial diversity in the context of increased mucosal inflammation and supports the role for microbial diversity as a marker or contributor to oral mucosal inflammatory disease activity and development.

Proteomic and microbiota analyses of the oral cavity during psychological stress

“…The alpha diversity of the oral microbiota was significantly reduced in the stress group compared to the controls. Reduced alpha diversity has been observed in patients with RAS and oral lichen planus [ 46 ]. Our findings may be consistent with the concept that psychological stress is an etiology of RAS and oral lichen planus [ 2 ].…”

Multi-Omics Analysis Reveals the Systematic Relationship Between Oral Homeostasis and Chronic Sleep Deprivation in Rats

“…Oral inflammation is a common physiological immune response that if persists may produce damage as well as increase the risk of progression to lesions ( 15 ). In addition, the oral mucosa may be accompanied by a low-grade chronic upregulation of inflammatory mediators that may be associated with microbes ( 16 ). A previous study proposed that certain low abundance microbial pathogens can interfere with the host immune system and remodel the microbiota, leading to oral inflammatory diseases such as gingivitis and periodontitis ( 17 ).…”

Effect of psychological stress on the oral-gut microbiota and the potential oral-gut-brain axis

“…Oral microbiota such as Prevotella and Ruminococcaceae were positively associated with IL-1β while Prevotella and Granulicatella were negatively associated with IL-8 [86] . In another study, a negative correlation was observed between microbial alpha diversity and salivary interferon-γ, interleukin-17A, and interleukin-1β in patients with stress-related diseases such as oral lichen planus and recurrent aphthous stomatitis [73] . Salivary glands may affect the oral microbiome by acting as a route to transmit microbiota into saliva.…”

“…Consistent with our findings, a previous experiment on wild red squirrels showed that the alpha diversity of the oral microbiome was lower in those with elevated fecal glucocorticoid metabolites, a measure of the hypothalamic-pituitary-adrenal axis [60] . Clinically, reductions in the alpha diversities of the oral microbiome have been observed in stress-related oral diseases, such as recurrent aphthous stomatitis, oral lichen planus, and Sjogren’s syndrome [73] . These findings indicate that a reduction in the alpha diversity of the oral microbiome might be associated with psychological stress.…”