NCT05972291 · VA Office of Research and Development
Mechanisms of Gulf War Illness
What this study is about
Many veterans with Gulf War Illness developed chronic gastrointestinal symptoms during their deployment to the Persian Gulf. The pathophysiologic mechanisms of these chronic gastrointestinal symptoms are not well understood but cause significant morbidity in veterans.
View original scientific description
Many veterans with Gulf War Illness developed chronic gastrointestinal symptoms during their deployment to the Persian Gulf. The pathophysiologic mechanisms of these chronic gastrointestinal symptoms are not well understood but cause significant morbidity in veterans. Our proposed studies will provide an innovative and novel treatment trial for chronic gastrointestinal symptoms in veterans with Gulf War Illness that were deployed into war zones. Given that there are currently no specific treatments for these disorders, and that current symptomatic approaches are far from ideal, proof of principle of our trial would be an extremely important advance as it would not only have a beneficial impact on the health of many thousands of our veterans, but also it would substantially reduce the many negative economic effects of this ailment on the VA Health Care System.
Interventions
DIETARY_SUPPLEMENT
Oral Glutamine
You will receive an unmarked packet with either glutamine or whey protein powder. Once the packet is opened, the powder should be mixed completely with 8 oz of water. You should completely drink this mixture within 10 minutes. You will consume one packet three times a day for 12 weeks. One packet 30 minutes before breakfast, one packet 30 minutes before lunch, and one packet 30 minutes before the evening meal.
OTHER
Control Arm
You will receive an unmarked packet with either glutamine or whey protein powder. Once the packet is opened, the powder should be mixed completely with 8 oz of water. You should completely drink this mixture within 10 minutes. You will consume one packet three times a day for 12 weeks. One packet 30 minutes before breakfast, one packet 30 minutes before lunch, and one packet 30 minutes before the evening meal.
Primary outcome measures
To determine if oral glutamine supplementation will improve the Symptom Severity Scale in Veterans with GWI and chronic GI Symptoms.
Time frame: 3 years
It's anticipated that veterans with GWI and GI symptoms will show a significant reduction, compared to placebo, in their chronic GI symptoms as reflected by their Symptom Severity Scale Score following glutamine therapy. For each participating subject, the Symptom Severity Scale score will be measured at baseline, and at 4, 8, and 12 weeks after the start of treatment. The investigators will have Symptom Severity Scale scores at 5 time points in each group (glutamine, placebo). These will be explored graphically with time course plots. At each time point, for Symptom Severity Scale scores, the investigators will also calculate descriptive statistics including mean and standard deviation, as well as median, median absolute deviation and inter-quartile range if the distribution of data is skewed. Box plots will be used to graphically demonstrate the distribution of Symptom Severity Scale scores at each time point. This will be done for both the glutamine and the placebo groups.
To determine if oral glutamine supplementation will restore intestinal permeability in Veterans with GWI.
Time frame: 3 years
Following our recent findings, we expect \>75% of veterans will restore normal intestinal permeability, while in the placebo group, this percentage is \~6%. One sample one sided proportion test (PROC FREQ in SAS) will be used to test whether the proportion of restoration is \>75% in each treatment group (glutamine supplementation or placebo) and two sample one sided proportion tests (PROC FREQ in SAS) to compare the difference between the two groups. To examine the association between the Symptom Severity Scale Score and restoration of normal intestinal permeability, Pearson's correlations between the Symptom Severity Scale and intestinal permeability will be calculated at baseline, and at 4, 8, and 12 weeks after the start of treatment, for both oral glutamine and placebo groups.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Veterans 18-65 years old with GWI and chronic GI symptoms (abdominal pain, diarrhea, bloating) that started during their deployment in the Persian Gulf
- Veterans 18-65 years old with GWI and chronic GI symptoms (abdominal pain, diarrhea, bloating)
- increased intestinal permeability on the lactulose/mannitol permeability test (ratio \>0.07)
- able and willing to cooperate with the study
Exclusion criteria
- current participation in another research protocol or unable to give informed consent
- women with a positive urine pregnancy test or breastfeeding
- history of inflammatory bowel disease, lactose intolerance and/or celiac sprue
- \+ hydrogen breath test for bacterial overgrowth
- \+ anti-endomysial antibody titer
- use of NSAIDs 2 weeks before or during the study
- known allergy to glutamine or whey protein
- abdominal surgery except for removal of gallbladder, uterus, or appendix \>6 months prior to entry into the study
- Abnormal serum BUN and/or creatinine
- Mannitol recovery out of the normal range of 5-25 U/g
- history of kidney disease
- allergies to monosodium glutamate
- current use of anti-seizure medications
Where
- Memphis, Tennessee
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Dec 5, 2025 · Source of record for eligibility and locations