Effects of metronidazole combined probiotics over metronidazole alone for the treatment of bacterial vaginosis: a meta-analysis of randomized clinical trials.

Object: To evaluate the curative effect of metronidazole combined probiotics over metronidazole alone in the treatment of BV.

Methods: We are searching randomized controlled trials on major online databases including PubMed, Science Direct, and Cochrane Database between 1990 and 2015. The primary outcome measure was the cure rate of BV. Cochran's Chi-square test (Q test) was used to test for heterogeneity among trials, and the I index. We used mixed-effects modeling for parameters of the summary hazard ratios (HRs), odds ratios (ORs), and their 95% confidence intervals (CIs).

Results: Analysis suggests the cure rate of BV [RR = 1.12, 95% CI (0.94-1.32), p = 0.20], and the I index was 83%. The value of I index decreased to 16% after removing the study of Anukam et al., and Amsel 1.04 (95% CI 0.96-1.13) (p = 0.35), Nugent 1.02 (95% CI 0.94-1.11), short-term 1.01 (95% CI 0.93-1.10) (p = 0.79), long-term 1.06 (95% CI 0.98-1.14) (p = 0.13), Europe 1.06 (95% CI 0.95-1.19) (p = 0.32), Non-Europe 0.99 (95% CI 0.94-1.05) (p = 0.83). When the two same groups data were combined, respectively, the RRs for all studies were the same as 1.03 (95% CI 0.96-1.09) (p = 0.42) showing that there is not statistically significant in relevant stratums.

Conclusion: The result has showed an overall little significance for the efficacy of metronidazole combined probiotics over metronidazole alone for the treatment of BV. We need more further studies to provide enough evidence to confirm the benefits of probiotics in the treatment of BV.