To Explore a Single-arm Phase II Study on Intestinal Microbiota Transplantation Combined With Neoadjuvant Immunotherapy and Chemoradiotherapy for Locally Advanced Rectal Cancer Under MSS/pMMR

Inclusion criteria

• ECOG PS 0-1
• The lower edge of the tumor is ≤12cm from the anal margin. After multidisciplinary assessment, R0 resection is possible
• RAS/BRAF wild type, pMMR/MSS status
• Patients of childbearing age need to take effective contraceptive measures.
• Voluntarily sign the informed consent form

Exclusion criteria

• dMMR/MSI-H type
• Has previously received anti-tumor treatment (including surgery, radiotherapy, chemotherapy, targeted therapy or immunotherapy);
• Active autoimmune diseases, inflammatory bowel disease;
• Active infection, immune deficiency, severe liver and kidney dysfunction;
• Severe intestinal obstruction, perforation or requiring emergency surgery;
• Pregnant or lactating women;
• Contraindications related to FMT (such as recent use of high-dose immunosuppressants, severe neutropenia, etc.);
• Other circumstances where participation in clinical trials is not suitable