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Saturday, July 9, 2016

It's All in Your Gut

A study out of Cornell University made the news recently when Maureen Hanson's team found distinct alterations in the gut flora of patients with ME/CFS. The headlines trumpeted the "first" biological marker for the disease in the microbiome.

Those of us who have kept track of the research know that this is not a "first." De Meirleir, Maes, Lemle, as well as Dunstan, and Butt in Australia have all published papers documenting alterations in gut flora in patients with ME/CFS (not to mention Lipkin and Hornig's huge Microbe Discovery Project). Those alterations laid the groundwork for Butt's successful treatment of ME with fecal transplants in the late 90s.

The question that needs to be asked is whether these alterations are the cause or the result of the disease. Every disease produces alterations in gut flora - diabetes, Crohn's, heart disease, HIV, and cancer are among them, as well as all infections. (For a good paper on this topic go HERE.) The gut, which is the seat of your immune system, responds instantly to pathogens. It even changes in accord with what you are eating withing a few hours.

But rather than chicken or egg, these gut changes could be chicken and egg. For example, the pathogen that causes ME results in changes to the microbiome, then subsequent chronicity due to an altered immune system results in a perpetuation of microbiome changes. These, in turn, lead to more chronicity as commensal bacteria enter the bloodstream.

It's a good model, even if it doesn't identify the original culprit that started this chain of events.

You can read the full study HERE.

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Key to chronic fatigue syndrome is in your gut, not head

By Melissa Osgood, Cornell University

Physicians have been mystified by chronic fatigue syndrome, a condition where normal exertion leads to debilitating fatigue that isn't alleviated by rest. There are no known triggers, and diagnosis requires lengthy tests administered by an expert.

Now, for the first time, Cornell University researchers report they have identified biological markers of the disease in gut bacteria and inflammatory microbial agents in the blood.

In a study published June 23 in the journal Microbiome, the team describes how they correctly diagnosed myalgic encephalomyeletis/chronic fatigue syndrome (ME/CFS) in 83 percent of patients through stool samples and blood work, offering a noninvasive diagnosis and a step toward understanding the cause of the disease.

"Our work demonstrates that the gut bacterial microbiome in chronic fatigue syndrome patients isn't normal, perhaps leading to gastrointestinal and inflammatory symptoms in victims of the disease," said Maureen Hanson, the Liberty Hyde Bailey Professor in the Department of Molecular Biology and Genetics at Cornell and the paper's senior author. "Furthermore, our detection of a biological abnormality provides further evidence against the ridiculous concept that the disease is psychological in origin."

"In the future, we could see this technique as a complement to other noninvasive diagnoses, but if we have a better idea of what is going on with these gut microbes and patients, maybe clinicians could consider changing diets, using prebiotics such as dietary fibers or probiotics to help treat the disease," said Ludovic Giloteaux, a postdoctoral researcher and first author of the study.

In the study, Ithaca campus researchers collaborated with Dr. Susan Levine, an ME/CFS specialist in New York City, who recruited 48 people diagnosed with ME/CFS and 39 healthy controls to provide stool and blood samples.

The researchers sequenced regions of microbial DNA from the stool samples to identify different types of bacteria. Overall, the diversity of types of bacteria was greatly reduced and there were fewer bacterial species known to be anti-inflammatory in ME/CFS patients compared with healthy people, an observation also seen in people with Crohn's disease and ulcerative colitis.

At the same time, the researchers discovered specific markers of inflammation in the blood, likely due to a leaky gut from intestinal problems that allow bacteria to enter the blood, Giloteaux said.

Bacteria in the blood will trigger an immune response, which could worsen symptoms.

The researchers have no evidence to distinguish whether the altered gut microbiome is a cause or a whether it is a consequence of disease, Giloteaux added.

In the future, the research team will look for evidence of viruses and fungi in the gut, to see whether one of these or an association of these along with bacteria may be causing or contributing to the illness.

Journal Reference: Ludovic Giloteaux, Julia K. Goodrich, William A. Walters, Susan M. Levine, Ruth E. Ley, Maureen R. Hanson. Reduced diversity and altered composition of the gut microbiome in individuals with myalgic encephalomyelitis/chronic fatigue syndrome. Microbiome, 2016; 4 (1) DOI: 10.1186/s40168-016-0171-4