Probiotic Administration on Mood

In recent years, the presence and awareness of a connection between the intestines and the brain has expanded leading to the understanding of developed communication pathways between the nervous, endocrine, and immune systems. Intestinal bacterial flora are active contributors to this axis through cellular signaling pathways and the release of immune system components, which fundamentally impact the function and action of various physiological systems. Interest in this area evolved through the understanding that various microbiota can produce neuroactive substances and neurotransmitters involved with the endocrine and autonomic nervous system pathways. This research has expanded to state that various bacterial products can influence cognitive functions, involving types of memory and problem-solving. Recent findings have begun to report on the impact that probiotic administration may have on mood, anxiety, and depression. Finally, recent work by Marotta et al. provided some of the first preliminary evidence that probiotic use may also impact mood and sleep quality. While initial work has developed this foundation, very little controlled research is available to help understand key contributing factors. For example, many key questions remain that future research should address to help better understand any impact probiotics may have on mood, depression, and anxiety. Some of these questions include:

Do all forms (genus, strain, etc.) of probiotics exert these impacts? How quickly do they exert impact? How large is the impact? Are certain aspect of affect more impacted than others? Once supplemented, how long is the residual impact (if there is any)? To help provided more guidance towards some of these basic research questions, this study is being proposed. The purpose of the study is to expand upon the previous work of Marotta et al. and determine the impact of probiotic administration on mood, depressive symptoms, anxiety, sleep quality, and other personality traits in a larger group of healthy men and women. This study will expand on the supplementation regimen and include a wider variety of hormonal assessments than what has previously been completed using this combination of probiotics.

Inclusion criteria

• between the ages of 18 - 50 years
• has a body mass index between 18.5 - 30 kg/m2.
• Anyone with a body mass index between 30 - 32 kg/m2, but has a body composition <25% fat -for men and <35% for women will be accepted into the study
• has been weight stable for the past three months (defined as less than a 5% variation in body -mass over this time)
• is determined to be healthy through completion of a health history questionnaire

Exclusion criteria

• Are currently diagnosed or being treated for any cardiac, respiratory, endocrine, psychiatric, musculoskeletal, - renal, hepatic, neuromuscular or metabolic disease or disorder that in the judgement of the study participant's personal physician or research nurse that will preclude their safe participation or will contraindicate quality control over the collected data
• are currently diagnosed with or are being treated for celiac disease, lactose intolerance, digestive insufficiencies or other gastrointestinal complications such as irritable bowel syndrome, ulcerative colitis, etc.
• report having used anabolic steroids within the past 30 days
• report have used any illicit or recreational drugs within the past 30 days
• report the intake of any prescription or over-the-counter medications (i.e., antibiotics) that may impact study outcomes
• report the current use of any dietary supplements known to impact digestion or sleep quality for the past 30 days
• report already taking a probiotic within the past 30 days
• have been actively trying to lose weight
• are currently following a ketogenic or low carbohydrate diet within the past 30 days