Scilight Press

Ulcerative colitis, precancerous polyps and colorectal carcinoma are associated with dysbiosis of gut microbiota. This study aimed at investigating the prevalence and phylogenetic analysis of Peptostreptococcus sp. and Bacteroides sp. among Iraqi patients. A total of 100 colorectal biopsy samples were collected from four groups including normal, ulcerative colitis, precancerous polyps and colorectal carcinoma patients. The detection of Peptostreptococcus sp. and Bacteroides sp. was performed by PCR and Sanger sequencing technique. Phylogenetic analysis of positive samples was carried out to identify the species of detected bacteria. The percent values for Peptostreptococcus positive samples were 0, 5.9, 18.2 and 13.2 in each of normal, colitis, precancerous polyps and CRC, respectively. While the per cent values for Bacteroides positive samples were 16, 29.4, 36.8 and 23.7 in each of normal, colitis, precancerous polyps, and CRC, respectively. Phylogenetic analysis showed that different species of Bacteroides were found in the samples, while only one strain, Peptostreptococcus anaerobium NCTCT 11460, was identified in all positive samples. The present study provides new insights into the association of Peptostreptococcus sp. and Bacteroides sp. with ulcerative colitis, precancerous polyps and colorectal carcinoma in the Iraqi population. Further studies are needed to elucidate the exact role of these bacteria in the pathogenesis of these diseases and to develop novel therapeutic strategies.