NCT07550023

Brief Summary

This study will investigate how adding a specific type of dietary fat to daily meals for two weeks affects the gut bacteria and their activity. Participants will be randomly assigned to consume one of four types of fat: butter, coconut oil, olive oil, or sunflower oil (60 mL each day for 2 weeks). Stool and blood samples (after an overnight fast) will be collected at 3 time points during the study (Days 1, 7, and 22). These samples will be used to measure metabolites produced by gut bacteria, the types of bacteria present in the gut, blood lipids, and inflammatory markers. The study, based on previous in vitro findings, aims to understand whether different types of fats (based on their structure and level of saturation) have different effects on gut bacteria and their activity in healthy subjects.

Trial Health

77
On Track

Trial Health Score

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

Enrollment
64

participants targeted

Target at P50-P75 for not_applicable

Timeline
23mo left

Started Mar 2026

Typical duration for not_applicable

Geographic Reach
1 country

1 active site

Status
recruiting

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

Trial Relationships

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Study Timeline

Key milestones and dates

Study Progress6%
Mar 2026Mar 2028

Study Start

First participant enrolled

March 23, 2026

Completed
25 days until next milestone

First Submitted

Initial submission to the registry

April 17, 2026

Completed
7 days until next milestone

First Posted

Study publicly available on registry

April 24, 2026

Completed
11 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

March 31, 2027

Expected
1 year until next milestone

Study Completion

Last participant's last visit for all outcomes

March 31, 2028

Last Updated

April 24, 2026

Status Verified

April 1, 2026

Enrollment Period

1 year

First QC Date

April 17, 2026

Last Update Submit

April 17, 2026

Conditions

Gut Microbiota Diversity and CompositionInflammation BiomarkersShort Chain Fatty Acids Concentration in StoolsBlood Lipid Profiles

Keywords

Gut microbiomeGut microbiotaDietary fatShort-chain fatty acidsSCFASaturated fatMonounsaturated fatPolyunsaturated fatButterOlive oilCoconut oilSunflower oilMUFAPUFA

Outcome Measures

Primary Outcomes (2)

  • Change in faecal short-chain fatty acid (SCFA) concentrations

    Faecal concentrations of short-chain fatty acids (acetate, propionate, and butyrate) will be measured using gas chromatography to assess changes in gut microbial metabolic activity in response to dietary fat intervention.

    Day 1 (pre run-in), Day 7 (baseline, post run-in), and Day 22 (post-intervention)

  • Change in gut microbiota composition

    Gut microbiota composition will be assessed using 16S rRNA gene amplicon sequencing to evaluate changes in bacterial diversity and relative abundance following the dietary fat intervention.

    Day 1 (pre run-in), Day 7 (baseline, post run-in), and Day 22 (post-intervention)

Secondary Outcomes (5)

  • Change in blood lipid profile

    Day 1 (pre run-in), Day 7 (baseline, post run-in), and Day 22 (post-intervention)

  • Change in inflammatory markers

    Day 1 (pre run-in), Day 7 (baseline, post run-in), and Day 22 (post-intervention)

  • Change in faecal pH

    Day 1 (pre run-in), Day 7 (baseline, post run-in), and Day 22 (post-intervention)

  • Change in fasting glucose concentrations

    Day 1 (pre run-in), Day 7 (baseline, post run-in), and Day 22 (post-intervention)

  • Change in faecal fat content

    Day 1 (pre run-in), Day 7 (baseline, post run-in), and Day 22 (post-intervention)

Study Arms (4)

Butter

EXPERIMENTAL

Following a one week run-in period (habitual diet), participants will be assigned to consume butter as their primary dietary fat.

Other: Butter

Coconut Oil

EXPERIMENTAL

Following a one week run-in period (habitual diet), participants will be assigned to consume coconut oil as their primary dietary fat.

Other: Coconut oil

Extra Virgin Olive Oil

EXPERIMENTAL

Following a one week run-in period (habitual diet), participants will be assigned to consume olive oil as their primary dietary fat.

Other: Extra Virgin Olive Oil

Sunflower Oil

EXPERIMENTAL

Following a one week run-in period (habitual diet), participants will be assigned to consume sunflower oil as their primary dietary fat.

Other: Sunflower Oil

Interventions

ButterOTHER

Participants will consume approximately 65 g/day of butter as their primary dietary fat for 14 days, replacing most habitual dietary fat intake.

Butter
Coconut oilOTHER

Participants will consume approximately 55 g/day of coconut oil as their primary dietary fat for 14 days, replacing most habitual dietary fat intake.

Coconut Oil
Extra Virgin Olive OilOTHER

Participants will consume 60 mL/day of olive oil as their primary dietary fat for 14 days, replacing most habitual dietary fat intake.

Extra Virgin Olive Oil
Sunflower OilOTHER

Participants will consume 60 mL/day of sunflower oil as their primary dietary fat for 14 days, replacing most habitual dietary fat intake.

Sunflower Oil

Eligibility Criteria

Age20 Years - 50 Years
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64)

You may qualify if:

  • 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

You may not qualify if:

  • 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

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

New Lister Building, Glasgow Royal Infirmary, 10-16 Alexandra Parade, G31 2ER

Glasgow, G31 2ER, United Kingdom

RECRUITING

MeSH Terms

Interventions

ButterCoconut OilSunflower Oil

Intervention Hierarchy (Ancestors)

Dietary FatsFatsLipidsDairy ProductsFoodDiet, Food, and NutritionPhysiological PhenomenaFood and BeveragesPlant OilsOilsPlant PreparationsBiological ProductsComplex Mixtures

Study Officials

  • Athanasios Koutsos

    University of Glasgow

    PRINCIPAL INVESTIGATOR

  • Dalia Malkova, PhD

    University of Glasgow

    PRINCIPAL INVESTIGATOR

  • Konstantinos Gerasimidis, PhD

    University of Glasgow

    PRINCIPAL INVESTIGATOR

Central Study Contacts

Linah Alhomidan

CONTACT

+447473477395linahalhomidan@gmail.com

Athanasios Koutsos

CONTACT

Athanasios.Koutsos@glasgow.ac.uk

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
NONE
Purpose
BASIC SCIENCE
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Lecturer in Human Nutrition

Study Record Dates

First Submitted

April 17, 2026

First Posted

April 24, 2026

Study Start

March 23, 2026

Primary Completion (Estimated)

March 31, 2027

Study Completion (Estimated)

March 31, 2028

Last Updated

April 24, 2026

Record last verified: 2026-04

Locations

GB(1)