The vaginal microbiota during pregnancy (original) (raw)
Related papers
Vaginal microbiota in pregnancy: Role in induction of labor and seeding the neonate’s microbiota?
Journal of Biosciences, 2019
Compared to other human microbiota, vaginal microbiota is fairly simple with low bacterial diversity and high relative abundance of Lactobacillus species. Lactobacillus dominance is even more pronounced during pregnancy. Genetic factors, such as ethnicity, along with environmental, individual and lifestyle factors all have an impact on vaginal microbiota composition. The composition of the vaginal microbiota appears to play an important role in pregnancy as recent studies have linked it to adverse obstetric outcomes such as preterm birth, a leading cause of neonatal morbidity and mortality worldwide. However, the same vaginal microbiota does not seem to cause the same response in all women, calling for future research to fully understand the complex host-microbiota interplay in normal and complicated pregnancies.
New Techniques to characterise the vaginal microbiome in pregnancy
AIMS Microbiology, 2016
Understanding of the vaginal microbiome in health and disease is essential to screen, detect and manage complications in pregnancy. One of the major complications of pregnancy is preterm birth, which is the leading worldwide cause of death and disability in children under five years of age. The aetiology of preterm birth is multifactorial, but a causal link has been established with infection. Despite the importance of understanding the vaginal microbiome in pregnancy in order to evaluate strategies to prevent and manage PTB, currently used culture based techniques provide limited information as not all pathogens are able to be cultured. The implementation of culture-independent high-throughput techniques and bioinformatics tools are advancing our understanding of the vaginal microbiome. New methods employing 16S rRNA and metagenomics analyses make possible a more comprehensive description of the bacteria of the human microbiome. Several studies on the vaginal microbiota of pregnant women have identified a large number of taxa. Studies also suggest reduced diversity of the microbiota in pregnancy compared to non-pregnant women, with a relative enrichment of the overall abundance of Lactobacillus species, and significant differences in the diversity of Lactobacillus spp. A number of advantages and disadvantages of these techniques are discussed briefly. The potential clinical importance of the new techniques is illustrated through recent reports where traditional culture-based techniques failed to identify pathogens in high risk complicated 56 AIMS Microbiology Volume 2, Issue 1, 55-68. pregnancies whose presence subsequently was established using culture-independent, highthroughput analyses.
2020
Early life microbiota has been linked to the development of chronic inflammatory diseases. It has been hypothesized that maternal vaginal microbiota is an important initial seeding source and therefore can have lifelong effects on disease risk. To understand maternal vaginal microbiota’s role in seeding the child’s microbiota and the extent of delivery mode-dependent transmission, we studied 700 mother-child dyads from the COPSAC2010 cohort.The maternal vaginal microbiota was evaluated in the third trimester and compared with the children’s fecal and airway microbiota.The vaginal samples displayed known stable community state types and only 1:6 changed over time. Only one OTU was significantly transferred to children’s fecal compartment, but an inflated number had positive transfer odds. A few taxonomic families showed early transfer enrichment to vaginally-born children, indicating vertical transfer, while half of the observed transfer effects were delivery mode independent enrichm...
Racioethnic diversity in the dynamics of the vaginal microbiome during pregnancy
Nature Medicine
rowing evidence suggests that the impact of the vaginal microbiome extends to the health of pregnant women and their neonates in utero and beyond. The vaginal microbiome consists of a finite number of discrete microbial communities dominated by different bacterial taxa or combinations thereof 1,2. A vaginal microbiome with microbial communities dominated by species of Lactobacillus has been associated with adverse conditions of health of the female reproductive tract, whereas a microbiome dominated by complex microbial communities of Gardnerella, Atopobium, Dialister, Peptoniphilus, Lachnospiraceae members (bacterial vaginosis (BV)-associated bacterium 1 (BVAB1)) and other anaerobes 3-5 has been associated with a higher risk. A complex vaginal microbiome is associated with BV, the most common gynecological condition of women of reproductive age 6 , as well as a higher risk of sexually transmitted infection, pelvic inflammatory disease and adverse pregnancy outcomes including preterm birth (PTB) 3,5,7. More than 10% of neonates in the United States are delivered preterm (<37 weeks' gestation), and certain racial and ethnic groups have even higher rates 8-10. Women of African ancestry in the United States are significantly more likely than women of European ancestry to have a premature birth or experience very preterm delivery (<32 weeks' gestation). This health disparity could be due to differences in the vaginal microbiomes of these women as the population attributable risk of BV for spontaneous PTB at <32 weeks' gestation has been estimated to be ~40% 11. Although environmental factors, including socioeconomic status (for example, household income, access to care and so on) are known to contribute to these differences, genetic factors also play a role 12-14. Recent studies 1,2,15-23 show that the vaginal microbiomes of women of African ancestry are less likely to be dominated by species of Lactobacillus, and more likely to comprise primarily Gardnerella vaginalis, Atopobium vaginae, Sneathia amnii, BVAB1 and other anaerobes. Independent of the
Increased richness and diversity of the vaginal microbiota and spontaneous preterm birth
Microbiome, 2018
The bacterial community present in the female lower genital tract plays an important role in maternal and neonatal health. Imbalances in this microbiota have been associated with negative reproductive outcomes, such as spontaneous preterm birth (sPTB), but the mechanisms underlying the association between a disturbed microbiota and sPTB remain poorly understood. An intrauterine infection ascending from the vagina is thought to be an important contributor to the onset of preterm labour. Our objective was to characterize the vaginal microbiota of pregnant women who had sPTB (n = 46) and compare to those of pregnant women who delivered at term (n = 170). Vaginal swabs were collected from women at 11–16 weeks of gestational age. Microbiota profiles were created by PCR amplification and pyrosequencing of the cpn60 universal target region.
The vaginal microbiome and preterm birth
Nature Medicine
pproximately 15 million preterm births at less than 37 weeks of gestation occur annually worldwide 1. Preterm birth (PTB) remains the second most common cause of neonatal death across the globe, and the most common cause of infant mortality in middle-and high-income economies 2. The consequences of PTB persist from early childhood into adolescence and adulthood 3,4. In the United States, striking population differences with respect to PTB exist, with women of African ancestry having a substantially larger burden of risk. The estimated annual cost of PTB in the United States alone is over US$26.2 billion 5. Despite these statistics, there remains a paucity of effective strategies for predicting and preventing PTB. Although maternal and fetal genetics, and gene-environment interactions, clearly play roles in determining the length of gestation, environmental factors, including the microbiome, are the most important contributors to PTB, particularly among women of African ancestry 6. Microbe-induced inflammation resulting from urinary tract infection, sexually transmitted infections, including trichomoniasis, or bacterial vaginosis is thought to be a cause of PTB 7,8. Ascension of microbes 7,9 from the lower reproductive tract to the placenta, fetal membranes and uterine cavity, and hematogenous spread of periodontal pathogens from the mouth, have also been invoked to explain the up to 40-50% of preterm births that are associated with microbial etiologies 10,11. A homogeneous Lactobacillus-dominated microbiome has long been considered the hallmark of health in the female reproductive tract. In contrast, a vaginal microbiome with high species diversity, as observed with bacterial vaginosis, has been associated with increased risk for acquisition and transmission of sexually
Med, 2021
Background: Lactobacillus was described as a keystone bacterial taxon in the human vagina >100 years ago. Using metagenomics, we and others have characterized lactobacilli and other vaginal taxa across health and disease states, including pregnancy. While shifts in community membership have been resolved at the genus/species level, strain dynamics remain poorly characterized. Methods: We performed a metagenomic analysis of the complex ecology of the vaginal econiche during and after pregnancy in a large US-based longitudinal cohort of women who were initially sampled in the third trimester of pregnancy, and then validated key findings in a second cohort of women initially sampled in the second trimester of pregnancy. Findings: First, we resolved microbial species and strains, interrogated their co-occurrence patterns, and probed the relationship between keystone species and preterm birth (PTB) outcomes. Second, to deter- mine the role of human heredity in shaping vaginal microbial ecology in relation to PTB, we performed a mtDNA-bacterial species association analysis. Finally, we explored the clinical utility of metagenomics in detection and co-occurrence patterns for the pathobiont group B Streptococcus (causative bacterium of invasive neonatal sepsis). Conclusions: Our highly refined resolutions of the vaginal ecology during and post-pregnancy not only provide insights into structural and functional community dynamics but also highlight the capacity of meta- genomics to reveal the finer aspects of the vaginal microbial ecologic framework. Funding: NIH-NINR R01NR014792, NIH-NICHD R01HD091731, NIH National Children’s Study Formative Research, Burroughs Wellcome Fund Preterm Birth Initiative, March of Dimes Preterm Birth Research Initiative, and NIH-NIGMS (K12GM084897, T32GM007330, T32GM088129).
The Perinatal Microbiome and Pregnancy: Moving Beyond the Vaginal Microbiome
Cold Spring Harbor Perspectives in Medicine, 2015
The human microbiome, the collective genome of the microbial community that is on and within us, has recently been mapped. The initial characterization of healthy subjects has provided investigators with a reference population for interrogating the microbiome in metabolic, intestinal, and reproductive health and disease states. Although it is known that bacteria can colonize the vagina, recent metagenomic studies have shown that the vaginal microbiome varies among reproductive age women. Similarly, the richness and diversity of intestinal microbiota also naturally fluctuate among gravidae in both human and nonhuman primates, as well as mice. Moreover, recent evidence suggests that microbiome niches in pregnancy are not limited to maternal body sites, as the placenta appears to harbor a low biomass microbiome that is presumptively established in early pregnancy and varies in association with a remote history of maternal antenatal infection as well as preterm birth. In this article, we will provide a brief overview on metagenomics science as a means to investigate the microbiome, observations pertaining to both variation and the presumptive potential role of a varied microbiome during pregnancy, and how future studies of the microbiome in pregnancy may lend to a better understanding of human biology, reproductive health, and parturition. C ompleted in 2012, the Human Microbiome Project (HMP) characterized the microbiome composition of multiple body sites in healthy individuals of different ethnicities located in two separate cities (