HealthyNCT04307628
Response of Gut Microbiota and Cardiometabolic Biomarkers to Consumption of Walnuts
A study testing Walnut and Nut-Free in people with Healthy and Normal Weight, run by University of California, Davis at 1 site in United States.
Trial summary
The researchers will investigate blood and fecal responses in qualified study participants after eating walnuts for 4 weeks compared to not eating walnuts for 4 weeks. The two dietary interventions will be separated by a 4 week washout period. Read more about this study
- Who is it for?
- Ages 20 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy, Normal Weight, Overweight
- What is being tested?
- Walnut and Nut-Free
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 0 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Jun 2022to 30 Nov 2024
- 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 20 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Generally healthy men and women between 20-65 years of age and BMI range of 20.0-34.9 kg/m2 will be recruited from the Davis - Sacramento metropolitan area. Enrolled subjects must be willing to consume 2 ounces (approximately 1/2 cup) of walnuts daily and modify their diet to avoid eating walnuts and other nuts, and foods or beverages high in polyphenols (a list will be provided) during study enrollment . Adults unable to consent, individuals who are not yet adults (infants, children, teenagers), pregnant or lactating women, women planning to become pregnant in the next four months and prisoners will be specifically excluded. Screening will take place by phone interview and through in-person screening and consent, including anthropometric and biochemical assessments and health history questionnaires.
Who cannot join
- Allergy to walnuts or other nuts
- Eating more than 25 grams of fiber per day, assessed by the Block Dietary-Fruit-Vegetable-Fiber Screener©
- Taking medications or supplements known to affect metabolism or gut microbiota composition (i.e. Metformin, statins, antibiotics within the past 3 months, fiber supplements, probiotics, and others)
- Documented chronic diseases including diabetes, renal or liver disease, metabolic syndrome, active cancer, MI or stroke, history of gastric bypass or GI disease (e.g. Crohn's Disease, Irritable Bowel Disease, diverticulosis/diverticulitis,etc)
- Smoker or living with a smoker, including vaporizer and/or electronic cigarettes.
- Illicit drug use, cannabis usage, or consuming >1 alcoholic drink/day
Show all 12Show fewer
- Extreme dietary or exercise patterns; vegan diet.
- Recent weight fluctuations (>10% in the last 6 months)
- Taking prescription lipid medications or supplements that may affect lipoprotein metabolism (i.e. >1 g of fish oil/day, antioxidant supplements)
- Taking exogenous hormones (e.g. hormonal birth control)
- Poor venous access
- Unwillingness to comply with study protocols
Trial locations and contacts
1 site in 1 country.
United States1 site
Ragle Human Nutrition Research Center
Davis, California, 95616
About this study
The researchers will investigate blood and fecal responses in qualified study participants after eating walnuts for 4 weeks compared to not eating walnuts for 4 weeks. The two dietary interventions will be separated by a 4 week washout period. The order of diets will be random; study participants will complete both interventions. Dietary modifications will be part of the study protocol.
Read the detailed description
The researchers hypothesize that walnut consumption will induce changes in fecal metagenome, identifiable walnut-derived bioactives (urolithins) and other microbial-derived products (short-chain fatty acids and secondary bile acids). The researchers hypothesize that walnut consumption will result in improvements to blood lipid profiles, including decreased total and LDL-cholesterol; increased HDL-related cholesterol efflux capacity and antioxidant protection; and decreased inflammatory biomarkers relative to control diet. The researchers hypothesize changes in cardiometabolic health biomarkers will be correlated with food bioactive metabolites and/or fecal metagenome. Pathway analysis will identify metabolic pathways differentially regulated by walnut-derived bioactives and walnut-responsive microbial genes.
- Conditions
- Healthy, Normal Weight, Overweight, Obese
- Being tested
- Walnut, Nut-Free
- Medical subject headings
- Overweight, Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
WalnutOther
Study participants will eat 2 ounces of walnuts each day.
Nut-FreeOther
Study participants will not eat nuts.
| Study group | Role | What they receive |
|---|---|---|
| Walnut | Active comparator | Eat 2 ounces of walnuts provided by the study. Eating any other nuts is to be avoided. Background diet will be low in polyphenols. Receives: Other: Walnut |
| Nut-Free | Placebo comparator | Eating any other nuts is to be avoided. Background diet will be low in polyphenols. Receives: Other: Nut-Free |
What is being measured
The primary outcome is the main question the study is designed to answer.
Assessing the influence of walnuts on the fecal metagenome
Changes in fecal metagenomics will be assessed via Illumina sequencing
Measured: Through study completion, an average of 12 weeks
Assessing the influence of walnuts on fecal secondary bile acids
Fecal secondary bile acids will be measured by LC-QTOF/MS
Measured: Through study completion, an average of 12 weeks
Assessing the influence of walnuts on fecal short-chain fatty acids
Short-chain fatty acids in fecal matter will be measured by LC-MS/MS
Measured: Through study completion, an average of 12 weeks
Urolithins measured in plasma by UPLC/MS
Measure for changes in the levels of urolithins in separated plasma; measured in units of ug/uL. Blood will be assessed at each of the 4 study visits.
Measured: Through study completion, an average of 12 weeks
Fecal calprotectin will be measured by ELISA
Measure for changes in the levels of calprotectin in collected fecal matter; measured in units of ug/g. Feces will be assessed at each of the 4 study visits.
Measured: Through study completion, an average of 12 weeks
Secondary outcomes (11)
Assessing the influence of walnuts on blood lipid measurements
Measure for changes in the levels of HDL and LDL in separated plasma; measured in units of mg/dL. Blood will be assessed at each of the 4 study visits
Measured: Through study completion, an average of 12 weeks
Assessing the influence of walnuts on paraoxonase-1 (PON-1) activity
Measure for changes in PON-1 activity in separated plasma at each study of the 4 study visits. Activity will be calculated based on linear rates of hydrolysis of phenyl acetate to phenol
Measured: Through study completion, an average of 12 weeks
Assessing the influence of walnuts on cholesterol ester transfer protein activity (CETP)
Changes in CETP activity will be measured at each of the 4 study visits. The isolated plasma will be co-incubated with donor and acceptor molecules using a commercially available assay kit.
Measured: Through study completion, an average of 12 weeks
Assessing the influence of walnuts on hsCRP will be measured in blood
hsCRP will be measured in blood at each study visit
Measured: Through study completion, an average of 12 weeks
Assessing the influence of walnuts on SAA will be measured in blood
SAA will be measured in blood at each study visit
Measured: Through study completion, an average of 12 weeks
Assessing the influence of walnuts on circulating cytokines
ICAM and VCAM will be measured in blood at each study visit using a commercially available ELISA kit.
Measured: Through study completion, an average of 12 weeks
Assessing the influence of walnuts on peripheral blood mononuclear cells (PBMC) using ex vivo stimulation assays
In-vitro: media from LPS stimulated monocytes will be used to measure gene expression and cytokines Measurement of changes in PBMC derived cytokines as a marker of inflammation at each of the 4 study visits. Assessment will be based on an increase or decrease in concentration in pg/ml.
Measured: Through study completion, an average of 12 weeks
Dietary record analysis
Use a computer program to check for study dietary requirements. Subjects are to avoid olives and olive containing products during study protocol periods. This will be done using a subject self-recorded 3-day food record submitted to study personnel.
Measured: Through study completion, an average of 12 weeks
Anthropometric measurements
Measure waist (cm) and hip circumference (cm) before the start of drawing blood on study day protocols.
Measured: Through study completion, an average of 12 weeks
Measure for changes in weight
Measure weight (kg) before the start of drawing blood on study day protocols
Measured: Through study completion, an average of 12 weeks
Measure for changes in blood pressure
Measure blood pressure (mmHg) before the start of drawing blood on study day protocols
Measured: Through study completion, an average of 12 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Mar 2020
- Study start1 Jun 2022 (estimated)
- Primary completion30 Jun 2024 (estimated)
- Study completion30 Nov 2024 (estimated)
Why it stopped: Study logistics still being worked out. On hold for now.
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HealthyStudies of the same condition, open and under way.
- More trials run by University of California, DavisThe 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
- Crossover
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 0 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of California, Davis
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Francene M Steinberg, PhD, RD, Principal investigator, University of California, Davis
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04307628
- Sponsor's protocol ID
- 1562149
- Status last verified
- May 2024
- First submitted
- 10 Mar 2020
- Last updated
- 22 May 2024
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 22 May 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Response of Gut Microbiota and Cardiometabolic Biomarkers to Consumption of Walnuts
- ClinicalTrials.gov ID
- NCT04307628
- Acronym / sponsor ID
- 1562149
- Conditions
- Healthy, Normal Weight, Overweight, Obese
- Study type
- Interventional
- Recruitment status
- WithdrawnReason stopped: Study logistics still being worked out. On hold for now.
- Enrolment
- 0 participants (actual)
- Lead sponsor
- University of California, DavisUniversity, hospital or other
- Study start
- 1 Jun 2022 (estimated)
- Primary completion
- 30 Jun 2024 (estimated)
- Study completion
- 30 Nov 2024 (estimated)
- First posted
- 13 Mar 2020 (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.
The researchers will investigate blood and fecal responses in qualified study participants after eating walnuts for 4 weeks compared to not eating walnuts for 4 weeks. The two dietary interventions will be separated by a 4 week washout period. The order of diets will be random; study participants will complete both interventions. Dietary modifications will be part of the study protocol.
Detailed description
The researchers hypothesize that walnut consumption will induce changes in fecal metagenome, identifiable walnut-derived bioactives (urolithins) and other microbial-derived products (short-chain fatty acids and secondary bile acids). The researchers hypothesize that walnut consumption will result in improvements to blood lipid profiles, including decreased total and LDL-cholesterol; increased HDL-related cholesterol efflux capacity and antioxidant protection; and decreased inflammatory biomarkers relative to control diet. The researchers hypothesize changes in cardiometabolic health biomarkers will be correlated with food bioactive metabolites and/or fecal metagenome. Pathway analysis will identify metabolic pathways differentially regulated by walnut-derived bioactives and walnut-responsive microbial genes.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Walnut | Active comparator | Other: WalnutEat 2 ounces of walnuts provided by the study. Eating any other nuts is to be avoided. Background diet will be low in polyphenols. |
| Nut-Free | Placebo comparator | Other: Nut-FreeEating any other nuts is to be avoided. Background diet will be low in polyphenols. |
Who may qualify
- Ages
- 20 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Generally healthy men and women between 20-65 years of age and BMI range of 20.0-34.9 kg/m2 will be recruited from the Davis - Sacramento metropolitan area. Enrolled subjects must be willing to consume 2 ounces (approximately 1/2 cup) of walnuts daily and modify their diet to avoid eating walnuts and other nuts, and foods or beverages high in polyphenols (a list will be provided) during study enrollment . Adults unable to consent, individuals who are not yet adults (infants, children, teenagers), pregnant or lactating women, women planning to become pregnant in the next four months and prisoners will be specifically excluded. Screening will take place by phone interview and through in-person screening and consent, including anthropometric and biochemical assessments and health history questionnaires.
Key exclusion criteria (12 listed)
- Allergy to walnuts or other nuts
- Eating more than 25 grams of fiber per day, assessed by the Block Dietary-Fruit-Vegetable-Fiber Screener©
- Taking medications or supplements known to affect metabolism or gut microbiota composition (i.e. Metformin, statins, antibiotics within the past 3 months, fiber supplements, probiotics, and others)
- Documented chronic diseases including diabetes, renal or liver disease, metabolic syndrome, active cancer, MI or stroke, history of gastric bypass or GI disease (e.g. Crohn's Disease, Irritable Bowel Disease, diverticulosis/diverticulitis,etc)
- Smoker or living with a smoker, including vaporizer and/or electronic cigarettes.
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 |
|---|---|---|
| WalnutStudy participants will eat 2 ounces of walnuts each day. | Other | Walnut |
| Nut-FreeStudy participants will not eat nuts. | Other | Nut-Free |
Primary outcome
Assessing the influence of walnuts on the fecal metagenome
Time frame: Through study completion, an average of 12 weeks
Changes in fecal metagenomics will be assessed via Illumina sequencing
Assessing the influence of walnuts on fecal secondary bile acids
Time frame: Through study completion, an average of 12 weeks
Fecal secondary bile acids will be measured by LC-QTOF/MS
Assessing the influence of walnuts on fecal short-chain fatty acids
Time frame: Through study completion, an average of 12 weeks
Short-chain fatty acids in fecal matter will be measured by LC-MS/MS
Urolithins measured in plasma by UPLC/MS
Time frame: Through study completion, an average of 12 weeks
Measure for changes in the levels of urolithins in separated plasma; measured in units of ug/uL. Blood will be assessed at each of the 4 study visits.
Fecal calprotectin will be measured by ELISA
Time frame: Through study completion, an average of 12 weeks
Measure for changes in the levels of calprotectin in collected fecal matter; measured in units of ug/g. Feces will be assessed at each of the 4 study visits.
11 secondary outcomes
Assessing the influence of walnuts on blood lipid measurements
Time frame: Through study completion, an average of 12 weeks
Assessing the influence of walnuts on paraoxonase-1 (PON-1) activity
Time frame: Through study completion, an average of 12 weeks
Assessing the influence of walnuts on cholesterol ester transfer protein activity (CETP)
Time frame: Through study completion, an average of 12 weeks
Assessing the influence of walnuts on hsCRP will be measured in blood
Time frame: Through study completion, an average of 12 weeks
Assessing the influence of walnuts on SAA will be measured in blood
Time frame: Through study completion, an average of 12 weeks
Assessing the influence of walnuts on circulating cytokines
Time frame: Through study completion, an average of 12 weeks
Assessing the influence of walnuts on peripheral blood mononuclear cells (PBMC) using ex vivo stimulation assays
Time frame: Through study completion, an average of 12 weeks
Dietary record analysis
Time frame: Through study completion, an average of 12 weeks
Anthropometric measurements
Time frame: Through study completion, an average of 12 weeks
Measure for changes in weight
Time frame: Through study completion, an average of 12 weeks
Measure for changes in blood pressure
Time frame: Through study completion, an average of 12 weeks
Results and safety
The study was withdrawn before enrolling participants, so there are no results.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 May 2024.
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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.
Francene M Steinberg, PhD, RD principal investigator
University of California, Davis
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Walnut and Nut-Free in people with Healthy and Normal Weight, run by University of California, Davis at 1 site in United States.
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 1 inclusion and 12 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: withdrawn, as of the sponsor's last update on 22 May 2024. 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 United States. 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?
The study was withdrawn before enrolling participants, so there are no results.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Assessing the influence of walnuts on the fecal metagenome (time frame: Through study completion, an average of 12 weeks). The study lists 5 primary outcomes in all. 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 22 May 2024.