Fusobacterium and Enterobacteriaceae: Important players for CRC?

• Microbial dysbiosis is associated with colorectal cancer.
• Specific microbes such as E. coli and F. nucleatum promote colorectal cancer.
• Microbial activities are important for colorectal cancer development.
• Complex interplay between microbes and host immune system dictate colorectal cancer susceptibility.

The gut microbiota plays an essential role in regulating intestinal homeostasis through its capacity to modulate various biological activities ranging from barrier, immunity and metabolic function. Not surprisingly, microbial dysbiosis is associated with numerous intestinal disorders including inflammatory bowel diseases (IBD) and colorectal cancer (CRC). In this piece, we will review recent evidence that gut microbial dysbiosis can influence intestinal disease, including colitis and CRC. We will discuss the biological events implicated in the development of microbial dysbiosis and the emergence of CRC-associated microorganisms, focusing on Escherichia coli and Fusobacterium nucleatum. Finally, the mechanisms by which E. coli and F. nucleatum exert potentially carcinogenic effects on the host will be reviewed.