Skip to main content
OpenTrials
Recruiting

NCT Number: NCT07143981

The Fecal Microbiome Transplant (FMT) Study for Anorexia Nervosa

Anorexia Nervosa (AN) is a severe, debilitating and potentially life threatening illness that is difficult to treat. A cardinal symptom of AN is the mistaken belief on the part of the individuals that they are overweight and must continue to restrict intake. This fixed false belief is a detrimental factor to recovery. It is known that AN involves disturbance in the gut microbiome (GM; the microbes that live in the lower intestinal tract). The GM also affects how one thinks and makes food choices - there appears to be a direct link between the GM and how the brain functions. This connection is thought to occur through chemical processes that convey information from the gut to the brain. It is known that fecal microbiome transplant (FMT) has been useful in treating several illnesses, including several mental illnesses. The investigators intend to deliver FMT to individuals with AN to determine the extent to which this modifies their GM, their biochemistry, their thinking processes and their moods and emotions. The investigators believe this will illuminate important aspects of AN that keep the illness in place, and that this will uncover useful approaches to better treat it.

Recruiting

Interested in participating?

Request Info

Key information

Conditions

Anorexia Nervosa Behavior Feeding and Eating Disorders Mental Disorders Pathological Conditions, Signs and Symptoms Personal Satisfaction Psychological Well-Being Signs and Symptoms Signs and Symptoms, Digestive

Age range

16 year–35 year

Sex eligibility

All sexes

Study type

Observational

Primary location

London Health Sciences Research Institute

London, Ontario, N6J 1A2, Canada

Location status: Recruiting

Location contact

Beth Osuch

CONTACT

[email protected]

519-685-8500 ext. 65188

About this study

The overall objective is to determine FMT's acceptability and the extent and means by which it helps patients with AN, restricting type. The investigators hypothesize that FMT will lead to diversification of the GM, improved metabolic and immunological status and reduced cognitive and psychiatric symptoms in patients with AN, details never investigated before. This will be due to FMT's ability to impart healthy microorganisms into the lower intestines and, thereby, improve GBM-axis signaling that may contribute to maintaining AN. The investigators propose that this will result in measurable improvement in cognitive distortions about weight, leading to reduced AN symptomatology, breaking the weight loss/AN cycle.

Specific Aims & Hypotheses

This is a one-group, pre-/post-intervention trial of FMT in AN-restricting type, with 1-week, 3-week and 3-month follow up, administered before specialized eating disorders treatment. The hypotheses are:

  • FMT will result in a sustained increase diversity of microbes with the metabolomic characteristics of increased short-chain fatty acids and bacteriophage composition compared with pre-treatment, as determined by targeted metabolomic approaches.
  • FMT will improve immune profiles, reducing IL6, IL1b and the proportion of Th17 cells, along with an increase in repair cytokines such as TARC, IL4, IL13 and BDNF and Th2 cells.
  • FMT will significantly improve cognitive and affective functioning, including task-switching efficiency, food aversion and obsessional thinking about weight, punishment and reward sensitivity, depression and anxiety symptomatology, and AN symptom severity.

This is a prospective, longitudinal, single-arm, pre-post intervention. Variables will be compared using repeated-measures analyses with each participant as their own comparator.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • meet DSM 5 criteria for AN, restricting type, moderate or higher severity, as indicated by a BMI<17
  • Participants must we willing and able to swallow FMT capsules without vomiting
  • Able to read and understand conversational English

Exclusion criteria

  • Medical or psychiatric instability needing hospitalization
  • Patients with AN binge/purge type
  • Use of antibiotics or probiotics in the month prior to treatment
  • Regular oral steroid use, or potent topical steroid use on large sections of skin
  • Chronic immune compromise and chronic illness affecting the intestinal tract or metabolic health
  • Pregnancy or intended pregnancy over the time of study
  • Patients enrolled in any treatment program that involves refeeding

Treatment and study plan

Primary outcomes

  1. Feasibility of Intervention

    Time frame: 1, 3, and 12 weeks post intervention

    Success will be evaluated using recruitment and retention rates, adverse event rates, and missing data rates. Scores at 75% or above will indicate high tolerability for this population that is in desperate need of additional intervention options.

Secondary outcomes

  1. Shannon's Diversity Index

    Time frame: Pre-intervention, 12 weeks post-intervention

    Metric of microbiome diversity that considers richness of number of species and abundance. Higher values indicate more diversity. A value of 0 indicates that a community only has one species.

  2. Activated blood cells producing Th17/Th2 cytokines

    Time frame: Pre-intervention, and 12-weeks post intervention

    Activated blood cells producing Th17/Th2 cytokines by Luminex - IL6, IL1b, IL17, IL4, IL13 to evaluate immune responses.

  3. Activated blood cells producing BDNF

    Time frame: Pre-intervention and 12-weeks post-intervention

    Activated blood cells producing BDNF measured by Enzyme-Linked Immunosorbent Assay (ELISA)

  4. RNA levels

    Time frame: Pre-intervention and 12-weeks post-intervention

    RT-PCR (reverse transcription-polymerase chain reaction) for RNA levels of CCR6, CRTh2, CCR4, CXCR5 (marker genes for Th17 and Th2 cells)

  5. Task-switching Efficiency

    Time frame: Pre-intervention, and 12 weeks post-intervention

    -Task-switching efficiency measured using the Cued Color-Shape Switching Task, CCSST. Accuracy and response time will be computed on both single-task blocks and mixed task blocks, where participants will need to switch between colour and shape responses. Switch costs and mixing costs will be calculated from these scores.

  6. Punishment sensitivity and reward sensitivity

    Time frame: Pre-intervention and 12-weeks post-intervention

    Punishment sensitivity and reward sensitivity using the Behavioural Inhibition System/Behavioural Activation System Scales (BIS/BAS). There are three BAS scales in which higher scores equate to greater sensitivity to reward. There is one BIS scale for which higher scores equate to greater sensitivity to punishment.

  7. Depression

    Time frame: Pre-intervention, and at 1-, 3-, 12-weeks post intervention

    Depression evaluated using the Montgomery Asberg Depression Rating Scale (MADRS). It is a 9-item scale where higher score indicates more severe depressive symptoms.

  8. Depression

    Time frame: Pre-intervention, and at 1-, 3-, 12-weeks post intervention

    Depression assessed with the Patient Health Questionnaire (PHQ-9), a 9-item scale evaluating the severity of depressive symptoms. Higher scores indicate more severe symptomatology.

  9. Anxiety

    Time frame: Pre-intervention, and at 1-, 3-, 12-weeks post intervention

    Anxiety assessed using the Spielberger State/Trait Anxiety Inventory (STAI)

  10. Anxiety

    Time frame: Pre-intervention, and at 1-, 3-, 12-weeks post intervention

    Anxiety assessed by the Generalized Anxiety Disorder 7-item scale (GAD-7)

  11. Eating Attitudes

    Time frame: Pre-intervention, and 1-, 3-, 12-weeks post intervention

    -Food aversion and obsessional thinking about weight using the Eating Attitudes Test (EAT-26)

  12. Anorexia Nervosa Symptoms

    Time frame: Pre-intervention, and at 1-, 3-, 12-weeks post intervention

    AN symptom severity with the Eating Disorders Examination Questionnaire (EDE-Q)

Study contacts

Contact information is provided by the study sponsor or research team.

Medina Meddaoui

CONTACT

[email protected]

Michael Wammes

CONTACT

[email protected]

519-646-6000 ext. 65196

Sponsors and collaborators

Lead sponsor

London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's

Other

Collaborators

  • Western University, Canada

Registry information

Official study title

Fecal Microbiome Transplant to Normalize Gut Microbiota, Metabolomics, Immunology, Cognitive and Affective Processing in Patients Suffering From Anorexia Nervosa

Important dates

Study start
2026
Primary completion
2026
Study completion
2027
First posted
Aug 27, 2025
Registry last updated
Jan 23, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.