Inclusion Criteria:
1. Male or female ≥ 18 years of age
2. Inactive Crohn's disease in clinical and objective remission with a Harvey-Bradshaw Index (HBI) \< 4
3. Permitted CD medications expected to remain stable during the period of the study (see Section 7 "Concomitant Crohn's Disease Medications" for allowed and prohibited drugs).
4. Crohn's disease history ≥ 6-month duration
5. CRP (C-reactive protein) within normal range at the Screening visit (based on normal range of the local laboratory)
6. Fecal calprotectin level ≤ 150 µg/g at the Screening visit
7. AIEC detected in the stool
8. Females of childbearing age must be using an effective method of contraception to prevent pregnancy and agree to continue to practice an acceptable method of contraception for the duration of participation in the study (contraceptive measures considered adequate are: intrauterine devices, hormonal contraceptives, such as contraceptive pills, implants, transdermal patches, hormonal vaginal devices or injections with prolonged release).
9. Negative pregnancy test for women of childbearing age (menarche to menopause)
10. Patient understands the study procedures, and can sign the informed consent, and the authorization to release relevant protected health information to the Study Investigator.
Exclusion Criteria:
1. Active Crohn's disease with a Harvey-Bradshaw Index (HBI) ≥ 4
2. Ongoing gastrointestinal pathology: colorectal tumor, gastrointestinal bleeding
3. Active malignancies or any malignant disease within the past 5 years
4. Indeterminate colitis, ulcerative colitis
5. Colectomy or partial colectomy (less than ileo-transverse colonic anastomosis).
6. Colonic or small bowel stoma
7. Active perianal lesions
8. Women who are pregnant or nursing, or plan to become pregnant during the study period
9. Severe uncontrolled diseases that could increase the risk for subjects participating in the study, including but not limited to: heart diseases, congestive heart failure, hypertension, lung diseases; endocrine diseases; clinically significant renal disease characterized by a glomerular filtration rate \< 60mL/min, hepatic diseases, haematological disorders, or other conditions that in the opinion of the Investigator could interfere with the interpretation of the study results.
10. Taking supplemental probiotics in the form of pills or tablets.
11. History or planned procedures specifically aimed at modifying the gastrointestinal microbiota within the past year.
12. Topical gastrointestinal treatment (e.g., enemas) in the 2 weeks prior to the Screening visit or planned during the study period
13. Use of bowel cleansing or preparation for endoscopy, TDM or MRI in the 4 weeks prior to the Screening visit or planned during the study period.
14. Receipt of antibiotics 4 weeks before the Screening visit or planned during the study period.
15. Known allergy or hypersensitivity to an excipient in the study drug or placebo
16. Psychological or linguistic incapability to sign the informed consent.
17. Lack or expected lack of cooperation or compliance with the study.
18. Receipt of mesalamine based therapies within 4 weeks of the screening visit.
19. Severe psychiatric, psychological, or neurological disorders.
20. Alcohol, drug or medication abuse within the past year.
21. Subject who cannot be contacted in case of emergency.
