Norwegian Microbiota Study in Anorexia Nervosa (NORMA)

Gut Microbiota Alterations in Anorexia Nervosa - Paving the Way for Personalized Prebiotic Treatment Strategies

Anorexia nervosa (AN) is a serious mental disorder occurring mainly in women. AN is characterized by severely restricted food-intake and subsequent low weight. The disease burden for the individual is high with medical complications and psychiatric comorbidities. Despite decades of research, there are large gaps in the understanding of the biological aspects of AN and lack of effective interventions. Current clinical treatment is associated with gastrointestinal problems, high rates of relapse and poor outcome causing long-term sickness absence and disability. During the COVID19 pandemic the prevalence and severity of AN has spiked. Therefore, there is great need of novel strategies for AN treatment, that can be easily implemented in the clinic without adding complexity to the standard care of treatment. During the resent years it has been proposed that mental disorders might be treated via manipulating the composition and function of the microbes that live in the gut (the microbiota) by adding or restricting fermentable nutrients (prebiotics) in the diet. However, in order to use prebiotics to treat the microbiota in AN patients, more knowledge is needed on how the AN microbiota is affected by the current standard care treatment. Whether prebiotics can be useful for normalizing AN microbiota remains to be established. The overall aim of the "Norwegian study of Microbiota in Anorexia Nervosa" (NORMA) is to join forces of researchers, clinical health care services and voluntary sector in a transdiciplinary approach to improve the understanding of the role of the gut microbiota in AN patients. The current project will include a clinical trial in AN patients and experimental studies to screen novel prebiotics for their ability to modify and normalize AN derived microbiota. The long-term goal of the project is to pave the way for a targeted and clinically feasible individualized treatment for better tolerable weight-restoration and improved health in AN patients.

Study Overview

• Status: Recruiting
• Conditions: Anorexia Nervosa; Diet; Microbiota; Mental Health Issue; Gastrointestinal Problems
• Intervention / Treatment: Other: standard care treatment program

• Study Type: Observational
• Enrollment (Estimated): 180

Contacts and Locations

• Study Contact: Name: Siv K Bøhn, PhD; Phone Number: +47 67232502; Email: sivb@nmbu.no
• Study Contact Backup: Name: Øyvind Rø, PhD; Phone Number: +47 23016230; Email: oeyvro@ous-hf.no

Study Locations

• Norway
  • Ås, Norway, 1433
    • Recruiting
    • Norwegian University of Life Sciences
    • Contact: Siv Kjølsrud Bøhn, PhD; Email: sivb@nmbu.no
    • Contact: Ida Heir Hovland, MSc; Email: ida.heir.hovland@nmbu.no

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

The female patients with anorexia nervosa (AN) are undergoing specialized nutritional rehabilitation treatment and will be recruited from five Norwegian specialized inpatient treatment units for eating disorders. The standard care treatment consists of a program of psychotherapy and nutritional rehabilitation to achieve normalization of food-intake and weight gain. Although the clinical strategy of AN treatment is standardized, both the psychotherapy and dietary advices are individualized. The dietary advice during standard care treatment is based on clinical experience, as specific guidelines are lacking. Diets are adapted to each individual in aspects of tolerability and preferences, but typically comprise a high-energy diets aiming for a weekly weight gain of 0.5-1.5 kilograms. Often enteral nutrition (i.e., tube feeding) is required. The control group will be aged-matched female subjects with normal weight - mildly overweight.

Description

Inclusion Criteria AN group

1. Sex: Female
2. Age: 16-50 years
3. BMI: <18.5 kg/m2
4. fulfilling ICD-10 criteria for AN
5. currently referred to specialized inpatient nutritional treatment for AN
6. able to understand the Norwegian questionnaires.

Exclusion Criteria AND group:

1. history of inflammatory bowel disease, celiac disease, or GI tract surgery;
2. treatment with oral antibiotics the past two months
3. high intake of probiotic supplements over the past two months.

Inclusion criteria control group

1. Sex: Female
2. Age: 16-50 years
3. BMI: >= 18.5 & < 27
4. able to understand the Norwegian questionnaires.

Exclusion Criteria AND group:

1. history of inflammatory bowel disease, celiac disease, or GI tract surgery;
2. treatment with oral antibiotics the past two months
3. high intake of probiotic supplements over the past two months.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Anorexia nervosa (AN) group; Female in-patients with anorexia nervosa, age 16-50 years with BMI below 18.5 kg/m2.	Other: standard care treatment program; The standard care treatment consists of a program of psychotherapy and nutritional rehabilitation to achieve normalization of food-intake and weight gain.
Heathy control (HC) group; Female healthy controls, age 16-50 with normal to mild overweight (18.5 ≤ BMI< 27 kg/m2). .

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Differences in the fecal microbiota composition	Comparison of fecal microbial composition between the patients with anorexia nervosa and healthy controls. We will compare different indices of α-diversity - investigating both richness and evenness (e.g. observed number of OTUs, Chao1, Shannon-Wiener, Simpson, and PD whole tree) and different indices of β-diversity (e.g. binary Jaccard, Bray-Curtis, and weighted Unifrac). Also differences in bacterial abundances at various taxonomic levels (phylum, class, order, family, and genus) will be investigated.	Cross-sectional study with only one time point. For AN-group; the baseline sample is delivered during the last week before start of clinical treatment. ]
Change in the fecal microbiota composition in patients with anorexia nervosa during the standard care treatment at the clinics for eating disorder.	Mixed model analyses will be performed to assess whether the standard care treatment at the clinics for eating disorder induce changes in the fecal microbiota composition. Both diversity measures ( α-diversity and β-diversity) and bacterial abundances at various taxonomic levels (phylum, class, order, family, and genus) will be investigated.	One group time-series design. Samples will be taken at baseline (~one week before admission to the clinic) and at ~6 weeks and ~12 weeks.
Change in mental scores during standard care treatment at the clinics for eating disorder	Mixed model analyses will be performed to assess whether the standard care treatment at the clinics for eating disorder induce changes in mental scores. Effects of time will be investigated in the AN group only. Mental scores will be assessed using digital questionnaires.	One group time-series design. Data will be collected at baseline, at admission to the clinic and at ~6 weeks and ~12 weeks.
Change in gastrointestinal problems during standard care treatment at the clinics for eating disorder	Mixed model analyses will be performed to assess whether the standard care treatment at the clinics for eating disorder induce changes in gastrointestinal problems. Effects of time will be investigated in the AN group only. Scores for gastrointestinal problems will be assessed using digital questionnaires.	One group time-series design. Data will be collected at baseline, at admission to the clinic and at ~6 weeks and ~12 weeks.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Associations between microbiota measures (diversity and abundance of specific species), serum biomarkers, dietary charachteristics, gastrointestinal issues and mental issues.	Associations between multiple variables will be investigated in both AN group (at baseline, 6 weeks and 12 weeks) and HC group at baseline using unsupervised learning algorithm techniques such as Principal Component Analysis and hireachical clustering techniques. Microbiota is charachterized as described under outcome 1, serum biomarkers include standard clinical biomarkers and biomarkers of inflammation and microbiota relevant biomarkers. Data on dietary charachteristics, gastrointestinal issues and mental issues are obtained by digital questionnaires.	Cross-sectional study with only one time point. For AN-group; the baseline sample is delivered during the last week before start of clinical treatment. ]
Associations between baseline microbiota composition and changes in gastrointestinal complaints during the standard care treatment at the clinics for eating disorder.	Associations between microbiota measures at baseline and changes in gastrointestinal complaint sduring the standard care treatment at the clinics for eating disorder will be investigated by unsupervised learning algorithm techniques such as Principal Component Analysis and by applying hireachical clustering techniques on correlation measures. Microbiota will be charachterized as described under outcome 1, serum biomarkers include standard clinical biomarkers and biomarkers of inflammation and microbiota relevant biomarkers. Data on dietary charachteristics, gastrointestinal issues and mental issues are obtained by digital questionnaires.	One group time-series design. Samples, data will be obtained at baseline (~one week before admission to the clinic) and at ~6 weeks and ~12 weeks.
Associations between baseline microbiota composition and changes in mental scores during the standard care treatment at the clinics for eating disorder.	Associations between microbiota measures at baseline and changes in mental scores during the standard care treatment at the clinics for eating disorder will be investigated by unsupervised learning algorithm techniques such as Principal Component Analysis and by applying hireachical clustering techniques on correlation measures. Microbiota will be charachterized as described under outcome 1, serum biomarkers include standard clinical biomarkers and biomarkers of inflammation and microbiota relevant biomarkers. Data on dietary charachteristics, gastrointestinal issues and mental issues are obtained by digital questionnaires.	One group time-series design. Samples, data will be obtained at baseline (~one week before admission to the clinic) and at ~6 weeks and ~12 weeks.

Collaborators and Investigators

• Sponsor: Norwegian University of Life Sciences
• Collaborators: Karolinska Institutet; Oslo University Hospital; Haukeland University Hospital; Helse Nord-Trøndelag HF; Nordlandssykehuset HF; Modum Bad; The Eating disorder Association, Norway (SPISFO); Counseling on eating disorders, Norway (ROS)
• Investigators: Principal Investigator: Siv K Bøhn, PhD, Norwegian University of Life Sciences

Study record dates

Study Major Dates

• Study Start (Actual): September 24, 2023
• Primary Completion (Estimated): September 1, 2025
• Study Completion (Estimated): September 1, 2043

Study Registration Dates

• First Submitted: September 22, 2023
• First Submitted That Met QC Criteria: November 17, 2023
• First Posted (Actual): November 22, 2023

Study Record Updates

• Last Update Posted (Actual): May 23, 2025
• Last Update Submitted That Met QC Criteria: May 20, 2025
• Last Verified: May 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Mental Disorders; Signs and Symptoms, Digestive; Feeding and Eating Disorders; Anorexia; Anorexia Nervosa
• Other Study ID Numbers: 336239_KBM_SKB2023

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

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