Impact of Probiotic Supplementation on Cognition and Related Health Outcomes Among Video Gamers

Study Overview
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Brief Summary
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The primary objective of the current study is to investigate the effect of two probiotic formulations on task-switching following acute stress in healthy, adult action video gamers. It is hypothesized that the participants that consume the probiotic formulations will have improved task-switching performance following acute stress compared to those who consume a placebo.

Detailed Description
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Participants who are action gamers will be recruited to participate in this randomized, placebo-controlled, 2-arm, parallel trial. Eligible participants will be enrolled in this study for 8 weeks. The study will consist of 2 laboratory visits: Baseline Visit and Post-Treatment Visit.

Official Title
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Impact of Probiotic Supplementation on Cognition and Related Health Outcomes Among Video Gamers: A Randomized, Placebo-Controlled, Double-Blind, Clinical Trial

Conditions
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Stress, Attention Disturbances

Intervention / Treatment
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* Dietary Supplement: Probiotic
* Dietary Supplement: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male and female adults aged 19 to 35 years-old. Have played action video games (i.e., first- and third-person shooter and action role playing games) for a minimum of 5 hours per week over the course of the previous year as assessed by self-report (as per [1]) Willingness to continue the same amount of video game playing throughout the duration of the study. Willingness to maintain eating habits throughout the duration of the study. Willingness to discontinue consumption of probiotic supplements and probiotic- fortified products, as well as fiber supplement consumption (e.g., Metamucil, Benefiber, etc.), throughout the duration of the study. Willingness to maintain current physical activity levels throughout the duration of the study. Willing and able to consume a probiotic or placebo supplement for 8 weeks. Willingness to complete questionnaires, records, and diaries associated with the study and to complete all study visits. Able to provide informed consent. Exclusion Criteria: Use of antidepressants, anti-anxiolytic medication, and/or medication that improves attention, including amphetamines, methylphenidates, dexmethylphenidates, and atomoxetine hydrochloride. Disordered gaming, as per a score above 32 on the Internet Gaming Disorder Scale Short Form (IGDS9-SF; [2]). Head trauma that was diagnosed by a medical professional as a concussion or was associated with a loss of consciousness within the past two years. Currently diagnosed with alcohol use disorder and/or substance use disorder. Diabetes (type I and II), blood/bleeding disorders, liver and/or kidney disorders, unstable cardiovascular diseases, neurological diseases (e.g., Alzheimer's disease, Parkinson's disease, epilepsy), gastrointestinal diseases (e.g., gastric ulcers, Crohn's disease, ulcerative colitis). Presence of unrelated sleep disorders, diagnosis of a mental disorder within the previous year, history of diagnosis of attention-deficit/hyperactivity disorder or attention-deficit disorder Immunodeficiency (immune-compromised and immune-suppressed participants; e.g., AIDS, lymphoma, participants undergoing long-term corticosteroid treatment, chemotherapy and allograft participants). Arthritis pain or other chronic pain. Currently suffering from periodontitis. Pregnancy (as per urine pregnancy test at screening), planning to be pregnant or currently breastfeeding. Females of childbearing potential not using a medically approved method of birth control (e.g. hormonal contraception, intrauterine devices, vasectomy/tubal ligation, barrier methods, double-barrier method) or true abstinence. Milk, soy, and/or yeast allergy. Lactose intolerance. Use of any antibiotic drug within 4 weeks of randomization. Volunteer could be eligible to participate after a 2-week washout period. Current use of probiotics. Volunteer can be eligible after a four (4)-week washout period. Currently enrolled in another clinical trial.

Ages Eligible for Study
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Minimum Age: 19 Years
Maximum Age: 35 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: Supportive Care
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Randomized, placebo-controlled, double-blinded.
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Probiotic<br>Participants will be randomized to receive the probiotic formulation for 8 weeks. | Dietary Supplement: Probiotic<br>* Participants will be asked to take 1 capsule (3 billion CFU) daily for 8 weeks in the morning with their first meal.<br>|
| Placebo Comparator: Placebo<br>Participants will be randomized to receive the placebo formulation for 8 weeks. | Dietary Supplement: Placebo<br>* Participants will be asked to take 1 capsule daily for 8 weeks in the morning with their first meal.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in reaction time | The statistical difference in change in reaction time (in milliseconds) from baseline during a computerized task-switching color-word Stroop task following acute stress between the probiotic and placebo groups. | 8 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in reaction time: acute stress condition | The statistical difference in changes in reaction time (in milliseconds) on a computerized incongruent CWST between probiotic and placebo groups following acute stress. | 8 weeks | 
| Change in accuracy: acute stress condition | The statistical difference in changes in accuracy (proportion correct) on a computerized task-switching CWST and incongruent CWST between probiotic and placebo groups following acute stress. | 8 weeks | 
| Change in reaction time: non-stressful condition | The statistical difference in changes in reaction time (in milliseconds) on a computerized task-switching and incongruent CWST and a visual search (VS) paradigm, between probiotic and placebo groups in a non-stressful condition. | 8 weeks | 
| Change in accuracy: non-stressful condition | The statistical difference in changes in accuracy (proportion correct; %false alarms) on a computerized task-switching and an incongruent CWST, a go/no-go paradigm, a visual working memory maintenance paradigm, and a visual working memory complex span task (SYMSPAN) between probiotic and placebo groups in a non-stressful condition. | 8 weeks | 
| Change in self-reported cognitive control: non-stressful condition | The statistical difference in changes in self-reported cognitive control and cognitive flexibility as per the Cognitive Control and Flexibility Questionnaire (CCFQ) between probiotic and placebo groups in a non-stressful condition. | 8 weeks | 
| Changes in oxyhemoglobin concentrations in pre-frontal cortex | The statistical difference in changes in concentrations of oxygenated hemoglobin in the prefrontal cortex (PFC) during the task-switching CWST from baseline between the probiotic and placebo groups following acute stress and under non-stress conditions. | 8 weeks | 
| Changes in cortisol | The statistical difference in changes in the cortisol response to acute stress from baseline, as measured by the area under the curve with respect to increase (AUCi) and with respect to ground (AUCg) between probiotic and placebo groups. | 8 weeks | 
| Changes in salivary DHEA-S | The statistical difference in salivary DHEA-S from baseline between the probiotic and placebo groups. | 8 weeks | 
| Changes in salivary cortisol/DHEA-S ratio | The statistical difference in the salivary cortisol/DHEA-S ratio from baseline between the probiotic and placebo groups. | 8 weeks | 
| Changes in immune activity markers | The statistical difference in changes in salivary levels of proinflammatory cytokines, interleukin-1 beta, and interleukin-6 from baseline between probiotic and placebo groups. | 8 weeks | 
| Changes in self-reported levels of depression symptomology | The statistical difference in changes in the depression subscale score of the Depression, Anxiety, and Stress Scale Short Form (DASS-21) from baseline between the probiotic and placebo groups. | 8 weeks | 
| Changes in self-reported levels of anxiety symptomology | The statistical difference in changes in the anxiety subscale score of the Depression, Anxiety, and Stress Scale Short Form (DASS-21) from baseline between the probiotic and placebo groups. | 8 weeks | 
| Changes in self-reported levels of perceived stress symptomology | The statistical difference in changes in the stress subscale score of the Depression, Anxiety, and Stress Scale Short Form (DASS-21) from baseline between the probiotic and placebo groups. | 8 weeks | 
| Changes in self-reported levels of anxiety, depression, and perceived stress symptomology | The statistical difference in changes in the total scale score of the Depression, Anxiety, and Stress Scale Short Form (DASS-21) between the probiotic and placebo groups. | 8 weeks | 
| Changes in self-reported sleep quality | The statistical differences in changes in total Pittsburgh Sleep Quality Index (PSQI) scores between the probiotic and placebo groups. | 8 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Attention, Cognition, Acute Stress, Task-switching, Probiotics, HPA-axis