Objectives: Smoking and weight of the human body were investigated as factors affecting the presence of E. coli harbouring colibactin genes. Methods: A case control study was performed, including 50 patients with colorectal polyps and 50 healthy individuals. Smoking condition and body weight of those subjects were determined. Rectal swabs were collected from subjects for isolation of E. coli and the presence of clbA and clbP genes as the main colibactin genes was determined. Results: E. coli isolated from smoker patients with colorectal polyp, especially in males with neoplastic polyps, revealed a significantly higher content of colibactin genes, while these genes were found in one non-smoker female with neoplastic polyps. Genes were also detected in three smoker healthy individuals and one non-smoker female. Colibactin genes were found more often in E. coli isolated from overweight and obese males with neoplasm. Four healthy individuals had also colibactin genes, two healthy obese females, and two males with overweight and obese condition. Conclusion: Colibactin genes were frequently found in E. coli of smoking and heavy-weight patients with colorectal polyps, especially in those with neoplastic polyps. The frequency of these genes in smokers and obese healthy individuals was raised. Keywords: Body weight, colibactin, colorectal polyp, smokers
Corresponding Author: AL-Janabi A.