Tag: gut-brain connection

Exogenous Players in Mitochondria-Related CNS Disorders: Viral Pathogens and Unbalanced Microbiota in the Gut-Brain Axis

Abstract:

Billions of years of co-evolution has made mitochondria central to the eukaryotic cell and organism life playing the role of cellular power plants, as indeed they are involved in most, if not all, important regulatory pathways. Neurological disorders depending on impaired mitochondrial function or homeostasis can be caused by the misregulation of “endogenous players”, such as nuclear or cytoplasmic regulators, which have been treated elsewhere. In this review, we focus on how exogenous agents, i.e., viral pathogens, or unbalanced microbiota in the gut-brain axis can also endanger mitochondrial dynamics in the central nervous system (CNS).

Neurotropic viruses such as Herpes, Rabies, West-Nile, and Polioviruses seem to hijack neuronal transport networks, commandeering the proteins that mitochondria typically use to move along neurites. However, several neurological complications are also associated to infections by pandemic viruses, such as Influenza A virus and SARS-CoV-2 coronavirus, representing a relevant risk associated to seasonal flu, coronavirus disease-19 (COVID-19) and “Long-COVID”.

Emerging evidence is depicting the gut microbiota as a source of signals, transmitted via sensory neurons innervating the gut, able to influence brain structure and function, including cognitive functions. Therefore, the direct connection between intestinal microbiota and mitochondrial functions might concur with the onset, progression, and severity of CNS diseases.

Source: Righetto I, Gasparotto M, Casalino L, Vacca M, Filippini F. Exogenous Players in Mitochondria-Related CNS Disorders: Viral Pathogens and Unbalanced Microbiota in the Gut-Brain Axis. Biomolecules. 2023 Jan 13;13(1):169. doi: 10.3390/biom13010169. PMID: 36671555; PMCID: PMC9855674. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9855674/ (Full text)

Antioxidants and Long Covid

Abstract:

Long Covid has many symptoms that overlap with ME(myalgic encephalomyelitis)/CFS(chronic fatigue syndrome), FM(fibromyalgia), EBV(Epstein-Barr virus), CMV(cytomegalovirus), CIRS (chronic inflammatory response syndrome), MCAS(mast cell activation syndrome), POTS(postural orthostatic tachycardia syndrome), and post viral fatigue syndrome. They all portend a “long haul” with an antioxidant shortfall and elevated Ca:Mg. Oxidative stress is the root cause.

Linkage between TGF(transforming growth factor)-β, IFN(interferon)-γ, the RAS(renin angiotensin system), and the KKS(kallikrein kinin system) is discussed. Technical explanations for the renin aldosterone paradox in POTS, the betrayal of TGF-β, and the commonality of markers for the Warburg effect are offered. The etiology of the common Long Covid symptoms of post exertional malaise, fatigue, and brain fog as well as anosmia, hair loss, and GI symptoms is technically discussed. Ca:Mg is critical to the glutamate/GABA balance. The role of GABA and butyrates from the “good” intestinal bacteria in the gut-brain axis and its correlation with chronic fatigue diseases are explored.

The crosstalk between the ENS(enteric nervous system) and the ANS(autonomic nervous system) and the role of the vagus in both are emphasized. HRV(heart rate variability), the fifth vital sign, points to an expanded gut-brain-heart/lung axis. A suggested approach to all of these – Long Covid, chronic fatigue diseases, post viral fatigue syndrome, and general health – is presented.

Source: Chambers, P. Antioxidants and Long Covid. Preprints 2022, 2022100195 (doi: 10.20944/preprints202210.0195.v1).  https://www.preprints.org/manuscript/202210.0195/v1 (Full text available as PDF file)

Disorders of gut-brain interaction in post-acute COVID-19 syndrome

Abstract:

The novel coronavirus SARS-CoV-2 is responsible for the devastating pandemic which has caused more than 5 million deaths across the world until today. Apart from causing acute respiratory illness and multiorgan dysfunction, there can be long-term multiorgan sequalae after recovery, which is termed ‘long COVID-19’ or ‘post-acute COVID-19 syndrome’. Little is known about long-term gastrointestinal (GI) consequences, occurrence of post-infection functional gastrointestinal disorders and impact the virus may have on overall intestinal health.

In this review, we put forth the various mechanisms which may lead to this entity and possible ways to diagnose and manage this disorder. Hence, making physicians aware of this spectrum of disease is of utmost importance in the present pandemic and this review will help clinicians understand and suspect the occurrence of functional GI disease post recovery from COVID-19 and manage it accordingly, avoiding unnecessary misconceptions and delay in treatment.

Source: Golla R, Vuyyuru SK, Kante B, Kedia S, Ahuja V. Disorders of gut-brain interaction in post-acute COVID-19 syndrome. Postgrad Med J. 2022 Jul 1:postgradmedj-2022-141749. doi: 10.1136/pmj-2022-141749. Epub ahead of print. PMID: 35777934. https://pmj.bmj.com/content/early/2022/07/01/pmj-2022-141749 (Full text)

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)