Impact of Yogurt on Gastrointestinal Health, Regularity, and Thoughts

Study Overview
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Brief Summary
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This study aims to test the central hypothesis that adding to the diet daily yogurt provides beneficial effects on digestive health and subjective mood in healthy adults.

Detailed Description
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This clinical trial will include a 4-week lead-in period and a 2-week treatment period. The lead-in period will be devoid of all supplemental and dietary probiotics, fermented dairy products, and fermented foods. Participants will be asked to refrain from consuming all supplemental and dietary probiotics, fermented dairy products, and fermented foods throughout the entire study. During the treatment period, participants will be given yogurt with sugar. This trial will serve as a continuation of the NECTAR Study (NCT04187950).

Official Title
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Impact of Yogurt on Gastrointestinal Health, Regularity, and Thoughts

Conditions
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Gastrointestinal Dysfunction, Physiological Stress, Cognition - Other

Intervention / Treatment
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* Dietary Supplement: Yogurt with B. lactis and added cane sugar


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Males and females Between the ages of 22-64 years at the time of consent Body mass index of 18.5 to 29.9 kg/m^2. Normal or corrected-to-normal vision based on the minimal 20/20 standard in order to complete the cognitive task (below 20/20 vision). Ability to drop off fecal sample within 30 minutes of defecation Have between 3-6 bowel movements per week Have completed the NECTAR Study (NCT04187950) Exclusion Criteria: Current pregnancy, lactation, or post-menopausal Tobacco use Honey allergy or intolerance Dairy allergy, lactose intolerance Food dye allergy/intolerance Prior physician diagnosed gastrointestinal disease (chronic constipation, diarrhea, Crohn's disease, celiac disease, ulcerative colitis, irritable bowel syndrome, diverticulosis, stomach or duodenal ulcers, hepatitis, or gastroesophageal reflux disease (GERD)) Current use or use of antibiotics in the past 3 months Current use of any of the following types of medications: laxatives, anti-diarrhea medications, narcotics, enemas, antispasmodics, anticonvulsants, prescription proton pump inhibitors, prokinetic agents, histamine-2 Rc antagonists (prescription GERD medication) Body mass index > 29.9 kg/m^2 Prior malabsorptive bariatric surgery (i.e. gastric bypass, sleeve gastrectomy) Restrictive bariatric surgery (i.e. adjustable gastric band) within the past 5 years Concurrent enrollment in another dietary, exercise, or medication study (except for the NECTAR Study (NCT04187950))

Ages Eligible for Study
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Minimum Age: 22 Years
Maximum Age: 64 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Intervention Model: Single Group Assignment
Interventional Model Description: Controlled single-group trial with a 4-week lead-in period and a 2-week treatment period. The treatment will consist of yogurt with sugar.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Yogurt with B. lactis and added cane sugar<br>Participants will consume yogurt with B. lactis and added cane sugar twice daily for 14 days. | Dietary Supplement: Yogurt with B. lactis and added cane sugar<br>* The intervention condition will utilize a commercially available yogurt (Activia) that contains Bifidobacterium animalis lactis DN-173 010/CNCM I-2494 (B. lactis). Participants will consume 170 g of yogurt with cane sugar twice daily for 14 days.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Intestinal transit time measured using colored dye markers | Determine the impact of consumption of daily yogurt with sugar on intestinal transit time in vivo. Intestinal transit time will be measured using colored dye markers. | 2 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Digestive health measured using daily stool records with the Bristol Stool Scale | Determine the impact of consumption of daily yogurt with sugar on digestive health using daily stool records. Within the records, participants rate stool consistency using the Bristol Stool Scale (1=hard to 7=watery). | 2 weeks | 
| Digestive health measured using rating scales of additional symptoms in daily stool records | Determine the impact of consumption of daily yogurt with sugar on other measures of digestive health using daily stool records. Within the records, ratings of additional gastrointestinal symptoms include ease of passage (1=very easy to 5=very difficult, abdominal pain, bloating, burping, flatulence, nausea, reflux, and rumblings (1=absent to 4=severe). | 2 weeks | 
| Digestive health measured using the Gastrointestinal Tolerability questionnaire | Determine the impact of consumption of daily yogurt with sugar on other measures of digestive health using the Gastrointestinal Tolerability questionnaire. This questionnaire assesses gastrointestinal health through 6 questions related to gastrointestinal health including nausea, bloating, rumblings, gas/flatulence, abdominal pain, and diarrhea (no more than usual to much more than usual). Each of the questions pertains to experience of symptoms in the past 7 days. | 2 weeks | 
| Digestive health measured using the Gastrointestinal Quality of Life Index (GIQLI) questionnaire | Determine the impact of consumption of daily yogurt with sugar on other measures of digestive health using the Gastrointestinal Quality of Life Index (GIQLI) questionnaire. The GIQLI assesses gastrointestinal health through a series of 36 questions pertaining to daily life and gastrointestinal symptoms experienced in the past 2 weeks. | 2 weeks | 
| Mood measured using the Emotional Image Task | Determine the impact of consumption of daily yogurt with sugar on mood states using the Emotional Image Task. This task measures response to neutral, positive, and negative image stimuli using participant valence, arousal, and dominance ratings. | 2 weeks | 
| Mood measured using the Positive and Negative Affect Schedule (PANAS) questionnaire | Determine the impact of consumption of daily yogurt with sugar on mood states using the Positive and Negative Affect Schedule (PANAS) questionnaire. The PANAS assesses general mood using a 20-item scale that includes words associated with either positive (10 words) or negative (10 words) emotions. | 2 weeks | 
| Mood measured using the Depression, Anxiety, and Stress Scales-42 (DASS-42) questionnaire | Determine the impact of consumption of daily yogurt with sugar on mood states using the Depression, Anxiety, and Stress Scales-42 (DASS-42) questionnaire. The DASS-42 includes subscales with 42 questions regarding negative emotional states and is used to assess mental health over the past week. The rating scale for each question is 0=did not apply to me at all to 3=applied to me very much, or most of the time. Lower scores indicate none or less symptoms of depression, anxiety, or stress. | 2 weeks | 
| Mood measured using Patient-Reported Outcomes Measurement Information System (PROMIS) questionnaires | Determine the impact of consumption of daily yogurt with sugar on mood states using Patient-Reported Outcomes Measurement Information System (PROMIS) questionnaires. Specific PROMIS surveys utilized included PROMIS SF v1.0 - Anger 8a, PROMIS SF v1.0 - Anxiety 8a, PROMIS SF v1.0 - Fatigue 8a, PROMIS SF v1.0 - Positive Affect 15a, PROMIS SF v1.0 - Self-Efficacy Manage Emotions 8a, PROMIS SF v1.0 - Fatigue 13a (FACIT-Fatigue), PROMIS SF v1.1 - Global Health, and PROMIS SF v2.0 - Cognitive Function 8a. PROMIS. Surveys were scored using the recommended HealthMeasures Scoring Service. | 2 weeks | 
| Cognitive function measured using the Spatial Reconstruction Task | Determine the impact of consumption of daily yogurt with sugar on cognitive function compared to control (yogurt containing heat-inactivated B. lactis) using the Spatial Reconstruction Task. This task requires participants to successfully encode and retrieve information pertaining to the position of six objects in relation to each other, necessitating recruitment of the hippocampal memory system. | 2 weeks | 
| Gastrointestinal microbiota assessed using relative abundances | Determine the impact of daily consumption of yogurt with sugar on the gastrointestinal microbiota. Relative abundances of the gastrointestinal microbiota will be measured with 16S amplicon sequencing. | 2 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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gastrointestinal transit time, mood, emotion