Dopamine is a neurotransmitter that plays a critical role both peripherally and centrally in
vital functions such as cognition, reward, satiety, voluntary motor movements, pleasure, and motivation. Optimal dopamine bioavailability is essential for normal brain functioning and protection
against the development of neurological diseases. Emerging evidence shows that gut microbiota
have significant roles in maintaining adequate concentrations of dopamine via intricate, bidirectional communication known as the microbiota-gut-brain axis. The vagus nerve, immune system,
hypothalamus–pituitary–adrenal axis, and microbial metabolites serve as important mediators of the
reciprocal microbiota-gut-brain signaling. Furthermore, gut microbiota contain intrinsic enzymatic
activity that is highly involved in dopamine metabolism, facilitating dopamine synthesis as well as its
metabolite breakdown. This review examines the relationship between key genera of gut microbiota
such as Prevotella, Bacteroides, Lactobacillus, Bifidobacterium, Clostridium, Enterococcus, and Ruminococcus
and their effects on dopamine. The effects of gut dysbiosis on dopamine bioavailability and the
subsequent impact on dopamine-related pathological conditions such as Parkinson’s disease are also
discussed. Understanding the role of gut microbiota in modulating dopamine activity and bioavailability both in the periphery and in the central nervous system can help identify new therapeutic
targets as well as optimize available methods to prevent, delay, or restore dopaminergic deficits in
neurologic and metabolic disorders. CLICK TO REVIEW