Fecal microbiota transfer for treating obesity and metabolic issues

Metabolic Outcome of Obese Subjects Receiving Fecal Microbiota Transplantation of Lean Versus Gastric Bypass Treated Subjects. A Pilot Study

Not applicable Interventional University Hospital Bergmannsheil Bochum · NCT06268990

This study is testing whether transferring gut bacteria from lean donors or people who have had weight-loss surgery can help obese individuals manage their weight and blood sugar better.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment30 (estimated)
Ages18 Years to 60 Years
SexAll
SponsorUniversity Hospital Bergmannsheil Bochum Academic / other
Drugs / interventionsmethotrexate
Locations1 site (Graz)
Trial IDNCT06268990 on ClinicalTrials.gov

What this trial studies

This double-blinded proof-of-concept study investigates the effects of fecal microbiota transfer (FMT) in obese individuals. Participants will receive FMT from either lean donors or from individuals who have successfully undergone Roux-en-Y Gastric Bypass (RYGB) surgery, while a control group will receive their own stool (autologous FMT). The study aims to analyze how these microbiota changes impact energy consumption and blood glucose regulation, utilizing extensive sequencing analyses to profile microbiota and metabolite composition. The goal is to explore targeted gut microbiota modulation as a potential management strategy for obesity and related metabolic diseases.

Who should consider this trial

Good fit: Ideal candidates include adults over 18 years with morbid obesity and prediabetes or diabetes.

Not a fit: Patients with poorly controlled diabetes or those on weight loss medications may not benefit from this study.

Why it matters

Potential benefit: If successful, this approach could lead to new treatments for obesity and metabolic disorders by harnessing the power of gut microbiota.

How similar studies have performed: While the concept of fecal microbiota transfer is being explored in various contexts, this specific approach comparing RYGB-derived microbiota to lean microbiota is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

\- Inclusion criteria for patients

* Age \>18 years
* Morbid obesity defined by a BMI ≥ 40 kg/m2
* Prediabetes or diabetes with HbA1C between ≥ 5.7 % OR
* Fasting plasma glucose \> 5.6 mmol/l (\> 100 mg/dl) (no caloric intake for at least 8 hours) OR
* Random plasma glucose \> 11.1 mmol/l (\> 200 mg/dl)
* Informed consent

Inclusion criteria for RYGB-FMT intervention donors

* Sustained total weight loss of ≥30% ≥12 months after RYGB surgery
* HbA1c \< 6.5% without insulin treatment or oral antidiabetic medication
* Age \>18 years
* Informed consent

Inclusion criteria for LEAN-FMT intervention donors

* Normal weight (BMI ≥ 20 to \< 25 \>18 years
* Informed consent

Exclusion Criteria:

Exclusion criteria for patients

• Non-Compliance

* Insulin dependent diabetes mellitus, treated with GLP-1 agonists or poorly controlled on oral antidiabetic medications (HbA1C \> 8%)
* Use of any weight loss medication or participation in a weight loss program
* History of recent body weight change (defined as body weight loss or body weight gain of ≥ 5 kg within the two months preceding study enrolment).
* Use of immunosuppressive medication or immune modulators (glucocorticoids, methotrexate, tacrolimus, cyclosporine, thalidomide, interleukin-10 or -11) within the last three months preceding study enrolment.
* Congenital or acquired immunodeficiencies.
* Anatomical reconstruction of the nutrient passage (i.e. hemicolectomy, resection of small bowel, gastrectomy, sleeve gastrectomy, gastric bypass surgery, biliopancreatic diversion, fundoplication etc) or cholecystectomy.
* Chronic diarrhoea
* History of serious chronic disease including malignancy, rheumatic heart disease, endocarditis, or valvular disease (due to risk of bacteremia)
* Any condition, based on clinical judgment that may make study participation unsafe
* Pregnancy or Breast Feeding

Exclusion criteria for RYGB-FMT intervention donors

* Intake of pre-, pro- or antibiotics within \< 3 months before study entry
* Use of immunosuppressive medication or immune modulators (glucocorticoids, methotrexate, tacrolimus, cyclosporine, thalidomide, interleukin-10 or -11) within the last three months preceding study enrolment.
* Congenital or acquired immunodeficiencies.
* Chronic or acute infectious diseases (specified under 6.2.1)
* Drug abuse
* Anatomical reconstruction of the nutrient passage other than surgical RYGB configuration (i.e. hemicolectomy, resection of small bowel, fundoplication, LSG-to-RYGB transformation etc) or cholecystectomy.
* History of recent body weight change (defined as body weight loss or body weight gain of ≥ 5 kg within the two months preceding study enrolment).
* Chronic diarrhoea or steatorrhea or acute gastrointestinal infection within ≤ 3 months before study entry.
* History of serious chronic disease including malignancy, chronic kidney disease (eGFR \< 60 ml/min), heart failure (NYHA ≥ III).
* Any further condition, based on clinical judgment that may disqualify the candidate as an appropriate donor.

Exclusion Criteria for Lean-FMT Intervention Donors • History of overweight or obesity in the past (BMI \> 25 kg/m2)

• History of recent body weight change (defined as body weight loss or body weight gain of ≥ 5 kg within the two months preceding study enrolment).

• HbA1C \> 6.5% or treatment with insulin or oral anti-diabetic medication.

• Use of any weight loss medication or participation in a weight loss program

• Use of immunosuppressive medication or immune modulators (glucocorticoids, methotrexate, tacrolimus, cyclosporine, thalidomide, interleukin-10 or -11) within the last three months preceding study enrolment.

• Congenital or acquired immunodeficiencies.

• Chronic or acute infectious diseases (specified under 6.2.1)

• Drug abuse

• Anatomical reconstruction of the nutrient passage (i.e. hemicolectomy, resection of small bowel, fundoplication etc) or cholecystectomy.

• Chronic diarrhoea or acute gastrointestinal infection within ≤ 3 months before study entry.

• History of serious chronic disease including malignancy, chronic kidney disease (eGFR \< 60 ml/min), heart failure (NYHA ≥ III).

• Any further condition, based on clinical judgment that may disqualify the candidate as an appropriate donor.

Where this trial is running

Graz

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 Morbid ObesityMetabolic SyndromeDiabetesPreDiabetesInsulin ResistanceFecal microbiota transferobesityglucose homeostasis
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.