Gum bacteria in people having bariatric surgery with BMI greater than 30

Non-interventional Study Exploring the Composition of the Periodontal Microbiota of Patients With Body Mass Index Greater Than 30 That Are Candidates for Bariatric Surgery

Observational University Hospital, Toulouse · NCT06781229

This will see if people with obesity (BMI ≥30) having bariatric surgery have different gum bacteria depending on whether their BMI is 30–35 or above 35.

Quick facts

Study typeObservational
Enrollment170 (estimated)
Ages18 Years and up
SexAll
SponsorUniversity Hospital, Toulouse Academic / other
Locations1 site (Toulouse)
Trial IDNCT06781229 on ClinicalTrials.gov

What this trial studies

This is a non-interventional, single-centre, cross-sectional comparison of periodontal microbiota in patients listed for bariatric surgery. Participants complete questionnaires about diet, oral hygiene and quality of life, undergo a dental exam with saliva and periodontal plaque sampling, and have standard radiological checks. During surgery small samples of visceral and possibly subcutaneous adipose tissue may be recovered as surgical waste and stored for future use. The study excludes recent antibiotic/probiotic use, pregnancy or breastfeeding, significant infectious diseases, and other conditions that may alter microbiota measurements.

Who should consider this trial

Good fit: Adults with BMI ≥30 who are on the waiting list for bariatric surgery and can understand written and spoken French.

Not a fit: People who recently took antibiotics or probiotics, are pregnant or breastfeeding, have disqualifying infectious diseases or renal insufficiency, or are not scheduled for bariatric surgery are unlikely to receive benefit from participation.

Why it matters

Potential benefit: If successful, the findings could identify microbial differences linked to obesity severity and inform targeted oral care or perioperative management.

How similar studies have performed: Prior studies have linked obesity with alterations in oral microbiota, but direct comparisons of BMI-defined obesity versus morbid obesity in the bariatric surgery population remain relatively limited.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* BMI greater than or equal to 30
* Be on the list of patients scheduled for bariatric surgery,
* Be able to receive information about the study and understand the information form in order to take part in the study. This implies mastering the French language,

Exclusion Criteria:

* Alcohol consumption \>30g/d (men) or 20g/d (women),
* Having taken antibiotics, prebiotics or probiotics in the month prior to inclusion (this has an influence on the composition of the patient's microbiota),
* During pregnancy or breastfeeding,
* For whom oral surgery is planned (surgery for benign or malignant tumours of the maxillary and mandibular bone bases), or with a history of oral surgery in the month prior to inclusion,
* At risk of infection (existence of one or more of the following known chronic infectious diseases: HIV, HBV, HCV and mononucleosis) and/or chronic renal insufficiency (creatinine clearance \< 60ml/min),
* Patients with a general pathology that contraindicates the performance of diagnostic procedures such as periodontal probing (patients at high risk of infective endocarditis according to the ANSM).
* Totally edentulous patients

Where this trial is running

Toulouse

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 Bariatric SurgeryObesity, Morbidmicrobiological compositionobesebypassBody mass index
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.