UK study tests new preventative therapy for contagious gut infection

A major new UK study into a life-threatening and highly contagious gut infection has begun. Researchers, supported by the Cambridge Clinical Research Facility,  have recruited the first patient in the world to test a new preventative therapy.

About C. diff

Clostridioides difficile, often called C. difficile or “C. diff”, is a bacterium that lives in the gut. When the normal balance of gut bacteria is disturbed — often after antibiotics — it can cause infection (CDI).

Symptoms include diarrhoea, stomach pain and fever. In severe cases, the infection can be life-threatening, especially for older or vulnerable people.

Nearly 19,000 CDI cases were reported in England last year, and numbers are rising. Around 1 in 7 patients die within 30 days — about 50 deaths each week. The bacteria spreads easily and can survive on surfaces for months or even years. Outbreaks can force hospital wards to close.

An industry-sponsored trial, supported by the NIHR, is testing a non-antibiotic drug designed to prevent CDI from coming back.

Patient experience

Lisa Shipp, a former business analyst, was first diagnosed with C. diff 3 years ago. She was diagnosed again in October 2025 and re-admitted to hospital.

Her treatment has been complicated by a pre-existing heart condition. Lisa — who previously took part in a trial related to her heart condition — struggled to maintain a normal diet because of her symptoms. She experienced diarrhoea and vomiting after developing the infection.

She said: “This research is vital because, currently, the preventative therapy options for this debilitating condition are so limited. A preventative therapy to stop recurrence can’t come quick enough.”

A new preventative approach

CDI can usually be treated with antibiotics. However, options to prevent it returning are limited. Repeat infections often mean more courses of antibiotics. This increases the risk of antibiotic resistance.

As resistance grows:

• infections become harder — or even impossible — to treat
• illness becomes more severe
• death rates rise
• pressure on the NHS increases

Researchers believe the new drug could reduce the risk of CDI returning. The study will assess how well it works and how safe it is.

Expert view

Dr Effrossyni Gkrania-Klotsas, pictured above, NIHR National Specialty Lead for Infection, is leading the trial at Cambridge University Hospitals (CUH), where she works as an Infectious Diseases Consultant. She said:

“C. diff can cause severe illness and can be life-threatening, particularly for older and vulnerable patients. And in hospital settings it is especially difficult to control, as it spreads easily and can survive on surfaces for long periods, requiring intensive infection-prevention measures. For patients, infection can mean prolonged illness and longer hospital stays; for staff, it can mean ward closures and disrupted care. So a non-antibiotic preventative approach could help protect patients while easing pressure on hospital services and improving overall patient safety.”

Recruiting the first patient also highlights the impact of the NIHR UK Vaccine Innovation Pathway (VIP). VIP brings together life sciences companies, the NHS and research partners to speed up clinical trials. This helps patients access new treatments sooner and strengthens the UK’s life sciences sector.

The first participant was recruited within 86 days — much faster than the government’s target of under 150 days to set up commercial trials. Being the first country to recruit into a global study is an important signal to international sponsors when deciding where to run trials.

Dr Maria Koufali, NIHR Life Sciences Industry Director, said:

“This global-first achievement at Cambridge University Hospitals demonstrates what the UK can deliver when the entire research system works as one. Through the Vaccine Innovation Pathway, we have coordinated the expertise, infrastructure and delivery capability of the NHS and NIHR to open complex studies at unprecedented speed.

“In 2026 we will extend this national model across all commercial trials, giving industry a predictable, rapid route to patients and ensuring people in the UK access breakthrough therapies earlier.

“As NIHR marks its twentieth year, this is exactly the role we exist to play — turning scientific excellence into real-world impact, from prevention and early diagnosis to life-saving therapies and better care.”

Dr Effrossyni Gkrania-Klotsas added:

“By bringing together the NIHR, the sponsor and delivery partners, CUH researchers showed how joined-up working across organisations can overcome complexity and deliver more than any one partner could alone. This work also supports the UK Government’s priority to shift from sickness to prevention, helping research reach patients faster and benefit more people.”

The research is supported by NIHR Cambridge Clinical Research Facility, NIHR Cambridge Biomedical Research Centre and the NIHR Research Delivery Network.