Abstract
PURPOSE: Evidence from studies mainly in children has shown that orally administered probiotics may prevent respiratory tract infections and associated antibiotic use. We evaluated whether advice to take daily probiotics can reduce antibiotic prescribing for winter respiratory tract infections in people with asthma. METHODS: We conducted a randomized controlled, parallel-group pragmatic study for participants aged 5 years and older with asthma in a UK primary care setting. The intervention was a postal leaflet with advice to take daily probiotics from October 2013 to March 2014, compared with a standard winter advice leaflet. Primary outcome was the proportion of participants prescribed antibiotics for respiratory tract infections. RESULTS: There were 1,302 participants randomly assigned to a control group (n = 650) or intervention group (n = 652). There was no significant difference in the primary outcome measure, with 27.7% receiving antibiotics in the intervention group and 26.9% receiving antibiotics in the control group (odds ratio = 1.04; 95% CI, 0.82-1.34). Uptake of probiotics was low, but outcomes were similar in those who accessed probiotics (adjusted odds ratio = 1.08; 95% CI, 0.69-1.69, compared with controls). We also found no evidence of an effect on respiratory tract infections or asthma exacerbations. CONCLUSIONS: In this pragmatic community-based trial in people with asthma, we found no evidence that advising use of winter probiotics reduces antibiotic prescribing.