An interventional study of Antibiotic treatment and Placebo in Obesity and Weight Loss, sponsored by Weizmann Institute of Science. Recruiting at 1 site in Israel. Open to participants aged 18 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-08-11.
Sponsored by Weizmann Institute of Science · Not applicable, Interventional, and Treatment
Among 128 studies in Obesity with a site in Israel — 22 open to participants now, 29 under way, 16 of them phase 3. Obesity · Israel.
Among the 128 studies in Obesity with a site in Israel, this one is the 38th largest by planned enrollment of the 98 interventional ones that give a count, is one of 8 that started in 2024, is one of 55 with no phase, reaches primary completion later than 11 of the 28 other live ones, and was the 112th registered.
11,522 studies on the registry are indexed under Obesity; 2,033 are open to participants now.
Browse Obesity studies →22 of the 128 studies in Obesity with a site in Israel are open now. Recruiting first, the newest first:
Eli Lilly and Company · Sites in Israel, United States, Belgium and 7 more countries
AstraZeneca · Sites in Israel, United States, Argentina and 8 more countries
Novo Nordisk A/S · Sites in Israel, United States, Argentina and 24 more countries
Eli Lilly and Company · Sites in Israel, United States, Australia and 11 more countries
Novo Nordisk A/S · Sites in Israel, United States, Australia and 23 more countries
A study can be open while its sites in Israel have not opened yet or have stopped. Only those recruiting at a site in Israel →
Of the 1,336 Obesity studies recruiting now, 377 (28%) set no upper age limit and 856 (64%) stop at 75 or younger; 168 take children under 18; 491 take healthy volunteers.
This study: 18 Years to 65 Years · all sexes · healthy volunteers too.
The full table on the hub →This tab as a report to print or save as PDF → With an account.
128 studies; the count open now beside each. This study's row is marked.
A study in two phases is counted once above. Listed by phase, each with its combined phases: Phase 1 3 · Phase 2 8 · Phase 3 29 · Phase 4 4
First in 2004; this study’s year is marked. 8 started in 2024.
This study's planned enrollment of 200 is above the median of 67 across 9,006 interventional studies indexed under Obesity.
Median enrollment 128 across the 98 interventional studies, 82 across the 29 observational. Of the 65 that completed or were terminated, 14 (22%) have results posted.
This tab as a report to print or save as PDF → With an account.
45 of 128 have an industry lead sponsor. The 10 most frequent:
Weizmann Institute of Science is the lead sponsor of 13 studies on the registry; 7 are open to participants now.
Weizmann Institute of Science has 1 study filed under Obesity — fewer than ten, so there is no comparison to draw.
7 of the studies in Obesity with a site in Israel that are under way reach primary completion within a year, 4 of them phase 3. Phase 3 first, then by date:
| Study | Primary completion |
|---|---|
| NCT06914895Phase 3Eli Lilly and CompanyA Study of Tirzepatide (LY3298176) Compared With Placebo in Adults With Type 1 Diabetes and Obesity or Overweight | 2026-11 |
| NCT06672549Phase 3Eli Lilly and CompanyA Platform Trial for Pediatric Participants With Obesity or Overweight (LY900040) | 2027-02 |
| NCT05556512Phase 3Eli Lilly and CompanyA Study of Tirzepatide (LY3298176) on the Reduction on Morbidity and Mortality in Adults With Obesity | 2027-10 |
| NCT06439277Phase 3Eli Lilly and CompanyA Study of Tirzepatide in Adolescents With Obesity and Weight-Related Comorbidities (SURMOUNT-ADOLESCENTS-2) | 2027-10 |
| NCT06681246Weizmann Institute of ScienceThe Role of Microbiome in Recurrent Obesity Before and After Antibiotic/Placebo Treatment | 2026-12 |
Among the 128 studies in Obesity with a site in Israel, from their registry updates:
This tab as a report to print or save as PDF → With an account.
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.
This is a placebo-controlled, double blinded interventional study evaluating the effect of antibiotic treatment in the prevention of weight regain after a successful weight loss intervention.
Volunteers will be recruited in the following ways: e-mail, and social media. Volunteers wishing to participate will be asked to complete a questionnaire regarding the aforementioned inclusion and exclusion criteria. Volunteers who qualify for the study will be invited to an introductory meeting at the Weizmann Institute of Science. The details of the experiment and potential risks or discomforts involved in it will be presented, after which the volunteers will sign an informed consent form. Volunteers will start the study and become active participants for a maximal duration of one year.
Samples collected for the study will be used for microbiota profiling (stool and oral), metabolomics (stool, blood) and for bomb calorimeter (stool).
The study will comprise of four parts:
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
intervention arm
Other: Antibiotic treatment
placebo capsules administration
Other: Placebo
10 days of either antibiotics- Augmentin (amoxicillin+clauvonate), 875mg, 2 /day
consist of a combination of agarose in normal saline/glycerol
microbiome composition
using stool and oral samples
Time frame: 1 year
weight
weight (kg)
Time frame: 1 year
glycemic response
continues glucose monitor (CGM)
Time frame: 1 year
Started Dec 2024 (actual). Primary completion is estimated for Dec 2026, 24 months after the start.
Of 3,680 non-industry interventional studies with no phase under Obesity, half reached primary completion within 23 months of starting (the median), counting those still running; a quarter within 10 and three quarters within 43. This study's planned 24 months is close to that.
Counting every sponsor, half of 3,843 studies reached it within 22 months; a quarter within 10 and three quarters within 42.
How these figures are worked out, and which studies are left out of them.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Weizmann Institute of Science