This study evaluates the effect of probiotic supplementation in patients with drug-resistant epilepsy. All the patients received the probiotic.

Epilepsy is a neurological disease with a prevalence of 0.6%. Despite the high number of antiepileptic drugs available, 20-30% of patients fail to control their seizures even with a correct treatment, this is known as drug-resistant epilepsy. This type of epilepsy limits severely the quality of life in patients and increases their morbidity and mortality.

There are different therapeutic strategies for the treatment of drug-resistant epilepsy such as the vagus nerve stimulation, which has an effectiveness of approximately 50% reduction of seizures in 50% of patients. Another one is epilepsy surgery, which can achieve up to 70% of crisis control with specifically selected surgery for certain patients. On the other hand, the ketogenic diet has nearly 30% effectiveness, which is defined as a seizure reduction of more than 50%. Despite all these treatments, there is still a group of patients that keeps showing epileptic seizures.

The microbiota is a collective of microorganisms that live in a symbiotic relationship within our organism. Currently, it is known that there is a bidirectional relationship between microbiota-gut-brain. Probiotics are live microorganisms that can benefit the health of the host when administered in adequate doses.

The purpose of the study is to prove the quality of life improvement in drug-resistant patients after the administration of a probiotic for 4 months in order to reduce the number of seizures. Additionally, the parameters of inflammatory cytokines will be evaluated as well as the probiotic medication safety will be assessed.

Inclusion Criteria:

• Older than 18 years-old.
• Diagnosis of drug-resistant epileptic seizures.
• Under stable treatment with antiepileptic drugs for at least 30 days before their inclusion.
• Occurrence of at least one seizure per month.
• Acceptance and informed consent for the inclusion of the patient in the study protocol.

Exclusion Criteria:

• Stable epilepsy.
• Idiopathic generalized epilepsy.
• Epileptic status in the previous 12 months.
• Change in the dose or type of antiepileptic drug within 30 days prior to the start of the study.
• Active consumption of alcohol or substances of abuse.
• Pregnancy and / or mothers during lactation period.
• Patients treated with probiotics from 30 days before the start of the study.
• Chronic gastrointestinal problems (for example irritable bowel).
• Liver or kidney problems.
• Lactose intolerant or celiac.
• Immunosuppressed.
• Patients on chronic antibiotic treatment.
• Impossibility to fill in a questionnaire, by the patient or the person responsible, and to follow the schedule of visits.
• Progressive neurological deterioration (tumors or metastasis of the central nervous system (CNS), Alzheimer's disease, vascular dementias).
• Use of antiepileptic drugs in research.
• Patients with an expectation of life <1 year.