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

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.

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.