Published in the ACTA Academiae Medicinae Sinicae – a Chinese scientific journal, the review was conducted by researchers from the Nursing School of Shandong University.
They analysed 12 randomised controlled trials (RCTs) that studied probiotics and asthma prevention available on databases such as PubMed, Embase, and Cochrane Library. Another six systematic review on probiotic intervention on asthma treatment were also studied.
Out of the 12 RCTs, the probiotic intervention was mainly administered on infants (5 RCTs), one was on pregnant mothers, and the remaining six of them on both pregnant mothers and infants. A total of 3,937 subjects were studied.
Pregnant mothers were included as some studies aim to find out if probiotic supplementation in mothers can affect infants’ health.
The RCTs have a follow-up period ranging from three to eight years, with the prevalence of asthma as one of the study parameters.
The probiotic strains administered in the RCTs ranged from lactobacillus acidophilus, lactobacillus rhamnosus, lactobacillus reuteri, lactobacillus paracasei to bifidobacterium longum.
From the RCTs, the researchers found that probiotic supplement was not significantly associated with a lower risk of asthma in infants – a result which corroborates with the meta-analysis findings conducted by Azad et al in 2012.
As for treatment of asthma, the review found that probiotics supplementation can improve the results of childhood asthma control test (C-ACT), but this effect was only reported in two RCTs.
While the review found that probiotics supplementation could improve the pulmonary function of subjects suffering from asthma, the researchers said more research was needed to validate the finding.
They also suggested future research to study probiotics’ effects on acute asthma attack.
Immunology wise, the review showed that there were no statistically significant differences in the level of lgE antibodies found in the blood samples of subjects taking probiotic and those on placebo.
Hence, there was a need to conduct further study on probiotics’ effect on immune markers such as IFN-γ, TNFα, and IL-4.
They also found that preventive probiotic supplementation was generally safe and did not cause major side-effects.
“Based on the currently available literature, probiotic supplementation cannot prevent asthma or wheeze. However, it may improve pulmonary function and asthma control in asthmatic patients, although further studies are needed,” the researchers concluded.
Source: ACTA Academiae Medicinae Sinicae
Roles of probiotic supplementation in the prevention and treatment of asthma: A systematic review
Authors: Chen and et al