A Phase 4 interventional study of Amoxicillin + Saccharomyces boulardii CNCM I-745 and Amoxicillin + Placebo in Erythema Migrans of Lyme Disease, sponsored by Biocodex. Recruiting at 1 site in Slovenia. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-08-27.
Sponsored by Biocodex · Phase 4, Interventional, and Supportive care
The aim of this study is to assess the effect of Saccharomyces boulardii CNCM I-745 on gut microbiota in patients undergoing antibiotic therapy (in the context of erythema migrans (early skin form of Lyme borreliosis)).
The study is designed to compare the efficacy of Saccharomyces boulardii CNCM-I-745 500 mg bid to a placebo in patients undergoing antibiotic therapy in the context of erythema migrans as the early form of Lyme borreliosis.
25 studies on the registry are indexed under Glossitis, Benign Migratory; 4 are open to participants now.
This study's planned enrollment of 120 is below the median of 200 across 13 interventional studies indexed under Glossitis, Benign Migratory.
Browse Glossitis, Benign Migratory studies →Biocodex is the lead sponsor of 19 studies on the registry; 6 are open to participants now.
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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.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Postmenopausal
Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Excipients
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The patients will received oral Amoxicillin (1000 mg capsules bid) for 14 days and oral Saccharomyces boulardii CNCM I-745 (®) 250 mg x 2 capsules twice a day for 21 days.
Drug: Amoxicillin + Saccharomyces boulardii CNCM I-745 · Other: Stool samples · Other: BSFS : Bristol Stool Form Scale · Other: GSRS : Gastrointestinal Symptom Rating Scale
The patients will received oral Amoxicillin (1000 mg capsules bid) for 14 days + oral Placebo capsules for 21 days.
Drug: Amoxicillin + Placebo · Other: Stool samples · Other: BSFS : Bristol Stool Form Scale · Other: GSRS : Gastrointestinal Symptom Rating Scale
At inclusion visit (V1), the Investigator will dispense and ask the subject to take Amoxicillin 1000 mg bid for 14 days + Saccharomyces boulardii 250 mg x 2 twice a day for 21 days
At inclusion visit (V1),the Investigator will dispense and ask the subject to take Amoxicillin 1000 mg bid for 14 days + a matching placebo bid for 21 days
The subject will be asked to collect thanks to four OMNIgene® •GUT OMR-200 kits : * an initial stool collection when returning home at D1 (in any case before any intake of amoxicillin and of the investigational medication and up to 1 day after D1). * a stool collection at home after the phone call 1, Day 7 (stool collection up to Day 7 + 1 day) * a stool collection at home after the phone call 2, Day 14 (stool collection up to Day 14 + 1 day) * at home the day of the Visit 2, Day 21 (stool collection up to Day 21 + 1 day)
All included subjects will have to complete a stool diary BSFS (Bristol Stool Form Scale) daily and at each bowel movement, from Day 1 until the end of study treatment (Day 21). The patient will fill the form with the date, the time, and the stool texture.
All included subjects will have to complete a GSRS (Gastrointestinal Symptom Response Score) questionnaire weekly from Day 1 until the end of the study treatment (Day 21).
Assessment of the effect of Saccharomyces boulardii CNCM I-745, an antibiotic, and their combination on the gut microbiota of patients receiving antibiotic
Primary endpoint : analysis of the intestinal microbiota in the patient's stools
Time frame: At Day 1, Day 7, Day 14 and Day 21
Assessment of the efficacy of Saccharomyces boulardii CNCM I-745 in prevention of antibiotic-associated diarrhoea (AAD) in patients undergoing antibiotic therapy
Secondary efficacy endpoint : Incidence of AAD (The number of AAD episodes that occurred during the treatment period) will be assessed using the Bristol Stool Form Scale (BSFS) recorded daily.
Time frame: At Day 1, Day 7, Day 14 and Day 21
Assessment of the efficacy of Saccharomyces boulardii CNCM I-745 on the stools in patients undergoing antibiotic therapy : Recorded stools in the Bristol Stool Form Scale (BSFS)
Secondary efficacy endpoint : Time frame in hours up to the time of the last liquid or loose stool (defined as types 6 or 7 on Bristol Stool Form Scale (BSFS)) followed by the first 24-hour period with stool consistency improvement (no liquid or loose stool), as recorded by the patients in the stool diary or as collected by the investigator
Time frame: At Day 1, Day 7, Day 14 and Day 21
Assess the effect of Saccharomyces boulardii CNCM I-745, an antibiotic, and their combination on the gastro-intestinal symptoms of patients receiving antibiotic therapy : Changes from baseline of the GSRS
Secondary efficacy endpoint : Changes from baseline of the Gastrointestinal Symptom Rating Scale (GSRS) score (total score) and diarrhea sub-scores will be compared weekly between the treatment groups. The questionnaire, which contains 15 items, uses a seven-graded Likert scale, where 1 represents the most positive option and 7 the most negative one.
Time frame: Weekly from Day 1 to Day 21
Assessment of the safety and tolerability of Saccharomyces boulardii CNCM I-745. Recording adverse events
Safety endpoint : Recorded adverse events (number of events and number of participants with at least one event), vital signs, and physical examination
Time frame: At each assessment time from baseline (Day 1 to Day 58)
Assess the effect of Saccharomyces boulardii CNCM I-745, an antibiotic, and their combination on the specific gastro-intestinal symptoms of patients receiving antibiotic therapy : Gastrointestinal Symptom Rating scale (GSRS)
Exploratory endpoint : Changes from baseline of the GSRS subscores (except diarrhea) will be compared weekly between the treatment groups.The questionnaire, which contains 15 items, uses a seven-graded Likert scale, where 1 represents the most positive option and 7 the most negative one.
Time frame: Weekly from Day 1 to Day 21
Assess the effect of Saccharomyces boulardii CNCM I-745, an antibiotic, and their combination on the gut resistome of patients receiving antibiotic : Changes on the fecal Antimicrobial Resistance Genes (ARGs)
Exploratory endpoint : Changes observed on the gut resistome, abundance and diversity of the fecal ARGs will be analysed by treatment group and at each assessment time.
Time frame: At Day 1, Day 7, Day 14 and Day 21
Plan to share: No
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