The Association Between Gestational Diabetes and Microbiota in Placenta and Cord Blood

Study information

Needs review

study design

cross-sectional observational, not case-control

Citation

PMID PubMed identifier for scientific articles.

33193081

DOI Digital object identifier for electronic documents.

10.3389/fendo.2020.550319

URI Uniform resource identifier for web resources.

https://pubmed.ncbi.nlm.nih.gov/33193081/

Authors

Tang N, Luo ZC, Zhang L, Zheng T, Fan P, Tao Y, Ouyang F

Journal

Frontiers in endocrinology

Year

2020

Objective: Early life is a critical period for gut microbial development. It is still controversial whether there is placental microbiota during a healthy pregnancy. Gestational diabetes mellitus (GDM) is associated with increased risk of metabolic syndrome in the offspring, and the mechanisms are unclear. We sought to explore whether microbiota in placenta and cord blood may be altered in GDM. Methods: Placenta and cord blood samples were collected from eight GDM and seven euglycemic (control) term pregnancies in cesarean deliveries without evidence of clinical infections. The Illumina MiSeq Sequencing System was used to detect the microbiota based on the V3-V4 hypervariable regions of the 16S ribosomal RNA gene. Results: The microbiota were detectable in all placental samples. Comparing GDM vs. controls, there were more operational taxonomic units (OTUs) (mean ± SE = 373.63 ± 14.61 vs. 332.43 ± 9.92, P = 0.024) and higher ACE index (395.15 ± 10.56 vs. 356.27 ± 8.47, P = 0.029) and Chao index (397.67 ± 10.24 vs. 361.32 ± 8.87, P = 0.04). The placental microbiota was mainly composed of four phyla: Bacteroidetes, Firmicutes, Actinobacteria, and Proteobacteria at the phylum level and 10 dominant genera at the genus level in both GDM and controls. Despite the dominant similarity in microbiota composition, at the OTU level, the abundance of Ruminococcus, Coprococcus, Paraprevotella, and Lactobacillus were higher, whereas Veillonella was lower in the placentas of GDM vs. controls. The microbiota was detected in one of the 15 cord blood samples, and its components were similar as to the corresponding placental microbiota at both phylum and genus levels suggesting placental microbiota as the potential source. Conclusions: The most abundant phyla and genus of placental microbiota were similar in GDM and euglycemic pregnancies, but GDM was associated with higher diversity of placental microbiota. Further study is needed to confirm the existence of microbiota in cord blood in pregnancies without clinical infection.

Experiment 1

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Needs review

Curated date: 2021/06/14

Curator: Madhubani Dey

Revision editor(s): Madhubani Dey, WikiWorks

Subjects

Location of subjects: China

Host species Species from which microbiome was sampled (if applicable): Homo sapiens

Body site Anatomical site where microbial samples were extracted from according to the Uber Anatomy Ontology: Placenta Allantoic placenta,Eutherian placenta,Placenta

Condition The experimental condition / phenotype studied according to the Experimental Factor Ontology: gestational diabetes diabetes in pregnancy,GDM,gestational diabetes,gestational diabetes mellitus,maternal gestational diabetes mellitus

Group 0 name Corresponds to the control (unexposed) group for case-control studies: euglycemic (control) singleton pregnant women
Group 1 name Corresponds to the case (exposed) group for case-control studies: Pregnant women with Gestational Diabetes Mellitus
Group 1 definition Diagnostic criteria applied to define the specific condition / phenotype represented in the case (exposed) group: Pregnant women with Gestational Diabetes Mellitus (GDM) who had prenatal care at Xinhua Hospital, a tertiary hospital in Shanghai, and were admitted to the hospital for cesarean deliveries
Group 0 sample size Number of subjects in the control (unexposed) group: 7
Group 1 sample size Number of subjects in the case (exposed) group: 8
Antibiotics exclusion Number of days without antibiotics usage (if applicable) and other antibiotics-related criteria used to exclude participants (if any): Women who were treated with any antibiotics during pregnancy

Lab analysis

Sequencing type: 16S

16S variable region One or more hypervariable region(s) of the bacterial 16S gene: V3-V4

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

Statistical Analysis

Statistical test: Mann-Whitney (Wilcoxon)

Significance threshold p-value or FDR threshold used for differential abundance testing (if any): 0.05
MHT correction Have statistical tests be corrected for multiple hypothesis testing (MHT)?: No

Alpha Diversity

Shannon Estimator of species richness and species evenness: more weight on species richness: unchanged
Chao1 Abundance-based estimator of species richness: increased
Richness Number of species: increased