Stress PhysiologyNCT05392556
Prebiotic and Probiotic Modulation of the Gut Microbiota-gut-brain Axis During Acute Stress
A study testing Probiotic and Prebiotic in people with Stress Physiology, run by United States Army Research Institute of Environmental Medicine at 1 site in United States.
Trial summary
Emerging evidence supports the existence of a microbiota-gut-brain axis through which gut microbes influence cognition, mood and behavior. Targeting this axis with probiotics and/or prebiotics may provide novel strategies for mitigating stress-induced decrements in gastrointestinal and cognitive function. Read more about this study
- Who is it for?
- Ages 17 to 39 yearsHealthy volunteers can take part
- Conditions the study is for
- Stress Physiology
- What is being tested?
- Probiotic and Prebiotic
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 73 participants
- Where
- 1 siteUnited States
- Study dates
- 6 Jul 2022to 28 Oct 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 17 to 39 years
- All sexes
- Healthy volunteers accepted
- Child, Adult
Who may be able to join
- Men and women aged 18 - 39 years (active duty personnel who are 17 yr of age will also be allowed to participate).
- In good health as determined by Medical Clearance.
- Physically active:
- If military, passed most recent record Combat or Physical Fitness Test, and ≥4 d/wk aerobic and/or resistance exercise.
- If civilian, ≥4 d/wk aerobic and/or resistance exercise.
- Meet Army weight for height and body composition standards as defined in Army Regulation 600-9:
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- Self-reports ≥4 bowel movements/week.
- Self-reports normal hearing.
- Willing to maintain usual diet until provided diet phase of study.
Who cannot join
- Pregnant, expecting to become pregnant during study, or breastfeeding.
- Abnormal menstrual cycles [i.e., not between 26-32 days in duration; or not 5-6 menstrual cycles within the past 6 months], or those that have had an IUD placed within the last month or removed within the past 3 months.
- Less than 20/20 acuity on the Snellen eye chart of normal or corrected-to-normal acuity.
- Any of the following medical conditions:
- Neurological or psychological disorder (such as depression, anxiety disorders, migraines, cluster headaches, seizures, post-traumatic stress disorder or panic attacks).
- Cardiac disease (including arrhythmia or fast or skipped heart beats) Hypertension Has a pacemaker Insomnia Musculoskeletal injuries that compromise exercise capability Metabolic or cardiovascular abnormalities (e.g., kidney disease, diabetes, etc.) Disease of the GI tract including, but not limited to diverticulitis, inflammatory bowel disease, irritable bowel syndrome, peptic ulcer disease, Crohn's disease, and ulcerative colitis Excessive alcohol use or other substance abuse issues Immunodeficiency disorder Allergy to skin adhesive
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- Colonoscopy within 3 months of study participation.
- Any use of antibiotics or antimycotics, except topical antibiotics/antimycotics, within 3 months of study participation.
- Regular use of over-the-counter medications (including antacids, laxatives, stool softeners, and anti-diarrheals) unless approved by medical office and study PI.
- Taking prescription medications other than a contraceptive (unless approved by medical office and study PI)
- Not willing or able to refrain from using over the counter medications for 72hr before stress exposure days.
- Not willing or able to stop consumption of dietary supplements at least 2 weeks before and throughout study participation.
- Not willing or able to stop consumption of probiotic-containing foods (e.g., yogurt, etc.) or foods containing added prebiotics (e.g., inulin) at least 2 weeks before and throughout study participation.
- Not willing to abstain from non-provided foods and beverages, including alcohol, during the controlled-diet period.
- Not willing to abstain from caffeine and any nicotine containing products (smoking, chewing, vaping, etc.) during the week prior to stress exposure days.
- Not willing to refrain from strenuous exercise for 24hr prior to stress exposure days.
- Allergies, intolerances, unwillingness or inability to eat intervention supplements, or provided foods and beverages.
- Following vegetarian/vegan diet or other highly restrictive diet (e.g., ketogenic diet, very high protein diet, Paleo diet).
- Any previous blood donation, within 8 weeks of a study blood draw, of a volume that when combined with the amount of blood to be collected during the study would exceed 550 mL
Trial locations and contacts
1 site in 1 country.
United States1 site
United States Army Research Institute of Environmental Medicine
Natick, Massachusetts, 01760
About this study
Emerging evidence supports the existence of a microbiota-gut-brain axis through which gut microbes influence cognition, mood and behavior. Targeting this axis with probiotics and/or prebiotics may provide novel strategies for mitigating stress-induced decrements in gastrointestinal and cognitive function. This double-blind, placebo-controlled, randomized, parallel-arm trial will determine the effects of a prebiotic and a probiotic dietary intervention on gastrointestinal, cognitive and physiologic responses to acute military-relevant physical and cognitive stress. Healthy men and women will be recruited and randomized to receive a placebo, probiotic or prebiotic for 4wk. Volunteers will be fed a controlled diet during the 4th week of supplementation. Fecal, blood, urine and saliva samples will be collected. Physical stress will be induced by a weighted walk on a treadmill, and will be followed by a cognitively challenging testing scenario that uses intermittent electric shocks to the abdomen to induce a stress response.
- Conditions
- Stress Physiology
- Being tested
- Probiotic, Prebiotic, Placebo
- Keywords
- Probiotic, Prebiotic, Microbiome, Stress
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ProbioticDietary supplement
Cerebiome (Lallemand Health Solutions): probiotic supplement containing Bifidobacterium longum R0175, Lactobacillus helveticus R0052, and maltodextrin. Dosing: Oral, 3.6 g/d containing 3x10^9 CFU/d (powder form)
PrebioticDietary supplement
Bimuno-GOS (Clasado Biosciences): Dosing: Oral; 3.6 g/d containing 2.75 g active GOS/d (powder form)
PlaceboOther
Maltodextrin 3.6 g/d (powder form)
| Study group | Role | What they receive |
|---|---|---|
| Probiotic | Experimental | Bifidobacterium longum R0175; Lactobacillus helveticus R0052 (Cerebiome; Lallemand Health Solutions) Receives: Dietary Supplement: Probiotic |
| Prebiotic | Experimental | Bimuno-galactooligosaccharide (Bimuno-GOS; Clasado Biosciences) Receives: Dietary Supplement: Prebiotic |
| Placebo | Placebo comparator | Maltodextrin placebo Receives: Other: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change from baseline in intestinal permeability
A differential sugar absorption test will be used to assess intestinal permeability. Participants will consume 2g sucralose and 4g mannitol dissolved in 180 mL water prior to starting exercise. Participants will then collect all urine produced over the subsequent 4hr. Urine sucralose and mannitol concentrations will be analyzed.
Measured: Days 0 and 29
Difference from baseline in circulating cortisol concentrations
Serum cortisol concentrations will be measured in serial blood samples collected via an indwelling venous catheter.
Measured: Before (-20min), during (60min) and immediately after (120min) exercise and immediately before and after cognitive stress exposure on days 0 and 29.
Secondary outcomes (28)
Change from baseline in mean heart rate variability
Heart rate variability will be measured using a chest-worn heart rate monitor.
Measured: During stress exposure (up to 4hr) on days 0 and 29.
Change from baseline in performance on decision making under conditions of ambiguity task
Decision making under conditions of ambiguity task will be completed using a virtual reality cognitive testing scenario, which probes shoot/don't-shoot decision-making and the ability to discriminate friend/foe camouflage patterns at varying levels of ambiguity.
Measured: Days 0 and 29
Difference from baseline in reaction time.
The reaction time task assesses simple and choice response time. In the task participants will be asked to perform a series of simple and choice reaction time trials in response to targets displayed on a computer monitor.
Measured: Before (-45min) exercise, after 40 and 100 min of exercise, and immediately after exercise on days 0 and 29.
Difference from baseline in response inhibition
The go/no-go task assesses response inhibition. In the task participants will be presented with two, neutral stimuli on a computer screen. Participants will be instructed to press a button on a response device as quickly as possible in response to one visual stimulus, but to withhold from responding to the other visual stimulus.
Measured: Before (-45min) exercise, after 40 and 100 min of exercise, and immediately after exercise on days 0 and 29.
Difference from baseline in working memory
This N-back task assesses working memory. Participants will be shown a series of letters on a computer screen and will be required to mentally take note of those depicted letters. Participants will then respond either "yes" or "no" if they were the same letters as either 1, 2, and/or 3 letters back.
Measured: Before (-45min) exercise, after 40 and 100 min of exercise, and immediately after exercise on days 0 and 29.
Difference from baseline in distractibility to emotional stimuli
The Emotional Interference Task task assesses spatial working memory and distractibility to emotional stimuli. Each trial has three phases: stimulus, delay and probe. The stimulus consists of three white dots appearing in pseudo-random locations against a black background. The stimulus phase begins with a "remember this…" instruction, and then the stimulus is presented, followed by a blank screen prior to delay. During the delay, either a neutral or a negative image is presented, selected at random without replacement (both during and across sessions) from an image directory. Finally, the probe is presented, depicting a white ring against a black background to indicate a screen location. The participant is asked to press either YES or NO to indicate whether the indicated location contained or did not contain a dot during the stimulus period.
Measured: Before (-45min) exercise, after 40 and 100 min of exercise, and immediately after exercise on days 0 and 29.
Difference from baseline in emotional states measured by the Depression, Anxiety and Stress Scale (DASS)
The DASS is a validated 42-item questionnaire designed to measure the three related negative emotional states of depression, anxiety and tension/stress. Score range for all subscales is 0-42; lower is better.
Measured: Day 0, Week 1, Week 2, Week 3, Day 29
Difference from baseline in mood state measured by the Profile of Mood States 2-A (POMS2A)
The POMS2-A is a validated 65-item inventory of self-reported mood states. Participants rate each of 65 mood-related adjectives on a five-point scale, in response to the question, "How are you feeling right now?" The adjectives factor into six mood sub-scales (tension/anxiety [range 0-40], depression/dejection [range 0-52], anger/hostility [range 0-44], vigor/activity [range 0-36], fatigue/inertia [range 0-24], and confusion/bewilderment [range 0-40], and total mood disturbance [range -36-200]. For all scores except vigor, lower is better.
Measured: Before (-45min) and immediately after exercise, and after cognitive stress exposure on days 0 and 29
Difference from baseline in feelings of pleasantness
The Feeling Scale is a one-item inventory that measures the extent to which participants feel pleasant or unpleasant. The scale ranges from "very good" (+5) to "very bad" (-5).
Measured: Before (-45min) exercise, after 40 and 100 min of exercise, and immediately after exercise on days 0 and 29.
Difference from baseline in feelings of arousal
The Felt Arousal Scale is a one-item inventory measures feeling of arousal. The scale ranges from "low arousal" (1) to "high arousal" (6).
Measured: Before (-45min) exercise, after 40 and 100 min of exercise, and immediately after exercise on days 0 and 29.
Difference from baseline in gastrointestinal discomfort
Subjective ratings of gastrointestinal discomfort will be measured by a modified version of the Irritable Bowel Syndrome-Symptom Severity Score Questionnaire (range 0-470; lower is better).
Measured: Day 0, Week 1, Week 2, Week 3, Day 29
Difference from baseline in gastrointestinal symptoms
Subjective ratings of gastrointestinal symptoms (e.g., flatulence, constipation, loose stool; range 0-4, higher is better) will be assessed weekly using a modified Gastrointestinal Quality of Life Index.
Measured: Day 0, Week 1, Week 2, Week 3, Day 29
Difference from baseline in circulating cytokines concentrations.
Serum interleukin (IL)-6, tumor necrosis factor (TNF)α, IL-17, IL-10, IL-8, IL-1ra, IL-1β, and interferon gamma concentrations will be measured in serial blood samples collected via an indwelling venous catheter.
Measured: Before (-20min), during (60min) and immediately after (120min) exercise and immediately before and after cognitive stress exposure on days 0 and 29
Difference from baseline in circulating dehydroepiandrosterone-sulfate (DHEA-S) concentrations
Serum DHEA-S concentrations will be measured in serial blood samples collected via an indwelling venous catheter.
Measured: Before (-20min), during (60min) and immediately after (120min) exercise and immediately before and after cognitive stress exposure on days 0 and 29
Difference from baseline in circulating epinephrine concentrations
Plasma epinephrine concentrations will be measured in serial blood samples collected via an indwelling venous catheter.
Measured: Before (-20min), during (60min) and immediately after (120min) exercise and immediately before and after cognitive stress exposure on days 0 and 29.
Difference from baseline in circulating norepinephrine concentrations
Plasma norepinephrine concentrations will be measured in serial blood samples collected via an indwelling venous catheter.
Measured: Before (-20min), during (60min) and immediately after (120min) exercise and immediately before and after cognitive stress exposure on days 0 and 29.
Difference from baseline in circulating neuropeptide Y concentrations
Serum neuropeptide Y concentrations will be measured in serial blood samples collected via an indwelling venous catheter.
Measured: Before (-20min) exercise and immediately before cognitive stress exposure on days 0 and 29
Difference from baseline in circulating brain-derived neurotrophic factor (BDNF) concentrations
Plasma BDNF concentrations will be measured in serial blood samples collected via an indwelling venous catheter.
Measured: Before (-20min) exercise and immediately before cognitive stress exposure on days 0 and 29
Difference from baseline in circulating S100 calcium binding protein B (S100B) concentrations
Serum S100B concentrations will be measured in serial blood samples collected via an indwelling venous catheter.
Measured: Before (-20min), during (60min) and immediately after (120min) exercise and immediately before and after cognitive stress exposure on days 0 and 29.
Difference from baseline in circulating lipopolysaccharide concentrations
Serum lipopolysaccharide concentrations will be measured in serial blood samples collected via an indwelling venous catheter.
Measured: Before (-20min), during (60min) and immediately after (120min) exercise and immediately before and after cognitive stress exposure on days 0 and 29.
Difference from baseline in circulating zonulin concentrations
Serum zonulin concentrations will be measured in serial blood samples collected via an indwelling venous catheter.
Measured: Before (-20min), during (60min) and immediately after (120min) exercise and immediately before and after cognitive stress exposure on days 0 and 29.
Difference from baseline in circulating intestinal fatty acid binding protein (I-FABP) concentrations.
Serum IFABP concentrations will be measured in serial blood samples collected via an indwelling venous catheter.
Measured: Before (-20min), during (60min) and immediately after (120min) exercise and immediately before and after cognitive stress exposure on days 0 and 29.
Difference from baseline in fecal acetate concentrations
Acetate concentrations will be measured in fecal samples
Measured: Pre-intervention, week 3 and week 4
Difference from baseline in fecal propionate concentrations
Propionate concentrations will be measured in fecal samples
Measured: Pre-intervention, week 3 and week 4
Difference from baseline in fecal butyrate concentrations
Butyrate concentrations will be measured in fecal samples
Measured: Pre-intervention, week 3 and week 4
Difference from baseline in gut microbiota composition
Fecal microbiota composition will be measured using 16S rRNA gene amplicon sequencing
Measured: Pre-intervention, week 3 and week 4
Change from baseline in salivary secretory immunoglobulin A
Secretory immunoglobulin A concentrations will be measured in saliva
Measured: Day 0 and Day 29
Difference from baseline in salivary cortisol concentrations
Cortisol concentrations will be serially measured in saliva
Measured: Before (-20min), during (60min) and immediately after (120min) exercise and immediately before and after cognitive stress exposure on days 0 and 29
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 May 2022
- Study start6 Jul 2022
- Primary completion28 Oct 2025
- Study completion28 Oct 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Stress PhysiologyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Randomized, double blind, placebo controlled
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 73 participants (actual)
Sponsor and investigators
- Lead sponsor
- United States Army Research Institute of Environmental Medicine
- Sponsor type
- US federal agency
- Collaborators
- United States Army Combat Capabilities Development Command Soldier Center, United States Air Force Research Laboratory
- Responsible party
- Sponsor
- Investigators
- J. Philip Karl, PhD, RD, Principal investigator, United States Army Research Institute of Environmental Medicine
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05392556
- Sponsor's protocol ID
- 21-03-HC
- Other IDs
- M-10901
- Status last verified
- Dec 2025
- First submitted
- 9 May 2022
- Last updated
- 26 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 26 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Prebiotic and Probiotic Modulation of the Gut Microbiota-gut-brain Axis During Acute Stress
- ClinicalTrials.gov ID
- NCT05392556
- Acronym / sponsor ID
- 21-03-HC
- Conditions
- Stress Physiology
- Keywords
- Probiotic, Prebiotic, Microbiome, Stress
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 73 participants (actual)
- Lead sponsor
- United States Army Research Institute of Environmental MedicineUS federal agency
- Collaborators
- United States Army Combat Capabilities Development Command Soldier Center, United States Air Force Research Laboratory
- Study start
- 6 Jul 2022 (actual)
- Primary completion
- 28 Oct 2025 (actual)
- Study completion
- 28 Oct 2025 (actual)
- First posted
- 26 May 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Emerging evidence supports the existence of a microbiota-gut-brain axis through which gut microbes influence cognition, mood and behavior. Targeting this axis with probiotics and/or prebiotics may provide novel strategies for mitigating stress-induced decrements in gastrointestinal and cognitive function. This double-blind, placebo-controlled, randomized, parallel-arm trial will determine the effects of a prebiotic and a probiotic dietary intervention on gastrointestinal, cognitive and physiologic responses to acute military-relevant physical and cognitive stress. Healthy men and women will be recruited and randomized to receive a placebo, probiotic or prebiotic for 4wk. Volunteers will be fed a controlled diet during the 4th week of supplementation. Fecal, blood, urine and saliva samples will be collected. Physical stress will be induced by a weighted walk on a treadmill, and will be followed by a cognitively challenging testing scenario that uses intermittent electric shocks to the abdomen to induce a stress response.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 3
- Model description
- Randomized, double blind, placebo controlled
| Arm | Type | Receives |
|---|---|---|
| Probiotic | Experimental | Dietary Supplement: ProbioticBifidobacterium longum R0175; Lactobacillus helveticus R0052 (Cerebiome; Lallemand Health Solutions) |
| Prebiotic | Experimental | Dietary Supplement: PrebioticBimuno-galactooligosaccharide (Bimuno-GOS; Clasado Biosciences) |
| Placebo | Placebo comparator | Other: PlaceboMaltodextrin placebo |
Who may qualify
- Ages
- 17 to 39 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult
Key inclusion criteria (9 listed)
- Men and women aged 18 - 39 years (active duty personnel who are 17 yr of age will also be allowed to participate).
- In good health as determined by Medical Clearance.
- Physically active:
- If military, passed most recent record Combat or Physical Fitness Test, and ≥4 d/wk aerobic and/or resistance exercise.
- If civilian, ≥4 d/wk aerobic and/or resistance exercise.
Key exclusion criteria (19 listed)
- Pregnant, expecting to become pregnant during study, or breastfeeding.
- Abnormal menstrual cycles [i.e., not between 26-32 days in duration; or not 5-6 menstrual cycles within the past 6 months], or those that have had an IUD placed within the last month or removed within the past 3 months.
- Less than 20/20 acuity on the Snellen eye chart of normal or corrected-to-normal acuity.
- Any of the following medical conditions:
- Neurological or psychological disorder (such as depression, anxiety disorders, migraines, cluster headaches, seizures, post-traumatic stress disorder or panic attacks).
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| ProbioticCerebiome (Lallemand Health Solutions): probiotic supplement containing Bifidobacterium longum R0175, Lactobacillus helveticus R0052, and maltodextrin. Dosing: Oral, 3.6 g/d containing 3x10^9 CFU/d (powder form) | Dietary supplement | Probiotic |
| PrebioticBimuno-GOS (Clasado Biosciences): Dosing: Oral; 3.6 g/d containing 2.75 g active GOS/d (powder form) | Dietary supplement | Prebiotic |
| PlaceboMaltodextrin 3.6 g/d (powder form) | Other | Placebo |
Primary outcome
Change from baseline in intestinal permeability
Time frame: Days 0 and 29
A differential sugar absorption test will be used to assess intestinal permeability. Participants will consume 2g sucralose and 4g mannitol dissolved in 180 mL water prior to starting exercise. Participants will then collect all urine produced over the subsequent 4hr. Urine sucralose and mannitol concentrations will be analyzed.
Difference from baseline in circulating cortisol concentrations
Time frame: Before (-20min), during (60min) and immediately after (120min) exercise and immediately before and after cognitive stress exposure on days 0 and 29.
Serum cortisol concentrations will be measured in serial blood samples collected via an indwelling venous catheter.
28 secondary outcomes
Change from baseline in mean heart rate variability
Time frame: During stress exposure (up to 4hr) on days 0 and 29.
Change from baseline in performance on decision making under conditions of ambiguity task
Time frame: Days 0 and 29
Difference from baseline in reaction time.
Time frame: Before (-45min) exercise, after 40 and 100 min of exercise, and immediately after exercise on days 0 and 29.
Difference from baseline in response inhibition
Time frame: Before (-45min) exercise, after 40 and 100 min of exercise, and immediately after exercise on days 0 and 29.
Difference from baseline in working memory
Time frame: Before (-45min) exercise, after 40 and 100 min of exercise, and immediately after exercise on days 0 and 29.
Difference from baseline in distractibility to emotional stimuli
Time frame: Before (-45min) exercise, after 40 and 100 min of exercise, and immediately after exercise on days 0 and 29.
Difference from baseline in emotional states measured by the Depression, Anxiety and Stress Scale (DASS)
Time frame: Day 0, Week 1, Week 2, Week 3, Day 29
Difference from baseline in mood state measured by the Profile of Mood States 2-A (POMS2A)
Time frame: Before (-45min) and immediately after exercise, and after cognitive stress exposure on days 0 and 29
Difference from baseline in feelings of pleasantness
Time frame: Before (-45min) exercise, after 40 and 100 min of exercise, and immediately after exercise on days 0 and 29.
Difference from baseline in feelings of arousal
Time frame: Before (-45min) exercise, after 40 and 100 min of exercise, and immediately after exercise on days 0 and 29.
Difference from baseline in gastrointestinal discomfort
Time frame: Day 0, Week 1, Week 2, Week 3, Day 29
Difference from baseline in gastrointestinal symptoms
Time frame: Day 0, Week 1, Week 2, Week 3, Day 29
Difference from baseline in circulating cytokines concentrations.
Time frame: Before (-20min), during (60min) and immediately after (120min) exercise and immediately before and after cognitive stress exposure on days 0 and 29
Difference from baseline in circulating dehydroepiandrosterone-sulfate (DHEA-S) concentrations
Time frame: Before (-20min), during (60min) and immediately after (120min) exercise and immediately before and after cognitive stress exposure on days 0 and 29
Difference from baseline in circulating epinephrine concentrations
Time frame: Before (-20min), during (60min) and immediately after (120min) exercise and immediately before and after cognitive stress exposure on days 0 and 29.
Difference from baseline in circulating norepinephrine concentrations
Time frame: Before (-20min), during (60min) and immediately after (120min) exercise and immediately before and after cognitive stress exposure on days 0 and 29.
Difference from baseline in circulating neuropeptide Y concentrations
Time frame: Before (-20min) exercise and immediately before cognitive stress exposure on days 0 and 29
Difference from baseline in circulating brain-derived neurotrophic factor (BDNF) concentrations
Time frame: Before (-20min) exercise and immediately before cognitive stress exposure on days 0 and 29
Difference from baseline in circulating S100 calcium binding protein B (S100B) concentrations
Time frame: Before (-20min), during (60min) and immediately after (120min) exercise and immediately before and after cognitive stress exposure on days 0 and 29.
Difference from baseline in circulating lipopolysaccharide concentrations
Time frame: Before (-20min), during (60min) and immediately after (120min) exercise and immediately before and after cognitive stress exposure on days 0 and 29.
Difference from baseline in circulating zonulin concentrations
Time frame: Before (-20min), during (60min) and immediately after (120min) exercise and immediately before and after cognitive stress exposure on days 0 and 29.
Difference from baseline in circulating intestinal fatty acid binding protein (I-FABP) concentrations.
Time frame: Before (-20min), during (60min) and immediately after (120min) exercise and immediately before and after cognitive stress exposure on days 0 and 29.
Difference from baseline in fecal acetate concentrations
Time frame: Pre-intervention, week 3 and week 4
Difference from baseline in fecal propionate concentrations
Time frame: Pre-intervention, week 3 and week 4
Difference from baseline in fecal butyrate concentrations
Time frame: Pre-intervention, week 3 and week 4
Difference from baseline in gut microbiota composition
Time frame: Pre-intervention, week 3 and week 4
Change from baseline in salivary secretory immunoglobulin A
Time frame: Day 0 and Day 29
Difference from baseline in salivary cortisol concentrations
Time frame: Before (-20min), during (60min) and immediately after (120min) exercise and immediately before and after cognitive stress exposure on days 0 and 29
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 26 Dec 2025.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
J. Philip Karl, PhD, RD principal investigator
United States Army Research Institute of Environmental Medicine
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Probiotic and Prebiotic in people with Stress Physiology, run by United States Army Research Institute of Environmental Medicine at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 9 inclusion and 19 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 26 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change from baseline in intestinal permeability (time frame: Days 0 and 29). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 26 Dec 2025.