The Emerging Role of Gut Microbiota in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): Current Evidence and Potential Therapeutic Applications

Abstract

The well-known symptoms of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) are chronic pain, cognitive dysfunction, post-exertional malaise and severe fatigue. Another class of symptoms commonly reported in the context of ME/CFS are gastrointestinal (GI) problems. These may occur due to comorbidities such as Crohn’s disease or irritable bowel syndrome (IBS), or as a symptom of ME/CFS itself due to an interruption of the complex interplay between the gut microbiota (GM) and the host GI tract. An altered composition and overall decrease in diversity of GM has been observed in ME/CFS cases compared to controls. In this review, we reflect on genetics, infections, and other influences that may factor into the alterations seen in the GM of ME/CFS individuals, we discuss consequences arising from these changes, and we contemplate the therapeutic potential of treating the gut to alleviate ME/CFS symptoms holistically.

Perspective: Drawing on Findings From Critical Illness to Explain Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

“…We propose that the sequence during critical illness-from splanchnic hypoperfusion to hypoxia, redox imbalance, altered gut microbiome, intestinal injury, gut-related endotoxemia, pro-inflammatory cytokines and systemic inflammatorymay also contribute to explain the emergence of ME/CFS following a physiological insult. Our proposal is in alignment with others' findings that intestinal injury and resulting inflammation are central to ME/CFS (73-81) and consistent with findings linking the gut microbiome to inflammation (82)(83)(84)(85) and to fatigue symptoms in ME/CFS (86). If verified, the existence of a vicious inflammatory cycle centered around intestinal injury could contribute to explain the perpetuation of ME/CFS.…”

Blood-Based Biomarkers for Alzheimer’s Disease Diagnosis and Progression: An Overview

“…Gut microbiota alterations have been reported in several different conditions, including neurodegeneration and AD [ 364 , 365 , 366 , 367 , 368 , 369 , 370 , 371 , 372 , 373 , 374 ]. Overall, AD patients seem to be characterized by dysbiosis, a condition of bacterial imbalance with a predominance of pro-inflammatory taxa and a decrease in beneficial anti-inflammatory species [ 375 , 376 , 377 , 378 ].…”

The Potential Role of Gut Microbiota in Alzheimer’s Disease: From Diagnosis to Treatment

“…Although the composition of a “healthy microbiota” has not yet been defined, a balanced environment between the host and microorganisms is known to be essential to carry on the necessary immunological and metabolic functions [ 58 ]. Over the past years, dysbiosis has been reported to be implicated in the development of several disorders, such as obesity, diabetes, chronic fatigue syndrome, intestinal bowel syndrome, cancer, autoimmune diseases, depression, anxiety, PD, multiple sclerosis, amyotrophic lateral sclerosis, and other neuropsychiatric disorders [ 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 ]. Recently, many studies have shown that gut microbiota alterations directly influence cognitive decline, actively participating in AD pathogenesis and progression [ 36 , 70 , 71 , 72 , 73 ].…”

“…Despite the potential application of FMT in AD treatment, several limitations still exist. Standardization of the therapeutic protocols, timings and length of administration, short and term risks, and inclusion criteria are all points that should be considered and addressed [ 68 , 240 , 241 , 242 , 243 , 244 ].…”