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

Evaluating the Effects of Lactobacillus Reuteri DSM 17938 on State and Trait Stress in Stressed Adults

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07216729
Enrollment
150
Registered
2025-10-15
Start date
2023-02-20
Completion date
2024-06-01
Last updated
2025-11-18

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Anxiety Symptoms, Perceived Stress, Depressive Symptoms

Keywords

Lactobacillus reuteri DSM 17938, Perceived stress, Anxiety, Depression, Probiotic, Randomized controlled trial

Brief summary

The goal of this randomized controlled trial is to learn if supplementation with the probiotic Lactobacillus reuteri DSM 17938 can reduce levels of trait and state perceived stress, anxiety, and depressive symptoms compared to a placebo in a population of stressed adults ages 18-45. This study also investigates several evidence-based moderators of treatment effects, evaluates whether the probiotic caused side effects, and evaluates whether effects endured at 1-month post-supplementation.

Interventions

5 drops (100 million CFUs) daily for 46 days of L. reuteri DSM 17938 in sunflower oil, medium chain triglyceride oil, and silicon dioxide.

OTHERPlacebo

5 drops daily for 46 days of placebo consisting of inactive ingredients from probiotic supplement, specifically sunflower oil, medium chain triglyceride oil, and silicon dioxide.

Sponsors

University of Colorado, Boulder
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
SUPPORTIVE_CARE
Masking
DOUBLE (Subject, Investigator)

Eligibility

Sex/Gender
ALL
Age
18 Years to 45 Years
Healthy volunteers
No

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

Design outcomes

Primary

MeasureTime frameDescription
State perceived stress as assessed by adapted PSS-4 using ecological momentary assessmentFive times per day (hourly, 12-7pm, sent via text with a 15 minute response window) during the last 5 days of supplementation, days 42 to 46, when the investigators expect participants to have reached maximum benefitPerceived stress scale-4 (PSS-4) administered via REDCap and adapted for state measurement. The investigators adapted this measure for state stress by asking participants to rate the intensity of perceived stress they were experiencing in the moment, as opposed to the frequency with which they experienced perceived stress over the past month. Possible score range of 0 to 16, with higher scores indicating higher levels of state stress.
Change from baseline in mean trait perceived stress as assessed by PSS-10Baseline and the end of treatment at 46 daysPerceived stress scale-10 (PSS-10) administered via REDCap. Possible score range of 0 to 40, with 0-13 considered low stress, 14-26 moderate stress, and 27-40 high stress.

Secondary

MeasureTime frameDescription
State anxiety symptoms as assessed with the SUDS using ecological momentary assessmentFive times per day (hourly, 12-7pm, sent via text with a 15 minute response window) during the last 5 days of supplementation, days 42 to 46, when the investigators expect participants to have reached maximum benefitSubjective units of distress scale (SUDS) administered via REDCap. Possible score range of 0 to 100, with higher scores indicating higher levels of state anxiety.
State depressive symptoms as assessed by SUDS using ecological momentary assessmentFive times per day (hourly, 12-7pm, sent via text with a 15 minute response window) during the last 5 days of supplementation, days 42 to 46, when the investigators expect participants to have reached maximum benefitSubjective Units of Distress Scale (SUDS) administered via REDCap. Possible score range of 0 to 100, with higher scores indicating higher levels of state depression.
Change from baseline in mean trait depressive symptoms as assessed by the PHQ-8Baseline and the end of treatment at 46 daysPatient Health Questionnaire-8 (PHQ-8) administered via REDCap. Possible score range of 0 to 24, with higher scores indicating higher levels of depression.
Change from baseline in mean trait anxiety symptoms as assessed by GAD-7Baseline and the end of treatment at 46 daysGeneralized Anxiety Disorder-7 scale (GAD-7) administered via REDCap. Possible score range of 0 to 21, with higher scores indicating higher levels of anxiety symptoms.

Other

MeasureTime frameDescription
Side effects as assessed on the final day of supplementation using the GASEEnd of treatment at day 46Generic Assessment of Side Effects (GASE), excluding the question assessing suicidality and administered on REDCap. This measure assesses 35 of the most common subjective side effects of clinical trials (e.g., nausea), and asks participants to rate whether they experienced each complaint on a scale from 0 (not present) to 3 (severe). If they endorsed experiencing a side effect (score of 1+), participants were then asked whether the complaint related to the probiotic (yes/no).

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026