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

• Published in: PloS one Vol. 12; no. 3; p. e0173686
• Main Authors: Nani, Bruno Dias, Lima, Patricia Oliveira de, Marcondes, Fernanda Klein, Groppo, Francisco Carlos, Rolim, Gustavo Sattolo, Moraes, Antonio Bento Alves de, Cogo-Müller, Karina, Franz-Montan, Michelle
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 20.03.2017; Public Library of Science (PLoS)
• Subjects: Actinomyces; Adolescent; Bacteria; Bacteria - metabolism; Bacteroides forsythus; Biology and Life Sciences; Burnout; Coexistence; Correlation; Dental materials; Dental schools; Dentistry; Dimethyl sulfide; Emission; Evaluation; Fusobacterium nucleatum; Gas chromatography; Halitosis - microbiology; Healthy Volunteers; Humans; Hydrogen; Hydrogen sulfide; Infections; Influence; Male; Medicine and Health Sciences; Methanethiol; Microbiota; Microbiota (Symbiotic organisms); Off odor; Oral hygiene; People and Places; Physical Sciences; Physiological aspects; Physiology; Porphyromonas gingivalis; Production processes; Saliva; Saliva - microbiology; Social Sciences; Solobacterium moorei; Stress; Stress (Psychology); Stress, Psychological - microbiology; Stresses; Students; Students - psychology; Sulfide; Sulfides; Sulfur; Sulfur compounds; Sulfur Compounds - chemistry; Sulfur Compounds - metabolism; Variance analysis; Volatilization; Young Adult
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0173686

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