NCT07672691

Brief Summary

Poniżej znajduje się bardziej płynna i mniej powtarzalna wersja tekstu: This 12-week randomized controlled trial will investigate the effects of dietary patterns with different macronutrient compositions on gut microbiota, intestinal inflammation, gene expression, and metabolic health in healthy adults. Participants will be randomly assigned to one of three dietary interventions: a ketogenic diet (KD), a vegetarian diet (VD), or a control diet (CD) reflecting their habitual mixed dietary pattern. Adherence to the assigned diet will be monitored through dietary records and regular nutritional counseling. The study will evaluate changes in gut microbiota composition, inflammatory biomarkers, transcriptomic profiles, and blood biochemical parameters associated with lipid and glucose metabolism. Blood and stool samples will be collected at predefined time points throughout the intervention, while participants in the KD group will additionally undergo ketone monitoring to assess dietary compliance. By comparing the ketogenic and vegetarian diets with a standard mixed diet, this study aims to determine their effects on gut health, metabolic function, and systemic inflammation, thereby providing evidence to inform dietary recommendations. Ta wersja eliminuje powtórzenia ("diet", "study", "monitor", "effects"), jest bardziej naturalna stylistycznie i odpowiada standardowi językowemu publikacji w czasopismach z zakresu żywienia i medycyny.

Trial Health

77
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
200

participants targeted

Target at P75+ for not_applicable

Timeline
30mo left

Started Sep 2024

Longer than P75 for not_applicable

Geographic Reach
1 country

2 active sites

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Progress44%
Sep 2024Dec 2028

Study Start

First participant enrolled

September 2, 2024

Completed
1 day until next milestone

Primary Completion

Last participant's last visit for primary outcome

September 3, 2024

Completed
1.8 years until next milestone

First Submitted

Initial submission to the registry

June 17, 2026

Completed
12 days until next milestone

First Posted

Study publicly available on registry

June 29, 2026

Completed
2.5 years until next milestone

Study Completion

Last participant's last visit for all outcomes

December 30, 2028

Expected
Last Updated

July 2, 2026

Status Verified

July 1, 2026

Enrollment Period

1 day

First QC Date

June 17, 2026

Last Update Submit

July 1, 2026

Conditions

NutritionKetogenic DietGene ExpressionDiet

Keywords

ketogenic dietgene expressiontranscriptomicsbiochemical parametersstool microbiomeketone bodies

Outcome Measures

Primary Outcomes (19)

  • β-hydroxybutyrate

    mmol/L

    12 weeks

  • Insulin

    IU/mL

    12 weeks

  • Glucose

    mg/dL

    12 weeks

  • Omega index

    12 weeks

  • HDL cholesterol

    mg/dL

    12 weeks

  • LDL cholesterol

    mg/dL

    12 weeks

  • Triacylglycerol

    mg/dL

    12 weeks

  • Grelin

    ng/mL

    12 weeks

  • cholecystokinin

    pg/mL

    12 weeks

  • glucagon-like peptide-1

    pg/mL

    12 weeks

  • leptin

    ng/mL

    12 weeks

  • peptide YY

    pg/mL

    12 weeks

  • gut microbiome

    CFU/g

    12 weeks

  • Transcriptomic

    log 2fold change

    12 weeks

  • Gene Polymorphism

    allel variance

    12 weeks

  • Total cholesterol

    mg/dL

    12 weeks

  • HbA1c

    12 weeks

  • Testosterone

    nmol/L

    12 weeks

  • Cortisol

    μg/dL

    12 weeks

Other Outcomes (1)

  • DEXA

    12 weeks

Study Arms (3)

Ketogenic diet

EXPERIMENTAL

Participants in this arm will follow a ketogenic diet characterized by high fat, very low carbohydrate, and moderate protein intake throughout the 12-week intervention period.

Other: Ketogenic Diet (KD)

Vegetarian Diet Group

EXPERIMENTAL

Participants in this arm will follow a plant-based vegan diet excluding all animal products throughout the 12-week intervention period.

Other: Vegetarian Diet (VD)

Control Diet Group (CD)

PLACEBO COMPARATOR

Participants in this arm will serve as the control group and will continue their current habitual mixed diet without specific dietary modifications throughout the 12-week study period.

Other: Control Diet (CD)

Interventions

Ketogenic Diet (KD)OTHER

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

Ketogenic diet
Vegetarian Diet (VD)OTHER

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

Vegetarian Diet Group
Control Diet (CD)OTHER

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

Control Diet Group (CD)

Eligibility Criteria

Age18 Years - 60 Years
Sexall(Gender-based eligibility)
Healthy VolunteersYes
Age GroupsAdult (18-64)

You may qualify if:

  • In addition to the physical activity requirements described above, the study will include men and women aged 18-60 years with:
  • BMI not exceeding 40kg/m²
  • Habitual mixed diet prior to study enrollment
  • Normal blood pressure

You may not qualify if:

  • Use of medications regulating \*\*glucose levels\*\* (e.g., metformin) or \*\*blood lipids\*\* (e.g., \*\*statins\*\*)
  • \*\*Hypertension\*\* or pharmacological treatment for hypertension
  • Diagnosed \*\*gastrointestinal disorders\*\*, including:
  • Gastric and duodenal ulcers
  • \*\*Irritable bowel syndrome (IBS)\*\*
  • \*\*Ulcerative colitis\*\*
  • \*\*Celiac disease\*\*
  • Chronic use of medications such as:
  • \*\*Mesalazine\*\*
  • \*\*Corticosteroids\*\*
  • \*\*Statins\*\*
  • \*\*Proton pump inhibitors (PPI)\*\*
  • \*\*Non-steroidal anti-inflammatory drugs (NSAIDs)\*\*
  • \*\*Anticonceptional medications\*\*
  • \*\*Any supplements\*\*
  • +3 more criteria

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (2)

Jaggielonian University

Krakow, Poland

RECRUITING

Pomeranian Medical University

Szczecin, Poland

RECRUITING

MeSH Terms

Interventions

Diet, KetogenicDiet, Vegetarian

Intervention Hierarchy (Ancestors)

Diet, Carbohydrate-RestrictedDiet TherapyNutrition TherapyTherapeuticsDietNutritional Physiological PhenomenaDiet, Food, and NutritionPhysiological PhenomenaDiet, Plant-Based

Study Officials

  • Małgorzata M Michalczyk, Assistante professor

    Institute of Sport Sciences, Jerzy Kukuczka Academy of Physical Education in Katowice

    PRINCIPAL INVESTIGATOR

Central Study Contacts

Małgorzata Magdalena Michalczyk, Assistante professor

CONTACT

+48535016532m.michalczyk@awf.katowice.pl

Małgorzata Magdalena Michalczyk, Assistante professor

CONTACT

535016532m.michalczyk@awf.katowice.pl

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
TRIPLE
Who Masked
PARTICIPANT, CARE PROVIDER, INVESTIGATOR
Purpose
BASIC SCIENCE
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
assistant professor

Study Record Dates

First Submitted

June 17, 2026

First Posted

June 29, 2026

Study Start

September 2, 2024

Primary Completion

September 3, 2024

Study Completion (Estimated)

December 30, 2028

Last Updated

July 2, 2026

Record last verified: 2026-07

Locations

PL(2)