Synbiotics and Fecal Microbiota Transplantation to Treat Non-Alcoholic Steatohepatitis

Inclusion Criteria: * biopsy-proven NASH obtained up to 32 weeks before screening: SAF Steatosis score ≥1, Activity ≥2, Fibrosis \<4; 50% of participants should at least have NASH fibrosis stage 1, 2 or 3 according to the NASH CRN fibrosis staging system based on tandem reading of two expert liver pathologists * fluency in Dutch or English * participants should be able to understand the information and give informed consent Exclusion Criteria: * Current or history of significant alcohol consumption for a period of more than 3 consecutive months within 1 year before screening (significant alcohol consumption is defined as more than 2 international units/day for females and more than 3 international units/day for males, on average; 1 international unit contains ±14 grams of alcohol) * liver cirrhosis or hepatocellular carcinoma * hepatitis B and/or C * auto-immune hepatitis * Wilson's disease * primary sclerosing cholangitis * primary biliary cholangitis * alpha-1-antitripsine deficiency and hemochromatosis * history of liver transplant, current placement on a liver transplant list * use of pre-, pro- or synbiotics * use of systemic antibiotics 3 month prior to randomization * use of tamoxifen, methotrexate or amiodarone * prior or planned bariatric surgery * active GLP-1 receptor agonist treated diabetes mellitus * bleeding disorder * International normalized ratio (INR) of prothrombin time \>1.4 or platelet count \<100 109/L at screening * anti-platelet/coagulant therapy use which cannot be temporarily discontinued * any major cardiovascular event within 6 months prior to screening (e.g. myocardial infarction, cerebrovascular accident) * prolonged compromised immunity (e.g. recent cytotoxic chemotherapy, HIV-infection with a CD4 count \< 240) * active or prior history of invasive malignancy (except for curatively treated in situ carcinomas \[e.g., cervix\] or non-melanoma skin cancer) unless a complete remission was achieved * surgery scheduled for the trial duration period, except for minor surgical procedures, in the opinion of the investigator * pregnant or nursing women * any condition which, in the investigator's opinion, might jeopardize participants' safety or compliance with the protocol * participation in another concomitant clinical trial.