MiCrobiota-gut-brain Axis in Resistant Epilepsy

Specific Aims and Experimental Design Accumulating evidence demonstrates strong associations between the GM and epilepsy, but no clear trend is emerging yet, which may be due to the small cohorts and environmental confounding factors. Whether microbial dysbiosis contributes to seizure triggering or is caused by anti-seizure medications (ASMs) remains to be elucidated. To better understand the interplay between MGBA - Microbiota-Gut-Brain-Axis and epilepsy, CARE project will enroll and longitudinally follow up to one year subjects at seizure onset and subjects with DRE, before and after procedures aimed at reducing the burden of such a chronic disabling condition (i.e., resective surgery, VNS, and KD).

AIM 1 specific tasks will be:

1.1 To enroll subjects at the seizure onset (naïve), and DRE patients divided in three populations according to the treatment procedure: DRE undergoing resective surgery (DRE-surgery), DRE undergoing VNS (DRE-VNS), and DRE on diet therapy (DRE-KD) 1.2 To set up a detailed database including clinical, biochemical, neurophysiological, neuroradiological and genetic records 1.3 Data analysis The enrolment goal has been set as at least 50 subjects at the seizure onset (naïve), 50 DRE-surgery, 10 DRE DRE-VNS, and 10 DRE-KD. Patients will visit the clinical center as an inpatient/outpatient regimen and remain in the study for about 15 months (from screening to last follow-up visit). Study time points are as follows: t0, at the enrolment (before ASMs for naïve and before any procedures for DRE); t1, at 1 month; t2, at 6 months; and t3, at 12 months (after ASM starting for naïve and after surgery, VNS, or KD).

The longitudinal nature of the study will compensate for well-known interindividual differences in gut microbiome features.

At t0, each participant will undergo a comprehensive clinical parameter evaluation: neurological and physical examination (number of seizures/month through the evaluation of seizure diaries, EEG, neurobehavioral comorbid symptoms by dedicated scales, and detailed drug regimen assessment) assessment of gastrointestinal (GI) symptoms (by a modified 6-item GI severity index -GISI- and the Bristol stool scale) a dietary survey, by a combined 3-day food diary and 24-hour recall, and anthropometric evaluation (body-mass index -BMI- and BMI z-score for children) quality of life assessment for children with Pediatric Quality of Life Inventory TM for Epilepsy (PedsQL TM) and for adults with the QOLIE-31 (Quality of Life in Epilepsy Inventory- 31 item) stool and blood sample collection. For seizure frequency, enrolled DRE will be asked to fill the seizure diary during the 30 days before entering the study. Data will be recorded as baseline. After 1 month (t1), we will contact each subject to record possible rapid changes of outcome measures. Clinical parameters will be assessed by online call by a clinician from each enrolling center, thus facilitating the compliance to the protocol. Fecal samples will be collected and stored. At t2 (6 months) and t3 (12 months), each subject will undergo a complete assessment as depicted for t0. For clinical and nutritional data, descriptive analyses will be conducted. Continuous variables will be analyzed with parametric (normally distributed variables) and non-parametric (non normally distributed) tests, while categorical variables will be analyzed using the Chi-square test or Fisher's test. Spearman correlations will be applied to estimate the strength of association between GM features (AIM 2 and 3), DNAmet and metabolites (AIM 3) and clinical response parameters (AIM 1). Two-tailed P < 0.05 will be considered statistically significant.