Randomization and masking
All patients were recruited by physicians and trial investigators at the Department of Neurology, Southwest Hospital, Chongqing. The enrolled participants were randomly assigned to the FMT group and the placebo group in a 1:1 ratio by using computer-generated random numbers. Participants were assigned to FMT or placebo group by trial investigators and remained masked to the allocation of treatment, while investigators and clinicians were not. The appearance of FMT and placebo capsules was indistinguishable, and all capsules were taken at the hospital to ensure that participants were unaware of the content.