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Dietary Macronutrients and Gut Microbiota, Inflammation, and Metabolic Markers
Sponsor: The Jerzy Kukuczka Academy of Physical Education in Katowice
Summary
This 12-week randomized controlled trial will examine how diets with different macronutrient compositions influence gut microbiota, intestinal inflammation, gene expression, and metabolic blood parameters in healthy adults. Participants will be randomly assigned to one of three groups: ketogenic diet (KD), vegetarian diet (VD), or control diet (CD, habitual mixed diet). The intervention will be monitored through dietary records and counseling to assess adherence. Primary and secondary outcomes include changes in gut microbiota composition, inflammatory markers, transcriptomic profiles, and biochemical blood parameters related to lipid and glucose metabolism. Biological samples (blood and stool) will be collected at multiple time points throughout the study, with additional ketone monitoring in the KD group. The aim is to compare the effects of ketogenic and vegetarian diets versus a standard mixed diet on gut health, metabolic status, and systemic inflammation, to support evidence-based dietary recommendations.
Official title: Effects of Diets Differing in Macronutrient Composition on Gut Microbiota Composition, Intestinal Inflammation Markers, Gene Expression Profiles, and Blood Biochemical Parameters in Diverse Populations.
Key Details
Gender
All
Age Range
18 Years - 60 Years
Study Type
INTERVENTIONAL
Enrollment
200
Start Date
2024-09-02
Completion Date
2028-12-30
Last Updated
2026-07-01
Healthy Volunteers
Yes
Interventions
Ketogenic Diet (KD)
Participants in the Ketogenic Diet Group (KD) will follow a strict ketogenic diet for 12 weeks. The ketogenic diet is characterized by: Fat intake: Approximately 70-80% of total daily energy Carbohydrate intake: Approximately 5-10% of total daily energy (typically \<50 g carbohydrates per day) Moderate protein intake: Approximately 15-20% of total daily energy Dietary Guidelines: Allowed foods: Fatty meats, fish, eggs, full-fat dairy products, butter, oils (olive oil, coconut oil, avocado oil), nuts, seeds, low-carbohydrate vegetables (e.g., leafy greens, broccoli, cauliflower), avocados Restricted foods: All grains (bread, pasta, rice, cereals), high-carbohydrate fruits (bananas, apples, oranges), starchy vegetables (potatoes, corn), legumes, sugar-sweetened foods and beverages, most processed foods Blood ketone levels will be measured once weekly by participants (morning, before breakfast) using a ketone meter (Optimum Xido) Duration: 12 weeks
Vegetarian Diet (VD)
Participants in the Vegetarin Diet Group (VD) will follow a plant-based vegetarian diet for 12 weeks. The vegetarin diet excludes all animal products and is characterized by: Macronutrient composition: Balanced intake of carbohydrates, proteins, and fats from plant sources Primary food sources: Vegetables, fruits, legumes (beans, lentils, peas), nuts, seeds, whole grains, plant-based oils Dietary Guidelines: Allowed foods: All vegetables, fruits, legumes, nuts, seeds, whole grains (rice, quinoa, oats, wheat), plant-based milks, tofu, tempeh, plant-based oils, avocados Restricted foods: All animal products including meat, poultry, fish, eggs, dairy products, honey, and any food containing animal-derived ingredients Dietary adherence will be monitored through regular food diaries and nutritional counseling sessions Participants will receive guidance on adequate protein intake, vitamin B12, iron, calcium, and omega-3 fatty acid supplementation if needed Duration: 12 weeks
Control Diet (CD)
Participants in the Control Diet Group (CD) will serve as the control group and will continue their current habitual mixed diet without specific dietary modifications for 12 weeks. Diet type: Habitual mixed diet (includes both plant and animal products) Macronutrient composition: No modifications; participants maintain their usual dietary intake No dietary restrictions or instructions: Participants are not instructed to change their eating patterns Monitoring: Dietary intake will be documented through regular food diaries Participants will attend visits with a dietitian at 4, 8, and 12 weeks for monitoring purposes only (no dietary changes instructed) Duration: 12 weeks
Locations (2)
Jaggielonian University
Krakow, Poland
Pomeranian Medical University
Szczecin, Poland