{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,29]],"date-time":"2026-09-29T22:10:38Z","timestamp":1790719838042,"version":"4.1.0"},"reference-count":51,"publisher":"Wiley","issue":"5","license":[{"start":{"date-parts":[[2026,5,8]],"date-time":"2026-05-08T00:00:00Z","timestamp":1778198400000},"content-version":"vor","delay-in-days":7,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"},{"start":{"date-parts":[[2026,5,1]],"date-time":"2026-05-01T00:00:00Z","timestamp":1777593600000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["American J Rep Immunol"],"published-print":{"date-parts":[[2026,5]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Problem<\/jats:title>\n                    <jats:p>The advent of high\u2010throughput 16S rRNA sequencing has enabled deeper insights into microbial communities associated with adverse pregnancy outcomes, including spontaneous preterm birth (sPTB). While microbial dysbiosis in the cervicovaginal and oral\u2010gut microbiomes has been implicated in sPTB, the existence of a placental microbiome remains contentious. Traditional paradigms of a \u201csterile womb\u201d have been challenged by studies suggesting a low\u2010biomass microbial community in the placenta, though recent evidence disputes this claim, attributing findings to contamination or transient microbial DNA signals.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Method<\/jats:title>\n                    <jats:p>This study systematically reviewed placental microbiome studies employing 16S rRNA sequencing and re\u2010analyzed publicly available datasets to determine microbial signatures in term and preterm placentas. Following a comprehensive search of three databases and stringent inclusion criteria, seven studies were included. The risk of bias was assessed using a modified Joanna\u2010Briggs tool, revealing moderate\u2010to\u2010low risk across studies. Methodological heterogeneity, including differences in contamination controls, sequencing regions, and analytical platforms, was a significant limitation.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>A re\u2010analysis of sequencing data showed no consistent microbiome signature distinguishing the term from preterm placentas. Beta diversity analysis revealed no group clustering, while alpha diversity indices showed comparable species richness. Bacterial DNA in placental tissues was primarily attributed to contamination from the urogenital tract or laboratory processes.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>Findings underscore the importance of robust contamination control and standardized protocols in low\u2010biomass microbiome research. Future studies should employ advanced techniques, such as metagenomics and fluorescence in situ hybridization, to evaluate the functional relevance of microbial communities in the placenta, as well as rule out microbial DNA deposited in the placenta through circulating bacterial extracellular vesicles (EVs).<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1111\/aji.70246","type":"journal-article","created":{"date-parts":[[2026,5,9]],"date-time":"2026-05-09T05:06:02Z","timestamp":1778303162000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["The Microbiome Signature of the Placenta and its Role in Spontaneous Preterm Birth: A Systematic Review and 16S rRNA Re\u2010Analysis"],"prefix":"10.1111","volume":"95","author":[{"given":"De Jesus Federico","family":"II C","sequence":"first","affiliation":[{"name":"Department of Medicine Philippines 1000 Philippine General Hospital, Ermita  Manila Metro Manila Philippine"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Manuel Jr. S","family":"Vidal","sequence":"additional","affiliation":[{"name":"College of Medicine Philippines 100 San Beda University  Manila Metro Manila Philippine"},{"name":"Department of Chemistry College of Science Philippines 100 De La Salle University Manila, Malate  Manila Metro Manila Philippine"},{"name":"College of Medicine Philippines 100 University of the Philippines Manila, Ermita  Manila Metro Manila Philippine"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0001-2671-1471","authenticated-orcid":false,"given":"Francheska Sophia E","family":"dela Cruz","sequence":"additional","affiliation":[{"name":"College of Medicine Philippines 100 University of the Philippines Manila, Ermita  Manila Metro Manila Philippine"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4535-8837","authenticated-orcid":false,"given":"Ourlad Alzeus G","family":"Tantengco","sequence":"additional","affiliation":[{"name":"Department of Physiology College of Medicine University of the Philippines Manila, Ermita  Manila Metro Manila Philippines"},{"name":"Division of Basic and Translational Research Department of Obstetrics and Gynecology University of Texas Medical Branch at Galveston  Galveston Texas USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ramkumar","family":"Menon","sequence":"additional","affiliation":[{"name":"Division of Basic and Translational Research Department of Obstetrics and Gynecology University of Texas Medical Branch at Galveston  Galveston Texas USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2026,5,8]]},"reference":[{"key":"e_1_2_9_2_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41467-022-28620-1"},{"key":"e_1_2_9_3_1","doi-asserted-by":"publisher","DOI":"10.1186\/s40168-016-0223-9"},{"key":"e_1_2_9_4_1","doi-asserted-by":"publisher","DOI":"10.3389\/fcimb.2021.579766"},{"key":"e_1_2_9_5_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41598-021-96495-1"},{"key":"e_1_2_9_6_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00281-020-00817-w"},{"key":"e_1_2_9_7_1","doi-asserted-by":"publisher","DOI":"10.1126\/scitranslmed.3008599"},{"key":"e_1_2_9_8_1","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pbio.1001631"},{"key":"e_1_2_9_9_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ajog.2005.02.128"},{"key":"e_1_2_9_10_1","doi-asserted-by":"publisher","DOI":"10.1016\/0028-2243(87)90050-5"},{"issue":"11","key":"e_1_2_9_11_1","first-page":"872","article-title":"Endometrial Bacteria in Asymptomatic, Nonpregnant Women","volume":"34","author":"Hemsell D. 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