Imbalanced Gut Bacteria : New Cause of Chronic Fatigue Syndrome

Highlights:

• Chronic fatigue syndrome (CFS) is a complicated, debilitating disorder that has no known underlying medical cause and no means of accurate diagnosis.
• New findings state that distinct levels of intestinal bacterial species could be an important biomarker of chronic fatigue syndrome.
• Individuals with CFS have a distinct mix of gut bacteria and related metabolic disturbances that may influence the severity of their disease.

Abnormal levels of specific gut bacteria are related to chronic fatigue syndrome or CFS, in patients with and without concurrent irritable bowel syndrome, or IBS.

The findings are by a team of researchers from the Center for Infection and Immunity (CII) at Columbia University's Mailman School of Public Health.

This is the first study to associate imbalances in the gut bacteria in individuals with ME/CFS and IBS.

Chronic Fatigue Syndrome, also known as myalgic encephalomyelitis or ME, is a complex, debilitating disorder, without any identifiable medical cause.

It is characterized by extreme fatigue that increases after physical and mental exertion. Other symptoms may include muscle and joint pain, cognitive dysfunction and sleep disturbance, and these symptoms do not improve with rest.

It usually affects people between 20-40 years of age. In the UK, around 250,000 people are estimated to have CFS.

Around 90% of people with ME/CFS also have IBS.

Study Findings
For the study, 100 people were recruited. Among them 50 patients had CFS and the remaining 50 served as healthy controls.

The participants were tested for bacterial species in fecal samples, and for immune molecules in blood samples.

The results showed that ME/CFS was strongly associated with distinct levels intestinal bacterial species like Faecalibacterium, Roseburia, Dorea, Coprococcus, Clostridium, Ruminococcus, Coprobacillus, and their combined relative abundance appeared to be predictive of diagnosis.

In people who have ME/CFS with IBS, the top biomarkers were increased abundance of unclassified Alistipes and decreased Faecalibacterium.

While in people without IBS, the top biomarkers were increased unclassified Bacteroides abundance and decreased Bacteroides vulgatus.

An analysis of metabolic pathways associated with disturbances in gut bacteria revealed distinct differences between ME/CFS relative to healthy controls.

There were no changes in immune markers suggesting that immune changes may only be evident when comparing short and long duration cases.

Opinions
"Individuals with ME/CFS have a distinct mix of gut bacteria and related metabolic disturbances that may influence the severity of their disease," says co-lead investigator Dorottya Nagy-Szakal, postdoctoral research scientist at CII.

"Our analysis suggests that we may be able to subtype patients with ME/CFS by analyzing their fecal microbiome," says co-lead investigator Brent L. Williams, assistant professor of Pathology and Cell Biology at CII. "Subtyping may provide clues to understanding differences in manifestations of disease."

"Much like IBS, ME/CFS may involve a breakdown in the bidirectional communication between the brain and the gut mediated by bacteria, their metabolites, and the molecules they influence," says senior author W. Ian Lipkin, director of CII and John Snow Professor of Epidemiology at Columbia's Mailman School. "By identifying the specific bacteria involved, we are one step closer to more accurate diagnosis and targeted therapies."

The findings are published in the journal Microbiome.

References:

1. Chronic fatigue syndrome - (http://www.mayoclinic.org/diseases-conditions/chronic-fatigue-syndrome/basics/definition/con-20022009)
2. Chronic Fatigue Syndrome - (http://www.nhs.uk/conditions/Chronic-fatigue-syndrome/Pages/Introduction.aspx)

Source-Medindia