Objective To explore the effects of Yisui Jianpi Decoction combined with XELOX chemotherapy on immune function and gut microbiota in patients with colorectal cancer.

Methods Eighty patients with colorectal cancer (CRC) were selected as the study subjects, and were randomly divided into control group (40 cases, XELOX chemotherapy) and observation group (40 cases, Yisui Jianpi Decoction based on the control group). The disease control rate, immune function indicatorsCD3⁺, CD4⁺, CD8⁺, and CD4⁺-to-CD8⁺ratio(CD4⁺/CD8⁺), tumor markers carcinoembryonic antigen (CEA), carbohydrate antigen 125 (CA125) and carbohydrate antigen 199 (CA199), gut microbiota indicators (Lactobacillus, Bifidobacterium, Escherichia coli), and occurrence of adverse reactions were compared between the two groups.

Results After treatment, the disease control rate in the observation group was 85.00% (34/40), which was obviously higher than 65.00% (26/40) in the control group (P < 0.05); after treatment, the number of T lymphocyte subsets CD3⁺, CD4⁺, CD4⁺/CD8⁺, the number of Lactobacillus and Bifidobacterium in the two groups obviously increased, and the observation group were higher than the control group (P < 0.05); after treatment, the levels of CD8⁺, CEA, CA125, CA199, and the number of Escherichia coli in both groups decreased, and the observation group was lower than the control group (P < 0.05). The total incidence of adverse reactions in the observation group was 17.50% (7/40), which was lower than 42.50% (17/40) in the control group (P < 0.05).

Conclusion The combination of Yisui Jianpi Decoction and XELOX chemotherapy can improve the therapeutic effect of colorectal cancer, adjust the distribution of intestinal flora, improve immune function, and reduce incidence of adverse reactions.