The maintenance of healthy vaginal microbiota is important for optimal pregnancy outcomes. Lactobacillus protects the vagina from pathogenic organism by producing antimicrobial agents such as hydrogen peroxide and bacteriocins , maintaining the vaginal PH through lactic acid production , and by immune modulation. Bacterial vaginosis is associated with premature labor, premature rupture of membranes, spontan abortion, and chorioamnioitis . Maternal infections are associated with % 30-50 of preterm labours. Bacterial vaginosis treatment study showed that a combination of orally administered lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 and metronidazole doubled the cure rate compared to metronidazole alone . Usually maternal Group B streptococus is asymptomatic , however it can cause endometritis, chorioamnioitis, and bacteriemi in pregnant women and may cause stillbirth and is the leading cause of early onset Group B septicemia and menengitis in infants . Lactobacilli have been shown to have inhibitory effects on GBS growth and vaginal lactobacillus counts from pregnanat women are inversely related to vaginal GBS colonization.