This study aims to assess the safety and efficacy of heterologous fecal microbiota transplantation (FMT) by Standardized Quantitative multi-donor Intestinal Microbiota Capsule (SQIMC-md) in mild-moderate ulcerative colitis patients who fail to achieve clinical remission over 4 weeks after full dose 5-Aminosalicylic acid(5-ASA). Intestinal microbiota transplant for FMT will be prepared from multiple healthy donors and prepared by standardized procedure with fixed quantitative dosage. This strategy might offer a novel and safe therapeutic approach for these patients before step up to corticosteroid, immunosuppressant or biologics therapy.

All candidates for mild-moderate ulcerative colitis treated in Dept. Gastroenterology, Tongji Hospital, Tongji Medical College of HUST, the second Xiangya Hospital of central south university and the first affiliated Hospital of Zhengzhou University will be screened for study inclusion and exclusion criteria. All consenting patients will 2:1 randomized into SQIMC-md treatment group or Placebo group. Three dose of SQIMC-md capsule will be orally administrated on day1, day2 and day3. Follow-up will be performed every 4 weeks and last for 12weeks. Full dose of 5-ASA is orally administrated simultaneously during the study. Clinical data and outcome will be collected and documented in electronic case reported form (eCRF).

FMT DONORS:

Potential healthy adult stool donors (between 18 and 28 years of age) will be recruited by the research staff. They will be asked to volunteer for the screening and regularly supply stool samples according to the study protocol.

Inclusion Criteria:

1. Patients must have a diagnosis of ulcerative colitis based on clinical symptoms, as well as laboratory and colonoscopic findings, including histopathologic results of the intestinal mucosa.
2. Ulcerative Colitis complete Mayo score range from 4 to 10 [mild-moderate activity] and Mayo endoscopic score ≥2 as assessed within 4 weeks prior to enrollment and clinical symptoms that are at least stable.
3. Patients failed to acquire clinical remission after full dose and adequate course (4 weeks) of 5-ASA or precursors treatment.
4. Patients ≥ 18 and < 70 years of age are eligible for this trial.
5. All patients must sign a written informed consent document. Assent, when appropriate, will be obtained according to institutional guidelines.

Exclusion Criteria:

1. Human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) or other severe immunodeficiency
2. Patients with severe prior allergic reaction to food or supplementary material of placebo will be excluded from the protocol.
3. Patients who are pregnant or lactating will be excluded from the protocol.
4. Suspected as CMV or EBV colitis by endoscopic findings and proved by immunohistochemistry and biopsy PCR.
5. Decompensated life-threatening disease including but not restricted to liver cirrhosis (bleeding varices, ascites, encephalopathy or icterus), heart attack, malignancy and so on.

We plan to share at least the ICF and CSR after the trial is ended. The data will be available after we finish the trial and the publication. The sharing of the data is planned to lasted for one year.

The data will be available after we finish the trial and the publication. The sharing of the data is planned to lasted for one year.

Not decided yet.