Naturally occurring psychoactive substances, such as opioids, cocaine, and cannabinoids, affect not only the central nervous system but also the functioning of the microbiota–gut–brain axis. Available evidence indicates that their use is associated with changes in the gut microbiota and modulation of immune responses. Escherichia coli, a permanent component of the gut microbiota under conditions favoring dysbiosis, can enhance inflammatory responses and influence neuroimmunological mechanisms related to the development of addiction. This study aims to review and analyze the available literature concerning the effects of selected naturally derived psychoactive substances on E. coli and on the functioning of the microbiota–gut–brain axis, with particular emphasis on inflammatory processes and their potential significance in the pathogenesis of addiction.
Wróblewska et al. (2026) studied this question.