A comparison of the gut microbiota among adult patients with drug-responsive and drug-resistant epilepsy: An exploratory study

Background: Approximately one-third of epilepsy patients suffer from drug-resistant epilepsy. The gut microbiome, which is the total genetic makeup of all of the total microbes inhabiting the gut, can affect the CNS through various mechanisms. However, there are only limited studies about the relationship between the gut microbiome and epilepsy. We investigated the composition and characteristics of the gut microbiota among adult patients who have drug-responsive and drug-resistant epilepsy. Methods: We prospectively included 44 adult epilepsy patients and classified them into drug-responsive and drugresistant groups. We collected fecal samples for the next-generation sequencing analysis. We statistically estimated the bacterial differences and alpha and beta diversities in each category. Results: Although there was no difference in demographic factors between the drug-responsive and drug-resistant groups, there was a significant difference in the composition of the gut microbiota. While the relative abundance of Bacteroides finegoldii and Ruminococcus_g2 increased in the drug-responsive group, the relative abundance of Negativicutes, which belong to Firmicutes increased in the drug-resistant group. Bifidobacterium was relatively abundant in epilepsy patients with a normal electroencephalogram. There was no significant difference between the two groups in analyses of alpha and beta diversities. Conclusions: We found a significant difference in the composition of the gut microbiota among adult patients with drug-responsive and drug-resistant epilepsy. Difference in gut microbiota can be used as a novel biomarker to predict prognosis and evaluate treatment response in epilepsy patients. In addition, modification of gut microbiome can be an effective treatment strategy for patient with drug-resistant epilepsy.