How common dietary fats change gut bacteria and metabolic markers
Effects Of Dietary Fats on Gut Microbiota Composition and Metabolic Activity in Healthy Adults
We will test whether replacing part of daily fat with butter, coconut oil, olive oil, or sunflower oil for two weeks changes gut bacteria and related blood markers in healthy adults aged 20–50.
Quick facts
| Phase | Not applicable |
|---|---|
| Study type | Interventional |
| Enrollment | 64 (estimated) |
| Ages | 20 Years to 50 Years |
| Sex | All |
| Sponsor | University of Glasgow Academic / other |
| Locations | 1 site (Glasgow) |
| Trial ID | NCT07550023 on ClinicalTrials.gov |
What this trial studies
This randomized, parallel pilot trial will enrol 64 healthy adults (age 20–50, BMI 20–30) in the Glasgow area and randomize them to one of four fat groups (butter, coconut oil, extra virgin olive oil, sunflower oil) with 60 mL consumed daily for two weeks following a one-week run-in. Stool and fasting blood samples are collected at baseline (Day 1), mid-intervention (Day 7), and post-intervention (Day 22) to measure short-chain fatty acids, microbiota composition, blood lipids, and inflammatory markers. The primary aim is to see whether fats that differ in chain length and saturation produce different microbial fermentation patterns and systemic metabolic effects. All visits take place at the New Lister Building, University of Glasgow.
Who should consider this trial
Good fit: Ideal candidates are generally healthy, non-smoking adults aged 20–50 with BMI 20–30, stable weight, living in the Glasgow area, without recent antibiotic use and not taking medications or supplements that affect the gut or metabolism.
Not a fit: People with chronic gastrointestinal, metabolic, cardiovascular, hepatobiliary, or pancreatic disease, diagnosed diabetes, recent antibiotic use, lipid‑lowering therapy, fat malabsorption, recent major GI surgery, restrictive diets, relevant food allergies/intolerances, pregnant or lactating, or post‑menopausal women are unlikely to be suitable or to benefit.
Why it matters
Potential benefit: If successful, the results could identify which commonly eaten fats promote healthier gut microbial activity and more favourable blood lipid or inflammatory profiles, helping to guide dietary advice.
How similar studies have performed: Prior in vitro work and some human studies suggest dietary fat composition can influence the microbiome and SCFA production, but direct randomized comparisons of multiple common fats with both microbiome and cardiometabolic endpoints in healthy adults are limited.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * Adults aged 20-50 years * Body mass index (BMI) between 20 and 30 kg/m² * Generally healthy * Stable body weight (±2 kg) over the past 2 months * Living in the Glasgow area * Non-smoker Exclusion Criteria: * Use of antibiotics within the past 3 months * Current use of medications affecting gut microbiota or cardiometabolic health * Regular use of dietary supplements that may influence study outcomes (e.g. probiotics, prebiotics, vitamins, minerals, fish oil), unless willing to discontinue prior to study start * Presence of chronic gastrointestinal, metabolic, cardiovascular, hepatobiliary, or pancreatic disease * History of major gastrointestinal surgery * Diagnosed diabetes or use of lipid-lowering therapy * Known fat malabsorption disorders * Pregnant or lactating women * Post-menopausal women * Following a restrictive or specific diet (e.g. vegan, ketogenic diet) * Food allergies or intolerances relevant to study interventions (e.g. dairy, coconut) * Recent significant weight change (±2 kg in the past month) * High reliance on ready meals or takeaway foods (\>7 main meals per week) * Participation in another research study that may interfere with this study
Where this trial is running
Glasgow
- New Lister Building, Glasgow Royal Infirmary, 10-16 Alexandra Parade, G31 2ER — Glasgow, United Kingdom (Recruiting)
Study contacts
- Principal investigator: Athanasios Koutsos — University of Glasgow
- Study coordinator: Linah Alhomidan
- Email: linahalhomidan@gmail.com
- Phone: +447473477395
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.