Salivary mycobiome dysbiosis and its potential impact on bacteriome shifts and host immunity in oral lichen planus / 国际口腔科学杂志·英文版

The biodiversity of the mycobiome, an important component of the oral microbial community, and the roles of fungal-bacterial and fungal-immune system interactions in the pathogenesis of oral lichen planus (OLP) remain largely uncharacterized. In this study, we sequenced the salivary mycobiome and bacteriome associated with OLP. First, we described the dysbiosis of the microbiome in OLP patients, which exhibits lower levels of fungi and higher levels of bacteria. Significantly higher abundances of the fungi Candida and Aspergillus in patients with reticular OLP and of Alternaria and Sclerotiniaceae_unidentified in patients with erosive OLP were observed compared to the healthy controls. Aspergillus was identified as an "OLP-associated" fungus because of its detection at a higher frequency than in the healthy controls. Second, the co-occurrence patterns of the salivary mycobiome-bacteriome demonstrated negative associations between specific fungal and bacterial taxa identified in the healthy controls, which diminished in the reticular OLP group and even became positive in the erosive OLP group. Moreover, the oral cavities of OLP patients were colonized by dysbiotic oral flora with lower ecological network complexity and decreased fungal-Firmicutes and increased fungal-Bacteroidetes sub-networks. Third, several keystone fungal genera (Bovista, Erysiphe, Psathyrella, etc.) demonstrated significant correlations with clinical scores and IL-17 levels. Thus, we established that fungal dysbiosis is associated with the aggravation of OLP. Fungal dysbiosis could alter the salivary bacteriome or may reflect a direct effect of host immunity, which participates in OLP pathogenesis.

[Taste signal transduction and the role of taste receptors in the regulation of microbial infection].

Taste receptors guide individuals to consume nutrients while avoiding potentially noxious substances. Interestingly, recent studies have shown that taste receptors are also expressed beyond the taste buds, including brain, respiratory system, and digestive system, etc. These extragustatory taste receptors play important roles in microbial infection, nutrient uptake and host homeostasis. Mang extragustatory taste receptors have been proposed to sense microorganisms and regulate host innate defense. More importantly, polymorphisms of genes encoding taste receptor, particularly bitter taste receptor, are linked to different innate defensive responses. This review introduces the molecular basis of taste signal transduction, and the role of taste receptors in the regulation of innate immunity during microbial infection were further discussed in detail.

[Bacterial diversity in the oral cavity of adolescents with different caries susceptibilities].

OBJECTIVE: To analyze the differences between the bacterial diversities in the saliva of caries-free and caries-susceptible adolescents through polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE). METHODS: Twenty adolescent subjects aged 12-18 years were recruited and subdivided into two groups: caries-free adolescents (n = 10) and caries-susceptible adolescents (n = 10). Saliva samples were collected. Total DNA was isolated directly from each sample. A portion of the 16S rRNA gene locus was PCR-amplified by using universal primers. Microbial diversity was analyzed through PCR-DGGE. RESULTS: Analyzing the DGGE profile, we found that the composition of the saliva microbiome exhibited great intra-individual differences; the average band numbers of the caries-free adolescent group and the caries-susceptible adolescent group were 32.5 ± 3.7 and 27.3 ± 3.4, respectively. The differences between the groups were statistically significant (P = 0.008). Shannon-Wiener's indexes of the caries-susceptible adolescent group and the caries-free adolescent group were 2.5 ± 0.2 and 2.6 ± 0.2, respectively, but the differences between the groups were not significant (P = 0.405). Clustering analysis results suggested that most of the samples in the same group clustered together; this observation showed a high community structure similarity. CONCLUSION: The microbial diversity and complexity of bacteria in saliva are significantly higher in caries-free adolescents than in caries-susceptible adolescents. During caries development, bacterial diversity in the saliva likely decreases.

Comparison of oral and gastrointestinal opportunistic pathogen contamination between tooth mugs placed up-ward and downward / 实用口腔医学杂志

The oral and gastrointestinal opportunistic pathogen contamination was compared between tooth mugs placed upward and down-ward(n=9)for 1 4 days.Selective cultivation of the pathogens was uesd to measure the extent of contamination.The colony forming units (CFU)of colibacillus in group up and group down were 4.25 ±0.71 and 2.84 ±1 .40(P=0.046),S.mutans 89 ±0.31 and 2.84 ±1 .40 (P<0.001 ),Candida 2.28 ±1 .36 and 2.53 ±1 .92(P=0.002),fungus 2.44 ±0.99 and 0,respecitvely.Thus,tooth mug placed open-ing down is superior for health.

Bacterial diversity in the oral cavity of adolescents with different caries susceptibilities / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To analyze the differences between the bacterial diversities in the saliva of caries-free and caries-susceptible adolescents through polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE).</p><p><b>METHODS</b>Twenty adolescent subjects aged 12-18 years were recruited and subdivided into two groups: caries-free adolescents (n = 10) and caries-susceptible adolescents (n = 10). Saliva samples were collected. Total DNA was isolated directly from each sample. A portion of the 16S rRNA gene locus was PCR-amplified by using universal primers. Microbial diversity was analyzed through PCR-DGGE.</p><p><b>RESULTS</b>Analyzing the DGGE profile, we found that the composition of the saliva microbiome exhibited great intra-individual differences; the average band numbers of the caries-free adolescent group and the caries-susceptible adolescent group were 32.5 ± 3.7 and 27.3 ± 3.4, respectively. The differences between the groups were statistically significant (P = 0.008). Shannon-Wiener's indexes of the caries-susceptible adolescent group and the caries-free adolescent group were 2.5 ± 0.2 and 2.6 ± 0.2, respectively, but the differences between the groups were not significant (P = 0.405). Clustering analysis results suggested that most of the samples in the same group clustered together; this observation showed a high community structure similarity.</p><p><b>CONCLUSION</b>The microbial diversity and complexity of bacteria in saliva are significantly higher in caries-free adolescents than in caries-susceptible adolescents. During caries development, bacterial diversity in the saliva likely decreases.</p>

Human buccal mucosa microbiota succession across age / 华西口腔医学杂志

<p><b>OBJECTIVE</b>This investigation aimed to examine how buccal mucosa microbiome succeeds in a healthy population with different ages and dentition stages.</p><p><b>METHODS</b>Twenty-five subjects were recruited and subdivided into five groups: primary dentition group, mixed dentition group, adolescent group, adult group, and elderly group. Individual mucosal microbiota was obtained by gently scraping both sides of the buccal mucosa with a cotton swab. Microbial diversity was analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE).</p><p><b>RESULTS</b>1) The composition of buccal mucosa microbiota has great intra-individual divergence. 2) The average band numbers of the primary dentition group, mixed dentition group, adolescent group, adult group, and elderly group were 21.2 +/- 4.0, 17.8 +/- 3.9, 15.8 +/- 4.3, 16.8 +/- 3.7, and 22.2 +/- 6.5, respectively. No between-group differences was observed (P > 0.05), indicating that predominant strains in the oral cavity may be stable throughout an individual's lifetime. 3) The Shannon indices of primary dentition group, mixed dentition group, adolescent group, adult group, and elderly group were 1.73 +/- 10.2, 1.43 +/- 0.1, 1.05 +/- 0.2, 1.45 +/- 0.2, and 1.63 +/- 0.3, respectively. A significant between-group difference was observed (P = 0.003), indicating that the microbial diversity of the buccal mucosa decreases from childhood through adolescence, but increases from adult through senescence. 4) The clustering analysis showed that most of the samples in the same group clustered together, indicating higher intra-group community structure similarity.</p><p><b>CONCLUSION</b>Composition of the buccal mucosa microbiota was different among age groups. Adolescence may be an essential turning point of microbial ecology succession throughout life.</p>