Probiotics for Asthma Do Not Reduce Antibiotic Use

Patients with asthma who take probiotics daily do not reduce their use of antibiotics for upper respiratory tract infections (URTIs) during the winter, according to a new pragmatic community-based trial.

“We found no evidence that the intervention of advice leaflets recommending probiotic supplementation, with free access to such supplements, can reduce antibiotic prescriptions or promote improved respiratory tract health,” stated the researchers, led by Timothy D. H. Smith, MBBCh, MRCGP, Harambee Surgery, National Health Service East Lancashire Clinical Commissioning Group, United Kingdom.

Previously, in randomized controlled trials of specific patient populations in a 2011 Cochrane review, probiotic prophylaxis significantly reduced both URTIs and antibiotic prescribing rates for these infections. A pilot study that assessed effects of probiotics (combined with acupuncture) on respiratory tract infection rates in persons with asthma found reduced infection rates, but this small study was underpowered and the findings were not statistically significant, the researchers stated.

Smith and colleagues set out to assess whether a recommendation to take probiotic treatment, implemented as part of routine winter infection advice, could reduce antibiotic prescription rates and respiratory tract infections in older children and adults with asthma in a primary care setting. They noted that “probiotics alone for preventing antibiotic use in asthmatics have not, to our knowledge, been evaluated in a prospective controlled trial.”

In the study, 650 patients registered in 1 primary care clinic were randomly assigned to receive a leaflet with standard advice for reducing respiratory infections and asthma exacerbations. Another 652 patients received a leaflet with additional advice to take 1 probiotic capsule daily from October through March. The intervention group received 3 tokens, each good for a 2-month supply of a proprietary blend of 4 probiotic bacteria strains.

The study had 13,102 participants. All were age 5 years and older because asthma diagnoses are unreliable in younger children, the researchers noted.

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. Only about 20% of participants followed the intervention leaflet advice and took probiotics. “Uptake of probiotics was low, but outcomes were similar in those who accessed probiotics,” the researchers stated. “We also found no evidence of an effect on respiratory tract infections or asthma exacerbations.”

“Our data suggest that real-world use of probiotics to prevent winter infections and reduce antibiotic use cannot yet be recommended despite positive findings in a Cochrane review-at least not in older children and adults with asthma,” they added, noting several differences between their study and the Cochrane review, including the age-group studied, the focus on persons with asthma, and the probiotic strains used.

“There is a need for new ways to prevent URTI and reduce antibiotic prescribing in asthmatic and non-asthmatic patients that are cost-effective, safe, and acceptable to patients,” they stated. “Further work is needed to evaluate whether specific probiotic formulations modulate systemic immune responses or mucosal defenses before developing new interventions to reduce the burden of respiratory tract infection.”

The researchers published their results in the September/October 2016 Annals of Family Medicine.