Le microbiome gastro-intestinal: une revue

Aperçu: G.M.

Le microbiome gastro-intestinal est un consortium divers de bactéries, d'archées, de champignons, de protozoaires et de virus qui habitent l'intestin de tous les mammifères. Des études chez l'homme et d'autres mammifères ont impliqué le microbiome dans une série de processus physiologiques vitaux pour la santé de l'hôte, comprenant l'homéostasie énergétique, le métabolisme, la santé épithéliale intestinale, l'activité immunologique et le développement neurocomportemental.

Le génome microbien confère des capacités métaboliques supérieures à celles de l'organisme hôte seul, faisant du microbiome intestinal un participant actif de la physiologie de l'hôte.

Les changements dans le microbiome gastro-intestinal sont associés à des maladies chez les humains et les animaux, y compris les maladies inflammatoires de l'intestin, l'asthme, l'obésité, le syndrome métabolique, les maladies cardiovasculaires, les troubles immunitaires et les troubles neurodéveloppementaux.  

J Vet Intern Med. 2017 Nov 24. doi: 10.1111/jvim.14875.

The Gastrointestinal Microbiome: A Review

Barko PC¹, McMichael MA¹, Swanson KS^1,2, Williams DA¹.

Author information

1

Veterinary Clinical Medicine, University of Illinois at Urbana-Champaign, Urbana, IL.

2

Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL.

Abstract

The gastrointestinal microbiome is a diverse consortium of bacteria, archaea, fungi, protozoa, and viruses that inhabit the gut of all mammals. Studies in humans and other mammals have implicated the microbiome in a range of physiologic processes that are vital to host health including energy homeostasis, metabolism, gut epithelial health, immunologic activity, and neurobehavioral development. The microbial genome confers metabolic capabilities exceeding those of the host organism alone, making the gut microbiome an active participant in host physiology. Recent advances in DNA sequencing technology and computational biology have revolutionized the field of microbiomics, permitting mechanistic evaluation of the relationships between an animal and its microbial symbionts. Changes in the gastrointestinal microbiome are associated with diseases in humans and animals including inflammatory bowel disease, asthma, obesity, metabolic syndrome, cardiovascular disease, immune-mediated conditions, and neurodevelopmental conditions such as autism spectrum disorder. While there remains a paucity of data regarding the intestinal microbiome in small animals, recent studies have helped to characterize its role in host animal health and associated disease states. This review is intended to familiarize small animal veterinarians with recent advances in the field of microbiomics and to prime them for a future in which diagnostic tests and therapies will incorporate these developments into clinical practice.

Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

PMID: 29171095

DOI:10.1111/jvim.14875

Le microbiote intestinal et les troubles du spectre de l'autisme

Aperçu: G.M.

Les symptômes gastro-intestinaux (GI) sont une comorbidité commune chez les patients ayant un diagnostic de trouble du spectre de l'autisme (TSA), mais les mécanismes sous-jacents sont inconnus. De nombreuses études ont montré des altérations dans la composition de la flore fécale et des produits métaboliques du microbiome intestinal chez les patients avec un diagnostic de TSA. Le microbiota intestinal influence le développement et les comportements du cerveau à travers les systèmes nerveux neuroendocrinien, neuroimmune et autonome. En outre, un microbiote intestinal anormal est associé à plusieurs maladies, telles que la maladie inflammatoire de l'intestin (MII), le TSA et les troubles de l'humeur.  

Dans cette étude, les auteurs examinent les interactions bidirectionnelles entre le système nerveux central et le tractus gastro-intestinal (axe cerveau-cerveau) et le rôle du microbiote intestinal dans le système nerveux central (SNC) et le TSA . Les thérapies à médiation par microbiome peuvent constituer un traitement efficace et sécurisé pour les TSA.

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Front Cell Neurosci. 2017 Apr 28;11:120. doi: 10.3389/fncel.2017.00120. eCollection 2017.

The Gut Microbiota and Autism Spectrum Disorders

Li Q¹, Han Y¹, Dy ABC², Hagerman RJ^3,4.

Author information

1

Department of Pediatrics, Peking University First HospitalBeijing, China.

2

School of Medicine and Public Health, Ateneo de Manila UniversityQuezon City, Philippines.

3

MIND Institute, University of California Davis Medical CenterSacramento, CA, USA.

4

Department of Pediatrics, University of California Davis Medical CenterSacramento, CA, USA.

Abstract

Gastrointestinal (GI) symptoms are a common comorbidity in patients with autism spectrum disorder (ASD), but the underlying mechanisms are unknown. Many studies have shown alterations in the composition of the fecal flora and metabolic products of the gut microbiome in patients with ASD. The gut microbiota influences brain development and behaviors through the neuroendocrine, neuroimmune and autonomic nervous systems. In addition, an abnormal gut microbiota is associated with several diseases, such as inflammatory bowel disease (IBD), ASD and mood disorders. Here, we review the bidirectional interactions between the central nervous system and the gastrointestinal tract (brain-gut axis) and the role of the gut microbiota in the central nervous system (CNS) and ASD. Microbiome-mediated therapies might be a safe and effective treatment for ASD.

PMID: 28503135

PMCID: PMC5408485

DOI: 10.3389/fncel.2017.00120

Altérations liées au sexe de la composition de microbiote intestinal dans le modèle de souris BTBR du trouble du spectre de l'autisme

Aperçu: G.M.

Des modifications de l'axe du microbiote-intestin-cerveau ont été invoquées dans la pathogenèse des troubles du spectre de l'autisme (TSA). Les modèles de souris pourraient représenter un excellent outil pour comprendre comment la dysbiose intestinale et les modifications connexes peuvent contribuer au phénotype autistique.  

Nous avons identifié les genres Bacteroides, Parabacteroides, Sutterella, Dehalobacterium et Oscillospira comme facteurs clés des profils de microbiota intestinal spécifiques au sexe associés à certains traits pathologiques.  

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Sci Rep. 2017 Mar 28;7:45356. doi: 10.1038/srep45356.

Sex-related alterations of gut microbiota composition in the BTBR mouse model of autism spectrum disorder

Coretti L¹, Cristiano C², Florio E³, Scala G⁴, Lama A², Keller S³, Cuomo M³, Russo R², Pero R³, Paciello O⁵, Mattace Raso G², Meli R², Cocozza S^1,3, Calignano A², Chiariotti L^1,3, Lembo F².

Author information

1

Institute of Endocrinologia ed Oncologia Sperimentale, IEOS, Consiglio Nazionale delle Ricerche CNR, Via S. Pansini, 5, 80131, Naples, Italy.

2

Department of Pharmacy, University of Naples Federico II, Via D. Montesano, 49, 80131, Naples, Italy.

3

Department of Medicina Molecolare e Biotecnologie Mediche, University of Naples Federico II, Via S. Pansini, 5, 80131, Naples, Italy.

4

Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, Naples, Italy.

5

Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Napoli, Italy.

Abstract

Alterations of microbiota-gut-brain axis have been invoked in the pathogenesis of autism spectrum disorders (ASD). Mouse models could represent an excellent tool to understand how gut dysbiosis and related alterations may contribute to autistic phenotype. In this study we paralleled gut microbiota (GM) profiles, behavioral characteristics, intestinal integrity and immunological features of colon tissues in BTBR T + tf/J (BTBR) inbred mice, a well established animal model of ASD. Sex differences, up to date poorly investigated in animal models, were specifically addressed. Results showed that BTBR mice of both sexes presented a marked intestinal dysbiosis, alterations of behavior, gut permeability and immunological state with respect to prosocial C57BL/6j (C57) strain. Noticeably, sex-related differences were clearly detected. We identified Bacteroides, Parabacteroides, Sutterella, Dehalobacterium and Oscillospira genera as key drivers of sex-specific gut microbiota profiles associated with selected pathological traits. Taken together, our findings indicate that alteration of GM in BTBR mice shows relevant sex-associated differences and supports the use of BTBR mouse model to dissect autism associated microbiota-gut-brain axis alteration.

PMID: 28349974

DOI: 10.1038/srep45356

Axe Cerveau-intestin et comportement

Aperçu: G.M.

Au cours des 5 dernières années, l'intérêt pour les interactions entre le microbiome intestinal, le cerveau et le comportement a explosé. Des preuves cliniques prouvent le rôle du microbiome intestinal dans les réponses comportementales associées à la douleur, aux émotions, aux interactions sociales et à l'apport alimentaire.Alors que les études réalisées chez des patients souffrant de dépression et de modèles de rongeurs générés par le transfert microbien fécal de ces patients suggèrent une causalité, il n'existe pas d'évidence d'une influence des altérations microbiennes aiguës sur les paramètres comportementaux et cliniques humains. Il y a peu de temps encore, une thérapie de transfert microbien ouverte chez des enfants avec un diagnostic de TSA a validé provisoirement le microbiote intestinal comme cible thérapeutique.

Nestle Nutr Inst Workshop Ser. 2017;88:45-53. doi: 10.1159/000461732. Epub 2017 Mar 27.

Gut-Brain Axis and Behavior

Martin CR, Mayer EA.

Abstract

In the last 5 years, interest in the interactions among the gut microbiome, brain, and behavior has exploded. Preclinical evidence supports a role of the gut microbiome in behavioral responses associated with pain, emotion, social interactions, and food intake. Limited, but growing, clinical evidence comes primarily from associations of gut microbial composition and function to behavioral and clinical features and brain structure and function. Converging evidence suggests that the brain and the gut microbiota are in bidirectional communication. Observed dysbiotic states in depression, chronic stress, and autism may reflect altered brain signaling to the gut, while altered gut microbial signaling to the brain may play a role in reinforcing brain alterations. On the other hand, primary dysbiotic states due to Western diets may signal to the brain, altering ingestive behavior. While studies performed in patients with depression and rodent models generated by fecal microbial transfer from such patients suggest causation, evidence for an influence of acute gut microbial alterations on human behavioral and clinical parameters is lacking. Only recently has an open-label microbial transfer therapy in children with autism tentatively validated the gut microbiota as a therapeutic target. The translational potential of preclinical findings remains unclear without further clinical investigation.

© 2017 Nestec Ltd., Vevey/S. Karger AG, Basel.

PMID: 28346923

DOI: 10.1159/000461732

L'axe cerveau-microbiote intestinal et ses effets sur les troubles neuropsychiatriques avec une suspicion de dérégulation immunitaire

Traduction: G.M.

 

Clin Ther. 2015 May 1;37(5):984-995. doi: 10.1016/j.clinthera.2015.04.002.

Gut-Microbiota-Brain Axis and Its Effect on Neuropsychiatric Disorders With Suspected Immune Dysregulation

Petra AI¹, Panagiotidou S¹, Hatziagelaki E², Stewart JM¹, Conti P³, Theoharides TC⁴.

Author information

• ¹Molecular Immunopharmacology and Drug Discovery Laboratory, Department of Integrative Physiology and Pathobiology, Tufts University School of Medicine, Boston, Massachusetts.
• ²Second Department of Internal Medicine, Attikon General Hospital, Athens Medical School, Athens, Greece.
• ³Department of Medical Sciences, Immunology Division, University of Chieti, Via dei Vestini, Chieti, Italy.
• ⁴Molecular Immunopharmacology and Drug Discovery Laboratory, Department of Integrative Physiology and Pathobiology, Tufts University School of Medicine, Boston, Massachusetts; Department of Internal Medicine, Tufts University School of Medicine and Tufts Medical Center, Boston, Massachusetts; Department of Psychiatry, Tufts University School of Medicine and Tufts Medical Center, Boston, Massachusetts. Electronic address: theoharis.theoharides@tufts.edu

Abstract

PURPOSE:

Gut microbiota regulate intestinal function and health. However, mounting evidence indicates that they can also influence the immune and nervous systems and vice versa. This article reviews the bidirectional relationship between the gut microbiota and the brain, termed the microbiota-gut-brain (MGB) axis, and discusses how it contributes to the pathogenesis of certain disorders that may involve brain inflammation.

Le microbiote intestinal régule la fonction et la santé intestinale. Toutefois, des preuves croissantes indiquent qu'il peut également influencer les systèmes immunitaires et nerveux et vice versa. Cet article examine la relation bidirectionnelle entre le microbiote intestinal et le cerveau, appelée l'axe microbiote-intestin-cerveau (MGB), et explique comment il contribue à la pathogenèse de certains troubles qui peuvent impliquer l'inflammation du cerveau.

METHODS:

Articles were identified with a search of Medline (starting in 1980) by using the key words anxiety, attention-deficit hypersensitivity disorder (ADHD), autism, cytokines, depression, gut, hypothalamic-pituitary-adrenal (HPA) axis, inflammation, immune system, microbiota, nervous system, neurologic, neurotransmitters, neuroimmune conditions, psychiatric, and stress.

Les articles ont été identifiés par une recherche dans Medline (à partir de 1980) en utilisant le mots clé anxiété, trouble déficit d'attention avec hypersensibilité (TDAH), autisme, cytokines, dépression, intestin, hypothalamo-hypophyso-surrénalien (HHS), inflammation, système immunitaire ,  microbiote, système nerveux, neurologique, neurotransmetteurs, conditions neuroimmunes, psychiatrique, et stress.

FINDINGS:

Various afferent or efferent pathways are involved in the MGB axis. Antibiotics, environmental and infectious agents, intestinal neurotransmitters/neuromodulators, sensory vagal fibers, cytokines, and essential metabolites all convey information to the central nervous system about the intestinal state. Conversely, the hypothalamic-pituitary-adrenal axis, the central nervous system regulatory areas of satiety, and neuropeptides released from sensory nerve fibers affect the gut microbiota composition directly or through nutrient availability. Such interactions seem to influence the pathogenesis of a number of disorders in which inflammation is implicated, such as mood disorder, autism-spectrum disorders, attention-deficit hypersensitivity disorder, multiple sclerosis, and obesity.

Diverses voies afférentes ou efférentes sont impliquées dans l'axe MGB. Les antibiotiques, des agents environnementaux et infectieux, des neurotransmetteurs / neuromodulateurs intestinaux, les fibres vagales sensorielles, des cytokines, et des métabolites essentiels transmettent toutes les informations au système nerveux central sur l'état intestinal. Inversement, l'axe hypothalamo-hypophyso-surrénalien, les domaines de la réglementation du système nerveux central de la satiété, et neuropeptides libérés à partir de fibres nerveuses sensorielles affectent directement  la composition du microbiote intestinal ou par la disponibilité des nutriments. Ces interactions semblent influencer la pathogenèse d'un certain nombre de troubles dans lesquels une inflammation est impliquée, tels que trouble de l'humeur, les troubles du spectre de l'autisme, le trouble de déficit de l'attention hypersensibilité, la sclérose en plaques, et l'obésité.

IMPLICATIONS:

Recognition of the relationship between the MGB axis and the neuroimmune systems provides a novel approach for better understanding and management of these disorders. Appropriate preventive measures early in life or corrective measures such as use of psychobiotics, fecal microbiota transplantation, and flavonoids are discussed.

La reconnaissance de la relation entre l'axe MGB et les systèmes neuroimmun fournit une nouvelle approche pour une meilleure compréhension et gestion de ces troubles. Les mesures préventives appropriées tôt dans la vie ou des mesures correctives telles que l'utilisation de psychobiotics, la transplantation du microbiotefécale , et les flavonoïdes sont discutées.

Copyright © 2015 Elsevier HS Journals, Inc. All rights reserved.

PMID: 26046241