The evidence for placental microbiome and its composition in healthy pregnancies: A systematic review

作者：Davis R. Zakis, Eva Paulissen, Liga Kornete, Amke Marije Kaan, Elena A. Nicu, Egija Zaura · 发表于：Journal of Reproductive Immunology · 年份：2021 · DOI：10.1016/j.jri.2021.103455 · 被引用次数：53 · 研究领域：Gut microbiota and health、Reproductive tract infections research、Oral microbiology and periodontitis research

OBJECTIVE: To assess the available scientific evidence regarding the placental microbial composition of a healthy pregnancy, the quality of this evidence, and the potential relation between placental and oral microbiome. MATERIALS AND METHODS: Data sources: MEDLINE and EMBASE up to August 1, 2019. STUDY ELIGIBILITY CRITERIA: Human subjects; healthy women; term deliveries; healthy normal birth weight; assessment of microorganisms (bacteria) in placental tissue; full research papers in English. The quality of the included studies was assessed by a modified Joanna Briggs Institute checklist for analytical cross-sectional studies. RESULTS: 57 studies passed the inclusion criteria. Of these, 33 had a high risk of quality bias (e.g., insufficient infection control, lack of negative controls, poor description of the healthy cases). The remaining 24 studies had a low (N = 12) to moderate (N = 12) risk of bias and were selected for in-depth analysis. Of these 24 studies, 22 reported microorganisms in placental tissues, where Lactobacillus (11 studies), Ureaplasma (7), Fusobacterium (7), Staphylococcus (7), Prevotella (6) and Streptococcus (6) were among the most frequently identified genera. Methylobacterium (4), Propionibacterium (3), Pseudomonas (3) and Escherichia (2), among others, although frequently reported in placental samples, were often reported as contaminants in studies that used negative controls. CONCLUSIONS: The results support the existence of a low biomass placental m...