Fecal Microbiota Transplant for Anorexia Nervosa (FMT-AN)

A Pilot Feasibility Randomized Controlled Trial of Fecal Microbiota Transplant for Adolescent Anorexia Nervosa

The purpose of this pilot randomized-controlled trial is to determine whether Fecal Microbiota Transplant (FMT) treatment demonstrates feasibility, acceptability, and prelinary effectiveness among patients with anorexia nervosa (AN). Specifically, the investigators aim to compare changes in weight, gut microbiome, urine, blood biomarkers and mood symptoms between participants receiving the FMT intervention and placebo.

Study Overview

• Status: Not yet recruiting
• Conditions: Anorexia Nervosa; Anorexia; Anorexia in Adolescence; Anorexia Nervosa Restricting Type; Anorexia in Children
• Intervention / Treatment: Biological: Fecal Microbiota Transplant; Drug: Placebo

Detailed Description

In the following pilot randomized-controlled trial, the investigators' aim is to determine whether FMT treatment demonstrates feasibility, acceptability, and preliminary effectiveness in pediatric AN participants. The investigators will assess how the use of FMT affects participants' rate of weight restoration, gut microbiome, relevant urine and blood biomarkers, and mood symptoms. The investigators' rationale for performing the study is to better understand the interactions between the intestinal microbiome, energy regulation, and behavior. This will be the first study to assess the role of FMT in pediatric AN and will help establish whether this adjunctive treatment modality has benefit in managing the metabolic and behavioral manifestations of this complex neuropsychiatric disorder.

In terms of study procedures, members of a pilot sample of 20 AN patients recruited from McMaster Children's Hospital will be randomized to receive FMT or placebo. All participants will be asked to complete a battery of assessments at regular intervals over the 8-week intervention period, and at a follow-up point at four weeks post-intervention.

The study's primary outcomes are recruitment and retention rates. Descriptive statistics will be used to determine the number of adolescents who will agree to participate in the study and those who will complete the study.

One of the study's secondary outcomes is participants' attitudes toward FMT. This will be measured through qualitative interviews among those who completed the intervention and those who do not agree to participate in the study.

The investigators will know we have reached saturation by using a method called "information power" and will explore how broad the research questions are, if there are clear theories to guide the analysis, how varied the participants in the study are, and how much useful information is accrued. Based on this, the investigators will determine the appropriate number of interviews to lead.

The remaining secondary outcome is a battery of preliminary outcomes (clinical, biological, biochemical and safety). The investigators will assess these outcomes at multiple timepoints using questionnaires, anthropometric data, stool analysis (16s rRNA), urine metabolic analysis, saliva ultra filtrates, changes in blood work, and common terminology criteria for adverse events for safety outcomes.

• Study Type: Interventional
• Enrollment (Estimated): 20
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Nikhil Pai, MD; Phone Number: 73587 905-521-2100; Email: pain@mcmaster.ca
• Study Contact Backup: Name: Jennifer L Couturier, MD, MSc; Phone Number: 76035 905-521-2100; Email: coutur@mcmaster.ca

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria: All study subjects will have been diagnosed with AN (restricting type or binge eating/purging type) by the primary physician on the ED team, as per standard approach. Study participants will:

• Be 12-17 years-old at time of recruitment
• Have capacity to consent
• Be assigned female sex at birth (may be gender diverse)
• Be active patients in the pediatric ED program at MCH
• Have a weight that is <85% of the Treatment Goal Weight, as determined by the treating physician

Exclusion Criteria: Potential study subjects will be excluded due to the following reasons:

• Exposure to antibiotics within two weeks of study randomization
• Initiation of new probiotics / oral nutritional supplements within two weeks of randomization
• Active pregnancy
• Active psychosis or suicidal ideation
• Other comorbidities that may affect weight or the gut microbiome including celiac disease, inflammatory bowel disease (or other conditions as determined by the study team)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Fecal Microbiota Transplant; Banked donor stools that have been previously screened, prepared and frozen per previous protocols will be used to prepare all oral FMT capsules (OFC) through the laboratory of a collaborator. Recipients will receive OFC (two capsules, twice a day, twice per week) prepared from a single donor throughout their 8-week treatment course, to support assessment of FMT engraftment in recipients; this totals to 64 capsules across the duration of the study. Each OFC will contain approximately 15.0g of dried healthy donor stool contained within a size 00 gelatin capsule.	Biological: Fecal Microbiota Transplant; An investigational biologic comprised of 15.0g of dried healthy donor stool contained within a size 00 gelatin capsule, to be taken twice per day, twice per week over an 8-week duration.
Placebo Comparator: Placebo; Matching oral placebo capsules (OPC) containing methylcellulose will be identical in terms of size, colour, taste, and dosing. Participants will be asked to take the Placebo treatment capsules twice a day for two days per week for a duration of eight weeks (total 64 capsules).	Drug: Placebo; Oral placebo capsules (OPC) containing methylcellulose, to be taken twice per day, twice per week over an 8-week duration.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Recruitment Rate	The number of participants who are consented into the study divided by the number of participants who show interest in the study.	Through study completion, an average of one year.
Retention Rate	The number of participants who completed the study divided by the number of participants consented into the study.	Through study completion, an average of one year.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Attitudes towards Fecal Microbiota Transplant	Attitudes towards FMT will be studied via semi-structured qualitative interviews of all participants: the 20 adolescents and their parents in the trial, and the 10 adolescents and their parents who decline participation, and their guardians. Using Qualitative Description, interviews will explore patient and guardian attitudes toward FMT, as well as their impressions of efficacy (if they participated in the trial). Questions will include perceptions of "natural" versus "drug" products, perspectives on causes of AN, and interests in other potential treatments. Interviews will be conducted virtually, using Zoom for Healthcare, transcribed verbatim and then coded for themes using NVivo. This analysis stays close to the data with little to no interpretation. Our analysis will also include a summative content analysis.	Week 12 (follow-up)
Height	Height will be collected.	Week 0 (baseline), Week 4 (mid-treatment), Week 8 (post-intervention), Week 12 (follow-up)
Weight	Weight will be measured between hospital visits using home weight scales provided to study participants.	Week 0 (baseline), Week 2, Week 4 (mid-treatment), Week 6, Week 8 (post-intervention), Week 10, Week 12 (follow-up)
Eating Disorder Examination Questionnaire	The EDEQ is a 28-item standardized questionnaire that measures the severity of symptoms of eating disorders, including menstrual status.	Week 0 (baseline), Week 4 (mid-treatment), Week 8 (post-intervention), Week 12 (follow-up)
Beck Depression Inventory	The BDI is a 21-item questionnaire used to measure the severity of depressive symptoms.	Week 0 (baseline), Week 4 (mid-treatment), Week 8 (post-intervention), Week 12 (follow-up)
Beck Anxiety Inventory	The BAI is a 21-item questionnaire used to measure the severity of anxiety symptoms.	Week 0 (baseline), Week 4 (mid-treatment), Week 8 (post-intervention), Week 12 (follow-up)
Yale-Brown-Cornell Eating Disorder Scale	The YBC-EDS assesses impairment, persistence and degree of obsessional thinking and compulsiveness about eating behaviors.	Week 0 (baseline), Week 4 (mid-treatment), Week 8 (post-intervention), Week 12 (follow-up)
Gastrointestinal Symptom Rating Scale	This is a 15-item rating scale to capture a variety of GI symptoms.	Week 0 (baseline), Week 4 (mid-treatment), Week 8 (post-intervention), Week 12 (follow-up)
Changes in stool metabolites	Stool will be collected in to examine changes in alpha- and beta- diversity of microbiota, as well as engraftment of donor specific strains/genes and microbially-derived metabolite levels throughout the study. All stool samples will be collected using an at-home collection kit. Samples will be collected and stored in locked, secure -80°C study freezers upon being brought to the hospital or shipped by paid courier by participants. Stool samples will be sequenced for 16s rRNA gene profiling. All 16s rRNA analyses will be performed using in-house bioinformatics pipelines through the laboratory of a collaborator to identify amplicon sequence variants, perform taxonomic assignments, and analyze alpha- and beta-diversity and differential taxonomic abundance.	Week 0 (baseline), Week 4 (mid-treatment), Week 8 (post-intervention), Week 12 (follow-up)
Changes in urine metabolomics	Urine samples will be collected from each participant. Nontargeted metabolite profiling is a method used to explore and identify as many metabolites as possible in a sample to identify whatever is present. This approach is designed to help discover new metabolites, and identify changes in metabolite levels that may correlate with other outcomes. We will report differences in highest-abundance metabolites using t-tests to compare their presence between groups, and correlation coefficients to identify associations between outcomes.	Week 0 (baseline), Week 4 (mid-treatment), Week 8 (post-intervention), Week 12 (follow-up)
Changes in saliva ultrafiltrates	Saliva samples will be collected for metabolomic analysis. Saliva ultrafiltrates will be analyzed as described above for stool and urine samples by a collaborator. All saliva ultrafiltrates will be reported using the same multisegment injection-capillary electrophoresis-mass spectrometer, where metabolites are reported using effect sizes to compare relative concentrations against reference standards.	Week 0 (baseline), Week 4 (mid-treatment), Week 8 (post-intervention), Week 12 (follow-up)
Changes in complete blood count	Using the provided blood samples, changes in complete blood count from baseline to post-intervention will be compared using paired t-tests. The complete blood count includes (with their measurement units): Red blood count (RBC)- cells/L Hemoglobin (Hb)- g/L Hematocrit- L/L Mean corpuscular volume (MCV)- fL Mean Corpuscular Hemoglobin (MCH)- pg Mean corpuscular hemoglobin concentration (MCHC)- g/L Red cell distribution width (RDW)- % White blood count (WBC) - cells/L Neutrophils - cells/L Lymphocytes - cells/L Eosinophils - cells/L Basophils - cells/L Monocytes - cells/L	Week 0 (baseline), Week 8 (post-intervention)
Changes in C-reactive protein	Using the provided blood samples, changes in C-reactive protein (CRP) from baseline to post-intervention will be compared using paired t-tests. CRP (measured in mg/L) is used to monitor inflammation in acute or chronic conditions.	Week 0 (baseline), Week 8 (post-intervention)
Changes in alkaline phosphatase	Using the provided blood samples, changes in alkaline phosphatase (ALP) from baseline to post-intervention will be compared using paired t-tests. ALP (measured in U/L) is associated with liver function.	Week 0 (baseline), Week 8 (post-intervention)
Changes in alanine aminotransferase	Using the provided blood samples, changes in alanine aminotransferase (ALT) from baseline to post-intervention will be compared using paired t-tests. ALT (measured in U/L) is associated with liver function.	Week 0 (baseline), Week 8 (post-intervention)
Changes in 25-OH Vitamin D	Using the provided blood samples, changes in 25-OH Vitamin D from baseline to post-intervention will be compared using paired t-tests. 25-OH Vitamin D (measured in ng/ml) is used as a measure of Vitamin D levels.	Week 0 (baseline), Week 8 (post-intervention)
Changes in albumin	Using the provided blood samples, changes in albumin from baseline to post-intervention will be compared using paired t-tests. Albumin (measured in g/L) is associated with liver and kidney function.	Week 0 (baseline), Week 8 (post-intervention)
Changes in follicle stimulating hormone	Using the provided blood samples, changes in follicle stimulating hormone (FSH) from baseline to post-intervention will be compared using paired t-tests. FSH (measured in mIU/mL) is important for determining aspects of fertility and menstruation.	Week 0 (baseline), Week 8 (post-intervention)
Changes in luteinizing hormone	Using the provided blood samples, changes in luteinizing hormone (LH) from baseline to post-intervention will be compared using paired t-tests. LH (measured in IU/L) is important for determining aspects of fertility and menstruation.	Week 0 (baseline), Week 8 (post-intervention)
Changes in free testosterone	Using the provided blood samples, changes in free testosterone from baseline to post-intervention will be compared using paired t-tests. Free testosterone (measured in nmol/L) is important for assessing various bodily functions related to hormones.	Week 0 (baseline), Week 8 (post-intervention)
Presence of safety outcomes	Common Terminology Criteria for Adverse Events (CTCAE) will be used to define adverse events and serious adverse events. This framework will be used to classify broad safety concerns throughout our trial.	Through study completion, an average of one year.

Collaborators and Investigators

• Sponsor: Hamilton Health Sciences Corporation
• Collaborators: McMaster University; Hamilton Academic Health Sciences Organization
• Investigators: Principal Investigator: Jennifer L Couturier, MD, MSc, Hamilton Health Sciences Corporation

Publications and helpful links

General Publications

• Couturier J, Kenner E, Nicula M, Chowdhury F, Surette M, Pai N. Protocol for a pilot feasibility randomised controlled trial of fecal microbiota transplantation for adolescent anorexia nervosa. BMJ Open. 2026 Apr 20;16(4):e109115. doi: 10.1136/bmjopen-2025-109115.

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): June 1, 2027
• Study Completion (Estimated): June 1, 2027

Study Registration Dates

• First Submitted: July 26, 2024
• First Submitted That Met QC Criteria: September 9, 2024
• First Posted (Actual): September 19, 2024

Study Record Updates

• Last Update Posted (Actual): May 27, 2026
• Last Update Submitted That Met QC Criteria: May 22, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: randomized controlled trial; feasibility; pilot study; anorexia nervosa; fecal microbiota transplant
• Additional Relevant MeSH Terms: Mental Disorders; Signs and Symptoms, Digestive; Feeding and Eating Disorders; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Anorexia; Anorexia Nervosa; Therapeutics; Biological Therapy; Fecal Microbiota Transplantation
• Other Study ID Numbers: FMTAN

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: There is no current plan to share individual participant data to other researchers.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No