Looking at Kyla Fuller today it is almost impossible to imagine that she spent more than a decade desperately ill. The 33-year-old practically radiates with enthusiasm, and has a zest for life that allows her to work on charter boats on Australia’s tropical Queensland coast.
But rewind two years and it was a different story. Her body was ravaged by such severe Crohn’s disease she was hospitalised several times with agonising bowel abscesses and abdominal pain. She could no longer tolerate normal food, and instead was relying on meal-replacement shakes for nutrition.
The chronic inflammatory bowel condition, which affects half a million people in the UK, is part of a spectrum of autoimmune diseases – those which cause the immune system to attack the body’s own healthy tissues. In the case of Crohn’s it causes the gut to become swollen, inflamed and ulcerated, leading to crippling cramps, diarrhoea, fatigue and weight loss.
There is no cure, and the treatments – which include immune-system suppressing drugs and surgery – can only help manage symptoms, with varying success and unpleasant side effects.
At one point Kyla weighed just 6st 8lb (42kg) and felt, like many with the disease, defeated.
But today she no longer suffers symptoms or takes medication. Her last serious flare-up was in April 2024 and she can eat normally again.
Blood and stool tests last month show, remarkably, that she is in remission from the disease.
Kyla Fuller, who has suffered with severe Crohn’s disease, is undertaking the alternative parasite treatment. Using a pipette, she deposits the contents on to a bandage which she affixes to her arm for 24 hours, allowing the worms to burrow into her skin
Kyla and others who have experimented with helminth therapy now post about their experiences on social media, in clips that often garner hundreds of thousands of views
And the reason for this unlikely turnaround? She believes it is due to a controversial alternative treatment using parasites.
Every few weeks, Kyla receives a vial of fluid through the post containing dozens of microscopic hookworm and whipworm larvae – intestinal parasitic worms. Using a pipette, she deposits the contents on to a bandage which she affixes to her arm for 24 hours, allowing the worms to burrow into her skin.
It sounds repulsive – and would be easy to dismiss as hokum. Certainly no UK doctors openly recommend it.
But there is a growing body of research that suggests these parasites, known as helminths, could hold vital clues in helping to treat some of our trickiest diseases, particularly autoimmune conditions.
Kyla and others who have experimented with helminth therapy now post about their experiences on social media, in clips that often garner hundreds of thousands of views. And they genuinely believe that the treatment has proved life-changing.
‘I feel like I’ve been given a second chance at life,’ Kyla says. ‘I don’t have any pain, nausea, urgency or blood in my stool.
How to get them into your body
The worms used in helminth therapy are parasites – microscopic organisms which have evolved to survive inside either humans or other animals.
Historically, humans became infected by walking barefoot on soil contaminated by their larvae or eggs, or by eating unwashed vegetables or fruit grown in contaminated soil.
But they are now cultivated by suppliers that deliver them internationally for research or therapeutic use.
Four main parasites are used for the treatment.
Human hookworms, or necator americanus, pictured left, are sold as larvae which are applied to the skin in a bandage. They burrow through skin and mature as they move through the body, which means they cannot be taken orally.
But the others – human whipworms, pig whipworms and rat tapeworms – are given in egg-form and can be taken in a drink, allowing them to hatch inside the body.
All are thought to work slightly differently, although quality evidence is limited.
Anecdotal evidence compiled by online groups suggests that hookworms are particularly effective for inflammatory diseases of the small intestine, while tapeworms might be better for alopecia.
‘I’m still coming to terms with the fact that I’m not sick any more. Autoimmune diseases are complex to manage and involve a lot of moving parts, but for many people I would argue that helminths could be a key missing piece of the puzzle.’
Scientists are now investigating whether parasites – specifically the chemicals they release inside the human body to prevent being killed by the immune system – could be harnessed against a range of diseases from allergies to cancer.
As Professor Hany Elsheikha, a parasite expert at the University of Nottingham, puts it: ‘I would never recommend anyone tries this with live parasites.
‘There is a lot of work still to be done, but the scientific possibilities they offer are definitely intriguing. There’s real potential there which, if researched properly, could be transformative.’
The theory that parasites could be helpful to human health is based on the ‘hygiene hypothesis’ – the idea that our immune system has evolved to be exposed to a variety of parasites, bacteria and microbes. But as sanitation has improved over the past two centuries, we no longer come into contact with these micro-organisms to the same extent. Without them, so the theory goes, our immune system has turned inward – it’s begun to attack the body and over-react to harmless substances such as pollen or peanuts.
Advocates of the theory say this has contributed to an explosion in allergies and autoimmune conditions such as Crohn’s, ulcerative colitis, multiple sclerosis and type 1 diabetes.
In the UK alone, autoimmune and allergic diseases have increased up to three-fold in recent decades.
Rick Maizels, a professor in parasitology from the University of Glasgow, says: ‘The rise in autoimmune diseases has come at the same time as we’ve been less exposed to parasites in general, alongside developments in our diets and socioeconomic changes.
‘Parasites aren’t the whole story, but there is good logic to the theory that they may play a role.
‘Essentially, we think that when these parasites are inside the human body, in order to survive they produce chemicals that switch off the immune system and dampen down any inflammation which might damage them.’
So what does the evidence on helminthic therapy tell us?
Scientists in the Netherlands compared a group of children in Africa who had been given deworming treatment with another group which had not, and found that those with parasites had a lower risk of allergies.
A separate experiment in Argentina found patients with multiple sclerosis – an autoimmune disease which affects the brain and spinal cord – who had parasitic infections saw their disease progress less quickly.
A small Australian study in 2015 involved giving hookworms to 12 patients with coeliac disease – an autoimmune disorder triggered by gluten. After a year, eight were able to eat a bowl of pasta without an issue.
A lab worker examines helminths, which could hold vital clues in helping to treat some of our trickiest diseases, particularly autoimmune conditions
But the therapy also comes with risks, including infection, gastrointestinal discomfort, anaemia, fatigue and malnutrition.
Prof Elsheikha warns that clinical trials have not found statistically significant benefits for most patients. He says: ‘Some people feel some clinical improvements to conditions such as Crohn’s. but the results aren’t consistent and people don’t always benefit.’
Most people trying helminthic therapy are not doing so with clinical oversight, so there is no record of successes or failures.
Few clinics offer it. One, the London Clinic of Nutrition, which claims to have ‘pioneered treating autoimmune disease patients with helminths’, failed to respond to queries from The Mail on Sunday. Biome Restoration, a Lancaster-based supplier, also did not respond.
Kyla began taking helminths in July 2023 and admits she initially thought it was ‘far too weird for me’ when it was recommended on a Facebook support group.
‘I thought, “Eww, no way”,’ she recalls. ‘But after I read into it, it started to make sense. It was equal parts desperation and logic that played a role in my decision.’
Without input from a doctor or clinic, she bought some hookworms online from an overseas supplier after seeking recommendations and advice online.
They were also the cheapest option, at about £400 a year.
The worms arrived with instructions to apply them to a bandage, which was also included, and to leave them on her arm for around 12 hours every few weeks.
The larvae enter the skin, then travel through the bloodstream to the lungs where they are coughed up and then swallowed, ending up in the small intestine where they mature and attach to the intestinal wall.
While they lay eggs, they do not multiply inside the body as the eggs need to be excreted in human faeces to hatch.
The adults survive inside the digestive system for anywhere between months and years.
It was not a quick fix for Kyla, with no effects for six months.
She stayed on her Crohn’s medication, which included the immunosuppressant azathioprine and the steroid prednisone, and says that her doctors were ‘pretty dismissive’ about the parasite therapy.
‘My symptoms actually got a bit worse,’ she says. ‘Either it was a natural fluctuation in my disease, or because my immune system was fighting the parasite infection. But after 25 weeks I was no longer feeling sick after eating simple foods.
‘Then the cramps, which normally lasted 20 to 30 minutes after eating, didn’t last as long. By week 36 the pain and nausea had significantly reduced.’
Today Kyla posts about her experience to her 4,000 followers on Instagram as @letshealibd. She is no longer taking Crohn’s medication, and the only symptom she still has occasionally is loose stools.
‘I’ve never felt this well in my adult life,’ she adds. ‘I try not to worry about my symptoms coming back – any time in remission is better than being in a flare-up, especially after being unwell for so long. I’m just going to enjoy it.
‘And if I need to go back on the drugs, I will.’
Others have successfully used helminth therapy to treat inflammatory conditions such as acne.
Lisa Strawther, 53, who runs health-coaching business Hippiewell in Las Vegas, says her food-related flare-ups eased off after she started using worms in 2019. ‘It took me a while to come around to the idea but I was desperate and it improved in a month,’ she says.
Experts say the future is not in using live parasites, but in being able to work out which beneficial chemicals they excrete and turning those into medicines.
Prof Maizels says: ‘Infecting people with parasites is essentially flying blind. What we’re doing in the laboratory is seeing if we can identify the helpful molecules in this process and distil them into a product which can be scaled up, standardised, and which is safe and effective.’
And there may be many more discoveries to come – there are already signs that parasites may have an anti-cancer effect.
‘They could be game-changing,’ Prof Elsheikha says. ‘It’s a long-term journey, but worthwhile.’
