Dataset Information

Changes in salivary microbiota increase volatile sulfur compounds production in healthy male subjects with academic-related chronic stress.

ABSTRACT:

Objective

To investigate the associations among salivary bacteria, oral emanations of volatile sulfur compounds, and academic-related chronic stress in healthy male subjects.

Materials and methods

Seventy-eight healthy male undergraduate dental students were classified as stressed or not by evaluation of burnout, a syndrome attributed to academic-related chronic stress. This evaluation was carried out using the Maslach Burnout Inventory-Student Survey questionnaire. Oral emanations of hydrogen sulfide, methyl mercaptan, and dimethyl sulfide were measured using an Oral Chroma™ portable gas chromatograph. The amounts in saliva of total bacteria and seven bacteria associated with halitosis were quantified by qPCR. The in vitro production of H2S by S. moorei and/or F. nucleatum was also measured with the Oral Chroma™ instrument.

Results

The stressed students group showed increased oral emanations of hydrogen sulfide and dimethyl sulfide, together with higher salivary Solobacterium moorei levels (p < 0.05, Mann Whitney test). There were moderate positive correlations between the following pairs of variables: Fusobacterium nucleatum and S. moorei; F. nucleatum and hydrogen sulfide; Tannerella forsythia and F. nucleatum; T. forsythia and S. moorei. These correlations only occurred for the stressed group (p < 0.05, Spearman correlation). The in vitro experiment demonstrated that S. moorei increased H2S production by F. nucleatum (p < 0.05, ANOVA and Tukey's test).

Conclusion

The increased amount of S. moorei in saliva, and its coexistence with F. nucleatum and T. forsythia, seemed to be responsible for increased oral hydrogen sulfide in the healthy male stressed subjects.

SUBMITTER: Nani BD

PROVIDER: S-EPMC5358872 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Changes in salivary microbiota increase volatile sulfur compounds production in healthy male subjects with academic-related chronic stress.

Nani Bruno Dias BD Lima Patricia Oliveira de PO Marcondes Fernanda Klein FK Groppo Francisco Carlos FC Rolim Gustavo Sattolo GS Moraes Antonio Bento Alves de AB Cogo-Müller Karina K Franz-Montan Michelle M

PloS one 20170320 3

<h4>Objective</h4>To investigate the associations among salivary bacteria, oral emanations of volatile sulfur compounds, and academic-related chronic stress in healthy male subjects.<h4>Materials and methods</h4>Seventy-eight healthy male undergraduate dental students were classified as stressed or not by evaluation of burnout, a syndrome attributed to academic-related chronic stress. This evaluation was carried out using the Maslach Burnout Inventory-Student Survey questionnaire. Oral emanation ...[more]

PMID: 28319129

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Project description:Adaptation to environmental perturbations requires living systems to coordinately regulate signaling pathways, gene expression, and metabolism. To better understand the mechanisms underlying adaptation, the regulatory nodes within networks must be elucidated. Here, ARO8-2 (which encodes an aminotransferase), PDC (which encodes a decarboxylase), and STR3 (which encodes a demethiolase) were identified as key genes involved in the catabolism of methionine in the mycoparasitic fungus Clonostachys rosea, isolated from Tuber melanosporum ascocarps. Exogenous Met induced the transcription of ARO8-2 and PDC but repressed the transcription of STR3, which is controlled by the putative MSN2 and GLN3 binding sites responding to nitrogen catabolite repression. Met and its structural derivatives function as glutamine synthetase inhibitors, resulting in the downregulation of STR3 expression. The putative GLN3 binding site was necessary for STR3 downregulation. In Saccharomyces cerevisiae, Met and its structural derivatives also triggered downregulation of demethiolase gene expression. Altogether, the results indicated that exogenous Met triggered nitrogen catabolite repression, which stimulated the Ehrlich pathway and negatively regulated the demethiolation pathway via the methionine sulfoximine-responsive regulatory pathway. This finding revealed the regulatory nodes within the networks controlling the catabolism of Met into volatile organic sulfur-containing compounds, thereby enhancing our understanding of adaptation.IMPORTANCE Methionine shuttles organic nitrogen and plays a central role in nitrogen metabolism. Exogenous Met strongly induces the expression of ARO8-2 and PDC, represses the expression of STR3, and generates volatile organic sulfur-containing compounds via the Ehrlich and demethiolation pathways. In this study, we used genetic, bioinformatic, and metabolite-based analyses to confirm that transcriptional control of the aminotransferase gene ARO8-2, the decarboxylase gene PDC, and the demethiolase gene STR3 modulates Met catabolism into volatile organic sulfur-containing compounds. Importantly, we found that, in addition to the Ehrlich pathway, the demethiolation pathway was regulated by a nitrogen catabolite repression-sensitive regulatory pathway that controlled the transcription of genes required to catabolize poor nitrogen sources. This work significantly advances our understanding of nitrogen catabolite repression-sensitive transcriptional regulation of sulfur-containing amino acid catabolism and provides a basis for engineering Met catabolism pathways for the production of fuel and valuable flavor alcohols.

Dataset Information

Changes in salivary microbiota increase volatile sulfur compounds production in healthy male subjects with academic-related chronic stress.

Objective

Materials and methods

Results

Conclusion

Publications

Changes in salivary microbiota increase volatile sulfur compounds production in healthy male subjects with academic-related chronic stress.

Similar Datasets

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