Abstract
Background: The gut–brain axis (GBA) is a complex bidirectional communication system that links the gastrointestinal tract and the central nervous system. Essential oils (EOs) have emerged as promising natural compounds capable of modulating this axis. Methods: A comprehensive analysis of the recent literature was conducted, focusing on studies investigating the effects of EOs on the GBA. Particular attention was given to the endocannabinoid system, the role of cannabis-derived EOs, and other plant-based EOs with potential neuroprotective and gut microbiota-modulating effects. Results: Among the EOs analyzed, cannabis essential oil (CEO) gained attention for its interaction with cannabinoid receptors (CBR1 and CBR2), modulating gut motility, immune responses, and neurotransmission. While acute administration of the CEO reduces inflammation and gut permeability, chronic use has been associated with alterations in gut microbiota composition, potentially impairing cognitive function. Other EOs, such as those from rosemary, lavender, eucalyptus, and oregano, demonstrated effects on neurotransmitter modulation, gut microbiota balance, and neuroinflammation, supporting their potential therapeutic applications in GBA-related disorders. Conclusions: EOs demonstrate promising potential in modulating the GBA through mechanisms including neurotransmitter regulation, gut microbiota modulation, and anti-inflammatory activity. At the same time, phytocannabinoids offer therapeutic value; their long-term use warrants caution due to potential impacts on microbiota. Future research should aim to identify EO-based interventions that can synergistically restore GBA homeostasis and mitigate neurodegenerative and gastrointestinal disorders.