Fecal Microbiota Transplantation (FMT) of FMP30 in Relapsing-Remitting Multiple Sclerosis

Inclusion Criteria:

1. Age 18-60 inclusive (at time of screening).
2. Diagnosis of relapsing-remitting multiple sclerosis (MS) by the International Panel McDonald Criteria (2010)(1), incorporating 2017 revisions, which reclassify select high-risk Clinically Isolated Syndromes under 2010 criteria as RRMS under 2017 criteria, and Lublin criteria (2014)(2). \[RRMS: relapsing remitting multiple sclerosis\]
3. Recent documented MS disease activity, defined as at least 1 clinical relapse within the past 1 year prior to baseline OR 2 clinical relapses in the past 2 years prior to baseline OR at least 1 new T2/FLAIR lesion on brain or spine MRI OR at least 1 gadolinium enhancing lesion on brain or spine MRI in the past 1 year prior to baseline.
4. Expanded Disability Status Scale (EDSS) less than or equal to 6.0; EDSS 5.5 or less if MS disease duration is greater than 15 years (no other disease duration restriction).
5. Must have positive serology for Epstein-Barr Virus (EBV) (IgG anti-EBNA positive) at screening, indicating prior exposure. \[EBNA: Epstein-Barr nuclear antigen\]
6. No prior MS disease-modifying therapy or a 12-week washout period for participants on glatiramer acetate or interferon-beta therapy.
7. At least 4 weeks from baseline since last use of IV or oral glucocorticoids. Protocol: MS-BIOME Study.
8. Agree to maintain a stable diet during the course of the study (over-the-counter probiotics are allowable).
9. Premenopausal women and women \<12 months after the onset of menopause must have a negative serum pregnancy test unless they have undergone surgical sterilization.
10. Female participants of childbearing potential who are sexually active with a non-sterilized male partner must agree to use a highly effective method of contraception; non-sterilized male participants who are sexually active with a female partner of childbearing potential must agree to use a highly effective method of contraception.
11. Not actively participating in another interventional MS clinical trial (participation in other observational research studies is allowable).

Exclusion Criteria:

1. Prior use of fingolimod, dimethyl fumarate, teriflunomide, natalizumab, alemtuzumab, mitoxantrone, cyclophosphamide, rituximab, ocrelizumab, daclizumab, methotrexate, azathioprine, mycophenolate mofetil, cyclosporine, leflunomide, or induction chemotherapy.
2. No use of diuretics like furosemide (Lasix) 1 week before the first dose of oral antibiotics. The use of hydrochlorothiazide (HCTZ) for hypertension at a dose \< 50 mg/day is allowable.
3. Progressive MS by Lublin criteria (2014).
4. No oral or IV antibiotics are allowed within 8 weeks prior to screening and within 12 weeks prior to the planned FMT procedure (for participants in the FMT arm) or prior to the first stool collection (for participants in the control arm). (Note that topical, otic, ocular antibiotics are specifically allowable, which is consistent with the IMSMS.org protocol for collaborative gut microbiome research in MS). \[IMSMS: International MS Microbiome Study\]
5. Hypersensitivity or allergy to study antibiotics, conscious sedation medications, or bowel preparation.
6. Contraindication to study procedures, including MRI, anesthesia (ASA criteria IV and V), colonoscopy, and phlebotomy.
7. History of inflammatory bowel disease (Crohn's Disease, Ulcerative Colitis) Protocol: MS-BIOME Study.
8. Active symptomatic C. Difficile infection (colonization is not an exclusion).
9. Active gastrointestinal condition being investigated (i.e. GI bleeding, colon cancer, active GI workup); history of known or suspected toxic megacolon and/or known small bowel ileus, major gastrointestinal surgery (e.g. significant bowel resection) within 3 months before enrollment (note that this does not include appendectomy or cholecystectomy); or history of total colectomy or bariatric surgery.
10. History of malignancy (except excised cutaneous basal cell carcinoma or squamous cell carcinoma, which are allowable), including no concurrent induction chemotherapy, radiation therapy, or biological treatment for active malignancy.
11. Pregnant or lactating women or intention of getting pregnant during the trial period.
12. Active infection, including untreated latent or active tuberculosis, HIV, hepatitis, syphilis, or other major active infection.
13. Known immunodeficiency, including Common Variable Immunodeficiency (CVID).
14. INR\>1.5, Platelets\<100, Hemoglobin \<8.5, WBC\<2.0, Absolute lymphocyte count \<0.8, Absolute Neutrophil Count \<0.5, CD4\<200, eGFR\<45. \[INR: international normalized ratio, WBC: White Blood cell, CD4: cluster of differentiation 4, eGFR: epidermal growth factor receptor\]
15. Any condition that in the opinion of the study PI could jeopardize the safety of the participant, would make it unlikely for the participant to complete the study or could confound the results of the study.
16. Unable or unwilling to comply with study protocol requirements.