Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
, 7, e8004
eCollection

Stability of the Vaginal, Oral, and Gut Microbiota Across Pregnancy Among African American Women: The Effect of Socioeconomic Status and Antibiotic Exposure

Affiliations

Stability of the Vaginal, Oral, and Gut Microbiota Across Pregnancy Among African American Women: The Effect of Socioeconomic Status and Antibiotic Exposure

Anne L Dunlop et al. PeerJ.

Abstract

Objective: A growing body of research has investigated the human microbiota and pregnancy outcomes, especially preterm birth. Most studies of the prenatal microbiota have focused on the vagina, with fewer investigating other body sites during pregnancy. Although pregnancy involves profound hormonal, immunological and metabolic changes, few studies have investigated either shifts in microbiota composition across pregnancy at different body sites or variation in composition at any site that may be explained by maternal characteristics. The purpose of this study was to investigate: (1) the stability of the vaginal, oral, and gut microbiota from early (8-14 weeks) through later (24-30 weeks) pregnancy among African American women according to measures of socioeconomic status, accounting for prenatal antibiotic use; (2) whether measures of socioeconomic status are associated with changes in microbiota composition over pregnancy; and (3) whether exposure to prenatal antibiotics mediate any observed associations between measures of socioeconomic status and stability of the vaginal, oral, and gut microbiota across pregnancy.

Methods: We used paired vaginal, oral, or gut samples available for 16S rRNA gene sequencing from two time points in pregnancy (8-14 and 24-30 weeks) to compare within-woman changes in measures of alpha diversity (Shannon and Chao1) and beta-diversity (Bray-Curtis dissimilarity) among pregnant African American women (n = 110). Multivariable linear regression was used to examine the effect of level of education and prenatal health insurance as explanatory variables for changes in diversity, considering antibiotic exposure as a mediator, adjusting for age, obstetrical history, and weeks between sampling.

Results: For the oral and gut microbiota, there were no significant associations between measures of socioeconomic status or prenatal antibiotic use and change in Shannon or Chao1 diversity. For the vaginal microbiota, low level of education (high school or less) was associated with an increase in Shannon and Chao1 diversity over pregnancy, with minimal attenuation when controlling for prenatal antibiotic use. Conversely, for within-woman Bray-Curtis dissimilarity for early compared to later pregnancy, low level of education and prenatal antibiotics were associated with greater dissimilarity for the oral and gut sites, with minimal attenuation when controlling for prenatal antibiotics, and no difference in dissimilarity for the vaginal site.

Conclusions: Measures of maternal socioeconomic status are variably associated with changes in diversity across pregnancy for the vaginal, oral, and gut microbiota, with minimal attenuation by prenatal antibiotic exposure. Studies that evaluate stability of the microbiota across pregnancy in association with health outcomes themselves associated with socioeconomic status (such as preterm birth) should incorporate measures of socioeconomic status to avoid finding spurious relationships.

Keywords: Microbiome; Microbiota; Pregnancy; Social class.

Conflict of interest statement

Timothy Read is an Academic Editor for PeerJ. The other authors declare that they have no competing interests.

Figures

Figure 1
Figure 1. Change in Shannon and Chao1 measures for Visit 1 and Visit 2 by body site.
(A) Distribution of change in Chao1 diversity from Visit 1 to Visit 2 for gut microbiota. (B) Distribution of change in Chao1 diversity from Visit 1 to Visit 2 for oral microbiota. (C) Distribution of change in Chao1 diversity from Visit 1 to Visit 2 for vaginal microbiota. (D) Distribution of change in Shannon diversity from Visit 1 to Visit 2 for gut microbiota. (E) Distribution of change in Shannon diversity from Visit 1 to Visit 2 for oral microbiota. (F) Distribution of change in Shannon diversity from Visit 1 to Visit 2 for vaginal microbiota.
Figure 2
Figure 2. Bray–Curtis dissimilarity measure for Visit 1 and Visit 2 by body site.
(A) Distribution of Bray–Curtis dissimilarity from Visit 1 to Visit 2 for oral microbiota. (B) Distribution of Bray–Curtis dissimilarity from Visit 1 to Visit 2 for gut microbiota. (C) Distribution of Bray–Curtis dissimilarity from Visit 1 to Visit 2 for vaginal microbiota.

Similar articles

See all similar articles

References

    1. Aagaard K, Versalovic J, Petrosino J, Mistretta T-A, Riehle K, Coarfa C, Raza S, Dowlin D, Rosenbaum S, Van den Veyver I, Milosavljevic A. 73: Metagenomic-based approach to a comprehensive characterization of the vaginal microbiome signature in pregnancy. American Journal of Obstetrics & Gynecology. 2011;204(1):S42.
    1. Agrawal V, Hirsch E. Intrauterine infection and preterm labor. Seminars in Fetal and Neonatal Medicine. 2012;17:12–19. - PMC - PubMed
    1. Althouse AD. Adjust for multiple comparisons? It’s not that simple. The Annals of Thoracic Surgery. 2016;101(5):1644–1645. doi: 10.1016/j.athoracsur.2015.11.024. - DOI - PubMed
    1. Amabebe E, Anumba DO. The vaginal microenvironment: the physiologic role of Lactobacilli. Frontiers in Medicine. 2018;5:181. doi: 10.3389/fmed.2018.00181. - DOI - PMC - PubMed
    1. Aziz Q, Doré J, Emmanuel A, Guarner F, Quigley E. Gut microbiota and gastrointestinal health: current concepts and future directions. Neurogastroenterology & Motility. 2013;25(1):4–15. doi: 10.1111/nmo.12046. - DOI - PubMed

LinkOut - more resources

Feedback