An interventional study of Fecal Microbiota Transplantation Capsule and Placebo Capsule(s) in Anorexia Nervosa, sponsored by Andreas Munk Petersen. Not yet recruiting at 2 sites in Denmark. Open to female participants aged 15 Years and older. Per ClinicalTrials.gov, last updated 2026-10-16.
Sponsored by Andreas Munk Petersen · Not applicable, Interventional, and Treatment
The goal of this clinical trial is to learn whether fecal microbiota transplantation (FMT) can change the gut microbiome and improve health outcomes in females with anorexia nervosa. FMT involves transferring microorganisms from the stool of a carefully screened healthy donor to the intestine of another person. In this study, FMT will be given as capsules that are swallowed by the participants.
The main questions the study aims to answer are:
Researchers will compare FMT capsules with placebo capsules to see whether FMT affects the gut microbiome, gastrointestinal function, and symptoms related to anorexia nervosa. Placebo capsules are similar to the FMT capsules but do not contain donor fecal material.
Participants will:
Neither the participants nor the study staff will know which treatment is being given during each treatment period. The study will include females aged 15 years or older with anorexia nervosa.
The study will help researchers better understand the relationship between the gut microbiome and anorexia nervosa and whether changing the gut microbiome with FMT could potentially be a future treatment approach.
Anorexia nervosa (AN) is a severe psychiatric disorder with high morbidity and limited effective treatment options. Emerging evidence suggests persistent gut microbiota (GM) dysbiosis in AN, potentially contributing to gastrointestinal symptoms, appetite dysregulation, and maintenance of the disorder via the gut-brain axis. While preliminary animal studies and human feasibility trials indicate that fecal microbiota transplantation (FMT) can induce biologically relevant GM shifts, no randomized controlled trials have evaluated repeated FMT in patients with AN.
Aim: To determine whether repeated oral FMT induces sustained changes in GM composition and improves clinical outcomes in adolescents and adults with AN.
Subjects and Methods: AN-SHIFT is a randomized, double-blind, placebo-controlled crossover study enrolling 60-80 female participants aged ≥15 years with AN defined by Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). Participants receive five weekly oral FMT treatments and five weekly placebo treatments in alternating sequence. Fecal and blood samples, gut-transit-time, toilet frequency and psychometric assessments are collected at baseline, during intervention, and at 3-month follow-up. The primary outcome is within-subject change in GM composition and donor-strain engraftment assessed by shotgun metagenomic sequencing. Secondary outcomes include, gut-transit-time alterations, eating disorder symptoms, gastrointestinal symptoms, appetite- and mood-related biomarkers, and their associations with GM changes. All participants will during the trial receive FMT either before or after placebo, and standard clinical care continues throughout the study period.
Perspectives: This study evaluates a biologically informed, low-risk intervention targeting a potential mechanism to alleviate comorbidities associated with AN in patients with AN. The findings will provide critical evidence on feasibility, safety, and biological efficacy and will inform future microbiome-based treatment strategies.
462 studies on the registry are indexed under Anorexia Nervosa; 127 are open to participants now.
This study's planned enrollment of 60 is above the median of 43 across 311 interventional studies indexed under Anorexia Nervosa.
Browse Anorexia Nervosa studies →Andreas Munk Petersen is the lead sponsor of 2 studies on the registry; 2 are open to participants now.
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Exclusion Criteria:
FMT week 1-5 → placebo week 6-10
Biological: Fecal Microbiota Transplantation Capsule · Other: Placebo Capsule(s)
Placebo week 1-5 → FMT week 6-10
Biological: Fecal Microbiota Transplantation Capsule · Other: Placebo Capsule(s)
Fecal microbiota transplantation (FMT) will be administered orally as capsules containing fecal material from carefully screened healthy donors. Participants will receive five weekly FMT treatments during the FMT treatment period. The FMT capsules will be prepared according to the study protocol and administered under the supervision of the study team.
Placebo capsules (low calorie) are made from saline containing 5% (v/v) glycerol, cornstarch and food coloring (food coloring E150).
Change in Gut Microbiome Composition (T0-T1)
The primary endpoint is defined as the change in GM composition from baseline (T0) to week 5 (T1), comparing participants randomized to receive FMT during the first treatment period with those randomized to receive placebo during the first treatment period. Microbiome compositions will be assessed using shotgun metagenomic sequencing of stool samples collected at T0 and T1. Global microbiome restructuring will be quantified using pre-specified compositional distance metrics based on centered log-ratio (CLR) transformed abundance data (e.g., Aitchison distance). In addition, the recipient microbiome distance to the assigned donor microbiome will be calculated to quantify movement toward donor composition following treatment. The primary analysis will estimate the difference between-group in microbiome compositional change and donor-recipient distance reduction during the first 5-week treatment period.
Time frame: Baseline (T0) - After first 5 weeks (T1)
Gut-/appetite-related clinical effects (T0-T1)
Change from baseline to week 5 in gastrointestinal and appetite-related symptoms, including: Self-reported BMI, gastrointestinal symptom burden, transit time, stool consistency and frequency, appetite and satiety-related biomarkers in serum, and food intake changes.
Time frame: Baseline (T0) - After first 5 weeks (T1)
Eating-disorder symptom severity (T0-T1)
Change in eating-disorder symptom severity from baseline compared to placebo using validated eating-disorder questionnaires
Time frame: Baseline (T0) - After first 5 weeks (T1)
Change in eating-disorder symptom severity from baseline (T0) to the 3-month follow-up (T3)
A secondary longer-term endpoint evaluates change in eating-disorder symptom severity from baseline (T0) to the 3-month follow-up (T3) using validated eating-disorder questionnaires. Because all participants receive FMT during the crossover study design, this outcome is not placebo-controlled and is therefore considered secondary and exploratory. It will determine whether microbiome restructuring, and gut-related clinical changes are associated with changes in eating-disorder symptoms from the participant's own baseline.
Time frame: From baseline (T0) to to the 3-month follow-up (T3)
Plan to share: No — Individual participant data will not be shared with other researchers because of data protection and privacy considerations. The study data will be handled and analyzed by the authorized researchers involved in the study in accordance with applicable data protection regulations.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Studies of the drug tested here: Fecal Microbiota Transplantation Capsule
Andreas Munk Petersen