Among critically ill patients requiring mechanical ventilation, the probiotic Lactobacillus rhamnosus GG does not prevent ventilator-associated pneumonia (VAP). VAP is a serious lung infection that is commonly acquired by intubated patients in hospital.
The findings appeared in the international, multi-centre Prevention of Severe Pneumonia and Endotracheal Colonization Trial (“PROSPECT”), recently published in JAMA.
Probiotics are defined by the World Health Organization live microorganisms that may exhibit health benefits. In clinical settings, probiotics are being studied for their efficacy across a range of infectious, inflammatory, and autoimmune conditions. Clinical guidelines currently suggest the use of probiotics for some groups of critical care patients.
Growing interest in the negative effects of a disrupted gut microbiome, which can be exacerbated in critical care patients, has researchers looking for effective treatments to restore gut health. Yet, findings from PROSPECT do not support the use of L. rhamnosus GG in critically ill patients, despite previous findings from smaller, single-centre trials.
PROSPECT was led by a critical care research team at St. Joseph’s Healthcare Hamilton, including co-principal investigators Dr. Deborah Cook (St. Joe’s) and Dr. Jennie Johnstone (Sinai Health). The trial was supported by ICU teams from St. Joe’s, Hamilton General and Juravinski Hospital associated with McMaster University and 41 other academic and community centres across Canada, the United States, and Saudi Arabia.
“Large studies truly take a village to complete, but begin with a community of open-minded clinicians and scientists who acknowledge an evidence gap or controversy about a topic,” said Dr. Cook.
While the findings do not support the use of L. rhamnosus GG in preventing VAP, the study protocol offers an important framework for future studies involving probiotics in many other care settings.
“It was a privilege to work with the St. Joe’s ICU staff, the Research Pharmacy group led by Christine Wallace, and the PROSPECT team – France Clarke, Lois Saunders, Mary Copland, and Neala Hoad,” said Nicole Zytaruk, a Research Manager who managed the four-year study. “Additionally, we are grateful to The Research Institute of St. Joe’s for their support of critical care research over the years.”
The study team has further plans for the PROSPECT database, including several secondary analyses of their large dataset on issues such as the infectious diarrhea caused by C. difficile.
“There is so much more to be learned from such a comprehensive dataset,” added Zytaruk. “We owe it to the patients and families who were interested in this topic, and graciously joined the trial, permitting their data to be contributed.”
The study received funding from the Canadian Institutes of Health Research, the Canadian Frailty Network, Physician Services Incorporated, the Hamilton Academic Health Sciences Organization (HAHSO), the Academic Medical Organization of Southwestern Ontario, St. Joseph’s Healthcare Hamilton, and McMaster University.