Abstract: Objective  To investigate the impacts of serum microRNA-448 (miR-448) and microRNA-153 (miR-153) expression on intestinal microbiota and immune function in colon cancer patients.Methods A total of 127 patients with colon cancer admitted to our hospital from February 2020 to February 2023 were collected as the study group,89 patients with benign colon lesions were collected as the benign colon lesion group,and 127 healthy individuals who underwent physical examination in our hospital during the same period were collected as the control group.The study group were grouped into miR-448 high expression group (63 cases) and miR-448 low expression group (64 cases),and the miR-153 high expression group (64 cases) and miR-153 low expression group (63 cases) based on the median expression levels of serum miR-448 (1.12) and miR-153 (0.98) as the critical values.Pearson method was applied to analyze the correlation between the expression levels of serum miR-448 and miR-153 and intestinal microbiota and immune function indicators in colon cancer patients;receiver operating characteristic (ROC) curve was plotted to analyze the diagnostic value of serum miR-448 and miR-153 for colon cancer.Results There were significant differences among the study group,the benign colon disease group and the control group in terms of Escherichia coli,bifidobacteria,bifidobacteria/Escherichia coli ratio,and immunoglobulin (Ig) G,IgM,IgA (P<0.05);The expression level of serum miR-448 in the study group (1.25±0.22) was higher than that in the control group (1.09±0.03) and colon benign lesion group (1.18±0.15),while the expression level of serum miR-153 (0.89±0.12) was lower than that in the control group (1.03±0.17) and colon benign lesion group (0.96±0.16) (P<0.05);there were significant differences in the Escherichia coli,bifidobacteria,bifidobacteria/Escherichia coli ratio,the expression levels of IgG,IgM,and IgA between the high and low expression groups of serum miR-448 and miR-153(P<0.05).There was significant correlation between serum miR-448,miR-153 and Escherichia coli,bifidobacteria,bifidobacteria/Escherichia coli ratio(r=0.657，-0.742，-0.753；r=-0.711，0.813，0.771，P<0.05);IgG,IgM,IgA were positively correlated with serum miR-448(r=0.686,0.709,0.744),and negatively correlated with miR-153 (r=-0.690，-0.841,-0.769，P<0.05);the combined detection of serum miR-448 and miR-153 for the diagnosis of colon cancer had an AUC of ^0.845,which was better than the individual detection (Zcombination-miR-448=4.561,Z combination-miR-153=2.426,P=0.000、0.015).Conclusion The expression levels of serum miR-448 and miR-153 in patients with colon cancer are correlated with intestinal microbiota and immune function,and the combination of the two has high diagnostic value for colon cancer.

Key words: colon cancer, micro RNA-448, micro RNA-153, intestinal microbiota, immune function