Psychotropic Drugs and the Microbiome

The human gut microbiome plays a key role in host physiology in health and disease. There is a growing emphasis on the bidirectional interaction between various medications and the gut microbiome. Here, we will first review how drugs can affect microbiome composition and how the microbiome can alter the pharmacodynamics and potentially pharmacokinetics of psychotropic medications. We will take into consideration different classes of psychotropics, including antipsychotics, antidepressants, antianxiety drugs, anticonvulsants/mood stabilisers, opioid analgesics, drugs of abuse, alcohol, nicotine, and xanthines. The varying effects of these widely used medications on microorganisms are becoming apparent from in vivo and in vitro studies. This has important implications for future drug discovery in psychiatry which will need to consider the host microbiome as a major potential target.