Evaluation of fecal Lactobacillus populations in dogs with idiopathic epilepsy: a pilot study

Abstract

BackgroundIdiopathic epilepsy is a common neurological disorder of dogs characterized by recurrent seizures for which no underlying basis is identified other than a presumed genetic predisposition. The pathogenesis of the disorder remains poorly understood, but environmental factors are presumed to influence the course of disease. Within the growing body of research into the microbiota-gut-brain axis, considerable attention has focused on the protective role of Lactobacilli in the development and progression of neurological disease. Investigations into the association between the gut microbiome and epilepsy are in their infancy, but some preliminary findings support a role for Lactobacilli in drug resistant epilepsy. To date, there are no published studies evaluating the gut microbiome in dogs with epilepsy. This pilot study was undertaken to evaluate fecal Lactobacillus populations in dogs with idiopathic epilepsy compared to healthy dogs.ResultsFecal samples were obtained from 13 pairs of dogs, consisting of a drug-naïve epileptic dog and a healthy dog from the same household and maintained on the same diet. Evaluation of large-scale microbial patterns based on 16S rRNA gene amplicon sequencing identified a household effect in the study population. Differential prevalence testing at the 16S rRNA gene sequence variant and genus levels did not identify any statistically significant differences between epileptic and control dogs. Quantitative PCR of Lactobacillus species isolated through culture revealed no statistically significant difference between the epileptic and control dogs (median concentration, 3.8 log10 CFU/g feces and 4.6 log10 CFU/g feces, respectively). Lactobacillus in culture was not killed by exposure to phenobarbital, potassium bromide, zonisamide, or levetiracetam.ConclusionsThis pilot study did not identify any difference in large-scale microbial patterns or relative or absolute abundance of Lactobacillus species in drug-naïve epileptic dogs compared to healthy dogs. Further studies are warranted to evaluate the role of the gut microbiome in disease progression and treatment response in dogs with epilepsy. Lactobacilli in culture were not killed or inhibited from growing when exposed to phenobarbital, potassium bromide, zonisamide or levetiracetam, suggesting that antiepileptic drug administration is less likely to be a confounding factor in future studies evaluating the role of Lactobacillus in epilepsy.