The purpose of the study is to evaluate the efficacy and safety of lyophilized PRIM-DJ2727 capsules given orally in subjects with ulcerative colitis at remission stage. This study will also include longitudinal analyses of recipient's gut microbiota taxonomy and metagenomics to determine potential associations with clinical outcomes in context of active FMT or placebo administration.

Inclusion Criteria:

1. Adult ≥18 years of age
2. History of active UC in the past 12 months based on standard clinical, endoscopic, or histologic criteria.
3. Remission of UC based on clinical grounds (partial Mayo score of ≤2 with each subscore ≤1), and on stable maintenance therapy.
4. Sexually active male and female subjects of childbearing potential must agree to use an effective method of birth control during the study.
5. Female subjects of childbearing potential must have a negative urine Qualitative HCG pregnancy test at enrolment and on the Week 1, Day 1 of the Treatment prior to administration of study drug.
6. Willing and able to sign an informed consent form and attend all study-related clinic visits, assessments, and follow-up phone calls.
7. Subject has an attending physician who will provide the non-FMT care.

Exclusion Criteria:

1. Unable to take multiple capsules orally.
2. Females who are pregnant, breastfeeding, or planning to become pregnant during the study.
3. Receipt of systemic non-topical antibiotics within 14 days of treatment day 1.
4. Positive results for active HIV, Hepatitis B, or Hepatitis C infections.
5. History of recurrent Clostridium difficile infection or FMT in the past 6-months.
6. History of other active gastrointestinal conditions such as irritable bowel syndrome, microscopic colitis, celiac disease, short gut syndrome, colostomy, colectomy, gastrointestinal fistulae or strictures, chronic parasitic infections, diverticulitis etc.
7. Known history of bile acid diarrhea
8. Compromised immune system (e.g. primary immune disorders or clinical immunosuppression due to a medical condition or medication e.g. taking oral prednisone >20 mg a day or prednisone-equivalent)
9. History of active cancer and/or ongoing chemotherapy (superficial non-metastatic cancers and maintenance chemotherapy are permitted).
10. History of use of an investigational drug within 90 days prior to the screening visit.
11. History of significant uncontrolled systemic disease that in the opinion of the study investigator could interfere with study participation and/or objectives.
12. Life expectancy of < 1 year.
13. In the opinion of investigator, subject for any reason, should be excluded from the study.