Objective: This study aims to evaluate the effectiveness of Clostridium butyricum in improving anxiety and depression in patients diagnosed with functional dyspepsia according to the Rome IV criteria.

Methods: This trial plans to enroll 180 patients (90 per group). The study will employ a double-blind design. For patients diagnosed with FD according to the Rome IV criteria, in addition to conventional treatment (treated with Mosapride Citrate Tablets (Guangdong Anno Guocai) for Postmeal Discomfort Syndrome (PDS) and Esomeprazole Enteric Coated Tablets (Shijiazhuang Longze Pharmaceutical Guocai) for Upper Abdominal Pain Syndrome (EPS)), the experimental group was treated with Clostridium butyricum, while the control group received a placebo with the same appearance and odor. The treatment intervention will last for 4 weeks. The main indicator of this experiment is the improvement of the Hospital Anxiety and Depression Scale (HADS score) after 4 weeks of treatment. The secondary indicators are the improvement rate of the overall treatment effectiveness evaluation questionnaire (OTE questionnaire), the improvement of the global overall symptom score (GOS score), the improvement of the simplified Nipin scale (SF-NDI), and the improvement of the Pittsburgh Sleep Index (PSQI) after 4 weeks of treatment. Upon completion of the trial, the patients' conditions will be re-evaluated, and treatment plans will be adjusted accordingly.