I deliberately let a two-metre long tapeworm live in my gut for two months, writes DR MICHAEL MOSLEY. Here's what it felt like...

Parasites, such as leeches and tapeworms, often get a bad press, but I find them fascinating. So much so, a few years ago, I deliberately infected myself with some tapeworms to see what would happen (more on that in a moment).

In the years since that rather grisly self experiment, there’s been mounting evidence that worms such as hookworm and tapeworm may hold the secret to reducing chronic inflammation. This is linked to many of the diseases we associate with old age, including dementia and cancer, but also to autoimmune conditions such as asthma and ulcerative colitis.

Indeed, recent research has shown being infected by a tapeworm can extend an animal’s life.

That said, I wouldn’t recommend it, not least because getting infected with tapeworms can have a considerable downside.

There was an extraordinary story in the US press recently. Robert F. Kennedy Jr, a prominent anti-vaxxer and a potential candidate to be the next president, said part of his brain had been damaged by a tapeworm.

There is mounting evidence that worms may hold the secret to reducing chronic inflammation

It was reported that, in 2010, he began suffering from problems with his memory, which was initially thought to be due to a brain tumour. But experts decided that a dark patch seen on a brain scan 'was caused by a worm that got into my brain and ate a portion of it and then died', he said in legal documents two years later.

Last week, his spokesman said that the worm — a pork tapeworm — hadn’t left him with any long-term physical or mental health problems and that he was fit to run for president.

A gruesome story, certainly, and one that highlights the dangers of eating undercooked pork, particularly if you do so in a country with lax hygiene rules. That’s why, when I deliberately infected myself with tapeworm, we decided to go for a beef tapeworm rather than a pig type.

The idea of the experiment was to see what impact, if any, the tapeworm would have on my immune system. And, unlike pig tapeworms, those from cows seem to be relatively benign and don’t go places where they really shouldn’t, such as the brain.

To get infected I had to travel to Kenya, find an infected cow, then swallow some cysts formed by the embryo tapeworms. Over the next eight weeks the cysts ‘hatched’ and the tapeworms latched on to my gut and started to grow.

While that was happening, researchers from Salford University monitored my blood, and they could see that the tapeworms were helping to dampen down my immune response. Otherwise I didn’t actually feel any different, nor did I lose any weight (the tapeworm diet doesn’t work). After two months, I swallowed a pill camera to film the worms — which by then were several metres long and wriggling away happily in my gut. My chief reaction was fascination, with a touch of revulsion. It was certainly without regret that I took a pill to kill them.

What we saw in this experiment was the immune-calming potential of parasitic worms — something that’s being harnessed by scientists to treat a range of conditions from Crohn’s disease and ulcerative colitis to eczema, asthma, allergies and even multiple sclerosis (MS). Although it’s still early days, there have been some promising results.

In a small study at Nottingham University, published in 2020 in the journal Neurology, 71 patients with relapsing remitting MS (where symptoms worsen, followed by periods of recovery) were given either a dose of hookworm larvae — around 25 of them — delivered via a plaster stuck on their arms, or a placebo plaster.

MS is typically caused by an overactive immune system which attacks the insulating layer that covers our nerves, leading to problems with movement and memory. The idea of this study was to see whether being infected by the worms would dampen down the immune response.

Although the worms didn’t significantly improve their symptoms, or make a visible difference to existing nerve damage, it did lead to an increase in ‘regulatory’ T cells in the patient’s blood — these help keep the immune system under control. And this seemed to be preventing fresh damage.

The MS Society, which funded the research, say that it’s very unlikely worm therapy will be approved any time soon, but this sort of study gives us valuable insights into how worms manipulate our immune system, hopefully leading to better treatments in the future.

In another small study, scientists from the Malaghan Institute of Medical Research in New Zealand infected patients who had Crohn’s disease (a form of inflammatory bowel disease) with hookworms to try to keep their symptoms at bay.

Over the course of a year, 40 per cent of the patients remained in remission (with no flare-ups), reported the Inflammatory Bowel Diseases journal last June. Again, more research is needed.

But perhaps the most dramatic benefit I’ve seen is a more recent study where German scientists showed that tapeworm infection can triple life expectancy — if you’re an ant, that is.

A team from the Johannes Gutenberg University Mainz found that ants infected with a particular species of tapeworm not only lived longer than normal, but seemed to do so because the parasites were pumping the insects with hundreds of different chemicals, including two powerful antioxidants that appear to protect them against damage normally caused by ageing.

It is, of course, a giant step from ants to humans, but it almost makes me regret that I decided to get rid of my own parasitic tapeworms. Almost.

We need to look after our livers. Here’s the fast track...

Our livers normally do a fabulous job of clearing the toxins from our blood, as well as producing bile, a fluid that helps us digest and absorb fats.

Unfortunately, our livers are in crisis, with deaths from liver disease rising fourfold in the past 50 years.

A lot of that is due to rising rates of obesity, which has led to a surge in non-alcohol related fatty liver disease (NAFLD). A normal, healthy liver should contain little or no fat, but when you put on more weight than your body can comfortably handle, some of that fat gets stored in your liver.

Up to one in three people in the UK now has early-stage NAFLD which, if left untreated, can lead to serious liver damage, including cirrhosis and liver failure. Signs of advanced NAFLD include tiredness, confusion, dark urine and itchy skin. If you do have any of these symptoms, see your doctor.

Our livers are in crisis, with deaths from liver disease rising fourfold in the past 50 years

There are no medical treatments for the condition, but studies have shown intermittent fasting, particularly the 5:2 diet (cutting your calories two days a week), is an effective way to get rid of it.

Is it just the loss in weight? Not according to research published last week in the journal Cell Metabolism. When researchers put mice on a 5:2 diet their livers produced two proteins that reduced chronic inflammation, but also helped protect the liver from going on to develop cancer. These proteins seem to work by preventing a build-up of fat in the liver. 

So, if you do develop signs of fatty liver disease, you know what to do.

I’ve finally beaten the really annoying cough that was keeping me up at night. In the end, what worked for me was taking some over-the-counter antihistamines, which apparently make your nose and throat feel less itchy. Either that or it just got better by itself.

I’m quite bad at keeping in touch with old friends. And I’m not alone: a recent review of studies by psychologists at the University of Sussex found two-thirds of us are as reluctant to message an old friend as to strike up a conversation with a stranger. To overcome this, the researchers asked volunteers to spend a few minutes sending messages to existing friends, or spend that time browsing social media. It was then suggested they contact an old friend later. More than half of those who’d sent the practice messages actually did it, compared with less than a third in the control group. I think I’ll give it a go.