Clinical Research Directory

Inclusion Criteria: * Males or females * Age ≥18 and ≤75 years * Large duct PSC verified by retrograde, operative, percutaneous or magnetic resonance cholangiography (MRC) demonstrating intrahepatic and /or extrahepatic biliary duct changes consistent with PSC * IBD diagnosed according to international guidelines (presence of endoscopic and histologic signs) * IBD inactive for at least 6 months (defined by no evidence of flare and no change in treatment) * ALP ≥ 1.3 ULN (at least 2 times within a 3 months pre-inclusion period) or elevated total bilirubin ≤50 umol/l (with concomitant elevated direct bilirubin). * Treatment with UDCA (13-23 mg/kg/d) for at least 6 months and at the same dosage for at least 3 months * Using contraceptive in women of childbearing potential and agrees to pursue it from inclusion until week 48. Women of childbearing potential, i.e. fertile, following menarche and until becoming post-menopaused unless permanently sterile, who are sexually active have to apply a highly effective method of birth control with a low failure rate (i.e. less than 1% per year) when used constantly and correctly. * Written informed consent signed * Subject affiliated to the French * Social Security System Exclusion Criteria: * Small duct PSC * Autoimmune hepatitis defined by the presence of moderate to severe interface hepatitis documented on liver biopsy and at least 1 of the 2 following criteria: AST or ALT \> 5 ULN, Positive anti smooth muscle auto antibodies or serum IgG \> 1.5 ULN * Secondary sclerosing cholangitis (notably IgG4-associated cholangitis) * Cirrhosis defined by Liver elastometry \>14.4 kPa or by current or past decompensation of cirrhosis * AST or ALT \> 7 ULN in the last 3 months * Platelets count in the last 3 months \< 100 000/mm3 * Albumin in the last 3 months \<35g/L * Prothrombin index in the last 3 months \< 70% * Hepatic comorbidity: HBV infection (defined by positive Ag HBS), HCV infection (defined by positive HCV RNA), alcohol abuse (defined by alcohol intake \> 30g/day), metabolic dysfunction associated steatohepatitis, primary biliary cholangitis, Hemochromatosis, Wilson disease, α1-antitrypsin deficiency, celiac disease * History of acute cholangitis in the last 3 months prior to inclusion or current acute cholangitis * HIV infection * Prior liver transplantation * Endoscopic treatment for bile duct stenosis ≤ 3 months prior to inclusion or planned within 3 months post randomization date * History of or established or suspected hepatobiliary carcinoma. * Any severe comorbidity that may reduce life expectancy * History of malignancy diagnosed or treated within 2 years (recent localized treatment of squamous or non-invasive basal skin cancers is permitted; cervical carcinoma in situ is allowed if appropriately treated prior to inclusion) * Dosage changes of treatment for liver disease in the last 3 months or new treatment for liver disease started in the last 3 months * History of colorectal carcinoma or high-grade dypsplasia in previous screening colonoscopy * History of total colectomy * Current active IBD defined by a partial Mayo score \> 2 in patients with ulcerative colitis (UC), unclassed colitis or a Crohn's Disease Activity Index (CDAI) \> 150 in patients with Crohn's disease * Changes in IBD treatment or initiation of a new treatment for IBD in the last 3 months * Current treatment with biologics (anti-TNF agent, vedolizumab, ustekinumab) or JAK inhibitors (tofacitinnib) or prednisone \> 10 mg/day or budesonide \> 3 mg /day) (or treatment initiated less than one month) * Any contra-indication to swallow capsules * Renal insufficiency (clearance\<60 ml/min) * Unable to consent, subject to legal or administrative decision (protection measure or deprivation of liberty) or involuntary psychiatric care. * Participation in another interventional research without prior consultation with the investigator responsible for the patient's monitoring in the present study (participation in other non-interventional studies is permitted) * Pregnancy or desire for pregnancy or breastfeeding Randomization criteria * No pregnancy (or desire for in the next year) * No other hepatic pathology: HBV (positive HBs Ag), HCV (positive HCV antibody and positive PCR), autoimmune hepatitis * No HIV infection (positive serology HIV1+2 antibodies) * No documented Clostridium difficile infection at inclusion or \< 10 days preceding randomization (in case of infection discovered at inclusion) * No treatment with antibiotics, antifungics or probiotics \< 4 weeks. * Available FMT with EBV and CMV compatibility