HealthyFOCUSNCT04951674
Dietary Fiber, Microbiota and Cognitive Function in Healthy Adults
A study testing High fiber diet in people with Healthy, run by University College Cork at 1 site in Ireland.
Trial summary
Dietary fiber is well-known for its many health benefits, including the support of gastrointestinal, metabolic, and mental health. Although studies investigating whole dietary patterns in relation to cognition have demonstrated that diet quality and a healthy dietary pattern are associated with better cognitive… Read more about this study
- Who is it for?
- Ages 30 to 60 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy
- What is being tested?
- High fiber diet
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 150 participants
- Where
- 1 siteIreland
- Study dates
- Jul 2021to Jul 2023
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 30 to 60 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Be able to give written informed consent.
- Be between 30 and 60 years of age.
- Be in generally good health as determined by the investigator.
Who cannot join
- Are less than 30 and greater than 60 years of age.
- Have a significant acute or chronic coexisting illness [cardiovascular, gastrointestinal (GI) [to include functional GI disorders, inflammatory bowel disease, celiac disease, lactose intolerance, food allergies], immunological, psychiatric [to include formal or as determined by MINI Psychiatric interview, diagnosis of current major depression, anxiety disorder, bipolar spectrum disorder, schizophrenia, other DSM-IV Axis I disorder], neurodevelopmental disorders, immunological, metabolic disorders [to include type I or II diabetes], or any condition which contraindicates, in the investigators judgement, entry to the study,
- Have a condition or taking a medication that the investigator believes would interfere with the objectives of the study, pose a safety risk or confound the interpretation of the study results; all psychoactive medications [to include anxiolytics, antipsychotics, antidepressants, anticonvulsants, centrally acting corticosteroids and opioid pain relievers), laxatives, enemas, antibiotics, anti-coagulants, over-the counter non-steroidal anti-inflammatories (NSAIDS). Participants should have a wash-out period of 4 weeks.
- Current prebiotic or probiotic supplement use (a wash-out period of 4 weeks after cessation will allow entry to the study).
- Females who are peri-menopausal, menopausal or post-menopausal.
- Females who are pregnant or planning a pregnancy, or lactating.
Show all 14Show fewer
- Participants who are not fluent in English or English is not first language.
- Are color blind.
- Have dyslexia or dyscalculia.
- Are a current habitual daily smoker.
- Individuals who, in the opinion of the investigator, are considered to be poor attendees or unlikely for any reason to be able to comply with the trial.
- Participants receiving treatment involving experimental drugs. If the subject has been in a recent experimental trial, these must have been completed not less than 30 days prior to this study.
- Have a malignant disease or any concomitant end-stage organ disease.
- Have completed a study in the laboratory in the past 4 years.
Trial locations and contacts
1 site in 1 country.
Ireland1 site, 1 recruiting
- Recruiting
APC Microbiome Ireland, University College Cork
Cork
John F Cryan, PhD, j.cryan@ucc.ie
Kirsten Berding, PhD, kirsten.berdingharold@ucc.ie
About this study
Official title: An Observational and Interventional Study on the Association Between Dietary Fibre and Cognitive Function in Healthy Volunteers
Dietary fiber is well-known for its many health benefits, including the support of gastrointestinal, metabolic, and mental health. Although studies investigating whole dietary patterns in relation to cognition have demonstrated that diet quality and a healthy dietary pattern are associated with better cognitive performance, the role of dietary fiber in this regard is understudied. In the last decade, the role of the microbiota (trillions of microbes inhabiting the gut) in influencing various aspects of human health, including mental health and behavior, has also become established. Importantly, dietary fiber has been shown to positively affect the microbiota composition.
In this study, the role of dietary fiber in cognition through the lens of the microbiota is investigated. A two-part study including an observational (study 1) and interventional (study 2) arm has been designed. In study 1, the observational arm, 150 healthy individuals (30-60 years of age) will be recruited and grouped into high-fiber (>25 g/day, n=75) and low-fiber (<18 grams/day, n=75) consumers based on habitual dietary intake. Cognitive tasks (attention, episodic memory, decision making), psychological dimensions including impulsivity and emotional reactivity, biological samples (feces, blood, saliva, urine) and questionnaires about general health will be collected. In study 2, the interventional arm, a subgroup (n=60) of individuals from the low-fiber group will further be randomized into an 8-week randomized-controlled, parallel, single-blinded intervention to either receive a high fiber (n=30, aim 30 grams/day) or control (n=30) diet education. During the intervention period, individuals will provide repeated fecal samples in order to assess temporal microbial changes. At the end of the intervention period, individuals will undergo the same testing regarding cognitive and psychological variables and the same biological samples will be collected.
The investigators hypothesize that participants with higher dietary fiber intake at baseline will perform better in the cognitive tasks compared to individuals with low fiber intake, and that this difference can, in part, be mediated by the gut microbiota. Further the investigators hypothesize that through the dietary intervention the microbiota composition will positively shift to include more beneficial microbes and that cognitive performance will improve following the intervention.
- Conditions
- Healthy
- Being tested
- High fiber diet, Control diet
- Keywords
- Dietary fiber, Microbiota, Cognition, Diet, Microbiota-Gut-Brain Axis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
High fiber dietOther
30 grams of fiber per day
Control dietOther
No diet education and change in diet
| Study group | Role | What they receive |
|---|---|---|
| DIET | Experimental | Participants will receive four individual, approximately 30-minute long dietary education sessions. The participants will receive detailed instructions (including meal plans, information on high fiber foods and serving sizes) on how to consume at least 30 grams of fiber per day. Receives: Other: High fiber diet |
| CONTROL | Placebo comparator | No diet education. Group will spend same amount of time with study dietitian, but discussion is limited to review of current eating habits and minimal input on eating habits with referencing the standard food pyramid. Receives: Other: Control diet |
What is being measured
The primary outcome is the main question the study is designed to answer.
Cognitive performance - Attention
Assessment of attention using the Paced Auditory Serial Addition Test (PASAT)
Measured: Differences between groups at baseline and changes after 8-week of diet intervention in active group
Cognitive performance - Episodic memory
Assessment of episodic memory using the Modified Rey Auditory Verbal Learning Test (ModRey)
Measured: Differences between groups at baseline and changes after 8-week of diet intervention in active group
Cognitive performance - Risky decision making
Assessment of risky decision making using the Cambridge Gambling Task (CGT)
Measured: Differences between groups at baseline and changes after 8-week of diet intervention in active group
Cognitive performance - Affective decision making
Assessment of affective decision making using the Iowa Gambling Task (IGT).
Measured: Differences between groups at baseline and changes after 8-week of diet intervention in active group
Secondary outcomes (7)
Microbiota composition and function
Shotgun sequencing of fecal samples
Measured: Differences between groups at baseline and changes after 8-week of diet intervention in active group
Blood inflammatory profile
Cytokine and chemokine levels (e.g., TNFalpha, IL-10, IL-6) will be measured in lipopolysaccharide stimulated and unstimulated bloods
Measured: Differences between groups at baseline and changes after 8-week of diet intervention in active group
Salivary cortisol concentrations
Morning cortisol awakening response
Measured: Differences between groups at baseline and changes after 8-week of diet intervention in active group
Stress assessment
Perceived Stress Scale (range 0 to 40 with higher scores indicating higher perceived stress)
Measured: Differences between groups at baseline and changes after 8-week of diet intervention in active group
Anxiety assessment
State Trait Anxiety Inventory (range 20-80 with higher scores indicating higher anxiety)
Measured: Differences between groups at baseline and changes after 8-week of diet intervention in active group
Emotion sensitivity, intensity, and persistence
Emotion Reactivity Scale (range 0-84 with higher scores indicating higher dysfunctional emotional reactivity)
Measured: Differences between groups at baseline and changes after 8-week of diet intervention in active group
Impulsivity-related traits
UPPS-P Impulsive Behavior Scale (range 59-236 with higher scores indicating higher dysfunctional impulsivity
Measured: Differences between groups at baseline and changes after 8-week of diet intervention in active group
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Jul 2021
- Study startJul 2021 (estimated)
- Primary completionJul 2023 (estimated)
- Study completionJul 2023 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for HealthyStudies of the same condition, open and under way.
- 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
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 150 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University College Cork
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, John Cryan, University College Cork
- Investigators
- John F Cryan, PhD, Principal investigator, APC Microbiome Ireland, University College CorkGerard Clarke, PhD, Principal investigator, APC Microbiome Ireland, University College Cork
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04951674
- Sponsor's protocol ID
- APC135
- Acronym
- FOCUS
- Status last verified
- Jul 2021
- First submitted
- 8 Jun 2021
- Last updated
- 7 Jul 2021
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Berding K, Carbia C, Cryan JF. Going with the grain: Fiber, cognition, and the microbiota-gut-brain-axis. Exp Biol Med (Maywood). 2021 Apr;246(7):796-811. doi: 10.1177/1535370221995785. Epub 2021 Feb 28.
PubMed 33641478Cryan JF, O'Riordan KJ, Cowan CSM, Sandhu KV, Bastiaanssen TFS, Boehme M, Codagnone MG, Cussotto S, Fulling C, Golubeva AV, Guzzetta KE, Jaggar M, Long-Smith CM, Lyte JM, Martin JA, Molinero-Perez A, Moloney G, Morelli E, Morillas E, O'Connor R, Cruz-Pereira JS, Peterson VL, Rea K, Ritz NL, Sherwin E, Spichak S, Teichman EM, van de Wouw M, Ventura-Silva AP, Wallace-Fitzsimons SE, Hyland N, Clarke G, Dinan TG. The Microbiota-Gut-Brain Axis. Physiol Rev. 2019 Oct 1;99(4):1877-2013. doi: 10.1152/physrev.00018.2018.
PubMed 31460832
Study at a glance
From the registry record, last updated by the sponsor on 7 Jul 2021. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Observational and Interventional Study on the Association Between Dietary Fibre and Cognitive Function in Healthy Volunteers
- ClinicalTrials.gov ID
- NCT04951674
- Acronym / sponsor ID
- FOCUS / APC135
- Conditions
- Healthy
- Keywords
- Dietary fiber, Microbiota, Cognition, Diet, Microbiota-Gut-Brain Axis
- Study type
- Interventional
- Recruitment status
- Unknown status
- Enrolment
- 150 participants (estimated)
- Lead sponsor
- University College CorkUniversity, hospital or other
- Study start
- Jul 2021 (estimated)
- Primary completion
- Jul 2023 (estimated)
- Study completion
- Jul 2023 (estimated)
- First posted
- 7 Jul 2021 (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.
Dietary fiber is well-known for its many health benefits, including the support of gastrointestinal, metabolic, and mental health. Although studies investigating whole dietary patterns in relation to cognition have demonstrated that diet quality and a healthy dietary pattern are associated with better cognitive performance, the role of dietary fiber in this regard is understudied. In the last decade, the role of the microbiota (trillions of microbes inhabiting the gut) in influencing various aspects of human health, including mental health and behavior, has also become established. Importantly, dietary fiber has been shown to positively affect the microbiota composition.
In this study, the role of dietary fiber in cognition through the lens of the microbiota is investigated. A two-part study including an observational (study 1) and interventional (study 2) arm has been designed. In study 1, the observational arm, 150 healthy individuals (30-60 years of age) will be recruited and grouped into high-fiber (>25 g/day, n=75) and low-fiber (<18 grams/day, n=75) consumers based on habitual dietary intake. Cognitive tasks (attention, episodic memory, decision making), psychological dimensions including impulsivity and emotional reactivity, biological samples (feces, blood, saliva, urine) and questionnaires about general health will be collected. In study 2, the interventional arm, a subgroup (n=60) of individuals from the low-fiber group will further be randomized into an 8-week randomized-controlled, parallel, single-blinded intervention to either receive a high fiber (n=30, aim 30 grams/day) or control (n=30) diet education. During the intervention period, individuals will provide repeated fecal samples in order to assess temporal microbial changes. At the end of the intervention period, individuals will undergo the same testing regarding cognitive and psychological variables and the same biological samples will be collected.
The investigators hypothesize that participants with higher dietary fiber intake at baseline will perform better in the cognitive tasks compared to individuals with low fiber intake, and that this difference can, in part, be mediated by the gut microbiota. Further the investigators hypothesize that through the dietary intervention the microbiota composition will positively shift to include more beneficial microbes and that cognitive performance will improve following the intervention.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| DIET | Experimental | Other: High fiber dietParticipants will receive four individual, approximately 30-minute long dietary education sessions. The participants will receive detailed instructions (including meal plans, information on high fiber foods and serving sizes) on how to consume at least 30 grams of fiber per day. |
| CONTROL | Placebo comparator | Other: Control dietNo diet education. Group will spend same amount of time with study dietitian, but discussion is limited to review of current eating habits and minimal input on eating habits with referencing the standard food pyramid. |
Who may qualify
- Ages
- 30 to 60 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- Be able to give written informed consent.
- Be between 30 and 60 years of age.
- Be in generally good health as determined by the investigator.
Key exclusion criteria (14 listed)
- Are less than 30 and greater than 60 years of age.
- Have a significant acute or chronic coexisting illness [cardiovascular, gastrointestinal (GI) [to include functional GI disorders, inflammatory bowel disease, celiac disease, lactose intolerance, food allergies], immunological, psychiatric [to include formal or as determined by MINI Psychiatric interview, diagnosis of current major depression, anxiety disorder, bipolar spectrum disorder, schizophrenia, other DSM-IV Axis I disorder], neurodevelopmental disorders, immunological, metabolic disorders [to include type I or II diabetes], or any condition which contraindicates, in the investigators judgement, entry to the study,
- Have a condition or taking a medication that the investigator believes would interfere with the objectives of the study, pose a safety risk or confound the interpretation of the study results; all psychoactive medications [to include anxiolytics, antipsychotics, antidepressants, anticonvulsants, centrally acting corticosteroids and opioid pain relievers), laxatives, enemas, antibiotics, anti-coagulants, over-the counter non-steroidal anti-inflammatories (NSAIDS). Participants should have a wash-out period of 4 weeks.
- Current prebiotic or probiotic supplement use (a wash-out period of 4 weeks after cessation will allow entry to the study).
- Females who are peri-menopausal, menopausal or post-menopausal.
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 |
|---|---|---|
| High fiber diet30 grams of fiber per day | Other | DIET |
| Control dietNo diet education and change in diet | Other | CONTROL |
Primary outcome
Cognitive performance - Attention
Time frame: Differences between groups at baseline and changes after 8-week of diet intervention in active group
Assessment of attention using the Paced Auditory Serial Addition Test (PASAT)
Cognitive performance - Episodic memory
Time frame: Differences between groups at baseline and changes after 8-week of diet intervention in active group
Assessment of episodic memory using the Modified Rey Auditory Verbal Learning Test (ModRey)
Cognitive performance - Risky decision making
Time frame: Differences between groups at baseline and changes after 8-week of diet intervention in active group
Assessment of risky decision making using the Cambridge Gambling Task (CGT)
Cognitive performance - Affective decision making
Time frame: Differences between groups at baseline and changes after 8-week of diet intervention in active group
Assessment of affective decision making using the Iowa Gambling Task (IGT).
7 secondary outcomes
Microbiota composition and function
Time frame: Differences between groups at baseline and changes after 8-week of diet intervention in active group
Blood inflammatory profile
Time frame: Differences between groups at baseline and changes after 8-week of diet intervention in active group
Salivary cortisol concentrations
Time frame: Differences between groups at baseline and changes after 8-week of diet intervention in active group
Stress assessment
Time frame: Differences between groups at baseline and changes after 8-week of diet intervention in active group
Anxiety assessment
Time frame: Differences between groups at baseline and changes after 8-week of diet intervention in active group
Emotion sensitivity, intensity, and persistence
Time frame: Differences between groups at baseline and changes after 8-week of diet intervention in active group
Impulsivity-related traits
Time frame: Differences between groups at baseline and changes after 8-week of diet intervention in active group
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 Jul 2021.
- Background: PubMed 33641478Berding K, Carbia C, Cryan JF. Going with the grain: Fiber, cognition, and the microbiota-gut-brain-axis. Exp Biol Med (Maywood). 2021 Apr;246(7):796-811. doi: 10.1177/1535370221995785. Epub 2021 Feb 28.
- Background: PubMed 31460832Cryan JF, O'Riordan KJ, Cowan CSM, Sandhu KV, Bastiaanssen TFS, Boehme M, Codagnone MG, Cussotto S, Fulling C, Golubeva AV, Guzzetta KE, Jaggar M, Long-Smith CM, Lyte JM, Martin JA, Molinero-Perez A, Moloney G, Morelli E, Morillas E, O'Connor R, Cruz-Pereira JS, Peterson VL, Rea K, Ritz NL, Sherwin E, Spichak S, Teichman EM, van de Wouw M, Ventura-Silva AP, Wallace-Fitzsimons SE, Hyland N, Clarke G, Dinan TG. The Microbiota-Gut-Brain Axis. Physiol Rev. 2019 Oct 1;99(4):1877-2013. doi: 10.1152/physrev.00018.2018.
- Individual participant dataSharing planned: No
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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. This study is not recruiting at the moment.
John F Cryan, PhD principal investigator
APC Microbiome Ireland, University College Cork
Gerard Clarke, PhD principal investigator
APC Microbiome Ireland, University College Cork
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing High fiber diet in people with Healthy, run by University College Cork at 1 site in Ireland.
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 3 inclusion and 14 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: status not confirmed, as of the sponsor's last update on 7 Jul 2021. 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 Ireland. 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?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
Contact Gerard Clarke, PhD (00353214901721, G.Clarke@ucc.ie), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Cognitive performance - Attention (time frame: Differences between groups at baseline and changes after 8-week of diet intervention in active group). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04951674, which also lists 2 linked publications.
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 7 Jul 2021.