StressCALMNCT07201909
CALM Study: Can A Prebiotic Fibre bLend Improve Stress, Mood, and Anxiety?
A study testing Prebiotic fibre blend and Maltodextrin powder in people with Stress, run by Myota GmbH at 1 site in United Kingdom.
Trial summary
This clinical trial will investigate whether a powdered prebiotic fibre blend can improve perceived stress levels in healthy adults with mild-severe stress levels. Read more about this study
- Who is it for?
- Ages 18 to 50 years
- Conditions the study is for
- Stress
- What is being tested?
- Prebiotic fibre blend and Maltodextrin powder
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 156 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 2 Oct 2025to 30 Dec 2026
- 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 50 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Aged 18-50 years of age
- Capacity to give informed consent to participate in the study
- Able to comply with study requirements and visits
- Meet the range required for mild-severe stress levels (as assessed by DASS-42 stress subscale)
- Normal or corrected to normal vision and/or hearing
Who cannot join
- Current smoker
- Having food allergies and/or intolerances
- Diagnosis of Type 1 or 2 diabetes or cardiovascular disease or psychiatric or neurological conditions (e.g. schizophrenia, dementia) including eating disorders
- Current or previous diagnosis of depression in past 6 months
- Receiving medications that lower cholesterol, blood pressure, blood glucose levels, or improve insulin sensitivity
- Receiving antidepressant or anti-anxiety medications or treatments
Show all 18Show fewer
- Receiving hormonal birth control
- Perimenopause or menopause
- Pregnancy, lactation, or an intent to become pregnant during the course of the study
- Continuous antibiotic use for > 3 days within 1 month prior to enrolment
- Continuous use of weight-loss drug for > 1 month before screening
- Major change in dietary intake in past month (e.g. excluding whole food groups)
- Currently consuming daily prebiotic or probiotic supplements
- Prior use (< 6 months) of any blood glucose or cholesterol lowering medication
- Any significant GI condition affecting GI absorption including (but not limited to) inflammatory bowel disease, weight loss surgery, irritable bowel disease.
- End stage renal disease
- Active cancer, or treatment for any cancer, in last 3 years
- Consuming more than 20g of fibre a day as assessed by the 18-item FiberScreen
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United Kingdom1 site, 1 recruiting
- Recruiting
CALM Study Site
London, EC2A 4BQ
Caitlin Hall, PhD, 07830709854, caitlin@myotahealth.com
About this study
Official title: Can A Prebiotic Fibre bLend Improve Stress, Mood, and Anxiety? Assessing the Impact of a Daily Prebiotic Fibre Blend on Affect, Inflammation, and the Gut Microbiome: a 12-week Double-blind Placebo-controlled RCT
This clinical trial will investigate whether a powdered prebiotic fibre blend can improve perceived stress levels in healthy adults with mild-severe stress levels.
Read the detailed description
There is growing interest in how the gut microbiota interacts with the brain to influence psychological outcomes, particularly stress. Even in otherwise healthy individuals, persistent psychological stress is associated with measurable physiological changes-including elevated cortisol levels, heightened hypothalamic-pituitary-adrenal (HPA) axis reactivity, and systemic low-grade inflammation. These biological signatures are increasingly understood to be shaped, in part, by the composition and activity of the gut microbiota.
In this study, we're investigating how a powdered prebiotic fibre supplement can improve stress levels. You may have heard people refer to this as the 'gut-brain axis'. We'll also be looking at the link between the prebiotic fibre supplement intake and changes in other areas of health, like depression, mood, anxiety, cognition, inflammation, and the gut microbiome.
- Conditions
- Stress
- Being tested
- Prebiotic fibre blend, Maltodextrin powder
- Keywords
- gut-brain axis, perceived stress, prebiotic fibre, cognitive function, anxiety, mood, depression, inflammation
- Medical subject headings
- Anxiety Disorders, Depression, Inflammation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Prebiotic fibre blendDietary supplement
A blend of prebiotic fibres in a powdered supplement form.
Maltodextrin powderDietary supplement
Maltodextrin powder
| Study group | Role | What they receive |
|---|---|---|
| Prebiotic fibre blend | Experimental | Prebiotic fibre blend, consisting of 10g of a powdered supplement, to be taken daily alongside usual diet for 12 weeks. Receives: Dietary Supplement: Prebiotic fibre blend |
| Placebo | Placebo comparator | Placebo will be 10g of maltodextrin powder, to be taken daily alongside usual diet for 12 weeks. Receives: Dietary Supplement: Maltodextrin powder |
What is being measured
The primary outcome is the main question the study is designed to answer.
Perceived Stress
The primary objective is to determine the effect of 12-week long daily administration of Prebiotic fibre blend as compared to Placebo on stress scores (Perceived Stress Scale) on a scale between 0 - 40 (where higher scores indicate higher stress).
Measured: Baseline and 12 weeks
Secondary outcomes (11)
Perceived Stress
To determine the effect of 12-week long daily administration of Prebiotic fibre blend as compared to Placebo on stress scores (Perceived Stress Scale) on a scale between 0 - 40 (where higher scores indicate higher stress).
Measured: Baseline and 8 weeks
Depression
To determine the effect of 12-week daily administration of Prebiotic fibre blend as compared to Placebo on depression scores (DASS-42), on a scale between 0 - 21 (where higher scores mean higher depression).
Measured: Baseline, 8 weeks, and 12 weeks
Mood
To determine the effect of 12-week daily administration of Prebiotic fibre blend as compared to Placebo on mood scores (PANAS-X), on a scale between 10 - 50 (where higher scores on the Positive Affect scale indicate higher levels of positive engagement with your environment; while higher scores on the Negative Affect scale indicate higher levels of negative engagement).
Measured: Baseline, 8 weeks and 12 weeks
Anxiety
To determine the effect of 12-week daily administration of Prebiotic fibre blend as compared to Placebo on anxiety scores (DASS-42), on a scale between 0 - 21 (where higher scores mean higher anxiety levels).
Measured: Baseline, Week 8, and Week 12
Serum hs-CRP
To determine the effect of 12-week daily administration of Prebiotic fibre blend as compared to Placebo on serum high sensitivity C-Reactive Protein (hs-CRP).
Measured: Baseline and Week 12
Gastrointestinal symptoms
To determine the effect of 12-week daily administration of Prebiotic fibre blend as compared to Placebo on gastrointestinal symptoms (GSRS), on a scale of 15 - 105 where higher scores indicate more severe gastrointestinal discomfort.
Measured: Baseline, Week 8, and Week 12
Cognition: Emotional Stroop
To determine the effect of 12-week daily administration of Prebiotic fibre blend as compared to Placebo on emotional interference in attention and processing (reaction time and accuracy), as assessed by the Emotional Stroop where better scores are achieved by lower reaction times and higher accuracy score.
Measured: Baseline and Week 12
Cognition: Affective 2-Back Task
To determine the effect of 12-week daily administration of Prebiotic fibre blend as compared to Placebo on emotional interference in working memory under emotional load, as assessed by the Affective 2-Back Task, where better scores are achieved by lower reaction times and higher accuracy score.
Measured: Baseline and Week 12
Cognition: Emotional Go-No-Go
To determine the effect of 12-week daily administration of Prebiotic fibre blend as compared to Placebo on emotion-related inhibitory control and response suppression, as assessed by the Emotional Go-No-Go, where better scores are achieved by higher correct response rates and lower commission errors.
Measured: Baseline and Week 12
Cognition: Number-Letter Task
To determine the effect of 12-week daily administration of Prebiotic fibre blend as compared to Placebo on cognitive flexibility and task-switching ability, as assessed by the Number-Letter Task, where better scores are achieved by higher numbers of correctly recalled items.
Measured: Baseline and Week 12
Cognition: Attentional Network Task
To determine the effect of 12-week daily administration of Prebiotic fibre blend as compared to Placebo on efficiency of alerting, orienting, and executive attention networks, as assessed by the Attentional Network Task , where better scores are achieved by lower reaction times and higher accuracy.
Measured: Baseline and Week 12
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Oct 2025
- Study start2 Oct 2025
- Primary completion30 Sep 2026 (estimated)
- Study completion30 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for StressStudies 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
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Two-arm, double-blind, placebo-controlled randomised trial
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 156 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Myota GmbH
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- University of Reading
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07201909
- Sponsor's protocol ID
- CALM
- Acronym
- CALM
- Status last verified
- Mar 2026
- First submitted
- 14 Aug 2025
- Last updated
- 13 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Participant data will not be shared.
Study at a glance
From the registry record, last updated by the sponsor on 13 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Can A Prebiotic Fibre bLend Improve Stress, Mood, and Anxiety? Assessing the Impact of a Daily Prebiotic Fibre Blend on Affect, Inflammation, and the Gut Microbiome: a 12-week Double-blind Placebo-controlled RCT
- ClinicalTrials.gov ID
- NCT07201909
- Acronym / sponsor ID
- CALM / CALM
- Conditions
- Stress
- Keywords
- gut-brain axis, perceived stress, prebiotic fibre, cognitive function, anxiety, mood, depression, inflammation
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 156 participants (estimated)
- Lead sponsor
- Myota GmbHIndustry (pharma, biotech, devices)
- Collaborators
- University of Reading
- Study start
- 2 Oct 2025 (actual)
- Primary completion
- 30 Sep 2026 (estimated)
- Study completion
- 30 Dec 2026 (estimated)
- First posted
- 1 Oct 2025 (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.
This clinical trial will investigate whether a powdered prebiotic fibre blend can improve perceived stress levels in healthy adults with mild-severe stress levels.
Detailed description
There is growing interest in how the gut microbiota interacts with the brain to influence psychological outcomes, particularly stress. Even in otherwise healthy individuals, persistent psychological stress is associated with measurable physiological changes-including elevated cortisol levels, heightened hypothalamic-pituitary-adrenal (HPA) axis reactivity, and systemic low-grade inflammation. These biological signatures are increasingly understood to be shaped, in part, by the composition and activity of the gut microbiota.
In this study, we're investigating how a powdered prebiotic fibre supplement can improve stress levels. You may have heard people refer to this as the 'gut-brain axis'. We'll also be looking at the link between the prebiotic fibre supplement intake and changes in other areas of health, like depression, mood, anxiety, cognition, inflammation, and the gut microbiome.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
- Model description
- Two-arm, double-blind, placebo-controlled randomised trial
| Arm | Type | Receives |
|---|---|---|
| Prebiotic fibre blend | Experimental | Dietary Supplement: Prebiotic fibre blendPrebiotic fibre blend, consisting of 10g of a powdered supplement, to be taken daily alongside usual diet for 12 weeks. |
| Placebo | Placebo comparator | Dietary Supplement: Maltodextrin powderPlacebo will be 10g of maltodextrin powder, to be taken daily alongside usual diet for 12 weeks. |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- Aged 18-50 years of age
- Capacity to give informed consent to participate in the study
- Able to comply with study requirements and visits
- Meet the range required for mild-severe stress levels (as assessed by DASS-42 stress subscale)
- Normal or corrected to normal vision and/or hearing
Key exclusion criteria (18 listed)
- Current smoker
- Having food allergies and/or intolerances
- Diagnosis of Type 1 or 2 diabetes or cardiovascular disease or psychiatric or neurological conditions (e.g. schizophrenia, dementia) including eating disorders
- Current or previous diagnosis of depression in past 6 months
- Receiving medications that lower cholesterol, blood pressure, blood glucose levels, or improve insulin sensitivity
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 |
|---|---|---|
| Prebiotic fibre blendA blend of prebiotic fibres in a powdered supplement form. | Dietary supplement | Prebiotic fibre blend |
| Maltodextrin powderMaltodextrin powder | Dietary supplement | Placebo |
Primary outcome
Perceived Stress
Time frame: Baseline and 12 weeks
The primary objective is to determine the effect of 12-week long daily administration of Prebiotic fibre blend as compared to Placebo on stress scores (Perceived Stress Scale) on a scale between 0 - 40 (where higher scores indicate higher stress).
11 secondary outcomes
Perceived Stress
Time frame: Baseline and 8 weeks
Depression
Time frame: Baseline, 8 weeks, and 12 weeks
Mood
Time frame: Baseline, 8 weeks and 12 weeks
Anxiety
Time frame: Baseline, Week 8, and Week 12
Serum hs-CRP
Time frame: Baseline and Week 12
Gastrointestinal symptoms
Time frame: Baseline, Week 8, and Week 12
Cognition: Emotional Stroop
Time frame: Baseline and Week 12
Cognition: Affective 2-Back Task
Time frame: Baseline and Week 12
Cognition: Emotional Go-No-Go
Time frame: Baseline and Week 12
Cognition: Number-Letter Task
Time frame: Baseline and Week 12
Cognition: Attentional Network Task
Time frame: Baseline and Week 12
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 13 Mar 2026.
- Individual participant dataSharing planned: No. Participant data will not be shared.
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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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Prebiotic fibre blend and Maltodextrin powder in people with Stress, run by Myota GmbH at 1 site in United Kingdom.
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 18 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 13 Mar 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 United Kingdom. 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 Caitlin Hall, PhD, RD (07830709854, caitlin@myotahealth.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Perceived Stress (time frame: Baseline and 12 weeks). 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 13 Mar 2026.