The goal of this observational study is to learn how the bacteria in the gut and mouth (called the microbiota) are linked to different types of epilepsy and how they may affect how well seizure medicines work. Researchers want to answer two main questions: Are certain types of epilepsy linked to changes in the gut or mouth microbiota? Do the bacteria in the gut change how seizure medicines work for each person? Epilepsy is a brain condition that causes seizures. Even though there are many medicines for epilepsy, some people still have seizures or side effects. Studies in animals show that gut bacteria can raise or lower the chance of seizures. Smaller studies in people suggest the same thing, but they have been limited in size and scope. In this study, researchers will collect biological samples from people who have newly diagnosed epilepsy and from people without epilepsy (called healthy controls). The samples will be tested to learn which bacteria are present. The researchers will then look for patterns that may explain which types of epilepsy are linked to changes in the microbiota. The study will also look at whether the bacteria in the gut and mouth affect how well anti-seizure medicines (ASMs) work. For example, the researchers will explore if certain bacteria make medicines work better or worse. Patients will provide blood, stool and saliva samples. If collected for medical reasons, cerebrospinal fluid (CSF) - the clear liquid that surrounds the brain and spinal cord -will also be used. Healthy controls will provide stool and saliva samples only All participants will be asked to fill an online questionnaire to share health and lifestyle information. Patients also allow researchers to confidentially access data from medical records related to diagnosis and treatment. By comparing data from many participants across Sweden, researchers hope to understand how gut and mouth bacteria influence epilepsy and seizure control. This research may help doctors in the future to use a person's microbiota profile to choose the best seizure medicine. The long-term goal is to improve seizure control, reduce side effects, and raise the quality of life for people living with epilepsy.