Role of Gut Microbiota through Gut-Brain Axis in Epileptogenesis: A Systematic Review of Human and Veterinary Medicine

Simple Summary Epilepsy is a common chronic neurological disease in both dogs and humans. Despite the elevated prevalence and the many advances in human and veterinary medicine, the etiology and pathophysiology of epilepsy still remain unclear. In this systematic review, the authors discussed the possible role of the gut microbiota in the canine idiopathic epilepsy etiopathogenesis via the gut-brain axis. Canine idiopathic epilepsy is a common neurological disease characterized by the enduring predisposition of the cerebral cortex to generate seizures. An etiological explanation has not been fully identified in humans and dogs, and, among the presumed causes, several studies support the possible involvement of gut microbiota. In this review, the authors summarize the evidence of the reasonable role of gut microbiota in epilepsy through the so-called gut-brain axis. The authors provide an overview of recent clinical and preclinical studies in humans and dogs in which the modulation of intestinal permeability, the alteration of local immune response, and the alteration in production of essential metabolites and neurotransmitters associated with dysbiosis could be responsible for the pathogenesis of canine epilepsy. A systematic review of the literature, following the PRISMA guidelines, was performed in two databases (PubMed and Web of Science). Eleven studies were included and reviewed supporting the connection between gut microbiota and epilepsy via the gut-brain axis.