This study will run in centers in Germany, Denmark, Austria, Czech Republic, and Switzerland, only.

This proof-of-concept study aims to evaluate the efficacy of three doses of oral TSO suspension vs. placebo for the induction of remission in Crohn's disease.

Major Inclusion Criteria:

• Signed informed consent,
• Man or woman between 18 and 75 years of age,
• Established diagnosis of Crohn's disease (CD) since at least 3 months prior to screening confirmed by endoscopic and histological, or endoscopic and radiological criteria,
• Negative pregnancy test in females of childbearing potential.

Major Exclusion Criteria:

• Bowel surgery within the last 3 months prior to baseline,
• Resection of more than 50 cm of the ileum,
• Ileostomy or colostomy,
• Septic complications,
• Evidence of infectious diarrhoea (i.e., pathogenic bacteria or Clostridium difficile toxin in stool culture),
• Abscess, perforation, fistulas, or perianal lesions,
• Immediate surgery required (e.g., major stenosis, serious bleeding, peritonitis, ileus),
• Clinical signs of stricturing disease,
• Parenteral or tube feeding,
• Abnormal hepatic function (ALT or ALP > 2.5 x upper limit of normal [ULN] at screening), liver cirrhosis, or portal hypertension,
• Abnormal renal function (Cystatin C > ULN) at screening,
• Any severe concomitant cardiovascular, renal, endocrine, or psychiatric disorder, which in the opinion of the investigator might have an influence on the patient's compliance or the interpretation of the results,
• Any condition associated with significant immunosuppression,
• Active malignancy or treatment with anticancer drugs during the last 5 years.
• Existing or intended pregnancy or breast-feeding,
• Participation in another clinical trial within the last 30 days, simultaneous participation in another clinical trial, or previous participation in this trial.