Gut microbes could be analysed to determine the tumour risk of an individual, a new study has suggested.
By studying an animal model, scientists found that transferring the microbes from mice with colon tumours to ones without such complications made the otherwise healthy animals more prone to tumours as a result of the switch.
"We know that humans have a number of different community structures in the gut. When you think about it, maybe different people - independent of their genetics - might be predisposed," explained one of the authors Joseph Zackular from the University of Michigan.
Published in mBio, the online journal of the American Society for Microbiology, the findings are significant as they could indicate that there is a microbial component implicated in the risk of colorectal cancer.
The development of the condition has been linked to a series of factors, such as eating a lot of red meat, alcohol consumption and chronic inflammation of the gastrointestinal tract.
Summarising the risk factor, co-author Patrick Schloss - also from the University of Michigan - explained: "It's not just the microbiome, it's not just the inflammation [that also plays a role in the development of colorectal cancer], it's both."
Further research into the condition published recently by Cell Press in the journal Cell Host & Microbe found that bacteria in the mouth known as fusobacteria may also be associated with the development of this form of cancer.
The microbes do this by stimulating bad immune responses, which in turn activate cancer growth genes that can result in colorectal tumours.
"Fusobacteria may provide not only a new way to group or describe colon cancers but also, more importantly, a new perspective on how to target pathways to halt tumor growth and spread," commented senior study author Wendy Garrett from the Harvard School of Public Health and the Dana-Farber Cancer Institute.
Official figures suggest that colorectal cancer - also referred to as colon, rectal or bowel cancer, depending on where it starts - is the third most common type of cancer in England.