Background: Colorectal cancer (CRC) is a heterogeneous disease of the gut epithelium up to 90% of disease risk is attributed to environmental factors like food and oncogenic bacteria.
Objectives: The current study's objectives are to determine the gut microbiota that is probably linked to CRC and to evaluate the degree of variation between patients and healthy people.
Patients and methods: The gut bacterial microbiome of 40 CRC patients and 40 healthy controls were analyzed using quantitative SYBR Green real-time PCR technique targeting 16S rRNA of selected bacteria.
Results: The gut microbiome of the patients contained a higher relative abundance of  Bacteroides as well as Clostridium difficile (C.difficile) and  lower  relative abundance of     Firmicutes , Prevotella , Ruminococcus , Bifidobacteria  and  F. prausnitzii  than controls. Shannon diversity index and Bray-Curtis dissimilarity index are statistically significant low in the CRC group compared to the control group.
Conclusion: The current study showed  evidence of changes in the gut Microbiome composition of CRC patients considering them less diverse and more dysbiotic compared to the healthy controls.