CALM Study: Can A Prebiotic Fibre bLend Improve Stress, Mood, and Anxiety?

Not Applicable

Not yet recruiting

• Conditions: Stress

• Registration Number: NCT07201909
• Lead Sponsor: Myota GmbH

Brief Summary

This clinical trial will investigate whether a powdered prebiotic fibre blend can improve perceived stress levels in healthy adults with mild-moderate 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 Timeline

• Study First Submitted: 2025-08-14
• Status Verified: 2025-09
• Study Start: 2025-09-22
• Study First Submitted QC: 2025-09-23
• Last Update Submitted: 2025-09-23
• Study First Posted: 2025-10-01
• Last Update Posted: 2025-10-01
• Primary Completion: 2026-09-30
• Study Completion: 2026-12-30

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 156

Inclusion Criteria

• 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-moderate stress levels (as assessed by DASS-42 stress subscale)
• Normal or corrected to normal vision and/or hearing

Exclusion Criteria

• 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
• 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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Perceived Stress	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).

Secondary Outcome Measures

Name	Time	Method
Perceived Stress	Baseline and 8 weeks	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).
Depression	Baseline, 8 weeks, and 12 weeks	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).
Mood	Baseline, 8 weeks and 12 weeks	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).
Anxiety	Baseline, Week 8, and Week 12	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).
Serum hs-CRP	Baseline and Week 12	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).
Gastrointestinal symptoms	Baseline, Week 8, and Week 12	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.
Cognition: Emotional Stroop	Baseline and Week 12	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.
Cognition: Affective 2-Back Task	Baseline and Week 12	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.
Cognition: Emotional Go-No-Go	Baseline and Week 12	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.
Cognition: Number-Letter Task	Baseline and Week 12	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.
Cognition: Attentional Network Task	Baseline and Week 12	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.

Trial Locations

Locations (1)

CALM Study Site; 🇬🇧 London, United Kingdom