(UK) Bowel cancer: leading cause of cancer-related deaths in young adults by 2030

April 29, 2025, Surrey Live: Professor says one childhood diet and drug may be driving surge in bowel cancer 

https://www.getsurrey.co.uk/news/health/professor-says-one-childhood-diet-31529675.amp

Cases of bowel cancer are rising so rapidly among young people it looks set to become the leading cause of cancer deaths

Cases of bowel cancer are increasing in younger people and if the rise continues, colorectal cancer is projected to become the leading cause of cancer-related deaths among young adults by 2030. Until recently, the reasons for this surge were unknown, but new research points to a surprising suspect: gut bacteria.

A recent study reveals that exposure during childhood or adolescence to a toxin produced by certain strains of E coli, whose growth is encouraged by highly processed diets, may lay the groundwork for aggressive bowel cancers decades later. This discovery could help explain why people under 50 are at the heart of one of the fastest-growing cancer epidemics of our time says Justin Stebbing, Professor of Biomedical Sciences at Anglia Ruskin University.

Colon cancer is the second biggest cause of cancer death, but only one in three cases are diagnosed in the earliest stages. It can take ten to 15 years to develop.

Professor Stebbing said researchers looked at the DNA of almost 1,000 bowel cancer tumours and found the same 'fingerprint' linked to mutation caused by some strains of E coli. The damage was 3.3 times more common in people under 40 than those over 70.

Analysis found the mutations often emerge within the first 10 years of a person's life - suggesting the toxin may silently colonise children’s guts and initiate cancerous changes early.

Countries including Argentina, Brazil, and Russia – where colorectal cancer rates are climbing – showed higher levels of colibactin-related mutations.

Professor Stebbing said: "Unlike lifestyle risks that build up over decades, colibactin seems to strike during a narrow window – when the microbiome is still forming in childhood or early adulthood. Potential triggers could include repeated antibiotic use that disrupts healthy gut bacteria, highly processed diets that favour E. coli growth and urban living that reduces exposure to diverse microbial environments.

"These findings may also point to new prevention strategies. Screening programs could focus on younger adults carrying these high-risk bacterial strains, using stool tests to detect colibactin genes. Diets high in fibre and low in processed foods might promote a healthier gut microbiome, potentially suppressing harmful bacteria. The research also adds weight to calls for lowering colorectal cancer screening ages worldwide, since many early-onset cases go undetected under current guidelines.

"While this study is a major step forward, many questions remain. Why do some people carry colibactin-producing bacteria but never develop cancer? How do modern lifestyle factors amplify – or mitigate – these microbial risks? What we do know is that cancer results from the complex interplay between our genes and our environment – including the microscopic world within us.

"As researchers continue to connect the dots, one thing is clear: the colorectal cancer epidemic of the 21st century may have begun with silent microbial battles in our guts, decades before diagnosis. This emerging view of cancer not just as a genetic or lifestyle disease, but also as a microbial one – could fundamentally reshape how we think about prevention for future generations."