Abnormal levels and types of gut bacteria may be behind chronic fatigue syndrome, researchers report. The findings add to the growing body of evidence that the microbiome is actively involved in our health outcomes.
Chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) only received official recognition as a disease in the 1980s. But although the condition has received much more attention in recent years, researchers are still in the dark about the etiology and manifestation of CFS. Patients with CFS/ME can exhibit a wide range of symptoms that aren't improved with rest. These include lethargy, sleep disturbances, to muscle and joint pain, and even altered cognitive abilities. Because the symptoms appear nonspecific and overlap with a host of other diseases, and because there’s no agreed-upon trigger, the condition is often misdiagnosed.
Researchers at the Columbia University's Mailman School of Public Health asked whether CFS may be caused by gut bacteria. The hypothesis isn’t as farfetched as it sounds - CFS has been linked to viral infection, hormonal imbalance, and even immune malfunctions. Furthermore, a large percentage of CFS patients also suffer from irritable bowel syndrome (IBS) - a condition with known influences from the gut bacteria.
The team analyzed fecal samples from 50 participants with CFS/ME and 50 healthy controls. They found that the gut bacteria of affected patients had high levels of certain bacteria: Faecalibacterium, Roseburia, Dorea, Coprococcus, Clostridium, Ruminococcus, Coprobacillus. Furthermore, the bacteria types were different among those who had CFS/ME only, and those who had both CFS/ME and IBS.
"Individuals with ME/CFS have a distinct mix of gut bacteria and related metabolic disturbances that may influence the severity of their disease,” said Dorottya Nagy-Szakal, the study’s lead investigator.
"Our analysis suggests that we may be able to subtype patients with ME/CFS by analyzing their fecal microbiome," said Brent L. Williams, the study’s co-author. "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," said W. Ian Lipkin, the study’s senior author. "By identifying the specific bacteria involved, we are one step closer to more accurate diagnosis and targeted therapies."
Of note, it’s not clear how IBS and CFS are interrelated - chronic fatigue syndrome may trigger IBS, vice versa, or the two conditions may be simultaneously triggered. However, the results suggest a look into the gut microbiome could one day give doctors the indications to more accurately predict and diagnose CFS. Furthermore, the results hint at new ways to treat the condition, possibly by modulating the levels of the bacteria in our bowels.