Norwegian Microbiota Study in Anorexia Nervosa

Study Overview
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Brief Summary
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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.

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

Conditions
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Anorexia Nervosa, Mental Health Issue, Microbiota, Diet, Gastrointestinal Problems

Intervention / Treatment
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* Other: standard care treatment program


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria AN group Sex: Female Age: 16-50 years BMI: <18.5 kg/m2 fulfilling ICD-10 criteria for AN currently referred to specialized inpatient nutritional treatment for AN able to understand the Norwegian questionnaires. Exclusion Criteria AND group: history of inflammatory bowel disease, celiac disease, or GI tract surgery; treatment with oral antibiotics the past two months high intake of probiotic supplements over the past two months. Inclusion criteria control group Sex: Female Age: 16-50 years BMI: >= 18.5 & < 27 able to understand the Norwegian questionnaires. Exclusion Criteria AND group: history of inflammatory bowel disease, celiac disease, or GI tract surgery; treatment with oral antibiotics the past two months high intake of probiotic supplements over the past two months.

Ages Eligible for Study
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Minimum Age: 16 Years
Maximum Age: 50 Years

Sexes Eligible for Study
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Female

Study Plan
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How is the study designed?
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Arms and Interventions

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

What is the study measuring?
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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. |