Comparing Two Types of Diets on Psychological and Gastrointestinal Symptoms

Study Overview
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Brief Summary
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This pilot study proposes to gain a better understanding of the health benefits of the popular paleo-diet in patients with irritable bowel syndrome (IBS) and explore underlying mechanisms of benefit.

Detailed Description
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In the proposed study, the primary hypothesis is that, compared with a customary diet, consumption of a paleo-diet will improve psychological and gastrointestinal symptoms in patients with irritable bowel syndrome. Investigators also hypothesize consumption of the Paleolithic diet will result in decreased intestinal permeability, decreased inflammatory markers, and changes in the gut microbiome and microbiologic profiles.

Official Title
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A Randomized Trial Comparing Two Types of Diets on Psychological and Gastrointestinal Symptoms

Conditions
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Irritable Bowel Syndrome

Intervention / Treatment
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* Other: Paleolithic diet
* Other: General Healthful Diet


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with mild to moderate Irritable Bowel Syndrome (IBS) and mild to moderate anxiety or depression Other causes of bowel symptoms excluded to the satisfaction of the Study Team Age at least 18 years at initial screening visit Patients who are able to sign and understand the study's informed consent form Patients able to complete all screening evaluations and procedures Exclusion Criteria: Patients in inpatient hospital care Severe or refractory bowel or psychological symptoms Current consumption of a Paleolithic diet Known Celiac disease Uncontrolled thyroid disease as indicated by an abnormal thyroid stimulating hormone (TSH) level Uncontrolled diabetes as indicated by a HbA1c equal to 6.5 or greater Patients unable to speak English Inability to obtain informed consent Pregnant or nursing women Any condition, which in the opinion of the investigator, would interfere with study requirements

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Paleolithic Diet<br>Paleolithic Diet | Other: Paleolithic diet<br>* Paleolithic diet<br>|
| Active Comparator: General Healthful Diet<br>General Healthful Diet | Other: General Healthful Diet<br>* General Healthful Diet<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Vitality | Vitality as measured on the vitality subscale of the short form health survey (SF36). This instrument assesses vitality (energy level and fatigue) and is a subscale of SF36, a general health survey designed for use in clinical practice and research, health policy evaluation and general population surveys. The Vitality Subscale score is determined by responses to 4 items: Did you feel full of life? Did you have a lot of energy? Did you feel worn out? Did you feel tired? The lower the score the more disability. The higher the score the less disability. | The change between baseline and 4 weeks (post-intervention). | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Anxiety | Anxiety as measured by the Generalized Anxiety Disorder 7-item (GAD-7) questionnaire. GAD-7 Questionnaire: This is a 7 item inventory rated on a 4 point Likert-type scale. Its purpose is to allow for brief and accurate detection of anxiety as well as for longitudinal anxiety symptom evaluation. Lower scores indicate less severe symptoms and higher scores equal more severe symptoms. | The change between baseline and 4 weeks (post-intervention). | 
| Depression | Depression as measured by the Patient Health Questionnaire-9' (PHQ-9) questionnaire. PHQ-9: This is a 9 item inventory rated on a 4 point Likert-type scale. Its purpose is to allow for brief and accurate diagnosis of depression as well as for longitudinal depression symptom evaluation. Lower scores indicate less severe symptoms and higher scores equal more severe symptoms. | The change between baseline and 4 weeks (post-intervention). | 
| Activity level | Activity level/amount of exercise as measured by the Godin Leisure-Time Exercise Questionnaire. The Godin Leisure-Time Exercise Questionnaire is a simple questionnaire to measure a person's leisure time exercise. It is designed to be reliable valid and easy to complete quickly without a need for detailed review. Lower scores indicate less activity and higher scores equal more activity. | The change between baseline and 4 weeks (post-intervention). | 
| Gastrointestinal symptoms | Gastrointestinal symptoms as measured by the NIH-Promis Gastrointestinal Symptom Scale a. NIH-Promis Gastrointestinal Symptom Scales for 8 domains: Gastroesophageal reflux (13 items), disrupted swallowing (7 items), diarrhea (5 items), bowel incontinence/soilage (4 items), nausea and vomiting (4 items), constipation (9 items), belly pain (6 items), and gas/bloat/flatulence (12 items). Lower scores indicate less severe symptoms and higher scores equal more severe symptoms. | The change between baseline and 4 weeks (post-intervention). | 
| Visceral sensitivity | Visceral sensitivity as measured by the Visceral Sensitivity Index. Visceral Sensitivity Index assesses gastrointestinal-specific anxiety, the cognitive, affective, and behavioral response to fear of gastrointestinal sensations, symptoms, and the context in which these visceral sensations and symptoms occur. Lower scores indicate less severe symptoms and higher scores equal more severe symptoms. | The change between baseline and 4 weeks (post-intervention). | 
| Overall health status (Short Health Scale) | Overall health status as measured by the Short Health Scale questionnaires. The Short Health Scale is a 4-item questionnaire covering aspects of subjective health. Lower scores indicate less severe symptoms and higher scores equal more severe symptoms. | The change between baseline and 4 weeks (post-intervention). | 
| Overall health status (EQ-5D) | Overall health status (global health outcomes measure) as measured by the EuroQol 5 Dimension (EQ-5D) The EQ-5D descriptive system consists of five dimensions: Mobility, Self-care, Usual activities, Pain/discomfort, Anxiety/depression. Scores range from 5-25, with higher scores indicating more severe symptoms/decreased quality of life.descriptive system consists of five dimensions: Mobility, Self-care, Usual activities, Pain/discomfort, Anxiety/depression. Lower scores indicate less severe symptoms and higher scores equal more severe symptoms. | The change between baseline and 4 weeks (post-intervention). |