The Microbiome and Neurotransmitter Activity

Abstract

Research has revealed that the gut microbiota impacts human health through several mechanisms, including modulating the immune response within the intestine, production of metabolites, and through the production of short chain fatty acids and vitamins. In this paper we explore the ability of microorganisms to produce key neurotransmitters or impact their expression through cell receptors. Neurotransmitter imbalances are implicated in a variety of human illnesses including anxiety, depression, insomnia, autism, multiple sclerosis and functional gastrointestinal disorders. A new research field is emerging to develop psychobiotics.  Psychobiotics consist of probiotics or the prebiotics which support probiotic growth and they have shown to have a beneficial impact on psychiatric or neurological disorders. Understanding the unique contributions of various bacterial strains to the production or expression of neurotransmitters is a key component in the development of these new therapies. The neurotransmitters explored include serotonin (SERT), gamma aminobutyric acid (GABA), melatonin, catecholamines (CATs) and histamine. The aim of this paper is to review and summarize the available literature on the inter-relationship between various microbes in the gut microbiome and neurotransmitter activity. This includes commensals, pathogens as well as probiotics. The collected information will provide a reference guide for correlating certain disease states and conditions to microbial activity and helping clinicians select appropriate commercially available probiotics supplements and foods for optimizing health associated with the particular neurotransmitters discussed in this review.