Inclusion Criteria:  1 year old <age ≤ 18 years old; After biopsy, histopathology and immunohistochemistry tests refer to the COG recommended neuroblastoma diagnostic criteria, pathological classification (INPC), and international neuroblastoma staging (INSS) Patients who were diagnosed with RB for the first time or received chemotherapy in our hospital for the first time after diagnosis ECOG scale (ECOG-PS) ≤ 2;  Exclusion Criteria:  No antibiotics and no gastrointestinal surgery within 3 months. Patients with autoimmune diseases; Patients with immunodeficiency; Patients who have been treated for relapsed/refractory diseases; relapsed NB is the appearance of new lesions at the primary site or other sites 4 weeks after the multidisciplinary comprehensive treatment reaches CR. Refractory NB is defined as induced by 2 to 4 courses of treatment The post-effect evaluation is progression disease (PD) during chemotherapy; Multiple organ failure; Uncontrolled infection and diarrhea