Tag: gut-brain connection

Intestinal flora and neurological disorders

Abstract:

The human intestinal flora is a highly diverse ecosystem composed of trillions of bacteria. The imbalance of the flora is related to a variety of diseases. The intestinal flora interacts with the nervous system bidirectionally in many ways through the gut-brain axis. It causes neuroimmune inflammatory response, dysfunction of gut mucosa and blood-brain barrier, direct stimulation of the vagus nerve, spinal nerve of the enteric nervous system, and the neuroendocrine hypothalamus-pituitary-adrenal axis, causing neurological disorders. The metabolites of the intestinal microbial community also play a role.

This article summarizes the characteristics of the altered intestinal flora and intervention measures in autism spectrum disorder, multiple sclerosis, Parkinson’s disease, epilepsy, Guillain-Barré syndrome, Alzheimer’s disease, neuromyelitis optica, hepatic encephalopathy, amyotrophic lateral sclerosis, schizophrenia, depression, chronic fatigue syndrome, Huntington’s disease and stroke. The current research on intestinal flora is still in its infancy, and very few studies were carried out on causality and the underlying mechanisms, which prevents the development of precise flora-based clinical intervention measures. It is expected the research on intestinal flora would lead to novel approaches for treatment of some neurological disorders.

Source: Tang Q, Cao L. [Intestinal flora and neurological disorders]. Sheng Wu Gong Cheng Xue Bao. 2021 Nov 25;37(11):3757-3780. Chinese. doi: 10.13345/j.cjb.210253. PMID: 34841782. https://pubmed.ncbi.nlm.nih.gov/34841782/

A randomized, double-blind, placebo-controlled pilot study of a probiotic in emotional symptoms of chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) is complex illness of unknown etiology. Among the broad range of symptoms, many patients report disturbances in the emotional realm, the most frequent of which is anxiety. Research shows that patients with CFS and other so-called functional somatic disorders have alterations in the intestinal microbial flora. Emerging studies have suggested that pathogenic and non-pathogenic gut bacteria might influence mood-related symptoms and even behavior in animals and humans.

In this pilot study, 39 CFS patients were randomized to receive either 24 billion colony forming units of Lactobacillus casei strain Shirota (LcS) or a placebo daily for two months. Patients provided stool samples and completed the Beck Depression and Beck Anxiety Inventories before and after the intervention. We found a significant rise in both Lactobacillus and Bifidobacteria in those taking the LcS, and there was also a significant decrease in anxiety symptoms among those taking the probiotic vs controls (p = 0.01). These results lend further support to the presence of a gut-brain interface, one that may be mediated by microbes that reside or pass through the intestinal tract.

 

Source: Rao AV, Bested AC, Beaulne TM, Katzman MA, Iorio C, Berardi JM, Logan AC. A randomized, double-blind, placebo-controlled pilot study of a probiotic in emotional symptoms of chronic fatigue syndrome. Gut Pathog. 2009 Mar 19;1(1):6. doi: 10.1186/1757-4749-1-6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2664325/ (Full article)