EndotoxemiaNCT07713641
Short-Chain Fatty Acids in Lypopolysaccharide-Induced Inflammation and Executive Function
A study testing Short-Chain Fatty Acid Colon-Delivery Capsules and Lipopolysaccharide (LPS) in people with Endotoxemia and Inflammation, run by Universitaire Ziekenhuizen KU Leuven at 1 site in Belgium.
Trial summary
Short-chain fatty acids (SCFAs) are substances produced by gut bacteria when they ferment dietary fiber. They can act as signals between the gut and the brain and may help regulate the body's immune and stress responses. Read more about this study
- Who is it for?
- Ages 18 to 45 yearsHealthy volunteers can take part
- Conditions the study is for
- Endotoxemia, Inflammation, Executive Function (Cognition)
- What is being tested?
- Short-Chain Fatty Acid Colon-Delivery Capsules and Lipopolysaccharide (LPS)
- Type of treatment
- Pill or oral medicine, Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 56 participants
- Where
- 1 siteBelgium
- Study dates
- 24 Oct 2025to 30 Mar 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 45 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Voluntary written informed consent obtained prior to any study procedure
- Healthy, with no gastrointestinal or psychological complaints
- Age 18-45 years
- BMI 18.5-27 kg/m2
- Proficiency in English and/or Dutch
Who cannot join
- History of previous or current neurological disorder (e.g., epilepsy, multiple sclerosis, migraine with aura)
- History of previous or current psychiatric disorder (e.g., depression, anxiety disorders, bipolar disorder, schizophrenia)
- History of previous or current gastrointestinal disorder (e.g., Crohn's disease, ulcerative colitis, irritable bowel syndrome)
- History of previous or current endocrine disorder (e.g., diabetes, thyroid disorders, polycystic ovary syndrome)
- History of immune system disorder, including inflammatory, autoimmune, or severe allergic conditions (e.g., rheumatoid arthritis, lupus, celiac disease, or severe allergies such as anaphylaxis)
- History of neuropsychiatric disorder (e.g., ADHD, autism spectrum disorder, learning disorder, Tourette's syndrome)
Show all 27Show fewer
- History of major head trauma (e.g., concussion with loss of consciousness or long-term symptoms)
- History of severe infection (e.g., sepsis, pneumonia requiring hospitalization, meningitis, endocarditis, or other systemic infection requiring hospitalization, intravenous antibiotics, or intensive care)
- One or more diagnoses based on the Mini International Neuropsychiatric Interview (MINI)
- One or more diagnoses based on ROME-IV criteria for gastrointestinal disorders
- Any disorder that, in the investigator's opinion, might jeopardise the participant's safety or compliance with the protocol
- Any prior or concomitant treatment that might jeopardise the participant's safety or compromise the integrity of the study
- Participation in an interventional trial with an investigational medicinal product (IMP) or device
- Current or recent (past month) prescribed medication use, with particular attention to cardiovascular drugs, steroids, NSAIDs, and centrally-acting drugs (excluding isolated over-the-counter use such as ibuprofen or paracetamol, and hormonal contraceptives in women)
- Use of psychotropic medication within the past year (e.g., antidepressants, anxiolytics, antipsychotics)
- Use of antibiotics within three months preceding the study
- Use of pre- or probiotics within one month preceding the study
- Current or recent (past month) infection (e.g., common cold, influenza, COVID-19)
- Recent (past month) vaccination
- Pregnant or lactating women
- Previous or current substance or alcohol dependence or abuse (>2 units/day or >14 units/week)
- Smoking
- Night-shift work
- Adherence to special diets (e.g., vegan, vegetarian, weight-loss, lactose-free, gluten-free)
- Previous experience with or knowledge of any of the cognitive tasks used in the study (questionnaires excluded)
- C-reactive protein higher than 0.5mg/dL on the day of the injection.
- Colour vision deficiency or colour-blindness
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Belgium1 site, 1 recruiting
- Recruiting
University Hospital Leuven (UZ Leuven)
Leuven, 3000
Franco Ruiz, M.D., +3256716114, franco.ruiz@kuleuven.be
Dina Satriawan, M.D., +32 16 71 03 66, dina.satriawan@kuleuven.be
About this study
Official title: Investigating the Role of Short-Chain Fatty Acids in Endotoxemia-Induced Inflammation and Core Executive Functioning: A Randomized, Triple-Blind, Placebo-Controlled Trial
Short-chain fatty acids (SCFAs) are substances produced by gut bacteria when they ferment dietary fiber. They can act as signals between the gut and the brain and may help regulate the body's immune and stress responses. Earlier work has shown that delivering SCFAs to the colon can lower the stress hormone response to a mental stress task in healthy people, and laboratory studies suggest SCFAs can reduce inflammation. However, it is not yet known whether SCFAs can reduce inflammation in humans, or whether doing so protects mental performance.
This study uses a controlled, acute, and short-lasting challenge. Healthy adults receive a single, low dose of a bacterial substance called lipopolysaccharide (LPS) through a vein. LPS briefly activates the immune system and causes mild, flu-like symptoms (such as fatigue, headache, and feeling unwell) that pass on their own within a few hours. It does not cause a real infection.
Read more
Participants are randomly assigned to take either SCFA capsules or inactive placebo capsules on the morning of the test day, before the LPS challenge. Neither the participants, the researchers running the visit, nor the researchers analyzing the results know who received which capsules until the study is complete (triple-blind).
The main goal of the study is to test whether SCFAs, compared with placebo, reduce the inflammatory response to LPS, measured by markers of inflammation in the blood. The study also examines whether SCFAs reduce the associated sickness symptoms and whether they protect performance on tasks that measure core executive functions: the ability to keep relevant information in mind (working memory), the ability to hold back automatic responses or thoughts (inhibition), and the ability to switch flexibly between tasks or rules (cognitive flexibility). Blood, saliva, and stool samples are collected to measure inflammation markers, SCFA levels, stress hormones, and gut bacteria.
Participants attend a screening visit, a test day with monitoring for several hours, and a short follow-up visit the next day.
Read the detailed description
INFLEX is a single-center, randomized, triple-blind, placebo-controlled, parallel-group interventional trial conducted at UZ Leuven / KU Leuven. Its primary aim is to test whether a single acute dose of colon-delivered SCFAs, relative to placebo, attenuates the systemic inflammatory response induced by experimental endotoxemia in healthy adults. Secondary aims are to test whether SCFAs attenuate LPS-induced sickness behaviour and mitigate endotoxemia-induced changes in core executive functioning, and to characterize associations between systemic SCFA uptake, the inflammatory response, and these outcomes.
Eligible participants are randomized to receive SCFA colon-delivery capsule or placebo capsules, taken on the morning of the test day with a standardized low-fiber breakfast. One hour after capsule intake, participants receive a single intravenous bolus of purified Escherichia coli lipopolysaccharide (0.4 ng/kg body weight), which serves as a fixed inflammatory challenge applied to all participants. The timing is designed so that peak circulating SCFA concentrations (approximately 3-4 hours after colonic delivery) coincide with the peak of LPS-induced cytokines and sickness behaviour (approximately 2-3 hours post-injection).
Participants are monitored for a minimum of 6 hours after the LPS challenge. Vital signs, sickness symptoms, and blood and saliva samples are collected hourly to quantify inflammatory markers (including IL-6 and hs-CRP), serum SCFA, cortisol, and ACTH. Core executive-function tasks are administered before and after the LPS challenge and at a 24-hour follow-up visit. A fecal sample collected at home prior to the test day is used for gut microbiota profiling. To standardize endogenous SCFA production, participants follow a low-fiber diet for three days before the test day and avoid caffeine, alcohol, and strenuous exercise beforehand. The night prior to the test day, participants are instructed to consume a standard dinner that is provided to them.
The study comprises three visits: a screening visit (~1 hour), the laboratory test day (~8 hours), and a follow-up visit (~30 minutes) 24 hours after the LPS challenge.
- Conditions
- Endotoxemia, Inflammation, Executive Function (Cognition)
- Being tested
- Short-Chain Fatty Acid Colon-Delivery Capsules, Placebo capsules, Lipopolysaccharide (LPS)
- Keywords
- scfa, short-chain fatty acids, butyrate, proprionate, acetate, lypopolysaccharide, lps, endotoxemia, lps challenge, experimental, inflammation, experimental inflammation, experimental endotoxemia, systemic inflammation, gut-brain axis, microbiota, microbiota-gut-brain axis, executive function, working memory, inhibition
- Medical subject headings
- Endotoxemia, Inflammation, Van der Woude syndrome, Inhibition, Psychological
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Short-Chain Fatty Acid Colon-Delivery CapsulesDietary supplement
Single acute oral dose of pH-dependent colon-delivery capsules delivering a short-chain fatty acid mixture to the colon. The mixture comprises sodium acetate,sodium butyrate, and sodium propionate (54.4%, 21.2%, and 24.4% by weight), providing approximately 186 mmol total SCFA per dose (111 mmol acetate, 32 mmol butyrate, 43 mmol propionate). Capsules are sub-coated with hydroxypropylcellulose and coated with a pH-dependent layer (Eudragit FS 30 D with PlasACRYL T20). Taken on the morning of the test day with a standardized low-fiber breakfast.
Placebo capsulesDietary supplement
Also called Placebo, microcrystalline cellulose
Single acute oral dose of placebo capsules containing microcrystalline cellulose and matching excipients, an inert non-fermentable substrate. Matched in appearance and number to the SCFA capsules and taken on the morning of the test day with a standardized low-fiber breakfast.
Lipopolysaccharide (LPS)Biological
Also called LPS, Endotoxin
Single intravenous bolus of purified Escherichia coli-derived lipopolysaccharide (0.4 ng/kg body weight), administered one hour after capsule intake to all participants as a standardized experimental inflammatory challenge common to both study arms.
| Study group | Role | What they receive |
|---|---|---|
| SCFA Colon-Delivery Capsules | Experimental | A single acute oral dose of colon-delivery capsules delivering a short-chain fatty acid mixture (approximately 186 mmol total SCFA: 111 mmol acetate, 43 mmol propionate, 32 mmol butyrate; molar ratio approximately 60:23:17), taken on the morning of the test day with a standardized low-fiber breakfast. Receives: Dietary Supplement: Short-Chain Fatty Acid Colon-Delivery Capsules; Biological: Lipopolysaccharide (LPS) |
| Placebo | Placebo comparator | Single acute oral dose of placebo capsules containing microcrystalline cellulose and matching excipients, matched in appearance and number to the SCFA capsules. Receives: Dietary Supplement: Placebo capsules; Biological: Lipopolysaccharide (LPS) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Serum interleukin-6 (IL-6) response to the LPS challenge
Effect of SCFA versus placebo on the systemic inflammatory response to experimental endotoxemia, indexed by serum IL-6 concentrations measured at serial timepoints across the test day following the intravenous LPS bolus. The primary analysis evaluates the treatment-by-timepoint interaction on the IL-6 time course using a linear mixed model, with treatment (SCFA vs. placebo) as a between-subject factor and timepoint as a within-subject factor.
Measured: 2 hours before LPS injection, and at 0, 1, 2, 3, 4, 5, and 6 hours after LPS injection
Secondary outcomes (14)
Serum pro- and anti-inflammatory cytokine response to the LPS challenge
Effect of SCFA versus placebo on serum concentrations of TNF-alpha, IL-1-beta, IFN-gamma, IL-8, IL-4, and IL-10. Analyzed as treatment-by-timepoint interactions using linear mixed models.
Measured: 2 hours before LPS injection, and at 0, 1, 2, 3, 4, 5, and 6 hours after LPS injection
High-sensitivity C-reactive protein (hs-CRP) response to the LPS challenge
Effect of SCFA versus placebo on serum high-sensitivity C-reactive protein (hs-CRP) concentrations, measured at selected timepoints on the test day and at the 24-hour follow-up visit.
Measured: 2 hours before LPS injection, and at 2, 6, and 24 hours after LPS injection
LPS-induced sickness behaviour (SicknessQ)
Effect of SCFA versus placebo on subjective sickness behaviour, assessed with the Sickness Questionnaire (SicknessQ), analyzed across timepoints on the test day.
Measured: 2 hours before LPS injection, and at 0, 1, 2, 3, 4, 5, and 6 hours after LPS injection
Body temperature response to the LPS challenge
Effect of SCFA versus placebo on body temperature (degrees Celsius).
Measured: 2 hours before LPS injection, and at 0, 1, 2, 3, 4, 5, and 6 hours after LPS injection
Heart rate response to LPS challenge
Effect of SCFA versus placebo on heart rate (beats per minute) across the monitoring period.
Measured: 2 hours before LPS injection, and at 0, 1, 2, 3, 4, 5, and 6 hours after LPS injection
Blood pressure response to the LPS challenge
Effect of SCFA versus placebo on systolic and diastolic blood pressure (mmHg).
Measured: 2 hours before LPS injection, and at 0, 1, 2, 3, 4, 5, and 6 hours after LPS injection
Salivary cortisol response to the LPS challenge
Effect of SCFA versus placebo on salivary cortisol concentrations (ng/ml).
Measured: At 0, 1, 2, 3, 4, and 6 hours after LPS injection
Plasma ACTH
Effect of SCFA versus placebo on plasma ACTH concentrations (ng/l)
Measured: At 0, 1, 2, 3, 4, and 6 hours after LPS injection
Working memory performance (3-back task)
Effect of SCFA versus placebo on working memory, assessed with the 3-back task (primary index: d-prime). Assessed at baseline (pre-LPS), post-LPS on the test day, and at the 24-hour follow-up.
Measured: 2 hours before LPS injection, 2.25 hours after LPS injection, and 24 hours after LPS injection
Response inhibition (Stop Signal Task)
Effect of SCFA versus placebo on response inhibition, assessed with the Stop Signal Task (outcome: stop-signal reaction time, SSRT, in milliseconds).
Measured: 2 hours before LPS injection, 2.25 hours after LPS injection, and 24 hours after LPS injection
Cognitive flexibility - task switching (Number-Letter task)
Effect of SCFA versus placebo on cognitive flexibility, assessed with the Number-Letter task (outcome: switch cost, in milliseconds).
Measured: 2 hours before LPS injection, 2.25 hours after LPS injection, and 24 hours after LPS injection
Cognitive inhibition (Stroop task)
Effect of SCFA versus placebo on cognitive inhibition, assessed with the Stroop task (outcome: congruency effect, in milliseconds).
Measured: 2 hours before LPS injection, 2.25 hours after LPS injection, and 24 hours after LPS injection
Cognitive flexibility - set shifting (Wisconsin Card Sorting Task)
Effect of SCFA versus placebo on cognitive flexibility, assessed with the Wisconsin Card Sorting Task (outcome: number of perseverative errors).
Measured: 2 hours before LPS injection, 2.25 hours after LPS injection, and 24 hours after LPS injection
Systemic SCFA uptake (serum SCFA concentrations)
Serum concentrations of acetate, propionate, and butyrate, assessed as a measure of systemic SCFA uptake to confirm target engagement of the colon-delivery intervention, and used as a mediator in mechanistic analyses of treatment effects on the inflammatory response.
Measured: 2 hours before LPS injection, and at 0, 1, 2, 3, 4, 5, and 6 hours after LPS injection
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Jul 2026
- Study start24 Oct 2025
- Primary completion30 Mar 2027 (estimated)
- Study completion30 Mar 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for EndotoxemiaStudies of the same condition, open and under way.
- More trials run by Universitaire Ziekenhuizen KU LeuvenThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Two-arm parallel-group design comparing SCFA colon-delivery capsules versus placebo. A single intravenous bolus of lipopolysaccharide (0.4 ng/kg body weight) is administered to all participants as a fixed inflammatory challenge condition.
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 56 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Universitaire Ziekenhuizen KU Leuven
- Sponsor type
- University, hospital or other
- Collaborators
- University Hospital, Essen, Flemish institute of biotechnology (VIB)
- Responsible party
- Sponsor
- Investigators
- Lukas Van Oudenhove, MD, PhD, Principal investigator, Laboratory for Brain-Gut Axis Studies, Translational Research Center for Gastrointestinal Disorders, Department of Chronic Diseases and Metabolism, KU Leuven, 3000 Leuven, BelgiumKristin Verbeke, PhD, Principal investigator, Translational Research Center for Gastrointestinal Disorders, Department of Chronic Diseases and Metabolism, KU Leuven, 3000 Leuven, BelgiumBoushra Dalile, PhD, Principal investigator, Laboratory for Brain-Gut Axis Studies, Translational Research Center for Gastrointestinal Disorders, Department of Chronic Diseases and Metabolism, KU Leuven, 3000 Leuven, Belgium
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07713641
- Sponsor's protocol ID
- S69844
- Status last verified
- Jun 2026
- First submitted
- 30 Jun 2026
- Last updated
- 20 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 20 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Investigating the Role of Short-Chain Fatty Acids in Endotoxemia-Induced Inflammation and Core Executive Functioning: A Randomized, Triple-Blind, Placebo-Controlled Trial
- ClinicalTrials.gov ID
- NCT07713641
- Acronym / sponsor ID
- S69844
- Conditions
- Endotoxemia, Inflammation, Executive Function (Cognition)
- Keywords
- scfa, short-chain fatty acids, butyrate, proprionate, acetate, lypopolysaccharide, lps, endotoxemia
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 56 participants (estimated)
- Lead sponsor
- Universitaire Ziekenhuizen KU LeuvenUniversity, hospital or other
- Collaborators
- University Hospital, Essen, Flemish institute of biotechnology (VIB)
- Study start
- 24 Oct 2025 (actual)
- Primary completion
- 30 Mar 2027 (estimated)
- Study completion
- 30 Mar 2027 (estimated)
- First posted
- 20 Jul 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Short-chain fatty acids (SCFAs) are substances produced by gut bacteria when they ferment dietary fiber. They can act as signals between the gut and the brain and may help regulate the body's immune and stress responses. Earlier work has shown that delivering SCFAs to the colon can lower the stress hormone response to a mental stress task in healthy people, and laboratory studies suggest SCFAs can reduce inflammation. However, it is not yet known whether SCFAs can reduce inflammation in humans, or whether doing so protects mental performance.
This study uses a controlled, acute, and short-lasting challenge. Healthy adults receive a single, low dose of a bacterial substance called lipopolysaccharide (LPS) through a vein. LPS briefly activates the immune system and causes mild, flu-like symptoms (such as fatigue, headache, and feeling unwell) that pass on their own within a few hours. It does not cause a real infection.
Participants are randomly assigned to take either SCFA capsules or inactive placebo capsules on the morning of the test day, before the LPS challenge. Neither the participants, the researchers running the visit, nor the researchers analyzing the results know who received which capsules until the study is complete (triple-blind).
The main goal of the study is to test whether SCFAs, compared with placebo, reduce the inflammatory response to LPS, measured by markers of inflammation in the blood. The study also examines whether SCFAs reduce the associated sickness symptoms and whether they protect performance on tasks that measure core executive functions: the ability to keep relevant information in mind (working memory), the ability to hold back automatic responses or thoughts (inhibition), and the ability to switch flexibly between tasks or rules (cognitive flexibility). Blood, saliva, and stool samples are collected to measure inflammation markers, SCFA levels, stress hormones, and gut bacteria.
Participants attend a screening visit, a test day with monitoring for several hours, and a short follow-up visit the next day.
Detailed description
INFLEX is a single-center, randomized, triple-blind, placebo-controlled, parallel-group interventional trial conducted at UZ Leuven / KU Leuven. Its primary aim is to test whether a single acute dose of colon-delivered SCFAs, relative to placebo, attenuates the systemic inflammatory response induced by experimental endotoxemia in healthy adults. Secondary aims are to test whether SCFAs attenuate LPS-induced sickness behaviour and mitigate endotoxemia-induced changes in core executive functioning, and to characterize associations between systemic SCFA uptake, the inflammatory response, and these outcomes.
Eligible participants are randomized to receive SCFA colon-delivery capsule or placebo capsules, taken on the morning of the test day with a standardized low-fiber breakfast. One hour after capsule intake, participants receive a single intravenous bolus of purified Escherichia coli lipopolysaccharide (0.4 ng/kg body weight), which serves as a fixed inflammatory challenge applied to all participants. The timing is designed so that peak circulating SCFA concentrations (approximately 3-4 hours after colonic delivery) coincide with the peak of LPS-induced cytokines and sickness behaviour (approximately 2-3 hours post-injection).
Participants are monitored for a minimum of 6 hours after the LPS challenge. Vital signs, sickness symptoms, and blood and saliva samples are collected hourly to quantify inflammatory markers (including IL-6 and hs-CRP), serum SCFA, cortisol, and ACTH. Core executive-function tasks are administered before and after the LPS challenge and at a 24-hour follow-up visit. A fecal sample collected at home prior to the test day is used for gut microbiota profiling. To standardize endogenous SCFA production, participants follow a low-fiber diet for three days before the test day and avoid caffeine, alcohol, and strenuous exercise beforehand. The night prior to the test day, participants are instructed to consume a standard dinner that is provided to them.
The study comprises three visits: a screening visit (~1 hour), the laboratory test day (~8 hours), and a follow-up visit (~30 minutes) 24 hours after the LPS challenge.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
- Model description
- Two-arm parallel-group design comparing SCFA colon-delivery capsules versus placebo. A single intravenous bolus of lipopolysaccharide (0.4 ng/kg body weight) is administered to all participants as a fixed inflammatory challenge condition.
| Arm | Type | Receives |
|---|---|---|
| SCFA Colon-Delivery Capsules | Experimental | Dietary Supplement: Short-Chain Fatty Acid Colon-Delivery Capsules, Biological: Lipopolysaccharide (LPS)A single acute oral dose of colon-delivery capsules delivering a short-chain fatty acid mixture (approximately 186 mmol total SCFA: 111 mmol acetate, 43 mmol propionate, 32 mmol butyrate; molar ratio approximately 60:23:17), taken on the morning of the test day with a standardized low-fiber breakfast. |
| Placebo | Placebo comparator | Dietary Supplement: Placebo capsules, Biological: Lipopolysaccharide (LPS)Single acute oral dose of placebo capsules containing microcrystalline cellulose and matching excipients, matched in appearance and number to the SCFA capsules. |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- Voluntary written informed consent obtained prior to any study procedure
- Healthy, with no gastrointestinal or psychological complaints
- Age 18-45 years
- BMI 18.5-27 kg/m2
- Proficiency in English and/or Dutch
Key exclusion criteria (27 listed)
- History of previous or current neurological disorder (e.g., epilepsy, multiple sclerosis, migraine with aura)
- History of previous or current psychiatric disorder (e.g., depression, anxiety disorders, bipolar disorder, schizophrenia)
- History of previous or current gastrointestinal disorder (e.g., Crohn's disease, ulcerative colitis, irritable bowel syndrome)
- History of previous or current endocrine disorder (e.g., diabetes, thyroid disorders, polycystic ovary syndrome)
- History of immune system disorder, including inflammatory, autoimmune, or severe allergic conditions (e.g., rheumatoid arthritis, lupus, celiac disease, or severe allergies such as anaphylaxis)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Short-Chain Fatty Acid Colon-Delivery CapsulesSingle acute oral dose of pH-dependent colon-delivery capsules delivering a short-chain fatty acid mixture to the colon. The mixture comprises sodium acetate,sodium butyrate, and sodium propionate (54.4%, 21.2%, and 24.4% by weight), providing approximately 186 mmol total SCFA per dose (111 mmol acetate, 32 mmol butyrate, 43 mmol propionate). Capsules are sub-coated with hydroxypropylcellulose and coated with a pH-dependent layer (Eudragit FS 30 D with PlasACRYL T20). Taken on the morning of the test day with a standardized low-fiber breakfast. | Dietary supplement | SCFA Colon-Delivery Capsules |
| Placebo capsulesAlso: Placebo, microcrystalline celluloseSingle acute oral dose of placebo capsules containing microcrystalline cellulose and matching excipients, an inert non-fermentable substrate. Matched in appearance and number to the SCFA capsules and taken on the morning of the test day with a standardized low-fiber breakfast. | Dietary supplement | Placebo |
| Lipopolysaccharide (LPS)Also: LPS, EndotoxinSingle intravenous bolus of purified Escherichia coli-derived lipopolysaccharide (0.4 ng/kg body weight), administered one hour after capsule intake to all participants as a standardized experimental inflammatory challenge common to both study arms. | Biological | Placebo, SCFA Colon-Delivery Capsules |
Primary outcome
Serum interleukin-6 (IL-6) response to the LPS challenge
Time frame: 2 hours before LPS injection, and at 0, 1, 2, 3, 4, 5, and 6 hours after LPS injection
Effect of SCFA versus placebo on the systemic inflammatory response to experimental endotoxemia, indexed by serum IL-6 concentrations measured at serial timepoints across the test day following the intravenous LPS bolus. The primary analysis evaluates the treatment-by-timepoint interaction on the IL-6 time course using a linear mixed model, with treatment (SCFA vs. placebo) as a between-subject factor and timepoint as a within-subject factor.
14 secondary outcomes
Serum pro- and anti-inflammatory cytokine response to the LPS challenge
Time frame: 2 hours before LPS injection, and at 0, 1, 2, 3, 4, 5, and 6 hours after LPS injection
High-sensitivity C-reactive protein (hs-CRP) response to the LPS challenge
Time frame: 2 hours before LPS injection, and at 2, 6, and 24 hours after LPS injection
LPS-induced sickness behaviour (SicknessQ)
Time frame: 2 hours before LPS injection, and at 0, 1, 2, 3, 4, 5, and 6 hours after LPS injection
Body temperature response to the LPS challenge
Time frame: 2 hours before LPS injection, and at 0, 1, 2, 3, 4, 5, and 6 hours after LPS injection
Heart rate response to LPS challenge
Time frame: 2 hours before LPS injection, and at 0, 1, 2, 3, 4, 5, and 6 hours after LPS injection
Blood pressure response to the LPS challenge
Time frame: 2 hours before LPS injection, and at 0, 1, 2, 3, 4, 5, and 6 hours after LPS injection
Salivary cortisol response to the LPS challenge
Time frame: At 0, 1, 2, 3, 4, and 6 hours after LPS injection
Plasma ACTH
Time frame: At 0, 1, 2, 3, 4, and 6 hours after LPS injection
Working memory performance (3-back task)
Time frame: 2 hours before LPS injection, 2.25 hours after LPS injection, and 24 hours after LPS injection
Response inhibition (Stop Signal Task)
Time frame: 2 hours before LPS injection, 2.25 hours after LPS injection, and 24 hours after LPS injection
Cognitive flexibility - task switching (Number-Letter task)
Time frame: 2 hours before LPS injection, 2.25 hours after LPS injection, and 24 hours after LPS injection
Cognitive inhibition (Stroop task)
Time frame: 2 hours before LPS injection, 2.25 hours after LPS injection, and 24 hours after LPS injection
Cognitive flexibility - set shifting (Wisconsin Card Sorting Task)
Time frame: 2 hours before LPS injection, 2.25 hours after LPS injection, and 24 hours after LPS injection
Systemic SCFA uptake (serum SCFA concentrations)
Time frame: 2 hours before LPS injection, and at 0, 1, 2, 3, 4, 5, and 6 hours after LPS injection
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 Jul 2026.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Lukas Van Oudenhove, MD, PhD principal investigator
Laboratory for Brain-Gut Axis Studies, Translational Research Center for Gastrointestinal Disorders, Department of Chronic Diseases and Metabolism, KU Leuven, 3000 Leuven, Belgium
Kristin Verbeke, PhD principal investigator
Translational Research Center for Gastrointestinal Disorders, Department of Chronic Diseases and Metabolism, KU Leuven, 3000 Leuven, Belgium
Boushra Dalile, PhD principal investigator
Laboratory for Brain-Gut Axis Studies, Translational Research Center for Gastrointestinal Disorders, Department of Chronic Diseases and Metabolism, KU Leuven, 3000 Leuven, Belgium
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Short-Chain Fatty Acid Colon-Delivery Capsules and Lipopolysaccharide (LPS) in people with Endotoxemia and Inflammation, run by Universitaire Ziekenhuizen KU Leuven at 1 site in Belgium.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 27 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 20 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Belgium. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Franco Ruiz, M.D. (+32456716114, franco.ruiz@kuleuven.be), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Serum interleukin-6 (IL-6) response to the LPS challenge (time frame: 2 hours before LPS injection, and at 0, 1, 2, 3, 4, 5, and 6 hours after LPS injection). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 20 Jul 2026.