Relationship between hydrogen sulfide-producing bacteria of the tongue coating and oral malodor

J. Washio, Takuichi Sato, Kyoko Ikawa, N. Tanda, M. Iwakura, T. Koseki, N. Takahashi

Research output: Contribution to journalReview articlepeer-review

1 Citation (Scopus)


Relationship between bacterial flora and H2S levels in breath air was investigated in this study. Oral malodor levels in 10 subjects (age: 21-56 years) were assessed with gas chromatography, Breathtron® and organoleptic score. Based on these assessments, subjects were divided into 2 groups; oral malodorous and nonodorous groups. Tongue coating were sampled and spread onto Fastidious Anaerobe Agar plates containing 0.05% cysteine, 0.12% glutathione and 0.02% lead acetate, and were then incubated anaerobically at 37 °C for 2 weeks. Bacteria forming black or gray colonies were designated as H2S-producing phenotypes, and were identified by 16S rRNA gene sequencing. The numbers of total bacteria (p < 0.005) and H2S-producing bacteria (p < 0.05) in the oral malodorous group were significantly larger than those in the nonodorous group. Veillonella, Actinomyces and Prevotella species were predominant in the H2S-producing bacteria both in the oral malodorous and nonodorous groups. These results suggest that an increase in the number of H2S-producing bacteria in the tongue biofilm is responsible for oral malodor.

Original languageEnglish
Pages (from-to)199-200
Number of pages2
JournalInternational Congress Series
Publication statusPublished - 2005 Sep


  • 16S ribosomal RNA
  • Hydrogen sulfide
  • Oral malodor
  • PCR
  • Tongue coating

ASJC Scopus subject areas

  • Medicine(all)


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