Distribution of methanogenic archaea in different oral sites amongst subjects with halitosis

Abstract

Introduction: Methanogenic archaea are single celled methanogenic anaerobic microorganisms that are potential hydrogen competitors. It serves as a syntrophic partners with other members of the subgingival biofilm community leading to methanogenesis, sulfate reduction and acetogenesis thereby producing hydrogen sulfide, a potent Volatile Sulphur compound to cause halitosis. Aim: To evaluate the presence of methanogenic archaea in supra gingival plaque, subgingival plaque and tongue coating in subjects with and without oral halitosis. Materials and Methods: A case control study of 50 subjects with 25 halitosis and 25 healthy subjects were included in the study. Supragingival plaque, subgingival plaque and tongue coating were collected from all the subjects. DNA extraction was done from the samples by Bacterial genome extraction kit. Conventional PCR was done to detect the presence of Methanogenic archaea. Results: The prevalence of methanogenic archaea in supra gingival plaque, subgingival plaque and tongue coating in halitosis subjects were 16%, 60% and 16% respectively and in controls without halitosis were 4%, 8% and 0% respectively. A highly statistical significant difference (p 0.000) was found between subgingival plaque samples of cases and controls. Conclusion: A significantly higher presence of methanogenic archaea was observed in halitosis subjects than controls, with increased detection in the subgingival plaque thereby fulfilling the association criteria of Socransky’s postulates. However, a larger sample size, identification of VSC production and synergistic activity with other microorganisms needs to be established. Keywords: Halitosis, Methanogenic Archaea, Plaque, Tongue coating, Oral malodor.