How the Mediterranean Diet Affects You: Predicting Responses Based on Your Microbiome

Not Applicable

Not yet recruiting

• Conditions: Healthy

• Registration Number: NCT06765369
• Lead Sponsor: University of British Columbia

Brief Summary

People respond differently to various diets-some may see significant benefits, while others may not. This project aims to personalize dietary recommendations by analyzing the gut microbiome to predict who will benefit most from the Mediterranean diet based on their unique biology, including their microbiome.

The study focuses on answering these key questions:

1. Are there specific microbes that influence who is most likely to benefit from the Mediterranean diet?

2. What changes occur in the gut microbiome when healthy individuals follow a Mediterranean diet?

To explore these questions, researchers will compare the effects of a Mediterranean diet to a Western-style diet. Participants will receive all their meals and snacks for the study to ensure accurate comparisons of how these diets impact the gut microbiome.

Detailed Description

Understanding the role of therapeutic dietary interventions in treating chronic diseases requires acknowledging that the response to nutrition varies in populations, subgroups and individual's. Varying responses to dietary intervention is dependent on interpersonal differences and environment. Personalized nutrition addresses these differences between individuals to maximize the benefits of dietary interventions. Many large, randomized controlled trials have effectively demonstrated that only 40% of a study cohort responds to dietary interventions, and lifestyle measures in regards to reducing disease risk. A more pragmatic approach to enhance the effectiveness of dietary treatment emerges by identifying microbiome-derived biomarkers capable of predicting and categorizing those most likely to benefit from specific nutritional interventions. Developing a predictive microbiome signature represents an advancement in this endeavour, offering the prospect of tailored, personalized nutrition interventions and a comprehensive understanding of the intricate interplay between diet, gut microbiota composition, and human health. Specifically, the Mediterranean diet (MD) has been investigated as a therapeutic diet for varying diseases due to its positive correlation with an array of health benefits. However, there is little consensus on specific microbial changes associated with the MD and how the MD alters the gut microbiome. This study aims to fill this knowledge gap that exists surrounding the MD and to determine a predictive microbiome associated with the MD. Ultimately producing a highly predictive microbiome signature that will have the ability to identifies those who will respond to the MD.

Study Timeline

• Study First Submitted: 2024-12-27
• Status Verified: 2025-01
• Study First Submitted QC: 2025-01-02
• Last Update Submitted: 2025-01-02
• Study Start: 2025-01-08
• Study First Posted: 2025-01-09
• Last Update Posted: 2025-01-09
• Primary Completion: 2025-12-31
• Study Completion: 2026-12-31

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 25

Inclusion Criteria

• Healthy participants, defined as free from cardiovascular disease, diabetes, and hypertension
• Body Mass Index of 20-25
• Between the ages 20-50 years
• Low adherence to the Mediterranean diet (MD serving score [MDSS] less than 10 points).
• Must live in the Okanagan area

Exclusion Criteria

• Individuals with a self-reported history of irritable bowel syndrome, inflammatory bowel disease, Type-2 diabetes, kidney disease, intestinal obstruction, infectious gastroenteritis, colitis or gastritis, Clostridium difficile infection (recurrent) or Helicobacter pylori infection (untreated), malabsorption (such as celiac disease), major surgery of the GI tract, or colorectal cancer
• Oral antibiotics within three months of the intervention start date
• Individuals with any known food allergies, reported dietary intolerances of any kind, and those with eating disorders
• Pregnant or breastfeeding
• Participants with a high MDSS (> 10 points)
• Individuals who are intermittent fasting or refuse to follow the study protocol

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Primary Outcome Measures

Name	Time	Method
Microbiome - Microbial Diversity	Baseline, Week 3, Week 9 and Week 12	Metagenomic sequencing will be employed to analyze stool samples, focusing on changes in the taxonomic composition of the gut microbiome in healthy individuals in response to interventions with the Mediterranean and Western diets.
Microbiome - Microbial Signature	Baseline, Week 3, Week 9 and Week 12	Metagenomic sequencing will be utilized to analyze stool samples, aiming to identify microbial signatures of the gut microbiome in healthy individuals following interventions with the Mediterranean and Western diets.

Secondary Outcome Measures

Name	Time	Method
Metabolomics - Change in fecal metabolites	Baseline, Week 3, Week 9 and Week 12	Fecal metabolites will be analyzed using a untargeted metabolomic platform with samples collected pre and post MD and Western diet. Quantification will be performed using untargeted reverse-phase ultrahigh-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS).
Metabolomics - Change in serum metabolites	Baseline, Week 3, Week 9 and Week 12	Serum metabolites will be analyzed using a untargeted metabolomic platform with samples collected pre and post MD and Western diet. Quantification will be performed using untargeted reverse-phase ultrahigh-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS).
Change in Quality of Life	Baseline, Week 3, Week 9, Week 12	Health-related quality of life will be measured using the 12-item short form-12 (SF-12). The SF-12 is comprised of two components: physical health and mental health. Scores range from 0 to 100, where a zero score indicates the lowest level of health and 100 indicates the highest level of health.
Dietary intake	Baseline, Week 9	Dietary intake and supplement use will be evaluated at both baseline and week 9 using two non-consecutive 24-hour food recalls collected through the ASA-24 Canadian version. These assessments will establish participants' habitual dietary patterns and help monitor dietary consistency during the washout period.
Appetite rating	The Visual Analog Scales (VAS) for Appetite will be completed daily throughout the dietary intervention period, which includes 3 weeks on the Mediterranean diet and 3 weeks on the Western diet.	Visual Analog Scales (VAS) for Appetite will be used to assess appetite of healthy participants in response to interventions with Mediterranean and Western diets. Higher values typically indicate greater intensity of the sensation being measured.
Change in Anxiety	Baseline, Week 3, Week 9 and Week 12	Anxiety will be assessed by the GAD-7 (Generalized Anxiety Disorder-7). It is a self-reported screening tool used to measure the severity of generalized anxiety disorder (GAD) symptoms over the past two weeks. The total score ranges from 0 to 21. A score of 10 or higher typically indicates clinically significant anxiety and suggests the need for further evaluation or intervention..
Change in Depression	Baseline, Week 3, Week 9 and Week 12	Depression levels will be assessed by PHQ-8 (Patient Health Questionnaire-8). It is a widely used self-report screening tool for assessing the severity of depressive symptoms over the past two weeks. The total score is the sum of all item responses, ranging from 0 to 24. A score of 10 or higher indicates the presence of clinically significant depressive symptoms and suggests the need for further evaluation or intervention.

Trial Locations

Locations (1)

University of British Columbia-Okanagan; 🇨🇦 Kelowna, British Columbia, Canada