PRINCESS

To answer the question of whether a probiotic supplement can reduce the number of infections in care home residents, to reduce antibiotic use in this vulnerable group and help curb antiobiotic drug resistance.

The PRINCESS trial will assess the efficacy and mechanisms of a nutritional intervention (daily probiotics) to enhance immune function and reduce infection in care home residents. This is anticipated to reduce antibiotic prescribing for common infectious diseases in a high-risk population.

Background

Care home residents (CHR) are particularly vulnerable to common infectious diseases which are the commonest cause of hospitalisation in this group, and often result in lasting health decline. Frailty, atypical presentation and bacterial colonisation patterns lead to high antibiotic use. Reducing antibiotic prescribing in the expanding care home sector is central to the challenge of containing antimicrobial resistance (AMR) in the UK.

The PRINCESS trial will assess the efficacy and mechanisms of a nutritional intervention (daily probiotics) to enhance immune function and reduce infection in care home residents. This is anticipated to reduce antibiotic prescribing for common infectious diseases in a high-risk population. Antibiotic prescribing directly correlates with resistance. Fewer antibiotics will reduce the driving influence on AMR and is expected to reduce the likelihood of subsequent resistant infection.

Results

The study found that there was no overall significant difference in how many antibiotics the two groups needed, with the probiotic group having antibiotics for 12.9 days on average, compared with 12 days for the placebo group. Residents’ overall health and wellbeing was generally similar between the two groups.

Conducting a clinical trial such as this in care homes was viewed positively by the people we interviewed, with the low-risk nature of the probiotic supplement being key to the acceptability. How involved care home managers were in the trial was an important factor in the successful running of the trial, with good working relationships between research nurses, and care home staff also being important. However, as care homes are very busy places, research activities were difficult to sustain without the continued engagement and regular visits by research nurses.

Conclusions

Although we found no evidence of a benefit from the probiotic capsule used in PRINCESS, the findings may not apply to other probiotics or to older people living outside of UK care homes. Conducting trials like PRINCESS can be difficult but building close relationships between research nurses and those living and working in care homes is key to carrying out research that improves the lives of older people living in care homes.

Read a full report of the PRINCESS Study findings.

View the published paper in JAMA.