Effect of probiotic use on antibiotic administration among care home residents: a randomized clinical trial

Importance: probiotics are frequently used by residents in care homes (residential homes or nursing homes that provide residents with 24-hour support for personal care or nursing care), although the evidence on whether probiotics prevent infections and reduce antibiotic use in these settings is limited.Objectives: to determine whether a daily oral probiotic combination of Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp. lactis BB-12 compared to placebo reduces antibiotic administration in care home residents. Design, setting and participants: placebo-controlled randomized trial of 310 care home residents aged 65 years and older recruited from 23 care homes in the UK between December 2016 and May 2018, with last follow up on 31st October 2018. Interventions: study participants were assigned to receive a daily capsule containing a probiotic combination of Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp. lactis BB-12 (total cell count per capsule 1.3x1010 - 1.6x1010) (n=155), or daily matched placebo (n=155), for up to one year. Main outcome measures: the primary outcome was cumulative antibiotic administration days for all cause infections measured from randomization for up to one year.Results: among 310 randomized care home residents (mean age 85.3 years; 66.8% women), 195 (62.9%) remained alive and completed the trial. Participant diary data (daily data including study product use, antibiotic administration, and signs of infection) were available for 97.4% randomized to placebo and 98.7% randomized to the probiotic group. Care home residents randomized to the probiotic group had a mean cumulative systemic antibiotic administration days of 12.9 days (95% CI: 0 to 18.05), and those randomized to placebo, 12.0 days (95% CI: 0 to 16.95) (absolute difference = 0.9 days, 95% CI: -3.25 to 5.05 days; adjusted incidence rate ratio = 1.13, 95% CI: 0.79 to 1.63, P=.50). A total of 120 care home residents experienced 283 adverse events, including 78 (58.6%) hospitalizations in the placebo group and 94 (62.7%) in probiotic group. There were 32 deaths (20.6%) in the placebo group and 33 (21.3%) in the probiotic group..Conclusions and relevance: among care home residents in the UK, a daily dose of a probiotic combination of Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp. lactis BB-12 did not significantly reduce antibiotic administration for all-cause infections. These findings do not support the use of probiotics in this setting.Trial registration: the trial is registered with the ISRCTN, Registry number ISRCTN16392920.