Mechanisms of Gulf War Illness

NCT ID: NCT05972291

Last Updated: 2025-12-05

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

RECRUITING

Clinical Phase

NA

Total Enrollment

80 participants

Study Classification

INTERVENTIONAL

Study Start Date

2023-10-16

Study Completion Date

2027-07-31

Brief Summary

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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.

Detailed Description

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Since 2001, more than 2.2 million US veterans have served in Operation Enduring Freedom (OEF) in Afghanistan and Operation Iraqi Freedom (OIF) in Iraq. The Gulf Registry of the VA Environmental Epidemiology Service identified the majority of these veterans as having chronic health complaints of undetermined etiology. Among the symptoms most frequently reported by veterans with Gulf War Illness (GWI) were chronic fatigue, frequent or persistent headache, frequent or persistent muscle or joint pain, and gastrointestinal (GI) symptoms. GI symptoms (e.g., diarrhea, bloating, and abdominal pain) reported by these veterans accounted for most complaints. Indeed, up to 33% of veterans with GWI suffer from chronic GI symptoms.

The investigators have shown that veterans with GWI and GI symptoms have increased intestinal permeability that drives GI symptoms (Zhang et al., 2019). Our research group recently completed a clinical trial demonstrating the effectiveness of oral glutamine supplementation in diarrhea-predominant IBS patients with increased intestinal permeability (Zhou et al., 2019). The investigators now have obtained preliminary evidence that oral glutamine supplementation may restore intestinal permeability in veterans with GWI and GI symptoms. Based on these new findings, the investigators hypothesize that oral glutamine supplementation will improve the Symptom Severity Scale and restore intestinal permeability in veterans with GWI and chronic GI symptoms. The investigators propose to conduct a randomized, double-blind, placebo-controlled clinical trial studying oral glutamine supplementation compared to placebo in veterans with GWI and GI symptoms.

The human GI tract is the major site of glutamine utilization in the body. Glutamine is a major energy source for rapidly dividing intestinal mucosal cells of the digestive tract. Glutamine helps to protect the lining of the GI tract. Its depletion results in epithelial atrophy and a subsequent increase in intestinal permeability. Glutamine supplementation has been shown to decrease bacterial translocation and intestinal permeability after intestinal injury. Glutamine supplementation has also been shown to decrease intestinal permeability and improve GI function in patients with Crohn's disease, advanced esophageal cancer, or metastatic cancer undergoing radio chemotherapy. There are no published studies to date to support the use of glutamine for veterans with GWI and chronic GI symptoms.

However, given our published studies, preliminary data demonstrating restoration of intestinal permeability with oral glutamine therapy, and the mechanisms of action of glutamine on the GI tract, research testing whether oral glutamine is an effective therapy in veterans with GWI is needed. Given that there are no effective treatments for these veterans and that current treatment approaches are far from ideal, this proposed clinical trial would be extremely important as it would not only have a beneficial impact on the health of many of our veterans, but also it would substantially reduce the negative economic effects on the VA Health Care System.

Conditions

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Gulf War Illness Irritable Bowel Syndrome Gastrointestinal Symptoms

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

In this study, the investigators will conduct a randomized, double-blind, placebo-controlled clinical trial studying glutamine 5 grams orally three times a day compared to a placebo 5 grams orally three times a day for 12 weeks in 80 Veterans with GWI and GI symptoms. This study will also look at Veterans that have chronic GI symptoms and do not have GWI. The Symptom Severity Scale and intestinal permeability will be measured at baseline, 4, 8, and 12 weeks.
Primary Study Purpose

TREATMENT

Blinding Strategy

SINGLE

Participants
Each person in this study will receive either glutamine or whey powder to mix in with water. This is done by a random assignment using a computer program for "yes" or "no". All odd numbers of participants will undergo the random choice of the computer program. All even number participants will get the opposite treatment of the previous odd number participant.

Study Groups

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Oral Glutamine

You will be asked to consume 5 grams of glutamine three times a day for 12 weeks. At week four, you will be asked to return to the CRC to be assessed, and then to return every four weeks until week 12, which will be the conclusion of the study.

Group Type EXPERIMENTAL

Oral Glutamine

Intervention Type DIETARY_SUPPLEMENT

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.

Whey Protein Powder

You will be asked to consume 5 grams of whey protein powder three times a day for 12 weeks. At week four, you will be asked to return to the CRC to be assessed, and then to return every four weeks until week 12, which will be the conclusion of the study.

Group Type PLACEBO_COMPARATOR

Control Arm

Intervention Type OTHER

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.

Interventions

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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.

Intervention Type DIETARY_SUPPLEMENT

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.

Intervention Type OTHER

Eligibility Criteria

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Inclusion Criteria

1. Veterans 18-65 years old with GWI and chronic GI symptoms (abdominal pain, diarrhea, bloating) that started during their deployment in the Persian Gulf
2. Veterans 18-65 years old with GWI and chronic GI symptoms (abdominal pain, diarrhea, bloating)
3. increased intestinal permeability on the lactulose/mannitol permeability test (ratio \>0.07)
4. able and willing to cooperate with the study

Exclusion Criteria

1. current participation in another research protocol or unable to give informed consent
2. women with a positive urine pregnancy test or breastfeeding
3. history of inflammatory bowel disease, lactose intolerance and/or celiac sprue
4. \+ hydrogen breath test for bacterial overgrowth
5. \+ anti-endomysial antibody titer
6. use of NSAIDs 2 weeks before or during the study
7. known allergy to glutamine or whey protein
8. abdominal surgery except for removal of gallbladder, uterus, or appendix \>6 months prior to entry into the study
9. Abnormal serum BUN and/or creatinine
10. Mannitol recovery out of the normal range of 5-25 U/g
11. history of kidney disease
12. allergies to monosodium glutamate
13. current use of anti-seizure medications
Minimum Eligible Age

18 Years

Maximum Eligible Age

65 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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VA Office of Research and Development

FED

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Principal Investigators

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QiQi Zhou, MD PhD

Role: PRINCIPAL_INVESTIGATOR

Memphis VA Medical Center, Memphis, TN

George N Verne

Role: PRINCIPAL_INVESTIGATOR

Memphis VA Medical Center, Memphis, TN

Locations

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Memphis VA Medical Center, Memphis, TN

Memphis, Tennessee, United States

Site Status RECRUITING

Countries

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United States

Central Contacts

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George N Verne

Role: CONTACT

(901) 523-8990 ext. 7571

QiQi Zhou, MD PhD

Role: CONTACT

(901) 523-8990 ext. 7226

Facility Contacts

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George N Verne

Role: primary

901-523-8990 ext. 7571

Sue A Theus, PhD

Role: backup

(901) 523-8990

Other Identifiers

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I01CX001477

Identifier Type: NIH

Identifier Source: secondary_id

View Link

SPLD-006-22F

Identifier Type: -

Identifier Source: org_study_id

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