Could a single friendly gut bacterium prevent recurrent c. diff?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Adult patient ≥18 years of age * ≥3rd episode of proven C. difficile infection (≥3 liquid stools per day and detection of toxigenic C. difficile in stool by PCR or enzyme-linked immunosorbent assay or immunochromatography or toxigenic culture) within 6 months with an interval ≤ 12 weeks since the end of treatment of the previous episode of resolved CDI or 2nd episode of proven C. difficile infection (≥3 liquid stools per day and detection of toxigenic C. difficile in the stools by PCR or enzyme-linked immunosorbent assay or immunochromatography or toxigenic culture) within 6 months with an interval ≤ 12 weeks since the end of treatment of the previous episode of resolved CDI with at least one of the following risk factors: * Age ≥70 years * Chronic renal failure (haemodialysis or GFR\<60ml/min * History of severe or severe-complicated CDI (excluding current episode) according to ESCMID 2021 criteria * ≥3 CDI in the last 12 months (including current episode) * CDI associated with care defined as CDI occurring during hospitalisation (\<3 months) * On current or planned vancomycin treatment per os * Patient able to give free, informed and written consent * Enrolled in compulsory national social security scheme Exclusion Criteria: * Currently participating or has participated in a study with an investigational compound or device within 3 months prior to the first dose of the study intervention. * Severe C. difficile infection severe (defined by the presence of a white blood cell count \>15×10⁹ cells/L or a body temperature \>38.5°C or \>50% increase in the patient's baseline creatinine related to CDI at the time of V1) and/or complicated (defined by any of the factors attributed to current Clostridioides difficile infection (CDI): hypotension, septic shock, elevated serum lactate, ileus, toxic megacolon, intestinal perforation or any fulminant course of the disease) * Refractory C. difficile infection defined as lack of response to well-conducted per os vancomycin or fidaxomicin treatment with ≥3 liquid stools per day after ≥5 days of treatment * Cirrhosis with Child C score * Hospitalization in continuing care unit or intensive care unit * Personal history of gastrointestinal resection other than appendectomy (gastrectomy, esophagectomy, colonic or small bowel resection, short small bowel syndrome). * Personal history of gastrointestinal resection resulting in chronic diarrhea (\>3 loose stools per day) * Inflammatory bowel disease * Proven uncontrolled celiac disease * Current stoma (ileostomy or colostomy) or within the last 6 months, or any other intra-abdominal surgery within the 3 months prior to treatment * major surgery or trauma ≤ 4 weeks before the start of treatment or, if \> 4 weeks ago, with an unresolved healing process that could affect the assessment or safety of the study treatment. * Antibiotic therapy in progress or planned during the study for an infection other than CDI * Surgery scheduled during the study requiring perioperative antibiotics. * -Women without contraception\*, pregnant or breastfeeding women * History of hypersensitivity to EXL01 and/or to any of its excipients (D-mannitol, sucrose, maltodextrin, L-cysteine, L-cysteine hydrochloride, magnesium stearate and hydroxypropylmethylcellulose), and/or to soy or soy-containing products. * History of hypersensitivity to vancomycin as mentioned in local prescribing information. * Personal history of fecal microbiota transplantation \< 6 months * Persons deprived of liberty by judicial or administrative decision * Adults under legal protection or unable to give consent * Swallowing disorders making oral treatment impossible * Participation in another interventional study within 3 months prior to inclusion. (Patients who have entered the follow-up phase of an interventional study may participate provided that more than 3 months have elapsed since the last intervention). * Expected life expectancy of less than 6 months * Presents a known psychiatric disorder that would interfere with adequate cooperation with study requirements. * Regular use of illicit or recreational drugs that may interfere with the administration of the medication or the interpretation of the data * History of chronic diarrhea (\> 3 watery stools per day for \> 4 weeks) not related to gastrointestinal infection. * Clinically significant medical or surgical condition not mentioned in the above criteria which, in the opinion of the investigator, could interfere with the administration of study drug, the interpretation of study safety or efficacy data, or compromise the safety or well-being of the subject.