Study on the Mechanism of Jianpi Guchang Formula in Regulating Short Chain Fatty Acid Metabolism to Protect Intestinal Barrier and Exert Anti-tumor Effects

LI Cunya; ZHONG Yi; LI Yun; LI Shiying; WU Zhonghua; ZHOU Zhangjie; FU Shujuan

Abstract：Objective To establish a subcutaneous xenograft model of colon cancer in nude mice with orthotopic inoculation,and to validate the effects of Jianpi Guchang formula(JGF)on intestinal barrier structure and function through short-chain fatty acid(SCFA)metabolism and the phosphatidylinositol 3-kinase(PI3K)/protein kinase B(Akt)pathway.Methods Twenty-four male nude mice were randomly divided into four groups(n=6 per group):blank control group,model group,JGF group,and SCFA group.A subcutaneous xenograft model of Lovo colon cancer with orthotopic inoculation was established.The JGF group received JGF granule solution via gavage,while the SCFA group was fed a mixed diet containing SCFA salt solution for 21 consecutive days.Serum levels of diamine oxidase(DAO)and D-lactate(D-LA)were measured by ELISA.Foxp3 mRNA expression in colon intestinal and tumor tissues was detected by RT-qPCR.Immunohistochemistry was used to analyze the expression and distribution of Akt,phosphorylated(p)-Akt,PI3K,and p-PI3K in tumor tissues.Fecal microbiota structure was assessed using 16S rRNA PCR.Results The general condition and body weight of mice in the JGF group were better than those in the model and SCFA groups,but the difference was not statistically significant(P>0.05).Compared with the model and SCFA groups,the JGF group showed a decreasing trend in serum DAO and D-LA levels.In tumor tissues,Foxp3 mRNA expression was upregulated in both the JGF and SCFA groups compared with the model group,but without statistical significance(P>0.05).The SCFA group exhibited significantly reduced p-Akt expression(P<0.01),while the JGF group showed significantly decreased expression of Akt,p-Akt,PI3K,and p-PI3K(P<0.01).16S rRNA PCR analysis revealed high similarity in operational taxonomic unit(OTU)composition between the JGF and SCFA groups.JGF treatment modulated gut microbiota abundance,and the difference compared with the SCFA group was not statistically significant(P>0.05).Conclusion JGF can stabilize gut microbiota by regulating SCFA metabolism,protect intestinal barrier function,and downregulate the PI3K/Akt signaling pathway to promote Foxp3 expression,thereby modulating the tumor immune microenvironment and exerting anti-tumor effects.