ObjectiveTo retrospectively analyze patients taking Bacteroides fragilis (BF839) alone for their "possible autoimmune-related epilepsy" to find new treatments for epilepsy. Methods15 newly diagnosed patients who were not treated with standard Anti-seizure medications were diagnosed with "possible autoimmune-related epilepsy" and were given oral BF839 to initiate treatment. Seizure changes, self-reported improvement of comorbidities, EEG, adverse reactions and other information were reviewed. ResultsDuring the follow-up period of 14~33 months, 73.33% (11/15) patients achieved 1-year remission during the follow-up period, 7 patients had a remission time of more than 24 months, and 4 patients had a remission time of more than 30 months. 73.33% (11/15) of the patients reported that their comorbidities improved, and the EEG improvement rate was 57.14% (4/7). No patients withdrew due to adverse reactions, and the 12-month retention rate was 73.33% (11/15).ConclusionIt is the first report that the early application of intestinal flora preparation alone can effectively treat “possible autoimmune-related epilepsy”, and it can also be used as a diagnostic treatment tool due to its lower adverse reactions and improvement of comorbidities. This is not only of great significance to significantly improve the early diagnosis rate and remission rate of autoimmune-related epilepsy, and to prevent patients from developing refractory epilepsy, but also refreshes our understanding of the etiology of epilepsy.