Actively Recruiting
The Role of Microbiome in Recurrent Obesity Before and After Antibiotic/Placebo Treatment
Led by Weizmann Institute of Science · Updated on 2026-01-20
200
Participants Needed
1
Research Sites
155 weeks
Total Duration
On this page
Sponsors
W
Weizmann Institute of Science
Lead Sponsor
H
Hadassah Medical Organization
Collaborating Sponsor
AI-Summary
What this Trial Is About
This past century witnessed a significant increase in the prevalence of obesity. Successful weight loss maintenance is defined as losing at least 10% of the initial body weight and maintaining it for at least one year. However, keeping a low body weight is rarely maintained, as 80% of people who lost 10% of their body weight will return to their initial weight within a year. Although there is no agreement as to what contributes to the recurrent weight regain phenomenon (also known as 'weight cycling' or 'yo-yo diet'), it is strongly associated with the risk of developing metabolic risk factors and their complications, including heart disease and all-cause mortality. Altering the gut microbiota is one method to treat disease states associated with gut bacteria. Antibiotics consumption is known to influence host glycemic response through changes induced in microbiome composition and function. Therefore, it may be a possible pathway to jumpstart changes in the gut microbiota. This study will determine whether microbiome modulation might be a possible future target against recurrent obesity in humans and whether orally administered antibiotic treatment post-weight loss might be an effective intervention to prevent weight regain.
CONDITIONS
Official Title
The Role of Microbiome in Recurrent Obesity Before and After Antibiotic/Placebo Treatment
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Body mass index (BMI) between 28 and 35
- Age between 18 and 65 years
- Able to use a smartphone application
You will not qualify if you...
- Use of antibiotics, probiotics, or oral antifungals within 2 months before the study
- Pregnancy, breastfeeding, or fertility treatments within 6 months before or during the study
- Chronic diseases as determined by the study team (e.g., AIDS, Cushing syndrome, chronic kidney disease, acromegaly)
- History of cancer or recent cancer treatment
- Psychiatric disorders as determined by the study team
- Blood clotting (coagulation) disorders
- Inflammatory bowel diseases (IBD)
- Previous bariatric surgery
- Eating disorders including anorexia nervosa, bulimia nervosa, binge eating disorder, or night eating syndrome
- Alcohol or substance abuse
- Use of weight loss medications within 6 months before the study
- Major changes in eating habits within 6 months before the study as determined by the study team
- Allergy to penicillin
- Life-threatening reaction to cephalosporin antibiotics
- History of Clostridioides difficile infection (CDI)
- Liver disease
- Serious unresolved diarrhea after antibiotic treatment as judged by the study doctor
AI-Screening
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Trial Site Locations
Total: 1 location
1
Weizmann Institute of Science
Rehovot, Israel
Actively Recruiting
Research Team
E
Eran Elinav, Professor
CONTACT
B
Barbara Raykhel
CONTACT
How is the study designed?
Study Type
INTERVENTIONAL
Masking
QUADRUPLE
Allocation
RANDOMIZED
Model
PARALLEL
Primary Purpose
TREATMENT
Number of Arms
2
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