The Hidden Threat: How E. coli Exposure May Drive Early Bowel Cancer

Commentary by Dr. Donald Greig

Although colorectal cancer awareness month has just passed, we are committed to keeping you informed about the latest research and health developments that may impact your well-being. Recently, significant studies have highlighted a concerning trend: the rising rates of bowel cancer in individuals under 50.

The Role of E. coli and Colibactin

Recent research, supported by Cancer Research UK, has uncovered a potential link between exposure to a specific strain of E. coli bacteria and an increased risk of bowel cancer in young adults. This strain produces a toxin called colibactin, which can alter DNA in bowel cells, potentially leading to cancer.

Key Findings:

• Childhood Exposure: Scientists found that exposure to colibactin before the age of ten may lead to DNA mutations in bowel cells, significantly increasing the risk of developing bowel cancer later in life, especially before the age of 50.

• Rising Incidence: Since the 1990s, there has been a staggering 52% increase in bowel cancer cases among adults aged 25 to 49. This trend is particularly pronounced in England, where early-onset cancers are rising more rapidly than in any other European country.

• Mutational Evidence: Researchers examined the genetic information of 981 bowel cancer cases and found that colibactin-related DNA mutations were 3.3 times more common in those diagnosed under 40 compared to those diagnosed after 70. These mutation patterns are especially prevalent in countries with higher rates of early-onset bowel cancer.

  
  

Insights from Experts:

Ludmil Alexandrov, a professor at the University of California San Diego and the study’s senior author, noted that colibactin-related mutations account for approximately 15% of early genetic alterations that promote bowel cancer. He emphasized that acquiring such mutations by the age of ten could lead to developing colorectal cancer decades earlier than expected.

Dr. David Scott, director of Cancer Grand Challenges, stated that many early-onset colorectal cancer patients have likely been exposed to colibactin in early life. The origins of this exposure remain unclear, but it may be related to a combination of dietary factors during crucial phases of gut microbiome development.

Implications for Health

Understanding the role of colibactin and its impact on DNA mutations can help healthcare providers develop better prevention strategies. This research adds an important piece to the puzzle of increasing bowel cancer rates among young adults, but further studies are needed to establish a definitive link.

What You Can Do

While research is ongoing, here are proactive steps you can take to support your health:

• Maintain a Balanced Diet: Focus on consuming a variety of fruits, vegetables, and whole grains. Reducing the intake of processed and red meats can also be beneficial.

• Stay Hydrated: Drinking plenty of water and limiting sugary drinks can support digestive health.

• Regular Check-Ups: Stay informed about recommended screenings, especially if you have risk factors such as a family history of bowel cancer.

Conclusion

The findings of this research highlight the potential impact of early-life exposure to E. coli and its toxin, colibactin, on the rising rates of bowel cancer in young adults. Awareness and continued research are essential in addressing this concerning trend. If you have any questions or concerns about your health, please do not hesitate to reach out to our team.

Stay healthy and informed!

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Article by Eleanor Hayward

E coli linked to rise and bowel cancer among under 50 year olds

E.coli bacteria is part of a normal gut microbiome but some strains can produce toxins

Exposure to E. coli bacteria in childhood could be driving an alarming increase in rates of bowel cancer in young adults, scientists have discovered.

A toxin called colibactin, which can cause changes in DNA, is produced by a strain of E. coli, though not the strain linked to symptoms such as diarrhoea.

Researchers backed by Cancer Research UK found that exposure to colibactin before the age of ten leads to mutations in the DNA of bowel cells, which may then increase the risk of developing cancer before the age of 50.

Experts believe the finding could help to solve the puzzle of why rates of bowel cancer are rising among young adults around the world.

Data from Cancer Research showed that there has been a 52 per cent increase in bowel cancer incidence among adults aged between 25 and 49 since the 1990s. Cases of such “early-onset” cancers are rising more rapidly in England than anywhere else in Europe.

Scientists have speculated that factors including obesity, lack of exercise and consumption of alcohol and ultra-processed foods are partly to blame for this increase. The latest study, published in the journal Nature, points to E Coli as another possible culprit.

The risk of developing bowel cancer could be increased by DNA mutations

Researchers examined the genetic information of 981 bowel cancers. They found that colibactin can leave behind specific patterns of DNA mutation that were 3.3 times more common in those diagnosed with bowel cancer aged under 40 than in those diagnosed after the age of 70. These mutation patterns were also particularly common in countries with a higher rate of early-onset bowel cancer.

Ludmil Alexandrov, a professor at the University of California San Diego and the study’s senior author, said: “These mutation patterns are a kind of historical record in the genome, and they point to early-life exposure to colibactin as a driving force behind early-onset disease.”

The study also found that colibactin-related mutations accounted for about 15 per cent of what are known as APC driver mutations — some of the earliest genetic alterations that directly promote cancer development in bowel cancer.

“If someone acquires one of these driver mutations by the time they’re ten years old, they could be decades ahead of schedule for developing colorectal cancer, getting it at age 40 instead of 60,” Alexandrov said.

The work is led by Mutographs, a project that is part of a £20 million cancer “grand challenge” tasked with solving the mystery of rising bowel cancer cases in the young.

Dr David Scott, the director of Cancer Grand Challenges, said: “Globally and in the UK, we’re witnessing an alarming increase in some types of cancer in people under the age of 50.

Dr David Scott says that scientists are keen to understand why rates of some cancers are increasing

“Many early-onset colorectal cancer patients appear to have been exposed to a toxin, called colibactin, produced by some strains of the bacteria E. coli in early life.

“It’s unclear how the exposure originates, but we suspect that a combination of factors — including diet — may intersect during a crucial phase in the development of the gut microbiome.

“This study adds an important piece to the puzzle of early-onset cancers, but it isn’t conclusive, and more research will be needed to establish a definitive link between colibactin and an increased risk of early-onset colorectal cancer.”

Professor Sir Mike Stratton says there is likely to be a combination of factors that increase cancer risk

Professor Sir Mike Stratton, the Mutographs team leader and senior group leader at the Wellcome Sanger Institute, said: “Our research has allowed us to generate the hypothesis that the presence of colibactin leads to an increased number of mutations in colon cells, which then causes a greater risk of colorectal cancer at an early age.

“If this turns out to be correct, we can explore preventive measures such as tests that tell us if the toxin, or the bacterium that makes it, is present, and finding ways to eliminate them from our bodies at a young age.

“We know that diet and lifestyle choices drive the risk of developing colorectal cancer, but this study has opened up a new and exciting route we can take when researching how to lower the rate of early-onset colorectal cancer.”

Bowel cancer is the fourth most common type of cancer in the UK, with 44,000 new cases and 17,000 deaths each year. While cases are rising in the young the vast majority are still in over-50s with about 2,600 cases diagnosed in people aged between 25 to 49 annually.

Those affected include Dame Deborah James, who died in 2022 aged 40, six years after being diagnosed.