Antimicrobial Therapy for Ulcerative Colitis (UC)

Study Purpose

The Aim of this randoized controlled pilot study is to find a better treatment strategy for active UC based on the recent knowledge regarding the microbiota in UC and the beneficial or detrimental effects of antibiotics in restoring gut health and reducing inflammation. This study is designed to determine whether therapy with two antibiotics during a flare - amoxicillin and doxycillin, will be better than the current published antibiotic treatment combination using these antibiotics with metronidazole ( as the latter which may degrade beneficial species without adding benefit towards reducing pathobionts)

Recruitment Criteria

Accepts Healthy Volunteers

Healthy volunteers are participants who do not have a disease or condition, or related conditions or symptoms

Study Type

An interventional clinical study is where participants are assigned to receive one or more interventions (or no intervention) so that researchers can evaluate the effects of the interventions on biomedical or health-related outcomes.

An observational clinical study is where participants identified as belonging to study groups are assessed for biomedical or health outcomes.

Searching Both is inclusive of interventional and observational studies.

Eligible Ages 13 Years - 60 Years
Gender All
More Inclusion & Exclusion Criteria

Inclusion Criteria:

1. Established diagnosis of UC, disease confined to the large intestine, involving the rectosigmoid for at least 3 months. 2. Weight >30 kg. 3. Mild to Moderate active disease, SCCAI of ≥5 and ≤ 10, 10 ≤ PUCAI ≤4. 4. Refractory to mesalamine 6 weeks, or steroids > 14 days, or immunomodulator 12 weeks or biologics at least 12 weeks therapy.

Exclusion Criteria:

1. Start of a new biologic in the previous 12 weeks. 2. Proctitis. 3. Evidence for Clostridium difficile infection. 4. Any proven current infection such as CMV, positive stool culture or parasite. 5. Current Extra intestinal manifestation of UC such as active arthritis or PSC. 6. Immune deficiency (other than drug induced). 7. Current use of a calcineurin inhibitor. 8. Pregnancy. 9. Suspected toxic megacolon, guarding on palpation, or signs of peritoneal inflammation. 10. Patients with other IBD unrelated disease such as autoimmune disorders, renal failure, fever or current infection (UTI, strep throat, pneumonia, etc), prior or current neoplasia. 11. Fever >38. 12. Participation in another clinical interventional trial. 13. An active malignant disease or a prior malignancy during the previous 5 years (excluding skin BCC). 14. Anticipation for antibiotic use within the study period (such as for elective surgery or dental treatment). 15. Acute severe UC in the past 3 months. 16. Presence of a pouch or pouchitis.

Trial Details

Trial ID:

This trial id was obtained from, a service of the U.S. National Institutes of Health, providing information on publicly and privately supported clinical studies of human participants with locations in all 50 States and in 196 countries.


Phase 1: Studies that emphasize safety and how the drug is metabolized and excreted in humans.

Phase 2: Studies that gather preliminary data on effectiveness (whether the drug works in people who have a certain disease or condition) and additional safety data.

Phase 3: Studies that gather more information about safety and effectiveness by studying different populations and different dosages and by using the drug in combination with other drugs.

Phase 4: Studies occurring after FDA has approved a drug for marketing, efficacy, or optimal use.

Phase 2
Lead Sponsor

The sponsor is the organization or person who oversees the clinical study and is responsible for analyzing the study data.

Wolfson Medical Center
Principal Investigator

The person who is responsible for the scientific and technical direction of the entire clinical study.

Dror Weiner, MD
Principal Investigator Affiliation Wolfson Medical Center
Agency Class

Category of organization(s) involved as sponsor (and collaborator) supporting the trial.

Overall Status Recruiting
Countries Israel

The disease, disorder, syndrome, illness, or injury that is being studied.

Ulcerative Colitis
Additional Details

Recent studies suggest that UC is associated with alterations of the microbiota. Further support for targeting the microbiota includes several studies demonstrating that antibiotics might be helpful for severe refractory colitis. Antibiotics may work by reducing pathobionts, by causing niche expansion of beneficial bacteria , and may harm if they do not reduce pathobionts or reduce beneficial commensals Recently, a triple antibiotic therapy with amoxicillin, metronidazole and tetracycline was developed for UC. However, a recent study on the effect of 11 different oral antibiotics on gut bacteria found that seven of them including metronidazole might cause lbacterial translocation . Anaerobes are critical for butyrate production. . Based on these recent studies, it would appear that tetracycline and amoxicillin are more likely to cause the beneficial effect, while metronidazole might actually be detrimental. Thus by removing metronidazole the investigators might actually have a better effect both for efficacy and safety.

Arms & Interventions


Active Comparator: Group 1 -Amoxycillin Doxycyclin and metronidazole

triple therapy with amoxicillin, metronidazole and tetracycline twice daily, for 2 weeks.

Experimental: Group 2 -Amoxycillin and Doxycyclin

double therapy with Amoxycillin and Doxycyclin twice daily, for 2 weeks.


Drug: - amoxicillin, metronidazole and doxycycline

antibiotics: Patient weight 30-50 kg Patient weight > 50 kg Tetracycline 50 mg X 2 Day X 2 weeks 100 mg X 2 Day X 2 weeks Amoxicillin 750 mg X 2 Day X 2 weeks 750 mg X 2 Day X 2 weeks Metronidazole 250 mg X 2 Day X 2 weeks 375 mg X 2 Day X 2 weeks

Drug: - amoxicillin and doxycyclin

antibiotics: Patient weight 30-50 kg Patient weight > 50 kg Tetracycline 50 mg X 2 Day X 2 weeks 100 mg X 2 Day X 2 weeks Amoxicillin 750 mg X 2 Day X 2 weeks 750 mg X 2 Day X 2 weeks

Contact a Trial Team

If you are interested in learning more about this trial, find the trial site nearest to your location and contact the site coordinator via email or phone. We also strongly recommend that you consult with your healthcare provider about the trials that may interest you and refer to our terms of service below.

International Sites

The E.Wolfson Medical Center, Holon, Israel




The E.Wolfson Medical Center

Holon, , 58100

Site Contact

Arie Levine, MD


The content provided on clinical trials is for informational purposes only and is not a substitute for medical consultation with your healthcare provider. We do not recommend or endorse any specific study and you are advised to discuss the information shown with your healthcare provider. While we believe the information presented on this website to be accurate at the time of writing, we do not guarantee that its contents are correct, complete, or applicable to any particular individual situation. We strongly encourage individuals to seek out appropriate medical advice and treatment from their physicians. We cannot guarantee the availability of any clinical trial listed and will not be responsible if you are considered ineligible to participate in a given clinical trial. We are also not liable for any injury arising as a result of participation. For a full description of terms please refer to our Terms, Conditions & Privacy.