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Relationship between stress and oral microbiota: the effect on the production of volatile sulphur compounds and the role of beta-defensin

Grant number: 13/26691-0
Support Opportunities:Scholarships in Brazil - Master
Effective date (Start): April 01, 2014
Effective date (End): February 29, 2016
Field of knowledge:Health Sciences - Dentistry
Principal Investigator:Michelle Franz Montan Braga Leite
Grantee:Bruno Dias Nani
Host Institution: Faculdade de Odontologia de Piracicaba (FOP). Universidade Estadual de Campinas (UNICAMP). Piracicaba , SP, Brazil
Associated research grant:11/50419-2 - Oral health and behavior: interdisciplinary perspectives and emotional aspects in the health-disease process, AP.TEM


Halitosis can be defined as a malodour that rises from the oral cavity. Around 96% of halitosis occurs as a consequence of an increased bacterial activity, which metabolize aminoacids into volatile sulphur compounds (VSC). In addition, stress has been suggested as a possible etiologic agent that causes oral malodour. In a previous study from our research group, it was observed that undergraduate students with an increased stress level, presented a higher production of VSC; higher saliva levels of alpha-amylase and a lower saliva levels of beta-defensin. However, the impact of this phenomenon on the etiology of halitosis is already unknown. Therefore, the aim of the present study is to determine the oral microbiota profile in oral healthy patients that presented some level of stress; to evaluate the influence of beta-defensin (BD) and alpha-amylase (AA) on bacterial growth and production of VSC from microorganisms determined in the first part of the present study. Saliva samples of undergraduate students from Dentistry course (samples previously collected in a prior study) will be evaluated by PCR-real time. The following species will be investigated: Solobacterium moorei, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Fusobacterium nucleatum, Actinomyces odontolyticus e Veillonella dispar. Furthermore, two of the bacterial species which presents higher amounts in saliva samples, will be selected for the study of the effects of the treatment with BD and AA on growth and viability on planktonic culture. In addition, gas chromatography (Oral Chroma®) will be performed to measure the VSC released direct from culture tubes, to evaluate the effect of BD and AA on production on this compounds by microorganisms. (AU)

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Scientific publications
(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)
DE LIMA, PATRICIA OLIVEIRA; NANI, BRUNO DIAS; ALMEIDA, BARBARA; MARCONDES, FERNANDA KLEIN; GROPPO, FRANCISCO CARLOS; ALVES DE MORAES, ANTONIO BENTO; FRANZ-MONTAN, MICHELLE; COGO-MUELLER, KARINA. Stress-related salivary proteins affect the production of volatile sulfur compounds by oral bacteria. ORAL DISEASES, v. 24, n. 7, p. 1358-1366, . (13/26691-0, 11/50419-2, 14/11481-2)
NANI, BRUNO DIAS; DE LIMA, PATRICIA OLIVEIRA; MARCONDES, FERNANDA KLEIN; GROPPO, FRANCISCO CARLOS; ROLIM, GUSTAVO SATTOLO; ALVES DE MORAES, ANTONIO BENTO; COGO-MUELLER, KARINA; FRANZ-MONTAN, MICHELLE. Changes in salivary microbiota increase volatile sulfur compounds production in healthy male subjects with academic-related chronic stress. PLoS One, v. 12, n. 3, . (11/50419-2, 13/26691-0)
Academic Publications
(References retrieved automatically from State of São Paulo Research Institutions)
NANI, Bruno Dias. Relationship between bacterial counts and volatile sulphur compounds production in healthy volunteers with academic stress. 2016. Master's Dissertation - Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba Campinas, SP.

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