STRAINS of a common bug have been linked to increasing cases of bowel cancer and other forms of the disease in the UK, scientists warn.
They said targeting specific strains of the bacteria causing the bug with vaccines or other treatments could help reduce the risk of bowel, bladder and prostate cancers.
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Escherichia coli – referred to as E.coli – is a group of bacteria that are normally harmless and live in the intestines of humans and animals.
But certain strains can make people sick and it’s well known for causing food poisoning, as well urinary tract infections (UTIs), pneumonia and sepsis.
The germ is responsible for thousands of infections every year, with 38,757 E.coli cases reported in England between 2022 and 2023.
A particularly nasty strain of the bug – known as shiga toxin-producing E.coli (STEC) – was at the centre of a UK outbreak earlier this year, which landed dozens in hospital and resulted in the death of one person.
Investigators have traced the source of the outbreak to lettuce used in ready-to-eat sandwiches.
A new study has suggested higher cases of certain cancers in countries such as the UK could be linked to two particular types of E.coli.
These strains produce a DNA-damaging chemical called colibactin that has been linked to bowel cancer.
Working to eradicate them “could offer huge public health benefits“, researchers said, including reducing the need for antibiotics to treat the infections they cause, as well as potentially lowering cancer risk.
Bowel cancer is the fourth most common cancer in the UK and second most common cause of cancer death, with around 16,800 lives lost every year.
Studies reveal that cases have surged by 52 per cent in 25-49 year-olds over the last 30 years.
Bladder cancer is less common, with about 10,000 people diagnosed every year.
But prostate cancer rates have increased in 25-49 year-olds since the early 1990s and more than 55,000 cases are diagnosed a year in the UK across all age groups, according to Cancer Research UK.
For the study, published in Lancet Microbe, researchers used genomic surveillance to track different strains across different countries, including the UK, Norway, Pakistan and Bangladesh.
The two strains academics focused on are more common in industrialised countries – such as the UK – and cause infections of the bloodstream and urinary tract, rather than food poisoning.
These countries also have higher levels of bowel, bladder and prostate cancers, according to researchers.
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Meanwhile, the team’s analysis showed the strains were much rarer in countries such as Bangladesh and Pakistan, where cases of bowel, bladder and prostate cancers are also lower.
Senior author Professor Jukka Corander, of the Wellcome Sanger Institute, University of Oslo, and the University of Helsinki, said: “We have been using large-scale genomics to track E.coli strains across multiple countries for the last five years, using data that goes back to the early 2000s.
“This has allowed us to start to see the possible connections between two E.coli strains and cancer incidence rates.”
First author Dr Tommi Maklin, of the University of Helsinki and the Wellcome Sanger Institute, added: “E.coli can be found around the world, in many different forms, and understanding how strains of this bacteria impact humans differently can give us a more complete picture of health and disease.
“Having access to global genomic data on which strains are found in an area can uncover new trends and possibilities, such as strains in industrialised countries potentially being linked to the risk of certain cancers.
“We also need to keep ensuring that countries and regions around the world are included in genomic surveillance research so that everyone benefits from new discoveries.”
Prof Corander said he hopes the findings unlock a way of potentially eradicating strains of E.coli which produce colibactin.
What are the red flag warning signs of bowel cancer?
IT’S the fourth most common cancer in the UK, the second deadliest – yet bowel cancer can be cured, if you catch it early enough.
While screening is one way of ensuring early diagnosis, there are things everyone can do to reduce their risk of the deadly disease.
Being aware of the signs and symptoms of bowel cancer, spotting any changes and checking with your GP can prove a life-saver.
If you notice any of the signs, don’t be embarrassed and don’t ignore them. Doctors are used to seeing lots of patients with bowel problems.
The five red-flag symptoms of bowel cancer include:
- Bleeding from the back passage, or blood in your poo
- A change in your normal toilet habits – going more frequently for example
- Pain or a lump in your tummy
- Extreme tiredness
- Losing weight
Tumours in the bowel typically bleed, which can cause a shortage of red blood cells, known as anaemia. It can cause tiredness and sometimes breathlessness.
In some cases bowel cancer can block the bowel, this is known as a bowel obstruction.
Other signs include:
- Gripping pains in the abdomen
- Feeling bloated
- Constipation and being unable to pass wind
- Being sick
- Feeling like you need to strain – like doing a number two – but after you’ve been to the loo
While these are all signs to watch out for, experts warn the most serious is noticing blood in your stools.
But, they warn it can prove tricky for doctors to diagnose the disease, because in most cases these symptoms will be a sign of a less serious disease.
“Science is not a stand-alone endeavour and by working together with cancer and microbiome experts, we are hopeful that in the future this work might lead to new ways to eradicate colibactin-producing E.coli strains,” he said.
“Vaccines or other interventions that target these E.coli strains could offer huge public health benefits, such as reducing the burden of infections and lessening the need for antibiotics to treat these, as well as reducing the risk of cancers that could be linked to the effects of colibactin exposure.”
Dr Trevor Lawley, of the Wellcome Sanger Institute, said: “In the future, it could be possible to develop therapeutic probiotics that help to displace unwanted bacterial strains, such as the ones that release colibactin.
“Understanding more about the interactions between E.coli and cancer risk highlights the impact our microbiome has on our health and is a crucial avenue to explore if we want to work with our bodies to help combat certain conditions.”
It comes after scientists announced that food poisoning bug salmonella could be manipulated to help fight bowel cancer.
