PRINCESS: General Study Information

Study Aims

The study aims to find out if a daily probiotic affects:

  1. antibiotic use for care home residents;
  2. the occurrence, site and duration of infections (respiratory, urinary, skin, gastointestinal, unexplained fever and other);
  3. the prevalence of C-difficile infection;
  4. levels of oral Candida (thrush);
  5. the immune response to the annual flu vaccine;
  6. general wellbeing.


We aim to recruit 330 care home residents from approximately 20 care homes in England and Wales.

Click here for a list of care homes currently taking part in the study.

The study is currently recruiting, with recruitment due to end in October 2017.

Study Management

The PRINCESS study is being undertaken as a joint venture by Cardiff University and Oxford University and is funded by the National Institute for Health Research (NIHR)

In Cardiff, the study is being coordinated by the Centre for Trials Research

In Oxford, the study is being coordinated by the Primary Care Clinical Trials Unit (PC-CTU)


The Study Team

The study is being led by Professor Chris Butler of Oxford University

Professor Chris Butler

PRINCESS Study Chief Investigator

The Cardiff PRINCESS Team

Dr Eleri Owen-Jones (Trial Manager)

Dr Jane Davies (Research Nurse)

Alison Edwards (Research Nurse)

Victoria Shepherd (Research Nurse)


The Oxford PRINCESS Team

Mina Davoudianfar (Trial Manager)

Heather Rutter (Research Nurse)

Luisa Saldana(Research Nurse)


Pippa Whitbread(Research Nurse)

Karen Madronal(Research Nurse)


Irene Noel(Research Nurse)