Abstract:Objective To observe the associations of high mobility group protein B-1 (HMGB-1) with clinicopathological characteristics and intestinal flora based on bioinformatics database system to explore whether its influences on the prognosis of colorectal cancer(CRC) was related to the intestinal flora imbalance. Methods The clinical data of three colorectal cancer tumor datasets obtained from GEO (Gene Expression Omnibus) database were collected to analyze the associations of HMGB-1 with the clinical features and outcome of colorectal cancer. Eighty-eight colorectal cancer patients from the First Affiliated Hospital of Hebei North University from May to November 2021 were enrolled to detect the expression of HMGB-1 in their serum samples, which were divided into high HMGB-1group(HMGB-1H) and low HMGB-1 group(HMGB-1L) with best cutoff value of 10.24ng/ml as the boundary. The stool samples of 10 patients in each group were collected for 16S rDNA sequencing. Results ROC curve showed that AUC of HMGB-1 level was 0.583 at the optimal cutoff value of 10.24ng/ml in predicting CRC prognosis. Compared with the patients in HMGB-1L group, the patients in HMGB-1H group presented with later stage of TNM (P=0.005) and shorter overall survival (P=0.033) and were more prone to recurrence and metastasis of CRC (P=0.005).High HMGB-1 level and advanced TNM stage were the independent risk factors of death in CRC patients (P<0.05).The 16S rDNA sequencing results suggested that the microbial community composition was similar in two groups. Pairwise comparison showed that, at the phylum level, the intestinal flora was dominated by Firmicutes in HMGB-1H group and was mainly Proteobacteria in HMGB-1L group; at the genus level, Providencia was found to be enriched in HMGB-1L group. Functional prediction of Tax4Fun showed that the functional enrichment of different intestinal flora was mainly concentrated in DNA damage repair, glycolysis, amino acid metabolism, and so on. Conclusions The elevation of HMGB-1 may introduce a decrease of Providencia and is closely related to the poor prognosis of colorectal cancer, which is associated with the DNA damage repair and metabolism of colorectal cancer cells.