Viral DNA inside gut bacteria linked to colorectal cancer

A virus hidden within a common gut bacterium is twice as prevalent in people with colorectal cancer. Scientists discovered previously unknown viruses, called prophages, embedded in the genome of Bacteroides fragilis. These prophages were significantly more common in bacteria from colorectal cancer patients compared to healthy individuals. This finding suggests that the genetic makeup of bacteria, including viral passengers, may play a role in colorectal cancer development, potentially leading to new screening methods.