The placenta harbors a unique microbiome.
Humans and their microbiomes have coevolved as a physiologic community composed of distinct body site niches with metabolic and antigenic diversity. The placental microbiome has not been robustly interrogated, despite recent demonstrations of intracellular bacteria with diverse metabolic and immune regulatory functions. A population-based cohort of placental specimens collected under sterile conditions from 320 subjects with extensive clinical data was established for comparative 16S ribosomal DNA-based and whole-genome shotgun (WGS) metagenomic studies. Identified taxa and their gene carriage patterns were compared to other human body site niches, including the oral, skin, airway (nasal), vaginal, and gut microbiomes from nonpregnant controls. We characterized a unique placental microbiome niche, composed of nonpathogenic commensal microbiota from the Firmicutes, Tenericutes, Proteobacteria, Bacteroidetes, and Fusobacteria phyla. In aggregate, the placental microbiome profiles were most akin (Bray-Curtis dissimilarity <0.3) to the human oral microbiome. 16S-based operational taxonomic unit analyses revealed associations of the placental microbiome with a remote history of antenatal infection (permutational multivariate analysis of variance, P = 0.006), such as urinary tract infection in the first trimester, as well as with preterm birth <37 weeks (P = 0.001).
Division of Maternal-Fetal Medicine, Departments of Obstetrics and Gynecology, Baylor College of Medicine and Texas Children's Hospital, Houston, TX 77030, USA. Department of Molecular and Human Genetics, Bioinformatics Research Laboratory, Baylor College of Medicine, Houston, TX 77030, USA. Department of Molecular and Cell Biology, Baylor College of Medicine, Houston, TX 77030, USA. aagaardt@bcm.edu.
Kjersti
K
Aagaard
Division of Maternal-Fetal Medicine, Departments of Obstetrics and Gynecology, Baylor College of Medicine and Texas Children's Hospital, Houston, TX 77030, USA. Department of Molecular and Human Genetics, Bioinformatics Research Laboratory, Baylor College of Medicine, Houston, TX 77030, USA.
Jun
J
Ma
Division of Maternal-Fetal Medicine, Departments of Obstetrics and Gynecology, Baylor College of Medicine and Texas Children's Hospital, Houston, TX 77030, USA.
Kathleen M
KM
Antony
Division of Maternal-Fetal Medicine, Departments of Obstetrics and Gynecology, Baylor College of Medicine and Texas Children's Hospital, Houston, TX 77030, USA.
Radhika
R
Ganu
Department of Microbiology and Molecular Virology, Alkek Center for Metagenomics and Microbiome Research, Baylor College of Medicine, Houston, TX 77030, USA.
Joseph
J
Petrosino
Department of Pathology and Immunology, Baylor College of Medicine and Texas Children's Hospital, Houston, TX 77030, USA.
James
J
Versalovic
D001419:Bacteria / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D002965:Classification; D004269:DNA, Bacterial / Q000235:genetics*; D005260:Female; D006801:Humans; D056186:Metagenomics; D064307:Microbiota / Q000235:genetics*; D015999:Multivariate Analysis; D010920:Placenta / Q000382:microbiology*; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000382:microbiology; D011261:Pregnancy Trimester, First; D047928:Premature Birth / Q000382:microbiology; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D021521:Ribotyping; D012307:Risk Factors; D014552:Urinary Tract Infections / Q000382:microbiology
D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S