Gut Microbiota Interaction with the Central Nervous System throughout Life

Abstract

During the last years, accumulating evidence has suggested that the gut microbiota plays a key role in the pathogenesis of neurodevelopmental and neurodegenerative diseases via the gut–brain axis. Moreover, current research has helped to elucidate different communication pathways between the gut microbiota and neural tissues (e.g., the vagus nerve, tryptophan production, extrinsic enteric-associated neurons, and short chain fatty acids). On the other hand, altering the composition of gut microbiota promotes a state known as dysbiosis, where the balance between helpful and pathogenic bacteria is disrupted, usually stimulating the last ones. Herein, we summarize selected findings of the recent literature concerning the gut microbiome on the onset and progression of neurodevelopmental and degenerative disorders, and the strategies to modulate its composition in the search for therapeutical approaches, focusing mainly on animal models studies. Readers are advised that this is a young field, based on early studies, that is rapidly growing and being updated as the field advances.

The Microbiota/Microbiome and the Gut–Brain Axis: How Much Do They Matter in Psychiatry?

“…The bacterial cells forming intestinal microbiota outnumber human cells by 10 times and encode for a gene set that is 150 times larger than the human one [ 1 ]. The human gut microbiota, mainly consisting of Proteobacterias, Firmicutes, Actinobacteria and Bacteroidetes, changes during the course of life, as it is constantly influenced by several individual factors, such as the type of birth, infections, therapies, diet, smoking, physical activity, stressful events, environmental factors and medical diseases [ 7 , 8 , 9 ]. It is also worth highlighting that the brain’s development, depending on pre- and post-natal genetic and environmental factors, occurs in parallel with the constitution of the microbiota.…”

Nutrition, Exercise, and Stress Management for Treatment and Prevention of Psychiatric Disorders. A Narrative Review Psychoneuroendocrineimmunology-Based

“…The Gut-brain axis is, therefore, more correctly referred to as the microbiota-gutbrain axis. Intestinal microbiota alterations have been related to mood disorders, anxiety, and depression, and also to Schizophrenia, Bipolar disorder, Anorexia nervosa, and other neuropsychiatric diseases such as Alzheimer's, Parkinson's, Autism, and Multiple Sclerosis [42].…”

The Microbiota-Gut-Brain Axis as a Key to Neuropsychiatric Disorders: A Mini Review

“…As a result, it is known that gut microbiota can modulate connection of them to maintain homeostasis. This crosstalk consists of multiple pathways, including the autonomic nervous system, the enteric nervous system (ENS), and hypothalamic-pituitary-adrenal, which use the vagus nerve for communication and immune, endocrine, and neural pathways use circulation for that [4]. The enteric nervous system is a quasi-autonomous part of the nervous system, which consists of two ganglia: the myenteric (Auerbach's) and submucosal (Meissner's) plexus, which together modulate the digestive system.…”

“…It is responsible for gut function such as digestion, gut motility and permeability secretion of bile, carbohydrate levels, mechanical distortion of the mucosa, maintenance of epithelial fluid level, luminal osmolality, mucus production, and mucosal immune response [5]. Not only ENS communicates with the central nervous system; there is growing evidence that gut microbiota can also do it, using their metabolites and neurotransmitters with neuromodulatory properties, such a tryptophan, 5-hydroxytryptamine (5-HT), gamma-aminobutyric acid (GABA), glutamine, histamine, short chain fatty acids (SCAFs), catecholamines and many others [4]. Serotonin (5-hydroxytryptamine, 5-HT), a neurotransmitter, is released from enterochromaffin (EC) cells in response to a number of stimuli, including signals from the gut microbiota.…”