To investigate the enrichment of Helicobacter pylori (Hp) in adenoma tissue of patients with colorectal adenoma, and analyze the correlation between the enrichment and the clinical and pathological characteristics of colorectal adenoma.

The data of 1,622 patients undergoing gastrointestinal endoscopy in the Endoscopy Center of Wenzhou Integrated Traditional Chinese and Western Medicine Hospital affiliated to Zhejiang University of Traditional Chinese Medicine from January 2019 to June 2021 were retrospectively collected. The general data, gastric Hp infection, clinical and pathological features of colorectal adenoma, methylene blue staining of adenoma Hp, immunohistochemistry of adenoma Hp and immunofluorescence staining of adenoma TLR5 protein. were compared between the colorectal adenoma group (743 cases) and the control group (879 cases).

There were 361 gastric Hp positive cases in the colorectal adenoma group, with a positive rate of 48.59%, and 331 gastric Hp positive cases in the control group, with a positive rate of 37.66%, and the difference was statistically significant (P < 0.001). Gastric Hp infection significantly correlates with the Hp enrichment in colorectal adenomas (OR: 28.449; 95%CI: 18.188-44.500; P < 0.001). Moreover, we found that Hp enrichment in colorectal adenomas was correlated with the diameter, pathological type, and malignancy of adenoma (OR: 3.536; 3.652; 2.833; all P < 0.001). Expression TLR5 protein was also increased in Hp-enriched adenoma tissue.

There is a correlation between gastric Hp infection and intestinal Hp enrichment. The intestinal Hp enrichment significantly correlates with the clinical and pathological characteristics of colorectal adenomas, and its tumor-promoting effect may be related to the up-regulation of mucosal TLR5 expression.