King's leads groundbreaking trial in cirrhosis care

30 September 2025

Chronic liver disease (CLD) is one of the UK’s fastest-growing health crises. Unlike most major chronic conditions, it’s still on the rise – and its most advanced stage, cirrhosis is now the nation's third biggest cause of premature death. People often die young, with more than one in ten patients in their 40s.

One of the greatest dangers facing people with cirrhosis is infection. Their immune systems are weakened, antibiotics are often less effective, and many face the terrifying prospect of ‘superbug’ infections. That’s why a pioneering new study – the PROMISE Trial, led by Professor Debbie Shawcross at King’s College Hospital – could be a gamechanger.

Turning gut bacteria into medicine

Our bodies are full of bacteria – trillions of them – and most are on our side, helping us fight infection and stay healthy. But in patients with cirrhosis, harmful bacteria in the gut multiply and make the immune system less able to cope.

The PROMISE Trial is testing a bold new approach: replacing the harmful bacteria with healthier ones, donated by carefully screened volunteers. The treatment is called faecal microbiota transplantation (FMT) – essentially, a gut bacteria transplant. Early trials using FMT delivered by endoscopy showed it was safe, but patients asked for something less invasive. The team listened.

Now, the same treatment is being tested in capsule form. Patients simply swallow five specially-prepared capsules every three months – far easier and more acceptable than an endoscopy.

What the trial will test

Over the next two years, patients with cirrhosis across the UK will take part. Some will receive FMT capsules, while others will receive a placebo – and neither patients nor doctors will know who is taking which.

Researchers will track whether FMT can:

• Reduce the risk of infections that lead to hospital admission
• Cut the use of antibiotics and lower the risk of super-bug infections
• Ease complications of cirrhosis and improve immune system function
• Reduce hospital admissions and even extend life expectancy

The trial is shaped by patients themselves, whose biggest concerns include repeated hospital stays, heavy antibiotic use, and fear of superbugs. PROMISE is designed to answer those concerns directly.

Speakingat the launch, Professor Debbie Shawcross said:

“It was an absolute privilege to bring together colleagues and patients from our 20 clinical sites across the UK to share our experiences and knowledge of being part of the PROMISE Trial. It was particularly humbling to hear the personal experiences of our patients enrolled on the trial and to hear the benefits of participating in clinical research tackling the complications of liver disease.”
– Professor Debbie Shawcross

Sharing the impact

Results from PROMISE will be shared not only in medical journals, but also with patient groups, the NHS and the wider public. The aim is simple: to ensure the findings influence patient care, shape clinical guidelines, and ultimately save lives.

This is research with the potential to change the way cirrhosis is treated – and to give patients and their families real hope. Thank you to everyone who has given their time, energy and support to help it launch. 

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