Data collection process
Data including study author(s), country of publication, sample size
(n ), age range, microorganism(s) of interest, treatment dosage,
mode, and treatment length, and results for both the experimental and
placebo groups were tabulated in an Excel sheet. Three reviewers
independently assessed the risk of bias assessment using the Cochrane
risk of bias tool version 2.0. The outcome for efficacy and safety were
tabulated by three authors and independently reviewed by the
4th author. Original investigators were contacted via
email to seek unreported or underreported information.