O-264 Vaginal Microbiota Transplantation (VMT) for treatment of vaginal dysbiosis without the use of antibiotics – A Randomized Controlled Trial in healthy women with vaginal dysbiosis

The vaginal microbiota impact of antibiotic and probiotic compounds and point-of-care testing for vaginal dysbiosis and sexually transmitted infections

Vaginal microbiota dysbiosis and bacterial vaginosis (BV) affect negatively women’s health. Understanding vaginal microbiota fluctuations in BV during and after antibiotic treatment would facilitate accurate decision-making on the treatment regimen, avoid unnecessary antibiotic use, and potentially mitigate recurrence. We investigated vaginal microbiota composition of 30 women with BV before and after 5-day metronidazole treatment and compared the results with 30 healthy women. Vaginal microbiota was assessed by Nugent score and analyzed by 16S rRNA gene sequencing in swabs on baseline Day 1, and on Day 8 and 15, after completion of antibiotic treatment by women with BV. Prior to antibiotic treatment (Day 1), BV-positive women were dominated by Lactobacillus iners (25.8%), Prevotella timonensis/bivia (18.0%), and Gardnerella vaginalis (14.6%), whereas healthy women were dominated by L. iners (37.5%) and Lactobacillus crispatus/acidophilus (19.2%). On Day 8, L. iners abundance increased in BV-treated women being significantly higher compared with healthy women (67.8% vs. 37.5%, p = 0.049). On Day 15, the relative abundance of all microbial taxa was similar between the groups. Vaginal microbiota of women with BV shifted to resemble that of healthy controls after metronidazole. Sequencing analysis provides more in-depth understanding of changes in vaginal microbiota. The role of L. iners in vaginal health and dysbiosis requires further investigations.

BackgroundFifteen longitudinal studies have shown associations between bacterial vaginosis and high risk human papillomavirus (hrHPV) acquisition and/or persistence, and/or cervical dysplasia. However, few studies assessed the vaginal microbiota (VMB) comprehensively,...

Antibiotic-free vaginal microbiota transplant with donor engraftment, dysbiosis resolution and live birth after recurrent pregnancy loss: a proof of concept case study

Background: Vaginal microbiota dysbiosis could lead to the vaginal health conditions. This imbalance in vaginal microbiota can be due to a number of factors including contraceptive methods. Objective: This study was carrried out to investigate the vaginal microbiota dysbiosis and associated vaginal health outcomes among women under contraception at Musasa health Center. Materials and Methods: This was a cross sectional study. 56 vaginal swab samples were collected from women enrolled in a family planning program, and transported to INES Ruhengeri clinical microbiology laboratory for vaginal microbial community analysis. The outcomes were evaluated by scheduled interviews. Chi square test was used to evaluate association of microbiota imbalances in the vagina and the vaginal health outcomes. Results: Lactobacilli (92.85%) was the most predominant microorganism observed in the vagina. Outcomes of the vaginal microbiota dysbiosis under different contraceptive regimes were observed. Vaginal microbial community imbalance in different family planning methods was statistically significant (x2 = 36.5, P = 0.049048) to be associated with vaginal health outcomes such as bacterial vaginosis, urinary tract infections, candidiasis and vaginitis. The association with contraceptives contraceptive methods and vaginal microbial community dysbiosis was statistically significant (x2 = 96.2403, P = 0.000491). The Implant for 5 years and Intrauterine device (IUD) were statistically significant (x2 = 28.533, P = 0.002681 and x2 = 27, P = 0.004595 respectively) to contribute to the vaginal microbiota balance. Conclusion: This study established that family planning methods could cause vaginal dysbiosis thereby exposing the vagina to adverse health outcomes and poor reproductive health. Women undergoing family planning should seek medical support if any sign of vaginal infection is observed.

Study question What is the relationship between self-reported vaginal symptoms and the composition of the vaginal microbiome? Summary answer Our study reveals a complex and multifactorial relationship between vaginal symptoms and the composition of the vaginal microbiome. What is known already Vaginal dysbiosis (VD) is a microbial condition characterized by the absence of beneficial lactobacilli and the presence of pathogenic bacteria in the vagina. VD is associated with elevated risks of sexually transmitted infections, preterm birth, pregnancy loss, infertility, and suboptimal outcomes in in vitro fertilization. Clinical manifestations often include increased vaginal discharge and malodour, although it’s noteworthy that a substantial proportion of women with VD remain asymptomatic, which makes diagnosing these women challenging. Study design, size, duration Our study was conducted as part of a Double-Blinded Randomized Controlled Trial (RCT) evaluating Vaginal Microbiota Transplantation (VMT) as a novel approach for treating vaginal dysbiosis without antibiotics. This study included 263 women aged 18-40 years. Participants/materials, setting, methods We employed shotgun metagenomic sequencing to analyse the vaginal microbiome on cycle day 10+/-2 days. Moreover, we collected data on vaginal symptoms, hormonal contraceptive use, and sexual behaviour. Main results and the role of chance Among the 263 participants, 65% exhibited eubiotic microbiomes, 23% had dysbiotic microbiomes, and 12% had intermediate microbiomes. Vaginal symptoms were reported by 33%, while 63% remained symptom-free. In terms of dominance, L. crispatus dominated in 40% of samples, followed by L. iners (30%) and G. vaginalis (9.1%). In symptomatic women, L. iners (22%) and L. crispatus (21%) were common taxa, while asymptomatic women showed higher prevalence of these taxa: L. crispatus (50%) and L. iners (34%). Symptoms analysis showed two significant clusters dominated by L. crispatus or L. iners, along with smaller dysbiotic clusters led by G. vaginalis and F. vaginae. Dysbiotic samples exhibited higher rates of increased discharge and malodor, while stinging and itching were more prevalent in eubiotic samples. Positive associations were noted between specific microbial taxa and distinct symptoms. Exploring external factors, contraceptive use revealed weak associations with microbial changes. Sexual behavior patterns also influenced microbial composition, notably in women with varying numbers of male sexual partners within the last 3 months. These findings provide valuable insights into the intricate interactions between vaginal microbiota, symptoms, and external factors, shedding light on the complex landscape of vaginal dysbiosis. Limitations, reasons for caution Our study is limited by the cross-sectional design, and causality cannot be inferred. Self-reporting of symptoms may introduce bias. Additionally, our findings may not be generalizable to all populations sin the majority of the women in our cohort are younger and likely to have higher education Wider implications of the findings Our findings highlight the complexity of VD symptomatology and underscore the need for further research into the relationship between vaginal symptoms, microbiota and clinical outcomes. Trial registration number NCT04855006

Vaginal microbiota transplantation for treatment of vaginal dysbiosis without the use of antibiotics: a double-blind, randomised controlled trial in women with vaginal dysbiosis.

To carry out longitudinal observation of the changes in vaginal microbiota from pre-pregnancy to the postpartum period. The present study enrolled 80 healthy Chinese women of childbearing age, following them up from pre-pregnancy to the postpartum period. Vaginal secretions were obtained from each of the women to determine bacterial density, bacterial diversity, dominant bacteria, vaginal pH, and Nugent score, by conducting direct microscopy, microscopic examination of Gram-stained samples, and pH test. The vaginal microbiota was classified diagnostically into normal flora, flora inhibition, vulvovaginal candidiasis, bacterial vaginosis, bacterial vaginosis + vulvovaginal candidiasis, and dysbacteria. The associations between the outcomes of both pregnancy and birth and the changes of vaginal microbiota were analyzed by SPSS. Statistically significant differences in vaginal pH, diversity/density, dominant bacteria, and Nugent scoring were see across five time points, ranging from pre-pregnancy to the postpartum period (F = 1307.91, P < 0.01; χ2 = 417.02, P < 0.01; χ2 = 402.04, P < 0.01; and χ2 = 24.62, P = 0.02; respectively). For pathogenic bacteria, fungi were examined at four of the five stages, not including pre-pregnancy. Significant differences were found between the five samples with respect to vaginal microbiota state, including normal, inhibition, and dysbiosis (χ2 = 416.971, P < 0.01). There were no statistically significant differences in the incidence of vaginal dysbiosis between different time points (all P > 0.05). From pre-pregnancy to late pregnancy, 20 women (25%) maintained normal vaginal microbiota throughout the whole period, while 60 (75%) underwent a dynamic change of vaginal microbiota starting from the early-pregnancy period. By comparing the outcomes of pregnancy between the normal and dysbiosis groups, no significant differences were found in terms of premature rupture of membranes, premature birth, infection, and cesarean section (all P > 0.05). Comparing the outcomes among newborns between the normal and dysbiosis groups at term, no significant differences were found in macrosomia, fetal growth restriction, neonatal jaundice, neonatal infection, and neonatal referral rate (all P > 0.05). In Chinese women, vaginal microbiota during gestation period undergoes dynamic change. Vaginal pH, diversity/density, dominant bacteria, and Nugent score at five time points were significantly different. Vaginal microbiota states, including normal, inhibition, and dysbiosis, were significantly different between the five sampling points. Whether the vaginal microbiota is normal or not is not related to pregnancy and newborn outcomes.

Background & objectives:The vaginal microbiota undergoes subtle changes during pregnancy and may affect several aspects of pregnancy outcomes. There has been no comprehensive study characterizing the gestational vaginal and gut microbiota and the dynamics of the microbiota with oral probiotics among Indian women. Hence, the study was aimed to explore the microbiota of pregnant women with normal microbiota and bacterial vaginosis (BV) environments and the effect of oral probiotics on the microbiota and the BV status in these women.Methods:Using high-throughput Illumina-MiSeq sequencing approach, the 16S rRNA gene amplicons were analyzed and the vaginal and gut microbiota of pregnant women with and without BV and pre- and post-probiotics (Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14) intervention for a month was characterized.Results:The study revealed a compositional difference in the vaginal and gut microbiota between BV and healthy pregnant women. The vaginal microbiota of healthy women was characteristically predominated by Lactobacillus helveticus, followed by L. iners and L. gasseri; in contrast, women positive for BV harboured higher α-diversity and had lower abundance of L. helveticus. Similarly, Prevotella copri, a gut microbe, associated with normal environment was detected in the vaginal samples of all pregnant women without BV, it remained undetected in women with the infection, while all women with BV had Gardnerella vaginalis, which decreased significantly with probiotic treatment. Gut microbiota also revealed dominant abundance of P. copri in healthy women, whereas it was significantly lower in women with BV. The bacterial clade, P. copri abundance increased from 9.17 to 16.49 per cent in the probiotic group and reduced from 7.75 to 4.84 per cent in the placebo group.Interpretation & conclusions:This study showed gestational vaginal and gut microbiota differences in normal and BV environments. With probiotic treatment, the dynamics of L. helveticus and P. copri hint towards a possible role of probiotics in modulating the vaginal microbiota.

Study question What role does the seminal microbiome play in the recovery of vaginal eubiosis after pharmacological treatment for dysbiosis in women? Summary answer Seminal bacterial communities may influence treatment effectiveness; higher relative abundance of Lactobacillus correlates with better response, while Staphylococcus is linked to non-response. What is known already Advances in sequencing technologies have enabled a more accurate characterization of the vaginal microbiome, linking a non-Lactobacillus-dominated microbiome to adverse outcomes, such as preterm birth, bacterial vaginosis or recurrent implantation failure. Additionally, some studies suggest that seminal microbiota composition is associated with low sperm quality. Pharmacological treatments aimed at restoring reproductive tract eubiosis could be crucial to achieving a successful pregnancy and full-term live birth. However, in some cases, treatments fail, limiting its potential benefits for reproductive health. To our knowledge, this is the first study to assess the influences of the partner’s microbiome on vaginal microbiome restoration after treatment. Study design, size, duration A prospective study was conducted between February 2021 and July 2024, involving forty-three couples undergoing reproductive treatment. Women with dysbiotic vaginal microbiomes received pharmacological treatment, including antibiotics and/or probiotics, to restore eubiosis. Following treatment, the vaginal microbiome of the women and the seminal plasma microbiome of their male partners were analysed. Females were divided into two groups based on whether vaginal eubiosis was successfully restored post-treatment, and microbiome compositions of the two partners were compared. Participants/materials, setting, methods For microbiome analysis, vaginal samples were collected from female participants using a sterile swab, while for males, semen samples were obtained through masturbation. Additionally, a seminogram was performed, and male participants completed a lifestyle habits questionnaire. Microbiomes were analysed by mass sequencing of the V3V4 region of 16S rRNA gene. The statistical analysis was conducted with R Statistical Software and bioinformatics analysis was performed using QIIME2, Phyloseq and MicrobiomeAnalyst packages. Main results and the role of chance Twenty-one women achieved a normal vaginal microbiome pattern after pharmacological treatment (recovered group), whereas twenty-two did not (non-recovered group). Recovery was defined as a Lactobacillus-dominated microbiota (abundance &amp;gt;90%). A descriptive analysis of male participants’ physical characteristics and lifestyle factors—such as age, weight, height, and smoking status—revealed no significant differences between the two groups. Similarly, semen quality parameters, including sperm count, morphology, and motility, were comparable. While the vaginal microbiome showed a relatively homogeneous composition, seminal microbiomes were characterized by low relative abundance and high diversity of genera. Comparison of seminal plasma microbiome composition between the recovered and non-recovered groups revealed no significant differences in alpha diversity, as measured by the Shannon (p = 0.69) and Simpson (p = 0.56) indexes, nor in beta diversity (p = 0.56). However, significant differences were observed in the relative abundance of specific bacterial genera. Seminal microbiomes in the recovered group exhibited a higher relative abundance of Lactobacillus compared to the non-recovered group (42.01% vs. 2.55%; p = 7.78 × 10-8), while the non-recovered group showed a greater relative abundance of Staphylococcus (12.51% vs. 1.02%; p = 0.001). These findings suggest that the composition of the seminal microbiome may influence vaginal microbiome recovery after treatment. Limitations, reasons for caution Limitations include the small sample size, variations in patients' lifestyle habits, and differences in the pharmacological treatments administered. Future prospective studies addressing treatment strategies for both women and men are warranted. Moreover, employing a metagenomic approach could provide deeper insights by identifying functional bacterial groups enabling a more comprehensive analysis. Wider implications of the findings The findings highlight a significant interaction between the vaginal and seminal microbiomes, suggesting their potential role in restoring bacterial eubiosis in the female reproductive tract. Consequently, a comprehensive approach that considers both the vaginal and seminal microbiomes could be critical for optimizing reproductive outcomes. Trial registration number No

STUDY QUESTIONHow does hormonal contraceptive use and menstrual cycle phase affect the female microbiome across different body sites?SUMMARY ANSWERThe menstrual cycle phase, but not hormonal contraceptive use, is associated with the vaginal and oral but not the gut microbiome composition in healthy young women.WHAT IS KNOWN ALREADYWomen with low vaginal levels of Lactobacillus crispatus are at increased risk of pre-term birth, fertility treatment failure, sexually transmitted infections and gynaecological cancers. Little is known about the effect of hormonal fluctuations on other body site’s microbiomes as well as the interplay between them.STUDY DESIGN, SIZE, DURATIONThis study includes a cohort of 160 healthy young Danish women using three different contraceptive regimens: non-hormonal methods (n = 54), combined oral contraceptive (COC, n = 52) or levonorgestrel intrauterine system (LNG-IUS, n = 54). Samples were collected from four body sites during the menstrual cycle (menses, follicular and luteal phases) at Copenhagen University Hospital, Rigshospitalet, Denmark.PARTICIPANTS/MATERIALS, SETTING, METHODSThe oral, vaginal, rectal and faecal microbiomes were characterized by shotgun sequencing. Microbial diversity and community distance measures were compared between study groups, menstrual phase timepoints and body sites. All participants answered an extensive questionnaire on current health, lifestyle and sex life. Confounding factors such as smoking, BMI and diet were analysed by PERMANOVA. Plasma oestradiol and progesterone levels are correlated with microbiome composition.MAIN RESULTS AND THE ROLE OF CHANCEThe use of COC and LNG-IUS was not associated with the microbiome composition or diversity. However, increased diversity in the vaginal microbiome was observed during menses, followed by a subsequent expansion of Lactobacillus spp. during the follicular and luteal phases which correlated with measured serum oestradiol levels (r = 0.11, P < 0.001). During menses, 89 women (58%) had a dysbiotic vaginal microbiome with <60% Lactobacillus spp. This declined to 49 (32%) in the follicular phase (P < 0.001) and 44 (29%) in the luteal phase (P < 0.001). During menses, bacterial richness and diversity in saliva reached its lowest point while no differences were observed in the faecal microbiome. The microbiome in different body sites was on average more similar within the same individual than between individuals, despite phase or hormonal treatment. Only the vagina presented a clear cluster structure with dominance of either L. crispatus, Lactobacillus iners, Gardnerella vaginalis or Prevotella spp.LARGE SCALE DATAThe microbiome samples analysed in this study were submitted to the European Nucleotide Archive under project number PRJEB37731, samples ERS4421369–ERS4422941.LIMITATIONS, REASONS FOR CAUTIONThe cohort is homogenous which limits extrapolation of the effects of ethnicity and socio-economic status on the microbiome. We only present three defined timepoints across the menstrual phase and miss potential important day to day fluctuations.WIDER IMPLICATIONS OF THE FINDINGSThe use of hormonal contraception did not significantly associate with the microbiome composition in the vagina, faeces, rectum or saliva in healthy young women. This is a welcome finding considering the widespread and prolonged use of these highly efficient contraceptive methods. The menstrual cycle is, however, a major confounding factor for the vaginal microbiome. As such, the time point in the menstrual cycle should be considered when analysing the microbiome of women of reproductive age, since stratifying by vaginal dysbiosis status during menstruation could be misleading. This is the first study to confirm by direct measurements of oestradiol, a correlation with the presence of L. crispatus, adding evidence of a possible hormonal mechanism for the maintenance of this desirable microbe.STUDY FUNDING/COMPETING INTEREST(S)This work was partly funded by the Ferring Pharmaceuticals through a research collaboration with The Centre for Translational Microbiome Research (CTMR) at the Karolinska Institutet (L.W.H., E.F., G.E. and I.S.-K.). Ferring Pharmaceuticals also funded the infrastructure to obtain the clinical samples at Copenhagen University Hospital ([#MiHSN01], M.C.K., Z.B., and H.S.N.). This work was also supported by funding from Rigshospitalet’s Research Funds ([#E-22614-01 and #E-22614-02] to M.C.K.) and Oda and Hans Svenningsen’s Foundation ([#F-22614-08] to H.S.N.). M.C.K., L.W.H., E.F., Z.B., G.E., L.E., I.S.-K. and H.S.N., are partially funded by Ferring Pharmaceuticals, which also provided funds for the collection and processing of the samples analysed in this study. H.S.N.’s research is further supported by Freya Biosciences and the BioInnovation Institute. H.S.N. has received honoraria from Ferring Pharmaceuticals, Merck A/S, Astra-Zeneca, Cook Medical and Ibsa Nordic. A.N.A. reports no competing interests.

Study question Is the vaginal or faecal microbiome different between primary RPL (pRPL) and secondary RPL (sRPL) patients, and is it related to reproductive outcome after referral? Summary answer Before pregnancy, the vaginal microbiome differed between pRPL and sRPL, and the faecal microbiome was altered in those who did not achieve pregnancy after follow-up. What is known already RPL is a heterogeneous condition leaving 50% of the couples without any known risk factors after the initial diagnostic workup. The microbiome of the reproductive tract seems to be an essential factor in women’s health, including pregnancy loss. Only a few studies have investigated the vaginal microbiome in women with RPL and found dysbiosis with a decrease in Lactobacillus crispatus. To our knowledge, the faecal microbiome in women with RPL has never been investigated. Study design, size, duration A prospective cohort study including 106 women referred with unexplained RPL between 04/2018 and 12/2019. Patients were routinely screened for established risk factors as recommended in the ESHRE RPL guideline. Exclusion criteria were &amp;gt;40 years, &amp;gt;1 shared child, the use of antibiotics, antimycotics and antiviral medication within the past two weeks, known chromosomal aberrations and major uterine malformations. Follow-up ranged between 12-31 months. Participants/materials, setting, methods The women were referred with a minimum of three unexplained consecutive pregnancy losses (64 pRPL and 42 sRPL) to the tertiary Recurrent Pregnancy Loss Unit at Copenhagen University Hospital (Rigshospitalet and Hvidovre Hospital), Denmark. Vaginal and faecal samples were collected before pregnancy and shot-gun sequenced on a DNBSEQ-G400 sequencer (MGI) using the high-throughput sequencing set (PE150 1000016952; MGI). Main results and the role of chance The beta diversity in the vaginal samples was significantly different (p = 0.001) between pRPL and sRPL, with Lactobacillus crispatus dominating more women with pRPL compared to sRPL who were dominated by Lactobacillus iners. Overall, twenty-nine patients (27.3% of the cohort) had vaginal dysbiosis defined as &amp;lt; 60% Lactobacillus spp. with no significant difference between pRPL and sRPL (vaginal dysbiosis in 21.8% vs. 35.7%, p = 0.118). During follow-up, 93 (87.7%) patients achieved pregnancy of which 50 (53.8%) resulted in a live birth and 43 (46.2%) in another pregnancy loss. There were no differences in age, BMI, alpha or beta diversity in the vaginal samples between the live birth group and pregnancy loss group. In the live birth group, 11 patients (22.0%) had vaginal dysbiosis compared with 32.1% of the rest of the cohort, p = 0.242. Ninety-three of 106 women collected a faecal sample at home after the first consultation and there was a significant difference in both alpha diversity (p = 0.014), beta diversity (p = 0.05) and richness (p = 0.001) between women who achieved pregnancy compared with those who did not conceive after follow-up. Limitations, reasons for caution Patients with recurrent pregnancy loss constitute a heterogenic population, which underlines the importance of subgroup comparisons such as pRPL and sRPL. Wider implications of the findings These findings underline the role of an altered vaginal and faecal microbiome as a potential risk factor for RPL. In-depth knowledge about the altered microbiome compositions in these patients can contribute to the generation of future treatment strategies and potentially improve patient care. Trial registration number not applicable

The vaginal microbiome undergoes dramatic shifts before and throughout pregnancy. Although the genetic and environmental factors that regulate the vaginal microbiome have yet to be fully elucidated, high-throughput sequencing has provided an unprecedented opportunity to interrogate the vaginal microbiome as a potential source of next-generation therapeutics. Accumulating data demonstrates that vaginal health during pregnancy includes commensal bacteria such as Lactobacillus that serve to reduce pH and prevent pathogenic invasion. Vaginal microbes have been studied as contributors to several conditions occurring before and during pregnancy, and an emerging topic in women's health is finding ways to alter and restore the vaginal microbiome. Among these restorations, perhaps the most significant effect could be preterm labor (PTL) prevention. Since bacterial vaginosis (BV) is known to increase risk of PTL, and vaginal and oral probiotics are effective as supplemental treatments for BV prevention, a potential therapeutic benefit exists for pregnant women at risk of PTL. A new method of restoration, vaginal microbiome transplants (VMTs) involves transfer of one women's cervicovaginal secretions to another. New studies investigating recurrent BV will determine if VMTs can safely establish a healthy Lactobacillus-dominant vaginal microbiome. Inmost cases, caution must be taken in attributing a disease state and vaginal dysbiosis with a causal relationship, since the underlying reason for dysbiosis is usually unknown. This review focuses on the impact of vaginal microflora on maternal outcomes before and during pregnancy, including PTL, gestational diabetes, preeclampsia, and infertility. It then reviews the clinical evidence focused on vaginal restoration strategies, including VMTs.

The aim of the research is to determine the effect of the probiotic preparation «Dialak» (dietary supplement), which includes the strain Lactobacillus casei IMV B-7280, on the vaginal microbiota and humoral immunity in women with bacterial vaginosis (BV). Methods. 40 female patients aged 20—45 years with disturbed vaginal microbiota and 10 healthy individuals were examined. The verification of 3 types of vaginal biocenosis states, namely normocenosis, intermediate type, and vaginal dysbiosis, was carried out on the basis of the Recommendations for the Treatment of Sexually Transmitted Infections Weekly Morbidity and Mortality Report (2021) and laboratory diagnostic methods according to the well-known criteria proposed by R. Amsel. Female patients with an intermediate type of BV (group 1) received suppositories and capsules of the probiotic (once daily) for 10 days. Women with vaginal dysbiosis (group 2) received metronidazole in a dosage of 500 mg twice a day for 7 days during the first stage, and then 1 suppository at night and oral capsules of the probiotic in the morning for 10 days during the second stage. The studied vaginal secretion was stained by the Gram method in the Kopeloff modification and also sown on nutrient media to determine facultatively anaerobic and obligately anaerobic microorganisms. Microorganism identification was carried out on the basis of morphological, cultural, biochemical, and antigenic properties according to the classification of D. H. Bergey (2009). The activity of humoral immunity was determined by evaluating the number of B-lymphocytes in the peripheral blood of patients using flow cytometry, as well as the levels of serum Ig A, M, and G before treatment and aft er 1 month using the immunoturbidimetric method and the Cobas 6000 test system from Roche Diagnostics (Switzerland). Results. When analyzing the vaginal microbiota in two groups of patients before treatment, a decrease in the number of Lactobacillus spp. and Bifidobacterium spp. and a significant increase in the number of obligate anaerobic microorganisms, including Gardnerella vaginalis, were found compared to the control group. Before treatment, the number of Lactobacillus spp. in women of group 2 was lower compared to group 1. In patients with vaginal dysbiosis before treatment, the number of obligate anaerobic microorganisms was higher than in patients with bacterial vaginosis, except for Eubacterium spp. At the same time, in women in both comparison groups, the indicators of the humoral immune response were partially disrupted, as evidenced by a decrease in the level of IgG and IgA (in women of group 2) in the serum against the normal level of B lymphocytes (CD19+ cells). However, these patients showed an increase in the IgM level in the serum, which may be due to the development of anaerobic microflora. After treatment, the number of Lactobacillus spp. and Bifidobacterium spp. in the vagina of women in both comparison groups increased compared to the indicators before treatment. However, the number of these bacteria in the vagina of patients with dysbiosis remained lower compared to patients with BV. In both groups, normalization of the number of obligate anaerobic microorganisms, including G. vaginalis, except for Veillonella spp., was also observed. After treatment, the humoral immune response indicators were normalized as well: the level of serum IgG and IgA increased, and the content of serum IgM decreased. Conclusions. In BV patients, the probiotic «Dialak» normalizes the vaginal microbiota, which was confirmed by increasing the number of Lactobacillus spp. and Bifidobacterium spp. along with decreasing the number of anaerobic microorganisms, including G. vaginalis, against the background of the dynamic disappearance of clinical signs of the disease, as well as restoration to the normal level of indicators of the immunity humoral link. The obtained data indicate the effective therapeutic effect of the probiotic «Dialak» on BV.

The human microbiome exhibits intricate populations across the body, with the vaginal tract serving as an ecosystem characterized by the prevalence of the genus Lactobacillus. Disruptions in the vaginal microbiota, which are frequently linked to variables such as sexual activity, hormonal fluctuations, and excessive use of antibiotics, can result in vaginal dysbiosis and the development of diseases such as bacterial vaginosis (BV) and candidiasis. Lactobacillus species, owing to their capacity to create an acidic environment through the production of lactic acid, have a key function within this complex microbial community: they inhibit the growth of harmful microorganisms. This study aimed to investigate the genomic characteristics of L. rhamnosus LR6, a newly discovered strain isolated from the vaginal microbiota of 20 healthy women to assess its potential as a vaginal probiotic. We performed a comparative investigation of the genetic traits of L. rhamnosus using 45 publicly available genomes from various sources. We evaluated the genetic characteristics related to carbohydrate utilization, adhesion to host cells, and the presence of bacteriocin clusters. A comprehensive study was conducted by integrating in silico evaluations with experimental techniques to authenticate the physiological characteristics of strain LR6. We further used a rat model to assess the impact of L. rhamnosus LR6 administration on the changes in the gastrointestinal tract and the vaginal microbiome. The assessments revealed a significantly high inhibitory activity against pathogens, enhanced adherence to host cells, and high lactic acid production. Rat experiments revealed changes in both the fecal and vaginal microbiota; in treated rats, Firmicutes increased in both; Lactobacillaceae increased in the fecal samples; and Enterobacteriaceae decreased but Enterococcaceae, Streptococcaceae, and Morganellaceae increased in the vaginal samples. The study results provide evidence of the genetic characteristics and probiotic properties of LR6, and suggest that oral administration of L. rhamnosus LR6 can alter both gut and vaginal microbiome. Collectively, these findings establish L. rhamnosus LR6 as a highly promising candidate for improving vaginal health.