A cross-sectional pilot study of birth mode and vaginal microbiota in reproductive-age women

Study information

Reviewed Marked as Reviewed by Fatima on 2023-6-8

study design

cross-sectional observational, not case-control

Citation

PMID PubMed identifier for scientific articles.

32236123

DOI Digital object identifier for electronic documents.

10.1371/journal.pone.0228574

URI

Authors

Stennett CA, Dyer TV, He X, Robinson CK, Ravel J, Ghanem KG, Brotman RM

Journal

PloS one

Year

2020

Recent studies suggest that birth mode (Cesarean section [C-section] or vaginal delivery) is an important event in the initial colonization of the human microbiome and may be associated with long-term health outcomes. We sought to determine the association between a woman's birth mode and her vaginal microbiota in adulthood. We re-contacted 144 adult women from two U.S. studies and administered a brief survey. Vaginal microbiota was characterized on a single sample by amplicon sequencing of the V3-V4 hypervariable regions of the 16S rRNA gene and clustered into community state types (CSTs). We evaluated the association between birth mode and a CST with low relative abundance of Lactobacillus spp. ("molecular bacterial vaginosis" [Molecular-BV]) compared to Lactobacillus-dominated CSTs in logistic regression modeling which adjusted for body mass index, a confounder in this analysis. Twenty-seven women (19%) reported C-section. Overall, C-section showed a non-significant trend towards increased odds of Molecular-BV (aOR = 1.22, 95% CI: 0.45, 3.32), and Prevotella bivia was the strongest single taxa associated with C-section. However, because the two archived studies had different inclusion criteria (interaction p = 0.048), we stratified the analysis by study site. In the study with a larger sample size (n = 88), women born by C-section had 3-fold higher odds of Molecular-BV compared to vaginally-delivered women (aOR = 3.55, p = 0.06, 95% CI: 0.97-13.02). No association was found in the smaller study (n = 56, aOR = 0.19, p = 0.14, 95% CI: 0.02-1.71). This pilot cross-sectional study suggests a possible association between C-section and Molecular-BV in adulthood. However, the analysis is limited by small sample size and lack of comparability in participant age and other characteristics between the study sites. Future longitudinal studies could recruit larger samples of women, address the temporal dynamics of vaginal microbiota, and explore other confounders, including maternal factors, breastfeeding history, and socioeconomic status, which may affect the relationship between birth mode and vaginal microbiota.

Experiment 1

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Reviewed Marked as Reviewed by Fatima on 2023-6-8

Curated date: 2023/06/01

Curator: Danyab56

Revision editor(s): Danyab56

Subjects

Location of subjects: United States of America

Host species Species from which microbiome was sampled. Contact us to have more species added.: Homo sapiens

Body site Anatomical site where microbial samples were extracted from according to the Uber Anatomy Ontology: Vaginal fluid Vaginal discharge,Vaginal secretion,Vaginal fluid,vaginal fluid

Condition The experimental condition / phenotype studied according to the Experimental Factor Ontology: Bacterial vaginosis BACT VAGINITIDES,BACT VAGINITIS,BACT VAGINOSES,BACT VAGINOSIS,Bacterial Vaginitides,Bacterial Vaginitis,Bacterial Vaginoses,bacterial vaginosis,BV,Nonspecific Vaginitis,VAGINITIDES BACT,Vaginitides, Bacterial,VAGINITIS BACT,Vaginitis, Bacterial,Vaginitis, Nonspecific,VAGINOSES BACT,Vaginoses, Bacterial,VAGINOSIS BACT,Vaginosis, Bacterial,Bacterial vaginosis

Group 0 name Corresponds to the control (unexposed) group for case-control studies: vaginal delivery

Group 1 name Corresponds to the case (exposed) group for case-control studies: cesarean section

Group 1 definition Diagnostic criteria applied to define the specific condition / phenotype represented in the case (exposed) group: women reported birth by C-section

Group 0 sample size Number of subjects in the control (unexposed) group: 117

Group 1 sample size Number of subjects in the case (exposed) group: 27

Antibiotics exclusion Number of days without antibiotics usage (if applicable) and other antibiotics-related criteria used to exclude participants (if any): women reported birth by vaginal delivery

Lab analysis

Sequencing type: PCR

16S variable region One or more hypervariable region(s) of the bacterial 16S gene: Not specified

Sequencing platform Manufacturer and experimental platform used for quantifying microbial abundance: Illumina

Statistical Analysis

Data transformation Data transformation applied to microbial abundance measurements prior to differential abundance testing (if any).: relative abundances

Statistical test: LEfSe

MHT correction Have statistical tests be corrected for multiple hypothesis testing (MHT)?: No

LDA Score above Threshold for the linear discriminant analysis (LDA) score for studies using the popular LEfSe tool: 4

Signature 1

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Curated date: 2023/06/01

Curator: Danyab56

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Source: Figure 2

Description: The bacterial taxa with the highest effect sizes (linear discriminant analysis [LDA] scores > 4) reflect marked abundance in one birth mode group and not in the other. Three taxa were differentially abundant at this level, with P. bivia being more abundant in C-section-delivered group and L. jensenii and L. iners being more abundant in the vaginally-delivered group. However, these differences were not statistically significant (0.05 < p < 0.30).

Abundance in Group 1: increased abundance in cesarean section

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Prevotella bivia

Revision editor(s): Danyab56

Signature 2

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Reviewed Marked as Reviewed by Fatima on 2023-6-8

Curated date: 2023/06/01

Curator: Danyab56

Revision editor(s): Danyab56

Source: Figure 2

Description: The bacterial taxa with the highest effect sizes (linear discriminant analysis [LDA] scores > 4) reflect marked abundance in one birth mode group and not in the other. Three taxa were differentially abundant at this level, with P. bivia being more abundant in C-section-delivered group and L. jensenii and L. iners being more abundant in the vaginally-delivered group. However, these differences were not statistically significant (0.05 < p < 0.30).

Abundance in Group 1: decreased abundance in cesarean section

NCBI	Quality Control	Links
Lactobacillus jensenii
Lactobacillus iners

Revision editor(s): Danyab56