Probiotics to Prevent Respiratory Infections in Nursing Homes: A Pilot Randomized Controlled Trial

ObjectivesTo assess the feasibility of conducting a large clinical trial to evaluate the effectiveness of probiotics to reduce influenza and other respiratory virus infections in residents of long-term and chronic care facilities (LTCFs). DesignRandomized, double-blind, placebo-controlled pilot trial. SettingFourteen nursing homes in Hamilton and surrounding region, Ontario, Canada. ParticipantsNursing home residents aged 65 and older (N=209). Those who were taking immunosuppressives (steroids or other immunosuppressives) or had a hematological malignancy, structural heart disease, or gastroesophageal or intestinal injury and others at high risk of an endovascular infection were excluded. InterventionParticipants were randomized to receive study probiotics2 capsules of Lactobacillus rhamnosus GG (estimated 10 billion colony forming units of L. rhamnosus GG per capsule) or placebo (calcium carbonate) daily for 6 months. MeasurementsLaboratory-confirmed respiratory viral infections. ResultsOne hundred ninety-six individuals were included in the analysis: 100 in the probiotics group and 96 in the placebo group. Laboratory-confirmed respiratory viral infections were observed in 14 (15.0%) residents in the probiotic group and 21 (22.9%) in the placebo group (hazard ratio=0.65, 95% confidence interval=0.32-1.31). ConclusionA larger trial is warranted to determine whether probiotics reduce influenza and other respiratory virus infections in residents of LTCFs.