The association between ethnicity and vaginal microbiota composition in Amsterdam, the Netherlands

Abstract

ObjectiveTo evaluate whether ethnicity is independently associated with vaginal microbiota (VMB) composition in women living in Amsterdam, the Netherlands, as has been shown for American women.MethodsWomen (18–34 years, non-pregnant, N = 610) representing the six largest ethnic groups (Dutch, African Surinamese, South-Asian Surinamese, Turkish, Moroccan, and Ghanaian) were sampled from the population-based HELIUS study. Sampling was performed irrespective of health status or healthcare seeking behavior. DNA was extracted from self-sampled vaginal swabs and sequenced by Illumina MiSeq (16S rRNA gene V3-V4 region).ResultsThe overall prevalence of VMBs not dominated by lactobacilli was 38.5%: 32.2% had a VMB resembling bacterial vaginosis and another 6.2% had a VMB dominated by Bifidobacteriaceae (not including Gardnerella vaginalis), Corynebacterium, or pathobionts (streptococci, staphylococci, Proteus or Enterobacteriaceae). The most prevalent VMB in ethnically Dutch women was a Lactobacillus crispatus-dominated VMB, in African Surinamese and Ghanaian women a polybacterial G. vaginalis-containing VMB, and in the other ethnic groups a L. iners-dominated VMB. After adjustment for sociodemographic, behavioral and clinical factors, African Surinamese ethnicity (adjusted odds ratio (aOR) 5.1, 95% confidence interval (CI) 2.1–12.0) and Ghanaian ethnicity (aOR 4.8, 95% CI 1.8–12.6) were associated with having a polybacterial G. vaginalis-containing VMB, and African Surinamese ethnicity with a L. iners-dominated VMB (aOR 2.8, 95% CI 1.2–6.2). Shorter steady relationship duration, inconsistent condom use with casual partners, and not using hormonal contraception were also associated with having a polybacterial G. vaginalis-containing VMB, but human papillomavirus infection was not. Other sexually transmitted infections were uncommon.ConclusionsThe overall prevalence of having a VMB not dominated by lactobacilli in this population-based cohort of women aged 18–34 years in Amsterdam was high (38.5%), and women of sub-Saharan African descent were significantly more likely to have a polybacterial G. vaginalis-containing VMB than Dutch women independent of modifiable behaviors.

Reviewing the Composition of Vaginal Microbiota: Inclusion of Nutrition and Probiotic Factors in the Maintenance of Eubiosis

“…Here, African communities were dominated by L. iners and by a variable mixture of facultative anaerobic bacteria [24,68,81]. Similarly, in a Dutch study about the composition of vaginal microbiome it was significantly associated with ethnic groups where women from African descents had the main occurrence of clusters determined by Gardnerella vaginalis or dysbiosis [82].…”

Pathobionts in the Vaginal Microbiota: Individual Participant Data Meta-Analysis of Three Sequencing Studies

“…Sampling was stratified by ethnic group and included the six largest ethnic groups in the city (Dutch, African Surinamese, South-Asian Surinamese, Turkish, Moroccan, and Ghanaian). In a subsample, a cross-sectional study on the association of ethnicity with VMB composition was performed (Borgdorff et al, 2017). For this sub-study, vaginal samples of 546 pre-menopausal women were sequenced.…”

“…Second, each ASV/OTU was assigned to one of four "bacterial groups" based on the published literature (Supplementary Material 1) as follows: (1) lactobacilli; (2) BVanaerobes; (3) pathobionts; and (4) a rest group called "other bacteria" (which contained mostly skin and Bifidobacteria). Pathobionts were defined as all bacterial taxa that have been reported in the literature as having been associated with invasive disease, and are not typically associated with BV; we also included STI pathogens in this category because their mean relative abundances were too low to justify a separate bacterial (Borgdorff et al, 2017;van de Wijgert et al, 2020a,b). b Non-minority is defined as at least 1% in at least one sample.…”

Comparative genomics of human Lactobacillus crispatus isolates reveals genes for glycosylation and glycogen degradation: Implications for in vivo dominance of the vaginal microbiota

“…Increasing evidence has shown that the bacteria within this community, referred to here as the vaginal microbiota (VM), play an important role in protecting the vaginal tract from pathogenic infection, which can have far reaching effects on a woman’s sexual and reproductive health [1, 2]. Several VM compositions have been described, including VM dominated by: 1) Lactobacillus iners; 2) L. crispatus; 3) L. gasseri ; 4) L. jensenii and; 5) VM that are not dominated by a single bacterial species but rather consist of diverse anaerobic bacteria, including Gardnerella vaginalis and members of Lachnospiraceae and Leptotrichiaceaeprevotella [3-5]. Particularly VM that are dominated by L. crispatus are associated with vaginal health, whereas a VM consisting of diverse anaerobes – commonly referred to as vaginal dysbiosis - have been shown to increase a woman’s odds for developing bacterial vaginosis (BV), acquiring STI’s, including HIV, and having an adverse pregnancy outcome [1, 2, 4, 6].…”