Journal of IiMER The gut microbiome in Myalgic Encephalomyelitis Maureen R. Hanson and Ludovic Giloteaux (Cornell University, USA) April 2017 © Biochemical Society O ver the last dozen years, increasingly powerful DNA sequencing methods have allowed characterization of the microbes residing on and in humans in much greater detail than ever possible before. Abnormalities present in the gut microbiome—those microbial communities residing in our intestines—have now been observed in a number of diseases. One such illness is Myalgic Encephalomyelitis (ME), also known as Chronic Fatigue Syndrome (CFS). CFS was a name coined by the US Centers for Disease Control (CDC) in 1988, and reviled by patients for the resultant trivializing of this serious illness. Recently, the US National Academy of Medicine (NAM) recommended a new name: Systemic Exertion Intolerance Disease, though this name is not yet widely used. In ME, as in other diseases, the diversity of the bacterial species in the gut microbiome is lower than in healthy individuals. Furthermore, the abundances of different bacterial residents of the gut, which influence health both favourably and negatively, differ between ME patients and healthy controls. Bacteria translocate into the blood in greater amount in ME, leading to inflammation. Dysbiosis in the gut likely contributes to symptoms in this life-limiting disease . Three to four times more women than men have ME. Children and adolescents as well as adults are susceptible to the disease. Prevalence is difficult to determine because of the lack of a simple, objective diagnostic test. While physicians experienced with the disease are readily able to make correct diagnoses, the clinical criteria often vary between studies, making enumeration of patients difficult. An investigation of ME in three regions of England found that about 0.2% fit a widely used 1994 CDC definition. A meta-analysis of 14 studies www.investinme.org found the prevalence by clinical assessment to be 0.76%. These numbers translate into 128,000 to 486,000 ME patients in the UK. Thus, even if the lower figure is used, ME does not fit the definition of a rare disease (see www.raredisease.org.uk). An example of a rare but serious disorder that affects intestinal function is Clostridium difficile infection which is at least 10 times less common than ME. The severity of the disease varies, though most affected individuals are unable to work or attend Page 25 of 82
26 Publizr Home