Clinical trial NCT06311097: Dairy Products to Your Gut and Brain
Official title: Dairy Products to Your Gut and Brain
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Healthy
Constipation
Keywords: Diet
Fermented dairy
Gut-brain axis
Microbiota
Lead sponsor: University of Copenhagen
Sponsor class: OTHER
Collaborators: name: University of Aarhus
name: APC Microbiome Ireland
First posted: 2024-03-15
Enrollment: 100
Sex: FEMALE
Minimum age (years): 45
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: Two 4-week intervention periods separated by a washout period of at least 4 weeks.

The crossover intervention will include 60 participants. Another 40 participants will only complete the first (baseline) visit.
Primary purpose: BASIC_SCIENCE

Brief summary: The goal of this intervention study is to compare the effects of fermented dairy and non-fermented dairy on bowel habits and cognitive performance in healthy women with defecations every other day or less. Furthermore, the study aims to explore underlying mechanisms linking the gut and the brain.

In addition, a sub-study will be conducted to explore differences in gut and brain measures between women with daily (reference group) and few (intervention group) weekly bowel movements, respectively, and to explore associations between measures of gut- and brain function.

Detailed description: Participants in the intervention study (n=60) will consume 300g of fermented dairy (yogurt) or non-fermented dairy (milk) daily for 4 weeks. After a washout period of at least 4 weeks, the participants will consume the alternative dairy product (yogurt or milk) for 4 weeks. The participants will collect samples at home and be tested at the institute before and after each condition (yogurt or milk).

Participants in the sub-study (n=40) will not undergo any dairy interventions and they will only take part in the baseline assessments.

Prior to all visits at the institute, the participants are asked to complete some study activities at home, including:

* consumption of sweet corns to estimate whole gut transit time
* collection of fecal- and urine samples
* measurement of methane and hydrogen in breath
* reporting of gastrointestinal symptoms, including stool frequency and Bristol Stool Scale

During all visits at the institute, the participants will undergo tests and measurements, including:

* measurement of methane and hydrogen in fasting breath
* collection of fasting blood samples
* completion of cognitive tests
* recordings of electrophysiological signals of the gut and the brain
* completion of questionnaires assessing mood, quality of life, and physical activity, among others

Eligibility criteria: Inclusion Criteria:

* Self-reported defecations every second day or less (intervention study only)
* Willing to consume 300g milk/yogurt on a daily basis (intervention study only)
* Owns a smartphone (iOS 11.0 and later or Android 5.0 and up)
* Understand Danish or English

Exclusion Criteria:

* Current pregnancy or lactation
* Dairy allergy or intolerance
* Prior diagnosis of psychiatric or neurological illness
* Current diagnosis of depression, anxiety, or stress
* Prior diagnosis of metabolic or gastrointestinal disease (e.g., cardiovascular disease, diabetes, chronic constipation or diarrhea, inflammatory bowel diseases (IBD), celiac disease, small intestinal bacterial overgrowth (SIBO), cancer, etc.)
* Use of antibiotics within the last month
* Use of peroral corticosteroids (inhalers excepted)
* Use of medications that alter normal bowel function and metabolism (e.g., laxatives, antidiarrheal agents, narcotics, diuretics, anticonvulsants, etc.)
* Use of neuroactive medications (e.g., antidepressants, anxiolytics, anticonvulsants, antipsychotics, antiparkinsonian, etc.)
* Concurrent participation in another trial
* Any condition that makes the project responsible researcher doubt the feasibility of the volunteer´s participation

Primary outcomes:
measure: Difference in change from baseline in defecation frequency between the interventions
timeFrame: Baseline and 4 weeks
Secondary outcomes:
measure: Difference in change from baseline in cognitive performance between the interventions
timeFrame: Baseline and 4 weeks
measure: Difference in change from baseline in phase-amplitude coupling between gastric slow-wave activity and cortical alpha activity between the interventions
timeFrame: Baseline and 4 weeks
measure: Difference in change from baseline in whole gut transit time between the interventions
timeFrame: Baseline and 4 weeks
measure: Difference in change from baseline in stool consistency between the interventions
timeFrame: Baseline and 4 weeks
measure: Difference in change from baseline in stool moisture between the interventions
timeFrame: Baseline and 4 weeks
measure: Difference in change from baseline in fecal abundance of Lactobacillus acidophilus between the interventions
timeFrame: Baseline and 4 weeks
measure: Difference in change from baseline in self-reported gastrointestinal symptoms between the interventions
timeFrame: Baseline and 4 weeks
Other outcomes:
measure: Difference in change from baseline in gut microbiota between the interventions
timeFrame: Baseline and 4 weeks
measure: Difference in change from baseline in fecal pH between the interventions
timeFrame: Baseline and 4 weeks
measure: Difference in change from baseline in breath hydrogen and methane levels between the interventions
timeFrame: Baseline and 4 weeks
measure: Difference in change from baseline in biomarkers of colonic fermentation between the interventions
timeFrame: Baseline and 4 weeks
measure: Difference in change from baseline in fecal short-chain fatty acids (SCFAs) between the interventions
timeFrame: Baseline and 4 weeks
measure: Difference in change from baseline in fecal zonulin levels between the interventions
timeFrame: Baseline and 4 weeks
measure: Difference in change from baseline in plasma levels of lipopolysaccharide-binding protein (LBP) between the interventions
timeFrame: Baseline and 4 weeks
measure: Difference in change from baseline in gut metabolome between the interventions
timeFrame: Baseline and 4 weeks
measure: Difference in change from baseline in urine metabolome between the interventions
timeFrame: Baseline and 4 weeks
measure: Difference in change from baseline in plasma metabolome between the interventions
timeFrame: Baseline and 4 weeks
measure: Difference in change from baseline in inflammatory biomarkers between the interventions
timeFrame: Baseline and 4 weeks
measure: Difference in change from baseline in plasma levels of cortisol between the interventions
timeFrame: Baseline and 4 weeks
measure: Difference in change from baseline in biomarkers of glucose and lipid metabolism between the interventions
timeFrame: Baseline and 4 weeks
measure: Difference in change from baseline in appetite hormones between the interventions
timeFrame: Baseline and 4 weeks
measure: Difference in change from baseline in plasma level of Brain Derived Neurotrophic Factor (BDNF) between the interventions
timeFrame: Baseline and 4 weeks
measure: Difference in change from baseline in self-reported stress and mood between the interventions
timeFrame: Baseline and 4 weeks
measure: Difference in change from baseline in self-reported sleeping patterns between the interventions
timeFrame: Baseline and 4 weeks
measure: Difference in change from baseline in resting-state cortical connectivity between the interventions
timeFrame: Baseline and 4 weeks
measure: Difference in change from baseline in event-related potentials evoked by a cognitive task between the interventions
timeFrame: Baseline and 4 weeks
measure: Difference in change from baseline in quality of life between the interventions
timeFrame: Baseline and 4 weeks
measure: Difference in change from baseline in habitual diet between the interventions
timeFrame: Baseline and 4 weeks
Locations:
city: Copenhagen
country: Denmark
facility: University of Copenhagen, Department of Nutrition, Exercise and Sports
Study officials:
References: