The Role of Microbiome in Recurrent Obesity Before and After Antibiotic/Placebo Treatment

NCT06681246 | Recruiting

• 1 other identifier: 0744-21-HMO
• Study Type: interventional
• Target: 200
• Locations: 1 country
• Sites: 1

Brief Summary

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

Obesity; Weight Loss

Outcome Measures

Primary Outcomes (2)

• microbiome composition

  using stool and oral samples

  1 year

• weight

  weight (kg)

  1 year

Secondary Outcomes (1)

• glycemic response

  1 year

Study Arms (2)

Antibiotic treatment

EXPERIMENTAL

intervention arm

Other: Antibiotic treatment

Placebo

PLACEBO COMPARATOR

placebo capsules administration

Other: Placebo

Interventions

Placebo OTHER

consist of a combination of agarose in normal saline/glycerol

Placebo

Antibiotic treatment OTHER

10 days of either antibiotics- Augmentin (amoxicillin+clauvonate), 875mg, 2 /day

Antibiotic treatment

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• \<BMI\<35
• Age - 18-65
• Capable of working with a smartphone application

You may not qualify if:

• Consumption of antibiotics/probiotics/oral antifungals 2 months prior to the first day of the experiment.
• Pregnancy, fertility treatments, breastfeeding women six months prior to enrollment and during the study.
• Chronic disease, to the discretion of the study team (e.g. AIDS, Cushing syndrome, CKD, acromegaly etc.)
• Cancer and recent anticancer treatment
• Psychiatric disorders, to the discretion of the study team.
• Coagulation disorders
• IBD (inflammatory bowel diseases)
• Bariatric surgery.
• Eating disorders (Anorexia nervosa. Bulimia nervosa. Binge eating disorder, Night eating syndrome).
• Alcohol or substance abuse
• Weight loss attempts 6 months prior to the first day of the experiment - using weight loss medication.
• Drastic changes in nutritional habits six months prior to the first day of the study - to the discretion of the study team.
• Allergy to penicillin.
• Life threatening reaction after consumption of cephalosporins.
• History of CDI

Sponsors & Collaborators

• Weizmann Institute of Science: lead
• Hadassah Medical Organization: collaborator

Study Sites (1)

Weizmann Institute of Science

Rehovot, Israel

RECRUITING

MeSH Terms

Conditions

Obesity; Weight Loss

Condition Hierarchy (Ancestors)

Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Body Weight Changes

Study Officials

• Hila Elinav, Doctor

  Hadassah Medical Organization

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Eran Elinav, Professor

CONTACT

+97289349174; Eran.Elinav@weizmann.ac.il

Barbara Raykhel

CONTACT

+97289346590; barbara.raykhel@weizmann.ac.il

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 6, 2024
• First Posted: November 8, 2024
• Study Start: December 11, 2024
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): December 1, 2027
• Last Updated: January 20, 2026

Record last verified: 2025-11

Locations

IL (1)