ABSTRACT
The gut microbiota has been found to interact with the brain through the microbiota-gut-brain axis, regulating various physiological processes. In recent years, the impacts of the gut microbiota on neurodevelopment through this axis have been increasingly appreciated. The gut microbiota is commonly considered to regulate neurodevelopment through three pathways, the immune pathway, the neuronal pathway, and the endocrine/systemic pathway, with overlaps and crosstalks in between. Accumulating studies have identified the role of the microbiota-gut-brain axis in neurodevelopmental disorders including autism spectrum disorder, attention deficit hyperactivity disorder, and Rett Syndrome. Numerous researchers have examined the physiological and pathophysiological mechanisms influenced by the gut microbiota in neurodevelopmental disorders (NDDs). This review aims to provide a comprehensive overview of advancements in research pertaining to the microbiota-gut-brain axis in NDDs. Furthermore, we analyzed both the current state of research progress and discuss future perspectives in this field.
Subject(s)
Humans , Brain-Gut Axis , Autism Spectrum Disorder/metabolism , Brain/metabolism , Gastrointestinal Microbiome , Neurodevelopmental Disorders/metabolismABSTRACT
The degeneration of monoaminergic system and the reduction of monoamine neurotransmitters(MNTs) are associated with the occurrence of a variety of neuropsychiatric diseases, becoming the key indicators for clinical diagnosis and treatment. Recent studies suggested gut microbiota could influence the occurrence, development, and treatment of neuropsychiatric diseases by directly or indirectly regulating the synthesis and metabolism of MNTs. Rich clinical experience has been accumulated in the amelioration and treatment of neuropsychiatric diseases by traditional Chinese medicines. The traditional oral administration method demonstrates obvious advantages in regulating gut microbiota. It provides a new idea for explaining the pharmacodynamic material basis and mechanism of traditional Chinese medicines in ameliorating neuropsychiatric disease by improving the levels of MNTs via gut microbiota regulation. Focusing on three common neuropsychiatric diseases including Alzheimer's disease, Parkinson's disease, and major depression, we summarized the pathways of gut microbiota in regulating the levels of MNTs and the paradigms of traditional Chinese medicines in ameliorating neuropsychiatric diseases via the "bacteria-gut-brain axis", aiming to provide ideas for the development of drugs and treatment schemes.
Subject(s)
Humans , Administration, Oral , Alzheimer Disease , Brain-Gut Axis , Gastrointestinal Microbiome , Neurotransmitter AgentsABSTRACT
Objective: To observe the intestinal time-dependent changes in Parkinson's disease (PD) mouse model constructed by intraperitoneal injection of paraquat (PQ) and to establish the brain-gut axis connection initially. Methods: In October 2019, 48 mice were randomly divided into treated group and control groups: treated 4-week (P-4) group, treated 6-week (P-6) group, treated 8-week (P-8) group, control 4-week (C-4) group, control 6-week (C-6) group, and control 8-week (C-8) group. The treated group was injected with 15 mg/kg PQ solution and the control group was injected with 0.9% saline (0.2 ml/20 g) by intraperitoneal injection twice a week. After the initial state (0 weeks) and the treatment at the end of 4, 6 and 8 weeks, the mood changes and motor functions of mice were assessed by neurobehavioral tests (open field test, pole climbing test, tail suspension test and elevated plus maze test) . And the number of fecal pellets for 1 h and water content were calculated to assess the functional status of the gastrointestinal tract. Western blotting experiments were performed to detect the expression levels of α-synuclein (α-syn) and tyrosine hydroxylase (TH) in the nigrostriatal region of the mouse brain, the tight junction markers zonula occludens-1 (ZO-1) and Occludin, the inflammatory markers of integrin αM subunit (CD11b) , inducible nitric oxide synthase (iNOS) , high mobility group box 1 (HMGB1) , interleukin-1β (IL-1β) , and the neuronal markers βⅢ-tubulin and α-syn protein in the colon.Immunohistochemical staining was performed to detect the expression levels of colonic tight junction proteins ZO-1 and Occludin. Immunofluorescence staining was performed to detect the expression levels of TH in the substantia nigra region of the midbrain, and the co-localization of colonic intestine neuronal marker (βⅢ-tubulin) and Ser129 α-syn in the colonic. Results: Compared with the initial state (0 weeks) and C-8 group, mice in the P-8 group had significantly higher pole climbing test scores and resting time, and significantly lower total active distance, mean active speed, percentage of open arm entry and 1 h fecal instances (P<0.05) . After poisoning, the 1 h fecal water content of model mice first increased and then decreased, the P-4 and P-6 groups were significantly higher than the simultaneous point control group, and the P-8 groups were significantly lower than the initial state (P<0.05) . Compared with control, P-4 and P-6 groups, the expression levels of ZO-1 and Occludin in the P-8 group were significantly decreased (P<0.05) . Compared with control group, the expression levels of CD11b and IL-1β in the P-4 group were significantly increased (P<0.05) . Compared with control and P-4 group, the expression levels of CD11b, iNOS, HMGB1 and IL-1β in the P-6 and P-8 groups were significantly increased (P<0.05) . Compared with the control and P-4 groups, the expression levels of βⅢ-tubulin in the colon of mice in the P-8 group were significantly decreased, and the expression levels of α-syn and Ser129 α-syn were significantly increased (P<0.05) . The expression level of Ser129 α-syn in the colon of model mice was negatively correlated with the expression level of βⅢ-tubulin (r(s)=-0.9149, 95%CI: -0.9771--0.7085, P<0.001) . Ser129 α-syn and βⅢ-tubulin co-localization in the colonic intermuscular plexus region increased gradually with the time of exposure. Compared with the control, P-4 and P-6 groups, the expression level of TH in the nigrostriatal region of the brain was significantly decreased, and the expression levels of α-syn and Ser129 α-syn were significantly increased in the P-8 group (P<0.05) . Correlation analysis showed that the relative expression level of Ser129 α-syn in the nigrostriatal region of the brain was negatively correlated with the expression level of TH in the model mice (r(s)=-0.9716, 95% CI: -0.9925--0.8953, P<0.001) . Conclusion: The PD mouse model is successfully established by PQ, and the intestinal function of the model mice is reduced in a time-dependent manner. And on this basis, it is preliminary determined that the abnormal aggregation of α-syn may be an important substance connecting the brain-gut axis.
Subject(s)
Animals , Mice , Brain-Gut Axis , Disease Models, Animal , HMGB1 Protein , Intestines , Mice, Inbred C57BL , Occludin , Paraquat/toxicity , Parkinson Disease , Tubulin , Tyrosine 3-Monooxygenase/metabolism , WaterABSTRACT
Os casos de transtorno de ansiedade têm apresentado crescimento considerável desde o início do século XX, onde a terapia medicamentosa oferecida, geralmente apresenta efeito sedativo, portanto, a busca por tratamentos adjuvantes para tratar quadros de ansiedade se fazem necessários. Estudos indicam que a modulação da microbiota intestinal pode estar relacionada à regulação neural dos indivíduos através de diversas vias, incluindo a aplicação de cepas probióticas e consumo de alimentos fermentados tradicionais como iogurte e kombucha, colaborando para a melhoria da qualidade de vida destes pacientes. Este projeto teve como objetivo buscar os metabólitos e neurotransmissores presentes no kombucha a fim de verificar seu potencial psicobióticos e comparar as aplicações e metabólitos produzidos por cepas probióticas existentes no mercado e em alimentos fermentados tradicionais que atuem no eixo intestino-cérebro. Foram realizadas pesquisas em bases de dados online, como Pubmed, Web of Science, Scielo, Scopus e Google Scholar no período entre 2002 e 2022 relacionados aos possíveis efeitos dos probióticos em condições de ansiedade, bem como como os mecanismos que envolvem o eixo cérebro-intestino, seja por meio de testes em humanos e em modelos animais. As espécies mais testadas quanto ao seu potencial probiótico e ação nos transtornos de ansiedade encontradas foram Lactobacillus paracasei, L. casei, L. rhamnosus, Bifidobacterium infanti e B. longum. Cada gênero demonstra um grau diferente na redução da ansiedade dos indivíduos. Os alimentos potencialmente probióticos, incluindo alimentos fermentados tradicionais, além de atuar como complemento à terapia em quadros de ansiedade, tem relevância no setor socioeconômico
Anxiety disorder cases have shown considerable growth since the beginning of the 20th century, where the drug therapy offered usually has a sedative effect. Therefore, the search for adjuvant treatments to treat anxiety disorders is necessary. Studies indicate that the modulation of the intestinal microbiota may be related to the neural regulation of individuals in several ways, including the application of probiotic strains and consumption of traditional fermented foods such as yogurt and kombucha, contributing to the improvement of the quality of life of these patients. This project aimed to identify and compare the psychobiotic effect in the gut-brain axis of the metabolites and neurotransmitters produced by kombucha and commercial probiotic strains. The research was carried out in online databases, such as Pubmed, Web of Science, Scielo, Scopus, and Google Scholar in the period between 2002 and 2022 related to the possible effects of probiotics in anxiety conditions as the mechanisms that involve the brain-gut axis either through tests in humans or animal models. The species most tested for their probiotic potential and action on anxiety disorders were Lactobacillus paracasei, L. casei, L. rhamnosus, Bifidobacterium infanti, and B. longum. Each genus demonstrates a different degree of reducing individuals' anxiety. Potentially probiotic foods, including traditional fermented foods, acting as a complement to therapy in cases of anxiety, have relevance in the socioeconomic sector
Subject(s)
Phobic Disorders/pathology , Kombucha Tea/analysis , Kombucha Tea/adverse effects , Serotonin/analogs & derivatives , Microbiota , Fermented Foods/adverse effects , Brain-Gut AxisABSTRACT
Unravelling the efficacy of gut biome has a major impact on health. An unbalanced microbiome composition is linked to many common illnesses such as gut dysbiosis, mental deformities and immunological imbalance. An optimistic influence on the gut biome can be made by consumingprobiotics. This would stimulate neuroprotection and immunomodulation intended by heavy metals pollution. Lead is a major source of neurotoxin that can induce neural deformities. Lactobacillusspecies isolated from curd were characterized to confirm its specificity. Zebra fish was reared at standard conditions and preclinical assessment on the intensity of induced neurotoxin lead was performed. The embryo toxic assay, immunomodulation effects and animal behavioural models endorsed the consequence of neurotoxicity. Different concentrations of bacterial isolate with standard antidepressant was considered for analysing the vigour of toxicity and its influence on cognitive behaviour by novel tank diving method. The restrain in the animal behaviour was also conferred by all the test samples with a decreased bottom dwelling time which was authenticated with haematology and histopathological studies. The alterations in morphology of the lymphocytes were balanced by the treated test samples. This study paves a twofold potential of probiotic as neuroprotectant and immune modulator against heavy metal toxicity.
Subject(s)
Animals , Bacteria/pathogenicity , Zebrafish , Probiotics/analysis , Neuroprotection/immunology , Brain-Gut Axis/immunology , Lead/analysis , Bacteria/virology , Congenital Abnormalities/virology , Lymphocytes/microbiology , Metals, Heavy/analysis , Toxicity , Immunomodulation/immunology , Dysbiosis/microbiology , Lactobacillus/immunologyABSTRACT
With the widespread application of next-generation sequencing(NGS), especially 16 S rRNA and shotgun sequencing, researchers are no longer troubled with massive data on the gut microbiota, and the correlation between the gut microbiota and the brain(central nervous system) has been gradually revealed. Research on the microbiota-gut-brain axis(MGBA) based on the gut microbiota have provided insights into the exploration of the pathogenesis and risk factors of ischemic stroke(IS), a cerebrovascular disease with high disability and mortality rates, and also facilitate the selection of therapeutic targets of this class of drugs. This study reviewed the application of NGS in the study of gut microbiota and the research progress of MGBA in recent years and systematically collated the research papers on the correlation between IS and gut microbiota. Furthermore, from the bi-directional regulation of MGBA, this study also discussed the high-risk factors of IS under the dysregulation of gut microbiota and the pathophysiological changes of gut microbiota after the occurrence of IS and summarized the related targets to provide a reliable reference for the therapeutic research of IS from the gut microbiota.
Subject(s)
Humans , Brain , Brain-Gut Axis , Gastrointestinal Microbiome , Ischemic Stroke , Stroke/geneticsABSTRACT
Abstract Recently, gut microbiota has emerged as an important mediator of several diseases such as diabetes, atherosclerosis, arterial hypertension, obesity, cancers and neuropsychiatric diseases including Alzheimer, autism and depression. Intestinal microbiota is formed by bacteria, fungi and viruses and its main function is to facilitate the absorption and metabolism of foods (protein, fat and carbohydrate). One example of the multiple actions of the gut microbiota is the bidirectional relationship between the intestine and the brain, the so-called "gut/brain axis". Furthermore, metabolites produced by gut microbiota can induce effects locally or at distance, which suggests that the intestine is an endocrine organ. Given the participation of the gut microbiota in several diseases, there is great interest in strategies that may positively affect the gut flora and prevent or even treat diseases. Among these strategies, lifestyle change, but specially diet modulation has gained importance. In this article, we review the mechanisms through which intestinal microbiota participates in cardiovascular diseases and possible therapeutic interventions.
Subject(s)
Cardiovascular Diseases/diet therapy , Cardiovascular Diseases/prevention & control , Gastrointestinal Microbiome/physiology , Cardiovascular Diseases/etiology , Diet, Mediterranean , Heart Disease Risk Factors , Brain-Gut AxisABSTRACT
Abstract Recent evidence suggests that dysfunction of the gut-brain axis may be an important factor contributing to many diseases of the nervous system. Increased gut permeability associated with chronic gastrointestinal dysfunction, as well as changes in the composition of the gut microbiota could contribute to exposure of the enteric and central nervous system to pathogens and its metabolites, including endotoxins and pro-inflammatory cytokines. As a consequence, dysfunction of the host's immune system could contribute to an abnormal immunological response leading to auto-immune conditions, such as multiple sclerosis. So far, gut dysbiosis has been reported in association with Parkinson's disease, Alzheimer's disease, multiple sclerosis, neurodevelopmental and neuropsychiatric conditions, and cerebrovascular disease. These findings suggest that the possibility of targeting the gut microbiota could become a future therapeutic option to treat these conditions. However, before this knowledge can be useful in the clinical setting, more data is needed to establish clear causal relationships between dysfunction of the gut-brain axis and neurological diseases.
Subject(s)
Neurodegenerative Diseases/etiology , Brain-Gut Axis/physiology , Neurodegenerative Diseases/prevention & control , Neurobehavioral Manifestations , Gastrointestinal Tract/physiology , Gastrointestinal MicrobiomeABSTRACT
Introducción: la enfermedad de Alzheimer es la forma más común de demencia, la cual se asocia con el deterioro pro-gresivo de las funciones cognitivas; se caracteriza por la for-mación de ovillos neurofibrilares y placas seniles conformadas por la sustancia ß-amiloide. Desarrollo: el eje microbiota-intestino-cerebro permite la co-municación entre el tracto gastrointestinal y el cerebro. La micro-biota intestinal sufre modificaciones por el envejecimiento como el incremento de la permeabilidad intestinal y la translocación bacteriana. En presencia de disbiosis, los cambios en la motilidad y la secreción gastrointestinal alteran las células neuroendocrinas y del sistema inmune, y afectan la liberación de neurotransmiso-res. Así, las modificaciones de la microbiota pueden ocasionar la neuroinflamación que se observa en la enfermedad de Alzhei-mer. Los productos prebióticos y cepas de probióticos demostra-ron ser beneficiosos a nivel neurológico en dicha enfermedad, detectándose expresión de neurotransmisores y mejoría en las funciones cognitivas. Conclusiones: se ha documentado el uso de prebióticos y pro-bióticos en la enfermedad de Alzheimer, y se refirió que ocasio-nan reducción de la inflamación intestinal y disbiosis, así como mejora de las funciones cognitivas en estos pacientes. Sin em-bargo, en el tratamiento de la enfermedad de Alzheimer aún no se contempla el uso de los probióticos y tampoco se ha consi-derado como manera preventiva dado que las investigaciones son recientes.