As a chronic encephalopathy, drug addiction is responsible for millions of deaths per year around the world. The gut microbiome is a crucial component of the human microbiome. Through dynamic bidirectional communication along the 'gut-brain axis,' gut bacteria cooperate with their hosts to regulate the development and function of the immune, metabolic, and nervous systems.These processes may affect human health because some brain diseases are related to the composition of gut bacteria, and disruptions in microbial communities have been implicated in neurological disorders.We review the compositional and functional diversity of the gut microbiome in drug addiction. We discuss intricate and crucial connections between the gut microbiota and the brain involving multiple biological systems and possible contributions by the gut microbiota to neurological disorders.Finally, the treatment of probiotics and fecal transplantation was summarized. This was done to further understand the role of intestinal microecology in the pathogenesis of drug addiction and to explore new methods for the treatment of drug addiction.Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.