scholarly journals Role of the gut microbiota in the development of various neurological diseases

Author(s):  
F. Castillo-Álvarez ◽  
M.E. Marzo-Sola
2020 ◽  
Vol 19 (7) ◽  
pp. 509-526
Author(s):  
Qin Huang ◽  
Fang Yu ◽  
Di Liao ◽  
Jian Xia

: Recent studies implicate microbiota-brain communication as an essential factor for physiology and pathophysiology in brain function and neurodevelopment. One of the pivotal mechanisms about gut to brain communication is through the regulation and interaction of gut microbiota on the host immune system. In this review, we will discuss the role of microbiota-immune systeminteractions in human neurological disorders. The characteristic features in the development of neurological diseases include gut dysbiosis, the disturbed intestinal/Blood-Brain Barrier (BBB) permeability, the activated inflammatory response, and the changed microbial metabolites. Neurological disorders contribute to gut dysbiosis and some relevant metabolites in a top-down way. In turn, the activated immune system induced by the change of gut microbiota may deteriorate the development of neurological diseases through the disturbed gut/BBB barrier in a down-top way. Understanding the characterization and identification of microbiome-immune- brain signaling pathways will help us to yield novel therapeutic strategies by targeting the gut microbiome in neurological disease.


Author(s):  
Camilla Ceccarani ◽  
Ilaria Viganò ◽  
Emerenziana Ottaviano ◽  
Maria Gaia Redaelli ◽  
Marco Severgnini ◽  
...  

Microbiota alterations have been recently investigated in individuals with epilepsy and in other neurological diseases as environmental factors that play a role, by acting through the gut-brain axis, in the pathological process. Most studies focus on the contribution of bacterial communities in refractory epilepsy and suggest a beneficial role of ketogenic diet in modulating the gut microbiota and seizure occurrence. However, they do not evaluate whether epilepsy itself alters the gut microbiota in these patients or if the gut microbial communities could contribute as a seizure trigger. In this pilot study, we performed 16S rRNA sequencing and investigated the gut microbial communities of eight children at their seizure onset and after anti-seizure was started (one year follow-up) and we compared microbial data with seven healthy children, age- and sex-matched. In drug-naive subjects, we observed a microbial signature that shared several features with those reported in refractory epilepsy, such as an increased abundance in Akkermansia spp. and Proteobacteria and a decreased relative abundance in Faecalibacterium spp.We suggest that a bacterial-mediated proinflammatory milieu could contribute to seizure occurrence in children with new onset of epilepsy, as already reported for individuals with drug-resistant epilepsy, and that it could vary during treatment in those who are drug-responsive.


2021 ◽  
Vol 12 ◽  
Author(s):  
Christian Barro ◽  
Anu Paul ◽  
Fermisk Saleh ◽  
Tanuja Chitnis ◽  
Howard L. Weiner

Background: There is an emerging evidence of the role of the microbiome in neurological diseases. Endotoxin is a component of gram-negative bacteria and thought to be one of the possible signals between the gut microbiota and the immune system. Previous studies explored the blood levels of endotoxin using an endpoint chromogenic assay.Methods: We validated and compared the analytical performance of two kinetic assays for the quantification of endotoxin in serum: (1) the Limulus Amebocyte Lysate (LAL) Kinetic-QCL assay and (2) the turbidimetric LAL Pyrogent-5000 assay. We used the best-performing validated assay to measure the endotoxin level in 20 patients with multiple sclerosis (MS) and eight healthy controls.Results: The Pyrogent-5000 and QCL assay achieved similar performance in regard to spike recovery and linear dilution; however, the Pyrogent-5000 had a better signal to noise in the calibrator curve. By using the Pyrogent-5000 assay, we found that serum samples from MS patients and healthy controls have a similar level of endotoxin; hence, we did not find evidence to support a penetration of endotoxin in the blood of MS patients. Our findings do not exclude a role of endotoxin in mediating signals from the gut microbiota in MS patients directly at the gut–blood barrier where numerous antigen-presenting cells are actively sensing metabolites and bacterial products.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Kajal Rawat ◽  
Neha Singh ◽  
Puja Kumari ◽  
Lekha Saha

AbstractThe gut microbiota plays an important role in neurological diseases via the gut–brain axis. Many factors such as diet, antibiotic therapy, stress, metabolism, age, geography and genetics are known to play a critical role in regulating the colonization pattern of the microbiota. Recent studies have shown the role of the low carbohydrate, adequate protein, and high fat “ketogenic diet” in remodeling the composition of the gut microbiome and thereby facilitating protective effects in various central nervous system (CNS) disorders. Gut microbes are found to be involved in the pathogenesis of various CNS disorders like epilepsy, Parkinson’s disease (PD), Alzheimer’s disease (AD), autism spectrum disorders (ASDs), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS) and stress, anxiety and depression. In vivo studies have shown an intricate link between gut microbes and KD and specific microbes/probiotics proved useful in in vivo CNS disease models. In the present review, we discuss the gut–brain bidirectional axis and the underlying mechanism of KD-based therapy targeting gut microbiome in in vivo animal models and clinical studies in neurological diseases. Also, we tried to infer how KD by altering the microbiota composition contributes towards the protective role in various CNS disorders. This review helps to uncover the mechanisms that are utilized by the KD and gut microbiota to modulate gut–brain axis functions and may provide novel opportunities to target therapies to the gut to treat neurologic disorders.


2021 ◽  
Vol 41 ◽  
pp. 01002
Author(s):  
Daria Guseva

The link between nutrition and human diseases has always been recognized, but only with modern molecular genetic analysis tools, the role of the gut microbiome including gastrointestinal tract function on neurodegenerative diseases has become obvious. Gut microbiota significantly influences metabolic and immune responses of the host organism, and thus, dietor infection-related imbalances (dysbiosis) of the gut microbiota disrupt the local and systemic homeostasis and often lead to digestive diseases, such as inflammatory bowel diseases (IBD), type II diabetes, obesity, as well as neurological diseases. The association of the gastrointestinal tract diseases with neurodegenerative diseases, as well as mental and neurological disorders such as depression, anxiety, autism, and schizophrenia has been described. This interaction is called the gut-brain axis and represents one of the most relevant targets for the treatment of IBD and cardiovascular and neurological diseases. One of the most important regulators of this axis is the gut microbiota and its metabolites, which influence brain functions via the immune system, tryptophan metabolism, vagus nerve, and enteric nervous system. We are studying the importance of gut microbiota and their metabolites in immune and glial/microglial reaction in the gastrointestinal tract and central nervous system, to provide valuable insights into the functional potential of the microbiome on the gut-brain axis via specific metabolites. We combine several modern techniques, including molecular manipulations, advanced cellular imaging techniques, and behavioral approaches, to address additional systems-level questions.


2020 ◽  
Vol 21 (20) ◽  
pp. 7551
Author(s):  
Kanmani Suganya ◽  
Byung-Soo Koo

The gut microbiome acts as an integral part of the gastrointestinal tract (GIT) that has the largest and vulnerable surface with desirable features to observe foods, nutrients, and environmental factors, as well as to differentiate commensals, invading pathogens, and others. It is well-known that the gut has a strong connection with the central nervous system (CNS) in the context of health and disease. A healthy gut with diverse microbes is vital for normal brain functions and emotional behaviors. In addition, the CNS controls most aspects of the GI physiology. The molecular interaction between the gut/microbiome and CNS is complex and bidirectional, ensuring the maintenance of gut homeostasis and proper digestion. Besides this, several mechanisms have been proposed, including endocrine, neuronal, toll-like receptor, and metabolites-dependent pathways. Changes in the bidirectional relationship between the GIT and CNS are linked with the pathogenesis of gastrointestinal and neurological disorders; therefore, the microbiota/gut-and-brain axis is an emerging and widely accepted concept. In this review, we summarize the recent findings supporting the role of the gut microbiota and immune system on the maintenance of brain functions and the development of neurological disorders. In addition, we highlight the recent advances in improving of neurological diseases by probiotics/prebiotics/synbiotics and fecal microbiota transplantation via the concept of the gut–brain axis.


2020 ◽  
Vol 78 (8) ◽  
pp. 494-500 ◽  
Author(s):  
Adalberto STUDART-NETO ◽  
Bruno Fukelmann GUEDES ◽  
Raphael de Luca e TUMA ◽  
Antonio Edvan CAMELO FILHO ◽  
Gabriel Taricani KUBOTA ◽  
...  

ABSTRACT Background: More than one-third of COVID-19 patients present neurological symptoms ranging from anosmia to stroke and encephalopathy. Furthermore, pre-existing neurological conditions may require special treatment and may be associated with worse outcomes. Notwithstanding, the role of neurologists in COVID-19 is probably underrecognized. Objective: The aim of this study was to report the reasons for requesting neurological consultations by internists and intensivists in a COVID-19-dedicated hospital. Methods: This retrospective study was carried out at Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Brazil, a 900-bed COVID-19 dedicated center (including 300 intensive care unit beds). COVID-19 diagnosis was confirmed by SARS-CoV-2-RT-PCR in nasal swabs. All inpatient neurology consultations between March 23rd and May 23rd, 2020 were analyzed. Neurologists performed the neurological exam, assessed all available data to diagnose the neurological condition, and requested additional tests deemed necessary. Difficult diagnoses were established in consensus meetings. After diagnosis, neurologists were involved in the treatment. Results: Neurological consultations were requested for 89 out of 1,208 (7.4%) inpatient COVID admissions during that period. Main neurological diagnoses included: encephalopathy (44.4%), stroke (16.7%), previous neurological diseases (9.0%), seizures (9.0%), neuromuscular disorders (5.6%), other acute brain lesions (3.4%), and other mild nonspecific symptoms (11.2%). Conclusions: Most neurological consultations in a COVID-19-dedicated hospital were requested for severe conditions that could have an impact on the outcome. First-line doctors should be able to recognize neurological symptoms; neurologists are important members of the medical team in COVID-19 hospital care.


Author(s):  
Dong-Yu Kan ◽  
Su-Juan Li ◽  
Chen-Chen Liu ◽  
Ren-Rong Wu

Schizophrenia is a chronic and severe mental disorder with antipsychotics as primary medications, but the antipsychotic-induced metabolic side effects may contribute to the elevated risk of overall morbidity and mortality in patients with psych-iatric diseases. With the development in sequencing technology and bioinformatics, dysbiosis has been shown to contribute to body weight gain and metabolic dysfunction. However, the role of gut microbiota in the antipsychotic-induced metabolic alteration remains unknown. In this paper, we reviewed the recent studies of the gut microbiota with psychiatric disorders and antipsychotic-induced metabolic dysfunction. Patients with neuropsychiatric disorders may have a different composi-tion of gut microbiota compared with healthy controls. In addition, it seems that the use of antipsychotics is concurrently associated with both altered composition of gut microbiota and metabolic disturbance. Further study is needed to address the role of gut microbiota in the development of neuropsychiatric disorders and antipsychotic-induced metabolic disturbance, to develop novel therapeutics for both neuropsychiatric disorders and metabolic dysfunction.


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