New research links Gulf War Illness to gastrointestinal disturbances

March 23, 2017

A new study from the University of South Carolina has found a gastrointestinal link that could help explain many of the health issues facing those with Gulf War Illness (GWI) as well as opening new pathways to treatment options that may improve both gastrointestinal and neurological symptoms associated with the disorder.

The research is the first study to link the gastrointestinal disturbances of GWI with changes in the intestinal microbiota. This connection potentially explains both the gastrointestinal inflammation and the (e.g., impairments to cognition, memory, learning) that define GWI.

GWI exposures alter the microbiome (i.e., bacterial content in the gut), and the affected microbiota then produce endotoxins, which pass through a thinned lining of the gut (i.e., leaky gut) and into the blood where they circulate throughout the body. These compounds trigger an inflammatory response that, in turn, initiates several neurological abnormalities commonly observed in GWI.

The findings were published by PLOS ONE and led by Saurabh Chatterjee, associate professor of environmental health sciences at USC's Arnold School of Public Health. The study looked at how the various exposures experienced by Gulf War veterans might have changed the microbiome. "Humans and animals have specific types of bacteria that help aid various physiological processes, including digestion, absorption, immunity and gut integrity, and when external factors change the bacterial composition in our digestive systems, we have problems," says Chatterjee. "Obesity, metabolic syndrome, inflammatory bowel syndrome, and liver disease have already been linked with changes in bacterial composition of the gut."

Characterized by symptoms such as chronic headache, cognitive difficulties, debilitating fatigue, widespread pain, respiratory problems, sleep problems, gastrointestinal problems, and other unexplained medical abnormalities, GWI continues to affect 25-32 percent of the 700,000 U.S. veterans who served in the 1990-1991 Persian Gulf War. Twenty years of scientific research has traced these symptoms to Gulf War chemical exposures and the drugs taken during deployment that were meant to prevent or counteract these exposures. However, the vast majority of these studies have focused on neurological effects (rather than gastrointestinal), and none of them have successfully revealed the pathways through which GWI affects the brain.

The study showed that not only did exposures to the suspected GWI agents lead to inflammation in the intestines, but to neuroinflammation as well. "Usually, the gut is very selective about letting only certain elements from what we eat and drink into our blood—thanks to good bacteria," explains Chatterjee. "But when the composition changes due to an increase in certain bad bacteria, this causes disruption to the mucosal lining of the intestinal walls—leading more intestinal contents to leak into the blood."

Once in the blood, the toxins travel throughout the body to affect the different organ systems. It is through this path that the toxins reach the brain, causing the neuroinflammation and corresponding that previous studies have extensively linked to GWI. Now that scientists can explain the neurological symptoms that characterize GWI, a new paradigm of research has been unlocked—one related to .

"We know that many diseases like obesity, liver disease, and inflammatory bowel syndrome can be cured or at least decreased by consuming good bacteria, like probiotics," says Chatterjee. "Now that this connection has been established, it opens the door to new studies where GWI patients take probiotics for a longer period of time and, hopefully, see improvement in symptoms connected with metabolic syndrome, gastrointestinal disturbances, and maybe even neuroinflammation."

These findings and treatments may also be applicable to other veterans who have served in subsequent conflicts in the Gulf region. Even soldiers who have served as recently as the War in Afghanistan have begun to emerge with similar, though not as pronounced, symptoms. The team is already pursuing next steps in this line of research in Chatterjee's Arnold School-based lab, the Environmental Health & Disease Laboratory, which specializes in how environmental toxins contribute to liver disease, metabolic syndrome, and obesity.

Explore further: Intestinal bacteria alter gut and brain function

More information: Firas Alhasson et al, Altered gut microbiome in a mouse model of Gulf War Illness causes neuroinflammation and intestinal injury via leaky gut and TLR4 activation, PLOS ONE (2017). DOI: 10.1371/journal.pone.0172914

Related Stories

Intestinal bacteria alter gut and brain function

March 1, 2017
Research from McMaster University has found that bacteria in the gut impacts both intestinal and behavioural symptoms in patients suffering from irritable bowel syndrome (IBS), a finding which could lead to new microbiota-directed ...

Food and antibiotics may change microorganisms in gut, causing IBS

January 27, 2017
A recent review of research suggests that changes to the microorganisms (microbiota) in the gastrointestinal (GI) tract may be a cause of irritable bowel syndrome (IBS). The review article is published in the American Journal ...

How gut microbiome and diet can affect depression

February 17, 2017
An international group of researchers headed by André Carvalho has published in Psychotherapy and Psychosomatics a paper that provides new data and prospects for the links between the intestinal flora and several disorders, ...

Scientists identify mechanisms driving gut bacterial imbalance and inflammation

February 8, 2017
A study led by UT Southwestern Medical Center researchers has uncovered key molecular pathways behind the disruption of the gut's delicate balance of bacteria during episodes of inflammatory disease.

Changes in blood-brain barrier, intestinal permeability found in individuals with autism

January 18, 2017
Autism spectrum disorder (ASD) has the dubious distinction of being the fastest-growing developmental disability in the U.S., according to the Centers for Disease Control and Prevention. With 1 in every 68 children born in ...

New report finds illness continues to be major effect linked to Gulf War military service

February 11, 2016
Although more than $500 million in federally funded research on Persian Gulf War veterans between 1994 and 2014 has produced many findings, there has been little substantial progress in the overall understanding of the health ...

Recommended for you

After a half-century of attempts, psilocybin has finally been synthesized in the lab

August 16, 2017
A team of researchers at Friedrich Schiller University Jena has figured how out to make psilocybin, the chemical responsible for creating hallucinations in people who consume the mushrooms that produce it naturally. In their ...

Using barcodes to trace cell development

August 16, 2017
How do the multiple different cell types in the blood develop? Scientists have been pursuing this question for a long time. According to the classical model, different developmental lines branch out like in a tree. The tree ...

The unexpected role of a well-known gene in creating blood

August 16, 2017
One of the first organ systems to form and function in the embryo is the cardiovascular system: in fact, this developmental process starts so early that scientists still have many unresolved questions on the origin of the ...

Researchers unlock clues to how cells move through the body

August 16, 2017
During its 120-day cycle the circulatory system transports red blood cells and nutrients throughout the human body. This system helps keep the body in balance and fight against infections and diseases by filtering old or ...

Eating habits affect skin's protection against sun

August 15, 2017
Sunbathers may want to avoid midnight snacks before catching some rays.

Chewing gum rapid test for inflammation

August 15, 2017
Dental implants occasionally entail complications. Six to 15 percent of patients develop an inflammatory response in the years after receiving a dental implant. This is caused by bacteria destroying the soft tissue and the ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.