Gut microbes are capable of producing most neurotransmitters found in the human brain. Evidence is accumulating to support the view that gut microbes influence central neurochemistry and behavior. ...Irritable bowel syndrome is regarded as the prototypic disorder of the brain-gut-microbiota axis that can be responsive to probiotic therapy. Translational studies indicate that certain bacteria may have an impact on stress responses and cognitive functioning. Manipulating the gut microbiota with psychobiotics, prebiotics, or even antibiotics offers a novel approach to altering brain function and treating gut-brain axis disorders, such as depression and autism.
The gut microbiota has emerged as a key player in health and disease. Here we discuss the vagus nerve, which connects the visceral organs and the brain, as an important communication pathway for the ...gut microbiota to influence brain and behavior.
The gut microbiota has emerged as a key player in health and disease. Here we discuss the vagus nerve, which connects the visceral organs and the brain, as an important communication pathway for the gut microbiota to influence brain and behavior.
The gut microbiome in neurological disorders Cryan, John F; O'Riordan, Kenneth J; Sandhu, Kiran ...
Lancet neurology,
February 2020, 2020-Feb, 2020-02-00, 20200201, Letnik:
19, Številka:
2
Journal Article
Recenzirano
Research into the role of the gut microbiome in modulating brain function has rapidly increased over the past 10 years, albeit chiefly in animal models. Increasing clinical and preclinical evidence ...implicates the microbiome as a possible key susceptibility factor for neurological disorders, including Alzheimer's disease, autism spectrum disorder, multiple sclerosis, Parkinson's disease, and stroke. Cross-sectional clinical studies are bolstering the concept of altered microbial composition contributing to the pathophysiology of such diseases. However, the field is nascent, and interpretation of such data is often difficult given that the composition of the microbiome is influenced by various factors such as diet and exercise. Longitudinal studies and randomised controlled trials in humans are needed to find out if targeting the microbiome can yield novel therapeutic strategies. Systems biology approaches will also be important in integrating such data with genomic and metabolomic datasets from clinical cohorts with neurological disease to help guide individual treatment selection.
The brain-gut-microbiota axis has been put forward as a new paradigm in neuroscience, which may be of relevance to mental illness. The mechanisms of signal transmission in the brain-gut-microbiota ...axis are complex and involve bidirectional communications that enable gut microbes to communicate with the brain and the brain to communicate with the microbes. This review assesses the potential usefulness and limitations of the paradigm.
A selective literature review was conducted to evaluate the current knowledge in clinical and preclinical brain-gut-microbiota interactions as related to psychiatric disorders.
Most published studies in the field are preclinical, and there is so far a lack of clinical studies. Preliminary studies in psychiatric populations support the view of a dysbiosis in some conditions, but studies are often small scale and marred by potential confounding variables. Preclinical studies support the view that psychobiotics ("bacteria which when ingested in adequate amounts have a positive mental health benefit") might be of use in treating some patients with mental health difficulties. To date, we have no well-conducted studies in clinical populations, although there are some studies in healthy volunteers. A cocktail of probiotics has been shown to alter brain activity as monitored by functional magnetic resonance imaging, and Bifidobacterium longum was reported to alter brain electrical activity.
It has yet to be convincingly demonstrated that the exciting findings of psychobiotic efficacy demonstrated in preclinical models of psychiatric illness will translate to patients.
The complex bidirectional communication between the gut and the brain is finely orchestrated by different systems, including the endocrine, immune, autonomic, and enteric nervous systems. Moreover, ...increasing evidence supports the role of the microbiome and microbiota-derived molecules in regulating such interactions; however, the mechanisms underpinning such effects are only beginning to be resolved. Microbiota–gut peptide interactions are poised to be of great significance in the regulation of gut–brain signaling. Given the emerging role of the gut–brain axis in a variety of brain disorders, such as anxiety and depression, it is important to understand the contribution of bidirectional interactions between peptide hormones released from the gut and intestinal bacteria in the context of this axis. Indeed, the gastrointestinal tract is the largest endocrine organ in mammals, secreting dozens of different signaling molecules, including peptides. Gut peptides in the systemic circulation can bind cognate receptors on immune cells and vagus nerve terminals thereby enabling indirect gut–brain communication. Gut peptide concentrations are not only modulated by enteric microbiota signals, but also vary according to the composition of the intestinal microbiota. In this review, we will discuss the gut microbiota as a regulator of anxiety and depression, and explore the role of gut-derived peptides as signaling molecules in microbiome–gut–brain communication. Here, we summarize the potential interactions of the microbiota with gut hormones and endocrine peptides, including neuropeptide Y, peptide YY, pancreatic polypeptide, cholecystokinin, glucagon-like peptide, corticotropin-releasing factor, oxytocin, and ghrelin in microbiome-to-brain signaling. Together, gut peptides are important regulators of microbiota–gut–brain signaling in health and stress-related psychiatric illnesses.
There is a growing appreciation of the role of the gut microbiota in all aspects of health and disease, including brain health. Indeed, roles for the bacterial commensals in various psychiatric and ...neurological conditions, such as depression, autism, stroke, Parkinson's disease, and Alzheimer's disease, are emerging. Microbiota dysregulation has been documented in all of these conditions or in animal models thereof. Moreover, depletion or modulation of the gut microbiota can affect the severity of the central pathology or behavioral deficits observed in a variety of brain disorders. However, the mechanisms underlying such effects are only slowly being unraveled. Additionally, recent preclinical and clinical evidence suggest that targeting the microbiota through prebiotic, probiotic, or dietary interventions may be an effective “psychobiotic” strategy for treating symptoms in mood, neurodevelopmental disorders, and neurodegenerative diseases.
Psychobiotics: A Novel Class of Psychotropic Dinan, Timothy G; Stanton, Catherine; Cryan, John F
Biological psychiatry (1969),
11/2013, Letnik:
74, Številka:
10
Journal Article
Recenzirano
Here, we define a psychobiotic as a live organism that, when ingested in adequate amounts, produces a health benefit in patients suffering from psychiatric illness. As a class of probiotic, these ...bacteria are capable of producing and delivering neuroactive substances such as gamma-aminobutyric acid and serotonin, which act on the brain-gut axis. Preclinical evaluation in rodents suggests that certain psychobiotics possess antidepressant or anxiolytic activity. Effects may be mediated via the vagus nerve, spinal cord, or neuroendocrine systems. So far, psychobiotics have been most extensively studied in a liaison psychiatric setting in patients with irritable bowel syndrome, where positive benefits have been reported for a number of organisms including Bifidobacterium infantis. Evidence is emerging of benefits in alleviating symptoms of depression and in chronic fatigue syndrome. Such benefits may be related to the anti-inflammatory actions of certain psychobiotics and a capacity to reduce hypothalamic-pituitary-adrenal axis activity. Results from large scale placebo-controlled studies are awaited.
Microbiota and the social brain Sherwin, Eoin; Bordenstein, Seth R; Quinn, John L ...
Science (American Association for the Advancement of Science),
11/2019, Letnik:
366, Številka:
6465
Journal Article
Recenzirano
Sociability can facilitate mutually beneficial outcomes such as division of labor, cooperative care, and increased immunity, but sociability can also promote negative outcomes, including aggression ...and coercion. Accumulating evidence suggests that symbiotic microorganisms, specifically the microbiota that reside within the gastrointestinal system, may influence neurodevelopment and programming of social behaviors across diverse animal species. This relationship between host and microbes hints that host-microbiota interactions may have influenced the evolution of social behaviors. Indeed, the gastrointestinal microbiota is used by certain species as a means to facilitate communication among conspecifics. Further understanding of how microbiota influence the brain in nature may be helpful for elucidating the causal mechanisms underlying sociability and for generating new therapeutic strategies for social disorders in humans, such as autism spectrum disorders (ASDs).
There is a growing realisation that the gut–brain axis and its regulation by the microbiota may play a key role in the biological and physiological basis of neurodevelopmental, age‐related and ...neurodegenerative disorders. The routes of communication between the microbiota and brain are being unravelled and include the vagus nerve, gut hormone signalling, the immune system, tryptophan metabolism or by way of microbial metabolites such as short chain fatty acids. The importance of early life gut microbiota in shaping future health outcomes is also emerging. Disturbances of this composition by way of antibiotic exposure, lack of breastfeeding, infection, stress and the environmental influences coupled with the influence of host genetics can result in long‐term effects on physiology and behaviour, at least in animal models. It is also worth noting that mode of delivery at birth influences microbiota composition with those born by Caesarean section having a distinctly different microbiota in early life to those born per vaginum. At the other extreme of life, ageing is associated with a narrowing in microbial diversity and healthy ageing correlates with a diverse microbiome. Recently, the gut microbiota has been implicated in a variety of conditions including depression, autism, schizophrenia and Parkinson's disease. There is still considerable debate as to whether or not the gut microbiota changes are core to the pathophysiology of such conditions or are merely epiphenomenal. It is plausible that such neuropsychiatric disorders might be treated in the future by targeting the microbiota either by microbiota transplantation, antibiotics or psychobiotics.
The developmental trajectory.
PDF
