Influence of Probiotics on the Vaginal Microbiota

Infertility is a global phenomenon affecting around 186 millions of people worldwide. Many circumstances have been identified to cause infertile conditions, with age being one of the most limiting factors. However, in recent years the microbiome has gained importance in the treatment of infertility and is considered as another important player to improve success rate of reproductive medicine treatments like in-vitro-fertilization (IVF).

Within the female reproductive tract the dominance of Lactobacilli is associated with a healthy vaginal microbial community in healthy reproductive-aged women. Since the microbiome has gained so much importance, its influence in IVF treatments is still controversially discussed. While some studies suggest a negative influence of vaginal dysbiosis on pregnancy rates a current meta-analysis showed no association between abnormal vaginal flora and conception rates following IVF treatment. One therapeutic approach is the administration of beneficial microorganisms (probiotics), mainly Lactobacillus species. The supplementation of exogenous lactobacilli strains has been suggested as cure for a dysbiotic vaginal flora to re-establish healthy conditions and improving female fertility health.

Hence, in the present study we wanted to investigate the impact of 4 probiotic strains (Lactobacillus crispatus LBV88, Lactobacillus rhamnosus LBV96, Lactobacillus gasseri LBV150N and Lactobacillus jensenii LBV116) on the relative abundance of vaginal microbiata species in women suffering from infertility.

80 infertile women suffering from infertility were included in the study within fertility treatment. 40 patients with IVF / ICSI were examined (20 with OMNi-BiOTiC® FLORA plus +, 20 as a control) and 40 patients with IUI / VZO (20 with OMNi-BiOTiC® FLORA plus +, 20 as a control). The control patients were selected from the routine patient collective of the Kinderwunsch Institut Schenk GmbH and receive no treatment with probiotics or placebo. Patients in the therapy group took 1 sachet of OMNi-BiOTiC® FLORA plus + (= 2 g) dissolved in 1/8 l of water once a day. Patients in the control group received no additional medication for routine treatment. Patients were randomized after inclusion in the study (block randomization).

On day 20 in the pre-cycle of hormonal stimulation, a vaginal smear sample was taken from the patient. The investigator introduced a sterile swab (eSwabTM, Copan Diagnostics Inc., USA), and took material from the mucosal surface. The eSwab was transferred to a sterile Falcon tube, stored at -72 ° C and then handed over to the company biovis Diagnostik MVZ GmbH (Germany) for 16s rRNA gene analysis. On day 20 in the stimulated cycle or subsequent cycle of the fertility treatment, another vaginal smear sample was taken and also stored in a sterile Falcon tube at -72 ° C.

The microbiota was determined using 16s rRNA gene analysis. The bacterial genomic DNA was isolated from the samples and the region V3-V4 was sequenced (Nextera XT, DNA Library Preparation Kit; Illumina MiSeq, Illumina, The Netherlands).