Researchers found that people with CFS have abnormalities in their gut microbiome.
Senior author Maureen Hanson, of the Departments of Molecular Biology and Genetics and Microbiology at Cornell, and colleagues publish their findings in the journal Microbiome.
Also referred to as myalgic encephalomyelitis (ME), chronic fatigue syndrome (CFS) is a condition characterized by extreme fatigue that does not improve with rest.
Aside from persistent fatigue, symptoms used to diagnose ME/CFS include unrefreshing sleep, headache, joint pain, sore throat, tender lymph nodes in the neck or armpits, problems with concentration and memory, and severe exhaustion and sickness after exercise or mental exertion.
A diagnosis of CFS may be made if four or more of these symptoms last 6 months or longer.
Other symptoms of the condition may include visual problems, dizziness or fainting, brain fog, and irritable bowel.
Because the symptoms of CFS are very similar to those of other illnesses, the condition can be tricky to diagnose. As such, it is unclear how many people in the United States have CFS, though estimates suggest it affects around 1 million Americans.
Another factor that makes CFS difficult to diagnose is that the cause of the condition is unknown.
Despite years of study, researchers have been unable to reach a definitive conclusion about what triggers CFS, leading some investigators to suggest the condition is psychosomatic – that is, it is caused by anxiety, stress, or other psychological factors.
However, Hanson and colleagues say their new study offers evidence that CFS is not psychosomatic, after finding that people with the condition have abnormalities in the gut microbiome – the population of microbes in the intestine.