Differences in Vaginal Lactobacilli Composition of Iranian Healthy and Bacterial Vaginosis Infected Women: A Comparative Analysis of Their Cytotoxic Effects with Commercial Vaginal Probiotics

Background: Vaginal flora of healthy women is dominated by Lactobacillus species which can prevent bacterial vaginosis. Objectives: The current study aimed to determine the differences in vaginal lactobacilli composition of Iranian healthy and bacterial vaginosis (BV) infected women and compared their cytotoxic effects with commercial vaginal probiotics. Patients and Methods: One hundred and seventy eight vaginal specimens were collected from healthy and BV infected women. Lactobacillus colonies were obtained by culturing on laked blood BHI and MRS medias and genetically defined by 16s rRNA sequencing. Differentiating the specimens to normal, intermediate and BV infected were carried out by Ison and Hey grading protocol. Identification of Lactobacillus strains in vaginal specimens were performed by Multiplex PCR. The inhibitory effects of lactobacilli on Hela (tumoral cervical cells) and HNCF-pi52 (normal cervical cells) were conducted by MTT and trypan blue assays. Results: L. crispatus, L. gasseri, L. iners, L. jensenii, L. acidophilus and L. rhamnosus were the most frequently occurring species in vagina of healthy Iranian women. L. crispatus and L. jensenni were significantly higher in the normal than in the BV infected groups. Also the cytotoxic effect of L. crispatus on tumoral cervical cells was higher than other lactobacilli including commercial probiotics. Conclusions: As L. crispatus and L. jensenni were significantly higher in BV infected women and the cytotoxic effect of L. crispatus on tumoral cervical cells was high, introduction of new probiotics seems necessary.