Salivary Microbiota and Antimicrobial Resistance in Relation to Chlorhexidine Use (SMARCH)
30 april 2026 uppdaterad av: Masaryk University
Study Protocol for 16S rRNA Sequencing of Healthy Oral Microbiota
This study evaluated the ecological effects of 0.06% chlorhexidine toothpaste on the salivary microbiota of healthy individuals, focusing on taxonomic composition, functional shifts, and prevalence of predicted antimicrobial resistance genes.
Saliva samples were collected from eleven healthy participants at three specific time points: baseline (following a 4-week run-in period using a control toothpaste), intervention (after 12 weeks of using 0.06% chlorhexidine digluconate toothpaste), and washout (after a subsequent 12-week period using the control toothpaste).
Sequencing targeted the 16S rRNA V3-V4 region.
Studieöversikt
Status
Avslutad
Betingelser
Intervention / Behandling
Studietyp
Interventionell
Inskrivning (Faktisk)
11
Fas
- Inte tillämpbar
Kontakter och platser
Det här avsnittet innehåller kontaktuppgifter för dem som genomför studien och information om var denna studie genomförs.
Studieorter
-
-
-
Brno, Tjeckien, 62500
- Department of Public Health, Faculty of Medicine, Masaryk University
-
Brno, Tjeckien, 62500
- Skydent s.r.o.
-
-
Deltagandekriterier
Forskare letar efter personer som passar en viss beskrivning, så kallade behörighetskriterier. Några exempel på dessa kriterier är en persons allmänna hälsotillstånd eller tidigare behandlingar.
Urvalskriterier
Åldrar som är berättigade till studier
- Vuxen
Tar emot friska volontärer
Ja
Beskrivning
Inclusion Criteria:
- Age: Between 25-44 years.
- General Health: Good systemic health (absence of chronic inflammatory diseases or conditions affecting oral tissues).
- Oral Hygiene Routine: Participants must perform toothbrushing twice a day and use interdental cleaning aids once a day.
- Plaque Index (PI): A score of 0.0-0.2 according to Silness and Löe.
- Gingival Index (GI): A score of 0.0-0.143 according to Silness and Löe.
Exclusion Criteria:
Systemic and Lifestyle Factors:
- Presence of any chronic systemic disease (e.g., diabetes mellitus, autoimmune disorders)
- Regular use of medications that may affect gingival status or saliva production.
- Use of antibiotics within the last 6 months prior to the study.
- Current pregnancy or lactation.
- Current smokers or users of other tobacco/nicotine products.
Oral and Dental Factors:
- Active dental disease: Presence of untreated tooth decay, gingivitis (GI > 0.143), or any form of periodontitis.
- Prosthetics and Implants: Presence of dental implants, dentures, or significant tooth loss (excluding extracted third molars).
- Ongoing fixed or removable orthodontic treatment.
Studieplan
Det här avsnittet ger detaljer om studieplanen, inklusive hur studien är utformad och vad studien mäter.
Hur är studien utformad?
Designdetaljer
- Primärt syfte: Hälsovårdsforskning
- Tilldelning: N/A
- Interventionsmodell: Enskild gruppuppgift
- Maskning: Ingen (Open Label)
Vapen och interventioner
Deltagargrupp / Arm |
Intervention / Behandling |
|---|---|
|
Experimentell: Experimental: Chlorhexidine group
A single group of 11 healthy volunteers.
The study consists of three consecutive phases: baseline (4 weeks), intervention with 0.06% chlorhexidine toothpaste (12 weeks), and washout (12 weeks).
|
Participants used the toothpaste twice daily for 12 weeks.
|
Vad mäter studien?
Primära resultatmått
Resultatmått |
Åtgärdsbeskrivning |
Tidsram |
|---|---|---|
|
Change in Salivary Microbial Alpha Diversity (Shannon and Simpson Indices)
Tidsram: Baseline (week 0), after intervention (week 12), and after washout (week 24).
|
Evaluation of microbial richness and evenness within individual saliva samples.
Alpha diversity is quantified using the Shannon and Simpson indices based on 16S rRNA gene sequencing data.
Differences between study phases (baseline, intervention, washout) are assessed using the Kruskal-Wallis test or Mann-Whitney U test, as appropriate, with a significance threshold of p < 0.05.
|
Baseline (week 0), after intervention (week 12), and after washout (week 24).
|
|
Change in Salivary Microbial Beta Diversity (Community Structure)
Tidsram: Baseline (week 0), after intervention (week 12), and after washout (week 24).
|
Evaluation of differences in microbial community composition between study phases.
Calculated using Bray-Curtis dissimilarity on Centered Log-Ratio (CLR) normalized data and assessed via PERMANOVA to detect significant shifts (p < 0.05).
|
Baseline (week 0), after intervention (week 12), and after washout (week 24).
|
Sekundära resultatmått
Resultatmått |
Åtgärdsbeskrivning |
Tidsram |
|---|---|---|
|
Differential Abundance of Salivary Bacterial Taxa
Tidsram: Baseline (week 0), after intervention (week 12), and after washout (week 24).
|
Evaluation of shifts in the relative abundance of bacterial taxa (at phylum, family, genus, and species levels) using 16S rRNA sequencing (V3-V4 region).
Statistical analysis is performed using DESeq2 and edgeR to identify significant differences between study phases, with multiple testing corrections applied using the Benjamini-Hochberg (FDR) method (FDR < 0.05).
|
Baseline (week 0), after intervention (week 12), and after washout (week 24).
|
|
Changes in Predicted Antimicrobial Resistance Genes (ARGs)
Tidsram: Baseline (week 0), after intervention (week 12), and after washout (week 24).
|
Functional prediction of the salivary microbiota conducted using PICRUSt2.
Assessment of metabolic potential and antimicrobial resistance pathways with significance assessed using adjusted p-values (p-adj < 0.05).
|
Baseline (week 0), after intervention (week 12), and after washout (week 24).
|
|
Gingival Index (GI) for Clinical Stability Assessment
Tidsram: Screening (Week -4) and after washout (Week 24).
|
Assessment of gingival health using the Silness and Löe Gingival Index (scale 0-3).
This measure is used to verify that participants maintain optimal oral health throughout the study.
Eligibility is strictly limited to participants with a maximum GI of 0.143 at screening to ensure a healthy baseline and to monitor that no gingival inflammation occurs during the study period.
|
Screening (Week -4) and after washout (Week 24).
|
|
Plaque Index (PI) for Clinical Stability Assessment
Tidsram: Screening (Week -4) and after washout (Week 24).
|
Assessment of dental plaque accumulation using the Silness and Löe Plaque Index (scale 0-3).
This measure is used to ensure consistent oral hygiene.
Eligibility is strictly limited to participants with a maximum PI of 0.2 at screening.
The index is monitored to confirm that participants adhere to the required oral hygiene protocol throughout the study.
|
Screening (Week -4) and after washout (Week 24).
|
Samarbetspartners och utredare
Det är här du hittar personer och organisationer som är involverade i denna studie.
Sponsor
Studieavstämningsdatum
Dessa datum spårar framstegen för inlämningar av studieposter och sammanfattande resultat till ClinicalTrials.gov. Studieposter och rapporterade resultat granskas av National Library of Medicine (NLM) för att säkerställa att de uppfyller specifika kvalitetskontrollstandarder innan de publiceras på den offentliga webbplatsen.
Studera stora datum
Studiestart (Faktisk)
11 april 2022
Primärt slutförande (Faktisk)
29 november 2022
Avslutad studie (Faktisk)
29 november 2022
Studieregistreringsdatum
Först inskickad
30 april 2026
Först inskickad som uppfyllde QC-kriterierna
30 april 2026
Första postat (Faktisk)
6 maj 2026
Uppdateringar av studier
Senaste uppdatering publicerad (Faktisk)
6 maj 2026
Senaste inskickade uppdateringen som uppfyllde QC-kriterierna
30 april 2026
Senast verifierad
1 april 2026
Mer information
Termer relaterade till denna studie
Nyckelord
Andra studie-ID-nummer
- 68/2020
- MUNI/A/1807/2025 (Annat bidrag/finansieringsnummer: Masaryk University)
Plan för individuella deltagardata (IPD)
Planerar du att dela individuella deltagardata (IPD)?
NEJ
Läkemedels- och apparatinformation, studiedokument
Studerar en amerikansk FDA-reglerad läkemedelsprodukt
Nej
Studerar en amerikansk FDA-reglerad produktprodukt
Nej
Denna information hämtades direkt från webbplatsen clinicaltrials.gov utan några ändringar. Om du har några önskemål om att ändra, ta bort eller uppdatera dina studieuppgifter, vänligen kontakta register@clinicaltrials.gov. Så snart en ändring har implementerats på clinicaltrials.gov, kommer denna att uppdateras automatiskt även på vår webbplats .