Special Issue: Recent Advances in Faecal Microbiota Transplantation, 2021, Review article and call for submissions.

[Sly Saint]

Fecal Microbiota Transplantation: A New Therapeutic Attempt from the Gut to the Brain
Hao-Ming Xu,1 Hong-Li Huang,1 You-Lian Zhou,1 Hai-Lan Zhao,1 Jing Xu,1 Di-Wen Shou,1 Yan-Di Liu,1 Yong-Jian Zhou,1 and Yu-Qiang Nie

Abstract
Gut dysbacteriosis is closely related to various intestinal and extraintestinal diseases. Fecal microbiota transplantation (FMT) is a biological therapy that entails transferring the gut microbiota from healthy individuals to patients in order to reconstruct the intestinal microflora in the latter. It has been proved to be an effective treatment for recurrent Clostridium difficile infection.

Studies show that the gut microbiota plays an important role in the pathophysiology of neurological and psychiatric disorders through the microbiota-gut-brain axis. Therefore, reconstruction of the healthy gut microbiota is a promising new strategy for treating cerebral diseases.

We have reviewed the latest research on the role of gut microbiota in different nervous system diseases as well as FMT in the context of its application in neurological, psychiatric, and other nervous system-related diseases (Parkinson’s disease, Alzheimer’s disease, multiple sclerosis, epilepsy, autism spectrum disorder, bipolar disorder, hepatic encephalopathy, neuropathic pain, etc.).

2.6. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is characterized by unexplained persistent fatigue, disturbed sleep, cognitive impairment, fever, postural intolerance, lymphadenopathy, and irritable bowel syndrome.

The gut microbiota is significantly altered in patients with ME/CFS [19], and the extent of microbial dysbiosis affects disease severity [122]. Sheedy et al. [123] observed increased relative abundance of gram-positive lactic acid-producing bacteria in the gut of ME/CFS patients, which may lower the mucosal pH and increase permeability.

Moreover, the transfer of lactic acid from intestine to the blood may be one of the reasons for the increase of lactate level in cerebrospinal fluid of ME/CFS patients [124–126]. Selective transplantation of 13 nonpathogenic enteric bacteria through colonoscopy [56] significantly improved intestinal and other symptoms in 42/60 ME/CFS patients. In addition, 7/12 patients who were followed up for 15 to 20 years showed complete remission, indicating FMT is a promising treatment for ME/CFS.

https://www.hindawi.com/journals/grp/2021/6699268/

 

[MeSci]

Disappointingly,

"However, there are several limitations of using FMT in treating neurological, mental, and psychological diseases: (1) for many diseases, the therapeutic effects of FMT are limited to animal models and isolated cases."

"Despite the promising results, the rationale for the clinical application of FMT is currently based on animal models and a few case reports and clinical studies. Large-scale randomized double-blind controlled trials are still needed to clarify the role of FMT in neurological diseases. At present, 33 clinical trials are ongoing on the potential therapeutic effects of FMT on mental and nervous system diseases (Table 3). Furthermore, the modes of delivering fecal microbiota also need to be improved. While a capsular form is more comfortable for the patients, fecal bacterial liquid in the form of washed/selective microbiota transplantation [188, 189] may be more effective in reducing the potential side effects."