Working in A&E, I see many tragic cases – but one of the worst is diagnosing a young person with advanced and incurable bowel cancer. This used to be a rarity. Not now.

Not so long ago I saw a farmer, in his early 30s who'd come to A&E at the insistence of his wife, who was worried he was so exhausted.

I initially dismissed his symptoms as the result of being a new dad and the sleepless nights that involves. But he was pale, with a hint of yellow in the whites of his eyes. So, just in case, I ran some blood tests – though fully expecting them to be normal.

These revealed he was extremely low in red blood cells and his liver was malfunctioning, explaining the yellow tint in his eyes (caused by a build-up of bilirubin, produced when the liver breaks down red blood cells).

I sent him for an urgent CT scan and it showed that he had stage 4 bowel cancer, which meant it had spread to the rest of his body. Two months later he died in a hospice.

When I was at medical school, I was taught that bowel cancer was something that only affected the elderly.

But over the past few years the number of young patients – those under 50 – with bowel cancer is rocketing, rising by 2 per cent every year since the 1990s. I see these patients in A&E, often because they've ignored symptoms – cancer is not on their radar – until it's too late.

Just a few weeks ago, a university student came in about blood in her stool. She, too, had ignored her symptoms until, during an internet search, ChatGPT had rightly advised her to seek medical attention.

With no obvious cause, such as piles, I made an urgent two-week referral for her to have bowel cancer tests.

In the past, I probably wouldn't have done so, because of her age. But that's changed, and I'm hyper alert about bowel cancer.

What's driving this surge in cases? To try to find the answer, Cancer Research UK and the Bowelbabe Fund (set up by Dame Deborah James before she died of bowel cancer in 2022) have just launched a multi-million-pound study. Over the next five years the researchers will look at all the possible causes.

But those five years may be too late for some.

There's little doubt in my mind that the rapid rise in Europe and the US points to lifestyle and environmental factors. For instance, we now know a diet high in ultra-processed food and processed meats – and low in fibre – is a risk factor for bowel cancer. So, too, is being overweight, smoking, alcohol and not taking exercise.

And research has suggested that environmental factors such as pesticides, plastics and air pollution could potentially also be contributing. 

But more recently, emerging evidence points to the role of our gut microbiome – the community of microbes that is found there – in protecting us from bowel cancer. Harm those microbes, and you have a higher risk of bowel cancer.

And, yes, not surprisingly, antibiotics are implicated. A 2022 study published in the British Journal of Cancer compared the rates of antibiotic use in cancer patients against people who were identical in every way except they didn't have cancer. 

The results showed that the under-50s had a nearly 50 per cent higher chance of getting bowel cancer if they'd had antibiotics. But in the over-50s, antibiotics use was only associated with a 9 per cent increased risk.

This is not necessarily proof that antibiotic use can increase your risk of bowel cancer, but it is an eye-opening piece of research with a good scientific explanation for what's going on. 

And that is that antibiotics reduce the levels of good bacteria that produce short-chain fatty acids (such as butyrate), which have anti- inflammatory and anti-cancer properties in the colon.

So why are young people affected more by antibiotics?

We cannot be sure, but possibly their microbiome is more diverse, so the damaging effect of antibiotics is more pronounced. In addition, there is increasing evidence that vaping has a damaging effect on the gut.

A 2021 study on mice, published in the journal Environmental Science and Pollution Research, showed that vapour from e-cigarettes directly damaged the lining of the gut of mice, causing inflammation.

This is what predisposes you to developing bowel cancer. The good news is that four weeks after stopping, the gut lining went back to normal.

As for what you can do now to protect yourself, my first port of call would be to take steps to improve your gut microbiome.

That means eating more fibre and less ultra-processed food – and try including fermented foods such as kefir and sauerkraut in your diet.

I also think a daily probiotic supplement is a good idea – look for one with at least one billion colony-forming units (or CFUs) per capsule. 

There is evidence for this: A 2021 review of studies on the role of probiotics in cancer prevention, published in the journal Cancers, concluded: 'There is a lot of evidence that the use of probiotics can play an important role in cancer prevention and support anti-cancer therapies.'

As for my patients, while I was once content to prescribe antibiotics fairly liberally, I'm now much more cautious – and I always tell them to take their prescription with probiotics, knowing this advice will do no harm and may very well reduce their risks of getting bowel cancer.

@drrobgalloway

New NHS league tables? Same old story

Last week, Health Secretary Wes Streeting announced plans to introduce league tables for hospital performance, including A&E waiting times.

External scrutiny is a good thing, but beware of the risk of unintended consequences, because we've been here before. 

When the four-hour target for A&E was introduced by the last Labour government, many hospitals would move patients to a ward – not because it was in the patients' best interests, but because it meant the hospital hit the targets. In other words, league table position came above patient care.

I'm also worried about the impact of the hospitals at the bottom of the table – it will damage morale among the staff who can make the changes needed and make it harder to recruit the best people.

But my biggest worry is that a hospital's waiting times actually reflect complicated problems beyond its control: In my A&E we see patients quickly, but because of a lack of beds they can't then just go to the ward. That lack of beds

is caused by delayed discharges because of a lack of community care – nothing to do with the hospital, which would be placed at the bottom of the table.

What we need is to improve health – and reduce the demand that's crippling the NHS – and these league tables won't help with that.