The gut microbiome in psychiatry: A primer for clinicians

Abstract

Research in the past decade has shown that variations in the gut microbiome may influence behavior, and vice versa. As such, interest in the role of the gut microbiome in psychiatric conditions has drawn immense interest. This is evidenced by the recent surge in published studies examining microbial dysbiosis in clinical psychiatric populations, particularly autism spectrum disorder and depression. However, critical examination of these studies reveals methodological flaws in design and execution, suggesting that they may not be held to the same standards as other bodies of clinical research. Given the complex nature of the gut microbiome, this narrative review attempts to clarify concepts critical to effectively examine its potential role in psychopathology to appropriately inform mental health researchers. More specifically, the numerous variables known to affect the gut microbiome are discussed, including inflammation, diet, weight, and medications. A comprehensive review of the extant microbiome literature in clinical psychiatric populations is also provided, in addition to clinical implications and suggestions for future directions of research. Although there is a clear need for additional studies to elucidate the gut microbiome's role in psychiatric disorders, there is an even greater need for well-designed, appropriately controlled studies to truly impact the field.

A Revolutionizing Approach to Autism Spectrum Disorder Using the Microbiome

“…In another perspective, the general lack of gut microbial richness and diversity in ASD group, predisposes them to a vulnerable gut environment which could lead to GI disturbances, infections and autistic behaviours [48]. In general, a significant alteration in gut microbial composition interferes with key physiological processes which have an influence on the neurobehavioral manifestation of ASD symptoms either through the absence of beneficial microbial metabolites, release of harmful microbial endotoxins, pathogenic invasion of the intestinal wall and/or through immune mediators catering to neuroimmune inflammation [6,47,48,50,55].…”

Gut instincts: vitamin D/vitamin D receptor and microbiome in neurodevelopment disorders

“…Following release into the synaptic cleft, dopamine activity is terminated via breakdown by monoamine oxidase [ 103 ] or via reuptake into the presynapse by the dopamine transporter (DAT) or into synaptic vesicles by vesicular monoamine transporter 2 (VMAT2) [ 104 ]. The main described pathway of ADHD involves overabundance of DAT resulting in diminished duration and intensity of DA action [ 105 ].…”

Microbiota-Gut-Brain Signaling: A Minireview

“…Butyrate, on the other hand, is generated by bacteria of the phylum Firmicutes (83). Data is accumulating to demonstrate that the gut microbiota influences the perception of pain (84); that it can influence the pathogenesis of Alzheimer's disease (85)(86)(87), Parkinson's disease (88), and some psychiatric disorders (89), such as attention deficit hyperactivity disorder (90) and autism spectrum disorder (91); and that it can be associated with problems of cognitive impairment (92). The relationship between various health problems and activation of the microbiota-gut-brain axis is schematically presented in Fig.…”