Effect of Lactobacillus plantarum IS-10506 supplementation with oral metronidazole for the treatment of bacterial vaginosis: A randomized placebo-controlled clinical trial

Background Replacement of Lactobacillus spp. by anaerobic and facultative bacteria is central in pathogenesis of bacterial vaginosis (BV). Oral metronidazole is currently recommended treatment. However, cure rate is variable. Probiotic supplementation was explored as alternative therapy. This study aimed to find out the effect of oral microencapsulated Lactobacillus plantarum IS-10506 supplementation on oral metronidazole 500 mg twice daily for the treatment of BV. Methods Twenty nine females with BV were treated with oral metronidazole and randomized into probiotic (Pro) (n=14) and placebo (Pla) (n=15) groups. Pro group received microencapsulated L. plantarum IS-10506 supplementation at 0.9x10⁹ CFU, twice daily. Pla group received placebo twice daily. Cure is defined from Amsel criteria and Nugent score 0-3. Metronidazole was stopped if subjects were cured. Probiotic and placebo were continued for 4 weeks. Cure rate and mean Nugent score were assessed at baseline, end of week 1, 2 and 4. Results Mean Nugent score for Pro against Pla group were 8.07 vs. 8.07, 5.36 vs. 6.20, 4.07 vs. 4.93, and 3.57 vs. 4.33 respectively at baseline, end of week 1, 2 and 4. Cure rate for Pro against Pla group were 28.6% vs 20.0%, 50.0% vs 33.3%, 64.3% vs 40.0% respectively at end of week 1, 2 and 4. Mean Nugent score significantly decreased in both groups at end of week 1, 2 and 4 (p≤0.05). Although not statistically significant, mean Nugent score was lower and cure rate was higher in Pro than Pla group at end of week 1, 2 and 4 (p>0.05). No adverse effect was recorded. Conclusion Oral probiotic L. plantarum IS-10506 supplementation in addition to oral metronidazole was safe and potentially better than oral metronidazole alone for the treatment of BV. Studies with longer probiotic supplementation and more subjects may be required to demonstrate significant effect of this combination treatment on BV.