Examining the Oral Microbiome and Immune Response in COVID-19

Role of the Oral Microbiome & Mucosal Immunity in COVID-19 Disease: Diagnostic/Prognostic Utility in South Asian Populations

Observational King's College London · NCT05212766

This study looks at how the mouth's germs and immune responses differ in people with COVID-19 compared to those without it, to see how oral health might affect COVID-19 outcomes.

Quick facts

Study typeObservational
Enrollment750 (estimated)
Ages18 Years and up
SexAll
SponsorKing's College London Academic / other
Locations1 site (London)
Trial IDNCT05212766 on ClinicalTrials.gov

What this trial studies

This observational study investigates the differences in mucosal innate immunity and oral microbiome characteristics between COVID-19 patients and control groups from South Asian and White British populations. Participants will provide stimulated whole mouth fluid and blood samples, which will be analyzed for immune responses to SARS-CoV-2 antigens and microbial DNA. The study includes both symptomatic and asymptomatic COVID-19 patients, as well as uninfected individuals, to understand the role of oral health in COVID-19 outcomes. Clinical examinations and questionnaires will also be utilized to gather comprehensive data on oral health status.

Who should consider this trial

Good fit: Ideal candidates include South Asian and White British individuals aged 18 and over, with either confirmed COVID-19 infection or no history of COVID-19.

Not a fit: Patients with a history of COVID-19 vaccination or those who are not willing to provide longitudinal samples may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could enhance understanding of how oral health impacts COVID-19 severity and recovery, potentially leading to improved patient management strategies.

How similar studies have performed: While the specific focus on the oral microbiome in relation to COVID-19 is novel, similar studies have shown that oral health can influence systemic diseases and immune responses.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* • South Asian and White British persons and those diagnosed with symptomatic or asymptomatic COVID-19 infection.

  * Aged 18 or over. Able to understand and consent.
  * Uninfected subjects: no history of COVID-19; not vaccinated; (negative for anti-SARS-CoV2 nucleoprotein antibodies at lab)
  * For patient groups: Confirmed COVID-19 positivity, symptoms and symptom onset within the past 21 days; Be recently hospitalised with COVID-19 disease; Have COVID-19 disease proven by PCR testing for SARS-CoV-2 within the last 21 days; COVID disease severity graded as per NIH/WHO.
  * Recovered groups: Have had COVID-19 disease proven by PCR testing for SARS-CoV-2. COVID disease severity graded as per WHO or NIH equivalent criteria
  * Those willing to participate on a single occasion but unwilling to participate with longitudinal samples will not be excluded.
  * Smoking, obesity, diabetes, heart disease, antibiotics or treatment related to COVID is not excluded.

Exclusion Criteria:

* • Those patients unwilling to participate, those unable to understand sufficiently to give informed consent and those unable to participate due to the severity of COVID-19 disease. Those patients classified as not either South Asian or White British heritage.

  * Patients with malignancy, pregnancy, long term immune suppression, inability to give informed consent, not willing or able to have oral examination.
  * Diabetes not excluded but screening for diabetes will be performed: glucose will be assessed in blood/serum sample (150ul).

Exclusion criteria summary:

* Critically ill participants who cannot give informed consent
* Those who are not willing to have an oral examination, or donate blood or saliva samples.
* Those who cannot chew / drool to provide a SWMF sample due to severe/critical medical conditions
* Participants with known malignancies or who are pregnant
* Participants who are on long-term immunosuppressants (e.g. for autoimmune diseases)
* Participation in other current research that is designed to, or is expected to alter the immune response.
* Inability to communicate, understand or read English.

Where this trial is running

London

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions COVID-19Microbial ColonizationOral DiseasePeriodontal DiseasesInnate Inflammatory ResponseMucosal Infectionperiodontal diseaseoral health
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.