Vaginal lactobacilli profile in pregnant women with normal & abnormal vaginal flora

Microbiome-Maternal Tract Interactions in Women with Recurrent Implantation Failure

Microorganisms play an important role in regulating various biological processes in our bodies. In women, abnormal changes in the reproductive tract microbiome are associated with various gynecological diseases and infertility. Recent studies suggest that patients with recurrent implantation failure (RIF) have a reduced genus Lactobacillus population, a predominant bacterial species in the vagina and uterus that protects the reproductive tract from pathogenic bacterial growth via the production of various metabolites (e.g., lactic acid, bacteriocin, and H2O2). Moreover, a higher percentage of pathogenic bacteria genera, including Atopobium, Gardnerella, Prevotella, Pseudomonas, and Streptococcus, was found in the uterus of RIF patients. This review aimed to examine the role of pathogenic bacteria in RIF, determine the factors altering the endometrial microbiome, and assess the impact of the microbiome on embryo implantation in RIF. Several factors can influence microbial balance, including the impact of extrinsic elements such as semen and antibiotics, which can lead to dysbiosis in the female reproductive tract and affect implantation. Additionally, probiotics such as Lacticaseibacillus rhamnosus were reported to have clinical potential in RIF patients. Future studies are needed to develop targeted probiotic therapies to restore microbial balance and enhance fertility outcomes. Research should also focus on understanding the mechanisms by which microorganisms generate metabolites to suppress pathogenic bacteria for embryo implantation. Identifying these interactions may contribute to innovative microbiome-based interventions for reproductive health.

Chronic Stress May Amplify Gender/Sex Differences in Amygdala Reactivity to Ambiguous Emotional Stimuli

Heightened reactivity to ambiguous emotional stimuli, such as surprized faces, is a transdiagnostic psychopathology risk factor. Women show elevated amygdala activation to ambiguous emotional stimuli relative to men, which may underlie their significantly higher risk for mood disorders. Moreover, there are sex/gender differences in the effects of stress on both emotion processing and emotion regulation, with greater impact of stress on negative emotionality in females. We predicted that chronic stress would be associated with stronger amygdala activation to surprized faces, and these effects would be amplified in girls/women. We tested the interactions of chronic stress and gender/sex on amygdala activity in a sample of 297 healthy participants (59% girls/women, age range 6-75 years) who provided a saliva sample and who viewed emotional face stimuli while undergoing functional neuroimaging. Saliva samples were assayed for two markers of chronic stress: Epstein-Barr Virus (EBV) expression and diversity of Lactobacilli species. Among girls/women, higher chronic stress was associated with greater amygdala activation to ambiguous emotional images than lower stress exposure, although this effect was not statistically significant. Counter to predictions, the reverse effect was found among boys/men (i.e., higher stress exposure was associated with lower amygdala activation). Results were similar across left and right amygdalae, and across both stress measures. Although our findings are preliminary and should be replicated, they align with findings on gender differences in valence bias, and broadly support the hypothesis that there are gender/sex differences in the effects of chronic stress on neural reactivity to emotional ambiguity, particularly in areas of the brain sensitive to emotion regulation. Possibly, stress does not universally increase negativity, but instead amplifies default emotional biases-which for boys/men, may result in less amygdala reactivity.

Bacterial vaginosis in pregnancy and early labour using Nugent scoring and the implication on foetal outcome

Background

To compare the pattern of vaginal microflora during pregnancy with pattern in early labour using Nugent scoring and determine the effect of these changes on fetal outcome.

Design

A prospective longitudinal study.

Setting and Population

Pregnant women attending antenatal clinics of Olabisi Onabanjo University Teaching Hospital, Sagamu, Nigeria between June 2017 and May 2018.

Methods

Consenting pregnant women who attended antenatal clinics were recruited. Vaginal secretions were obtained for Nugent scoring during pregnancy and at presentation in labour.

Main Outcome Measures

Prevalence of abnormal vaginal flora in pregnancy and early labour, birth outcome, birth weight, gestational age at delivery, APGAR scores, need for neonatal ward admission.

Results

Sixty-seven (33.3%) of pregnant women had abnormal flora which was consistent with bacterial vaginosis. At the presentation of these women in labour, 14.4% of them had bacterial vaginosis thus indicating a significant reduction in abnormal vaginal flora in labour compared to the proportion of abnormal flora in antenatal period (P<0.001). There were no significant differences in the fetal outcomes of mothers with bacterial vaginosis when compared with those with normal vaginal flora (P-value >0.05).

Conclusions

Persistence of abnormal vaginal microflora from pregnancy till early labour did not seem to be associated with poorer foetal outcomes when compared with women with normal vaginal microflora in labour. The possibility of persistent infection or re-infection before labour may justify the need for re-evaluation of vaginal smears in the late third trimester to allow for prompt treatment before the onset of labour.

Funding

This research work was sponsored by the Tertiary Education Trust Fund, Nigeria (TETFund) with reference number OOU/IBR/010.

Comparative genome analyses of Lactobacillus crispatus isolated from different ecological niches reveal an environmental adaptation of this species to the human vaginal environment

Vaginal microbiota is defined as the community of bacteria residing in the human vaginal tract. Recent studies have demonstrated that the vaginal microbiota is dominated by members of the Lactobacillus genus, whose relative abundance and microbial taxa composition are dependent on the healthy status of this human body site. Particularly, among members of this genus, the high prevalence of Lactobacillus crispatus is commonly associated with a healthy vaginal environment. In the current study, we assessed the microbial composition of 94 healthy vaginal microbiome samples through shotgun metagenomics analyses. Based on our results we observed that L. crispatus was the most representative species and correlated negatively with bacteria involved in vaginal infections. Therefore, we isolated fifteen L. crispatus strains from different environments in which this species is abounding, ranging from vaginal swabs of healthy women to chicken fecal samples. The genomes of these strains were decoded and their genetic content was analyzed and correlated with their physiological features. An extensive comparative genomic analysis encompassing all publicly available genome sequences of L. crispatus and combined with those decoded in this study, revealed a genetic adaptation of strains to their ecological niche. In addition, in vitro growth experiments involving all isolated L. crispatus strains together with a synthetic vaginal microbiota reveal how this species is able to modulate the composition of the vaginal microbial consortia at strain level. Overall, our findings suggest that L. crispatus plays an important ecological role in reducing the complexity of the vaginal microbiota by depleting pathogenic bacteria.Importance The vaginal microbiota is defined as the community of bacteria residing in the human vaginal tract. Recent studies have demonstrated that the high prevalence of Lactobacillus crispatus species is commonly associated with a healthy vaginal environment. In the current study, we assessed the microbial composition of 94 public healthy vaginal samples through shotgun metagenomics analyses. Results showed that L. crispatus was the most representative species and correlated negatively with bacteria involved in vaginal infections. Moreover, we isolated and sequenced the genome of new L. crispatus strains from different environments and the comparative genomics analysis revealed a genetic adaptation of strains to their ecological niche. In addition, in-vitro growth experiments display the capability of this species to modulate the composition of the vaginal microbial consortia. Overall, our findings suggest an ecological role exploited by L. crispatus in reducing the complexity of the vaginal microbiota toward a depletion of pathogenic bacteria.

Lactobacillus iners and gasseri, Prevotella bivia and HPV Belong to the Microbiological Signature Negatively Affecting Human Reproduction

Infertile couples undergoing the use of assisted reproductive technology are a good study model to evaluate the microbiological signatures affecting reproductive health. We tested vaginal lavages, follicular fluids, embryo culture mediums, and seminal fluids from 47 couples for their microbiome composition and HPV infection. Twenty-five infertile couples were diagnosed with unexplained infertility, whereas 22 were diagnosed with explained infertility. Lactobacilli were dominant in the vaginal lavages of both patient groups, and the most abundant species was L. iners (CST III), which is linked to a decreased fertility rate. Besides this, L. gasseri—which is known to be associated with oocyte DNA fragmentation and decreased sperm mobility—was identified in the seminal fluids, follicular fluids, and embryo culture media of the unexplained infertility group. Prevotella was increased in the seminal fluids of the explained infertility group, along with HPV-positive seminal fluids: an infection commonly associated with infertility, especially male infertility. Prevotella has been described to negatively affect sperm motility. Taken together, these results suggest that the profiling of the reproductive tract microbiome can add new perspectives to human reproduction.

The Disordered Vaginal Microbiota Is a Potential Indicator for a Higher Failure of in vitro Fertilization

Infertility is one of the most common reproductive system diseases, and no effective method is available for its treatment. Although in vitro fertilization (IVF) has been widely used to enhance the clinical pregnancy outcome of infertility, the unsatisfied pregnancy rate with unknown reasons is obtained. To identify the possible cause of IVF failure, 555 patients were enrolled in the present study to determine their relevant clinical characteristics and vaginal microbiota. Our results indicated that the age and endometrium thickness significantly affected the pregnancy success rate of pregnant patients (P group) and non-pregnant patients (NP group) receiving IVF, and high values of luteinizing hormone, estrogen and progesterone were observed from P group. Furthermore, the Partial Least Squares Discriminant Analysis (PLS-DA) indicated a different microbial composition in P group and NP group, and a higher microbial abundance had been identified in non-pregnant patients compared with pregnant patients. At phylum level, a higher abundance of Firmicutes and Proteobacteria, and a lower abundance of Actinobacteria, Fusobacteria, and Bacteroidetes were obtained in pregnant patients compared with non-pregnant patients. At genus level, a lower abundance of the probiotic Lactobacillus, and higher abundance of pathogens Gardnerella and Prevotella were identified from non-pregnant patients. Therefore, the disordered microbiota, characterizing by the reduction of probiotics and overgrowth of pathogens in non-pregnant patients, may be used as a potential indicator for a higher IVF failure rate.