Fecal Microbiota Transplantation for the Treatment of Diarrhea-Predominant Irritable Bowel Syndrome

The objectives of this study are (1) to determine the efficacy of fecal microbiota transplantation (FMT), given as oral capsules, compared with placebo for the treatment of refractory diarrhea-predominant irritable bowel syndrome (IBS-D); (2) determine the impact of FMT on the intestinal microbiome of patients with IBS-D; and (3) assess the safety, feasibility, and tolerability of FMT for patients with IBS-D.

This is a multicenter study including Montefiore Medical Center, Concorde Medical Group PLLC and the Medical Research Center of Connecticut/Yale-New Haven Hospital Langone Medical Center. Patients with IBS-D will be recruited from outpatient gastroenterology clinics at these institutions and referrals from the medical community.

FMT capsules and placebo capsules, provided by OpenBiome, Medford, MA, will be used for this study. Patients will be randomized to undergo FMT using fecal capsules (experimental group) or placebo capsules (control group) via a computer-generated program. All patients will cross-over into the alternate arm of the study at 12 weeks. Therefore, all patients enrolled will receive the experimental drug during the course of the study. Each patient will be enrolled in the study for a total of 6 months.

Intestinal microbiome analyses using DNA sequencing and non-cultivation-based approaches (16S DNA technology) will be performed in all patients in the experimental and control groups to assess stability of the microbiome over time.

Eligibility Criteria:
Inclusion Criteria:

* age 19-65 years
* established diagnosis of IBS-D as determined by Rome III Criteria
* moderate-severe disease activity (as determined by an IBS-Symptom Severity Score ≥175)
* persistent symptoms despite conventional therapy
* normal colonoscopy with biopsies in the past for work-up of IBS symptoms
* negative work-up for celiac disease either by duodenal biopsies or negative serologies

Exclusion Criteria:

* pregnancy
* nursing
* cognitive impairment or severe neuropsychiatric comorbidities who are incapable of providing their own informed consent
* severely immunocompromised or immunosuppressed patients (e.g., organ transplant recipients, severe neutropenia with an absolute neutrophil count of \<500cells/mL, current treatment or treatment within 3 months with anti-neoplastic agents and HIV-positive patients with CD4 counts \<200cells/mm\^3)
* treated with any antibiotics in the 3 months prior to FMT
* GI symptoms can be explained by the presence of an underlying organic disease including, underlying inflammatory bowel disease, infectious enteritis, previously established and untreated small intestinal bacterial overgrowth or known motility disorder
* previous FMT
* severe (anaphylactic) food allergy
* unable to comply with protocol requirements
* American Society of Anesthesiologists (ASA) Physical Status classification IV and V
* acute illness or fever on the day of planned FMT will be excluded (not randomized) with the option of including that subject at a future date
* new antidepressant started or dose of antidepressant change \<3 months prior to enrollment
* elevated ESR or CRP within the past 3 months
* baseline laboratory abnormalities on CBC, chemistry or liver tests
* pain score \>75 on IBS-SSS