Study Purpose: This study aims to systematically analyze changes in the gut microbiota of colon polyp patients under different intervention models. It will evaluate the regulatory effects of modified Si-Ni-San on the composition, diversity, and potential functional characteristics of the gut microbiota. Additionally, the study seeks to identify key microbiota species associated with inflammation regulation and potential recurrence risk, providing theoretical support for microbiota-targeted intervention strategies.

Methods: This is a single-center, prospective, exploratory, randomized controlled trial involving patients who have undergone colon polyp removal via colonoscopy. After resuming normal oral diet, patients will be randomly assigned to either the Traditional Chinese Medicine (TCM) intervention group or the control group. The control group will receive a combination of glutamine and probiotics, while the TCM intervention group will receive modified Si-Ni-San. Both groups will undergo a 4-week intervention period (with 4 treatment cycles of 7 days each). Clinical symptoms will be assessed before and 1 week after the intervention using a Traditional Chinese Medicine symptom scale. Blood and stool samples will be collected to measure serum IL-6 and TNF-α levels, and 16S rRNA gene sequencing will be performed on the stool microbiota. The study will compare changes in the gut microbiota composition and diversity at different time points and between the two groups. Differential microbiota will be identified through indicator species analysis and LEfSe, and effect sizes and 95% confidence intervals will be reported. Additionally, a random forest model will be built, and ROC curves will be used to evaluate key discriminative bacterial genera. Exploratory analysis of microbiota phenotypes and potential functions will be performed using BugBase and PICRUSt.

Study Title Efficacy of Modified Si Ni San in Post-Polypectomy Management and Its Impact on Gut Microbiota in Colorectal Polyp Patients Study Type Interventional (Clinical Trial) Study Design Study Type: Single-center, prospective, exploratory randomized controlled trial Sample Size: 32 colorectal polyp patients Study Population: Patients who underwent polypectomy via colonoscopy Study Location: Xi'an Traditional Chinese Medicine Hospital, Xi'an, China Intervention Group: Modified Si Ni San (Chinese herbal treatment, 4 weeks) Control Group: Glutamine compound combined with probiotics (4 weeks) Intervention Time: Each intervention lasts for 4 weeks, 7 days per cycle, with 4 cycles in total Follow-up Time: Pre-treatment and 1 week post-treatment assessment Outcome Measures: Assessment of clinical symptoms, blood inflammatory cytokines (IL-6, TNF-α), and fecal microbiota using 16S rRNA sequencing.

Primary Objective To explore the therapeutic efficacy of Modified Si Ni San in regulating gut microbiota and its potential role in preventing post-polypectomy recurrence in colorectal polyp patients.

Secondary Objective To assess the impact of Modified Si Ni San on gut microbiota composition, community diversity, and functional characteristics, and to identify key microbiota associated with inflammation regulation and potential recurrence risk.

Research Hypothesis The investigators hypothesize that Modified Si Ni San, through its modulation of gut microbiota, can reduce the risk of recurrence in colorectal polyps post-surgery, with its mechanism involving the regulation of inflammatory responses and gut micro-ecosystem balance.

Study Methods

Intervention:

Herbal Intervention: The intervention group will receive Modified Si Ni San, consisting of specific Chinese herbs (e.g., Bupleurum, Paeonia, Tangerine Peel, etc.) prepared at Xi'an Traditional Chinese Medicine Hospital. The dosage is 1 dose per day, divided into two administrations (morning and evening) for 7 days per cycle. A total of 4 cycles will be administered, with a 2-day interval between each cycle.

Control Intervention: The control group will receive a combination of glutamine compound and probiotics, with the same duration and frequency of administration as the intervention group.

Outcome Assessment:

Symptom Evaluation: Using Traditional Chinese Medicine Symptom Quantification Table to evaluate clinical symptoms pre- and post-intervention.

Biological Sample Collection: Blood and fecal samples will be collected pre-treatment and 1 week post-treatment for analysis of inflammatory cytokines (IL-6, TNF-α) and gut microbiota (16S rRNA sequencing).

Statistical Methods:Comparison of microbiota composition at different time points and between groups.Indication species analysis and LEfSe to identify differential microbiota.Random Forest modeling and ROC curve to assess key discriminative microbiota.Exploratory analysis of microbiota phenotypes and potential functions using BugBase and PICRUSt.

Eligibility Criteria

Inclusion Criteria:

• Aged 18 to 70 years；
• Diagnosed with colorectal polyps and underwent polypectomy via colonoscopy;
• Normal blood routine and liver/kidney function;
• Able to understand and sign informed consent.

Exclusion Criteria:

• History of colorectal cancer or a family history of colorectal polyps;
• Severe gastrointestinal diseases (e.g., inflammatory bowel disease, active infection);
• Pregnant or breastfeeding women;
• Severe comorbid conditions (e.g., diabetes, cardiovascular diseases) that may interfere with study results.

Randomization and Allocation Random allocation will be performed using a pre-set random sequence, and the sequence generation and allocation concealment will be done by non-research staff to minimize bias.

Ethics and Informed Consent Ethics Approval: This study has been approved by the Ethics Committee of Xi'an Traditional Chinese Medicine Hospital (Approval Number: YJSLLSCP2025029).

Informed Consent: All participants will be provided with a detailed explanation of the study, including its purpose, procedures, potential risks, and benefits. Informed consent will be obtained from all participants prior to inclusion in the study.

Participant Recruitment Sample Size: 32 participants with colorectal polyps will be recruited. Reruitment Period: March 2025 to October 2025. Recruitment Status: Completed Recruitment Process: Participants were recruited from Xi'an Traditional Chinese Medicine Hospital, and those who met the inclusion criteria were invited to participate after being informed about the study and signing the informed consent.

Inclusion Criteria:

• Aged 18 to 70 years;
• Diagnosed with colorectal polyps and underwent polypectomy via colonoscopy;
• Normal blood routine and liver/kidney function;
• Able to understand and sign informed consent.

Exclusion Criteria:

• History of colorectal cancer or a family history of colorectal polyps;
• Severe gastrointestinal diseases (e.g., inflammatory bowel disease, active infection);
• Pregnant or breastfeeding women;
• Severe comorbid conditions (e.g., diabetes, cardiovascular diseases) that may interfere with study results.

Due to the sensitive nature of the clinical data, particularly regarding patient health and privacy concerns, the investigators do not plan to share IPD with other researchers at this time. The data will be used solely for the purposes of this study and will remain confidential.