Dysbiosis of Methanogenic Archaea and Nanoarchaea in the Oral Microbiome (METHAORAL)

Need to improve understanding of oral dysbiosis in the elderly and/or immunocompromised individuals (involvement of nanogenes in these dysbiosis) Comparison of dysbiosis identification between results from dental plaque samples and saliva samples (the saliva sample is non-operator-dependent due to its ease of collection). Comparison of the reliability of results obtained with this type of saliva sample versus results obtained with dental plaque samples, which are considered the reference sample type (Antézack 2023).

Primary objective To estimate the prevalence of dysbiosis in individuals with oral frailty versus individuals without oral frailty.

In this project:

• Dysbiosis will be defined by the presence of Archaea (Bringuier 2013). For the primary objective, prevalence will be estimated based on dental plaque samples.
• The population with oral frailty will be defined as individuals over 60 years of age or those with immunosuppression.

Hypothesis: The expected proportion of dysbiosis in the population with oral health vulnerability is 40%, whereas the expected proportion of dysbiosis in the population without oral health vulnerability is 20% (Li CL 2009).

Secondary objectives Estimate the prevalence of dysbiosis in the two populations based on a saliva sample

- Compare the results from the sample

Study Overview

• Status: Not yet recruiting
• Conditions: Oral Health
• Intervention / Treatment: Diagnostic test: Dental plaque sample; Diagnostic test: Saliva sample

Detailed Description

Study Design A cross-sectional case-control study. Participation in the study will be offered to all eligible subjects who meet the inclusion criteria.

Number of Patients 250 patients. For each patient, a dental plaque sample and a saliva sample will be collected during the visit.

• Study Type: Interventional
• Enrollment (Estimated): 250
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: alexandra GIULIANI; Phone Number: +33491382870; Email: alexandra.giuliani@ap-hm.fr

Study Locations

• France
  • Marseille, France
    • Assistance Publique Hopitaux de Marseille
    • Principal Investigator: elodie TERREE, PU-PH

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

Case selection criteria:

Cases are defined as subjects with oral health vulnerability

• Men or women aged 60 years or older
• and/or immunocompromised individuals without periodontal disease (gingivitis, periodontitis, and peri-implantitis) clinically diagnosed by the dentist during the consultation.
• Patients who have received information about the study and have not expressed objection
• Patients who are beneficiaries or eligible for a social security program Control group selection criteria Controls are defined as subjects without oral health vulnerability • Men and women under 60 years of age without periodontal disease (gingivitis, periodontitis, and peri-implantitis) clinically diagnosed by the dentist during the consultation.

The clinical examination allows for the diagnosis of the absence or presence of periodontal disease, with particular attention to: bleeding on probing, the depth of periodontal pocket(s), tooth mobility, bone destruction in furcation areas, and the assessment of radiographic bone level taking age into account.

Exclusion Criteria:

• Patients who are currently excluded from another research protocol at the time the informed consent form is collected.
• Subjects covered by Articles L1121-5 through L1121-8 of the Public Health Code (minors, adults under guardianship or conservatorship, patients deprived of their liberty, pregnant or breastfeeding women),
• Men and women with periodontal disease (gingivitis, periodontitis, and peri-implantitis)
• Men and women with any systemic disease
• Men and women currently undergoing drug treatment

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Sham Comparator: Individuals with periodontal vulnerability; those over 60 without periodontal disease and/or who are immunocompromised	Diagnostic test: Dental plaque sample; Dental plaque sample; Diagnostic test: Saliva sample; Saliva sample using a swab
Active Comparator: Control group; individuals under 60 without periodontal disease	Diagnostic test: Dental plaque sample; Dental plaque sample; Diagnostic test: Saliva sample; Saliva sample using a swab

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Estimate the prevalence of dysbiosis	Estimate the prevalence of dysbiosis in the two populations based on dental plaque sample	3 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Estimate the prevalence of dysbiosis i	Estimate the prevalence of dysbiosis in the two populations based on a saliva sample	3 years

Collaborators and Investigators

• Sponsor: Assistance Publique Hopitaux De Marseille
• Investigators: Study Director: Mathilde LEFEVRE, Assistance Publique Hopitaux de Marseille

Study record dates

Study Major Dates

• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): September 1, 2029
• Study Completion (Estimated): December 1, 2029

Study Registration Dates

• First Submitted: March 30, 2026
• First Submitted That Met QC Criteria: April 8, 2026
• First Posted (Actual): April 13, 2026

Study Record Updates

• Last Update Posted (Actual): April 13, 2026
• Last Update Submitted That Met QC Criteria: April 8, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: oral health issues; without oral health issues
• Other Study ID Numbers: RCAPHM25_0384; 2025-A02266-43 (Other Identifier: ANSM)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No