NCT05260346

Modulation of the Gut-brain Axis by Cranberries: Impact on University Students' Mental Wellbeing

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 64 (actual)
• Sponsor: King's College London · Academic / Other
• Sex: All
• Age: 20 Years – 25 Years
• Healthy volunteers: Accepted

Summary

In this work, the investigators will assess whether cranberry (poly)phenols improve mood disorders including stress, anxiety and depression via the gut-brain axis in university students. The investigators will evaluate whether the effects observed are related to an improvement in gut microbiome diversity and function, and whether the mechanism of action may be mediated by a decrease in inflammatory markers, modulation of neurotransmitters or via an alteration of BDNF levels. The investigators will also quantify the most comprehensive panel of cranberry (poly)phenol metabolites. A double-blind, randomized placebo controlled 2-arm parallel study will be conducted in the Metabolic Research Unit (MRU, Department of Nutritional Sciences at KCL).

Detailed description

The study population will be final year BSc and MSc university students between 20-25 years old (n=60), who are generally healthy and not taking any medication. The study will be conducted during the period prior to their final exams (January until September). The intervention will be cranberry and placebo juice, consumed daily for 12 weeks, and will be provided free of cost by the Cranberry Institute. After a screening visit to evaluate inclusion and exclusion criteria, informed consent will be obtained, and subjects will be randomized to the treatments. The study will consist in a total of 4 visits, one visit every 4 weeks over a total of 12 weeks intervention. Volunteers will consume a cranberry or a control drink every day for 12 weeks. The day before each visit (pre-visit), volunteers will self-collect a total of 6 saliva samples throughout the day to measure cortisol levels as a biomarker of stress. Mental health, cognitive function, diet and physical activity will also be assessed using self-reported questionnaires, an online cognitive battery test and an online 24 h dietary recall. In addition, on the day before visits 1 and 4 (baseline and 12 weeks), a stool sample will be self-collected to assess changes in gut microbiome diversity and composition. On the day of each visit, a spot urine sample will be self-collected after waking up and before breakfast. During each visit, volunteers will drop the self-collected samples, and will collect new kits for the next visit. Visits 1 and 4 will last approximately 20 min, while visits 2 and 3 will last approximately 5 minutes. In addition, during visits 1 and 4, blood samples will be taken to investigate changes in gut-brain axis and cranberry related metabolites. Blood samples will also be collected at baseline to assess general health status of participants (blood lipids, markers of liver and kidney function, urea, uric acid, creatinine, and glucose).

Conditions

• Healthy

Interventions

Type	Name	Description
DIETARY_SUPPLEMENT	Cranberry juice	composition: Water, cranberry juice concentrate
DIETARY_SUPPLEMENT	Placebo	composition: Water, dextrose, citric acid, malic acid, fumaric acid, colorants, xanthan gum, natural flavor, emulsion

Timeline

• Start date: 2022-01-10
• Primary completion: 2022-08-22
• Completion: 2022-08-22
• First posted: 2022-03-02
• Last updated: 2022-11-22

Locations

1 site across 1 country: United Kingdom