Probiotic on Psychological and Cognitive Effects

Evaluation of a Probiotic on Psychological and Cognitive Effects in Middle and Older Adults

This study will determine whether supplementation of probiotic Lactobacillus Rhamnosus GG improves psychological status in middle age and older adults through a 12-week, randomized, double-blind, placebo-controlled clinical trial. Secondary analyses will be conducted to examine the possible benefits of probiotic supplementation on cognitive function and markers of physical health.

Inclusion Criteria:

• Age 55-75 years
• Able to speak and read English

Exclusion Criteria:

• History of neurological, developmental, or severe psychiatric disorder (e.g. dementia, stroke, schizophrenia);
• Antibiotic use in the past 30 days;
• History of significant stomach or GI surgery (e.g. gastric bypass, cholecystectomy);
• History of alcohol or illicit drug dependence;
• History of severe heart, kidney, or liver problems (e.g. heart failure, liver failure);
• Regular use of an acid-blocking medication in the past 30 days (i.e. proton pump inhibitor, H2 blocker);
• Likely immunosuppression (e.g. chemotherapy treatment);
• Regular use of other pre- or probiotic supplements in the past 30 days;
• Severe gastrointestinal conditions including celiac disease, Crohn's disease, or diverticulitis.