The Effects of Probiotic Supplementation on State and Trait Stress, Anxiety, and Depression Symptoms in Stressed Adults

Inclusion Criteria: * age 18 - 45 * scoring 14+ on the perceived stress scale-10 indicating medium stress or higher * ability to provide informed consent * willingness not to take probiotic supplements (pills, tablets, oils, etc.) other than the product provided in the clinical study until all study procedures are completed * own a smartphone and are willing to receive study materials and complete study procedures by text Exclusion Criteria: * a history of gastrointestinal discomfort or surgery, urinary incontinence, cancer, toxic shock syndrome, frequent diarrhea, vital signs outside of the acceptable range (i.e., blood pressure \>160/100, oral temperature \>100°F, pulse \>100), heart disease, heart attack, lung/respiratory disease, any pulmonary, cardiovascular, gastrointestinal, hepatic or renal functional abnormality (i.e. a medical diagnosis related to lungs, heart, stomach/intestines, liver, or kidneys), HIV, Hepatitis B, Hepatitis C, bipolar disorder, psychosis, or confirmed or suspected immunosuppression or immunodeficiency * current (past month) alcohol or substance abuse or dependence (score of 2+ on the UNCOPE) * consistent (e.g., 5x/week or greater) probiotic supplementation within the last month, including probiotic food products such as yogurt * receiving antibiotics within the last month * receiving medications that interfere with gut motility (opiates, loperamide, stool softeners) * use of systemic antibiotics, antifungals, antivirals, or antiparasitics (intravenous, intramuscular, or oral) * use of oral, intravenous, intramuscular, nasal or inhaled corticosteroids * use of cytokines or cytokine inhibitors * use of methotrexate or immunosuppressive cytotoxic agents * receiving immunosuppressive drugs/medications or treatment including antineoplastic therapy, post-transplantation immunosuppressive therapy, and/or radiation therapy * participation in conflicting interventional research protocol * unstable dietary history as defined by major changes in diet during the previous month, where the subject has eliminated or significantly increased a major food group in their diet * female who is pregnant or lactating or reports expecting to get pregnant during the course of the study * currently involved in the criminal justice system as a prisoner or ward of the state