{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,28]],"date-time":"2026-09-28T10:58:41Z","timestamp":1790593121268,"version":"4.1.0"},"reference-count":46,"publisher":"Wiley","license":[{"start":{"date-parts":[[2026,9,28]],"date-time":"2026-09-28T00:00:00Z","timestamp":1790553600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2026,9,28]],"date-time":"2026-09-28T00:00:00Z","timestamp":1790553600000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"funder":[{"DOI":"10.13039\/100001424","name":"American Liver Foundation","doi-asserted-by":"publisher","award":["RV\u2010967705"],"award-info":[{"award-number":["RV\u2010967705"]}],"id":[{"id":"10.13039\/100001424","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Int Endodontic J"],"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Aim<\/jats:title>\n                    <jats:p>Root canal infections harbour complex microbial communities that may vary across geographic populations. This study aimed to compare the root canal microbiome across Spain, Sweden, and the USA, identifying key microbial taxa, compositional and functional differences, and cohort\u2010associated microbial signatures.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>\n                      16S rRNA gene sequencing datasets from primary root canal infections were retrieved from three geographic cohorts (Spain\n                      <jats:italic>n<\/jats:italic>\n                      \u2009=\u200932, Sweden\n                      <jats:italic>n<\/jats:italic>\n                      \u2009=\u200914, USA\n                      <jats:italic>n<\/jats:italic>\n                      \u2009=\u200925). All samples targeted the V3\u2010V4 region and were sequenced using the Illumina MiSeq platform. Alpha and beta diversity metrics were assessed to evaluate within\u2010 and between\u2010sample variation. Taxonomic composition was characterized, followed by differential abundance analysis and identification of the core microbiome. Microbial co\u2010occurrence networks were inferred using the SPRING method, and hub taxa were identified based on eigenvector centrality.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Significant differences in microbial richness between cohorts were observed based on Chao1 index and observed richness. Beta diversity analyses revealed statistically significant but modest separation of microbial communities among populations (\n                      <jats:italic>R<\/jats:italic>\n                      <jats:sup>2<\/jats:sup>\n                      \u2009=\u20096.8%), with substantial overlap between cohorts. Bacillota, Bacteroidota, Fusobacteriota, and Actinomycetota were dominant across cohorts, although their relative abundances varied. Core microbiome analysis identified both shared and cohort\u2010associated taxa at genus and species levels. SPRING\u2010based co\u2010occurrence networks identified cohort\u2010associated hub taxa, including\n                      <jats:italic>Fretibacterium fastidiosum<\/jats:italic>\n                      in the USA,\n                      <jats:styled-content style=\"fixed-case\">\n                        <jats:italic>Dialister pneumosintes<\/jats:italic>\n                      <\/jats:styled-content>\n                      in Spain, and\n                      <jats:styled-content style=\"fixed-case\">\n                        <jats:italic>Treponema denticola<\/jats:italic>\n                      <\/jats:styled-content>\n                      in Sweden. Furthermore, predictive functional profiling suggested differences in microbial functional potential among geographic cohorts.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>While root canal infections share a core microbiome, subtle population\u2010specific microbial signatures were identified. However, the modest effect size suggests that geographic variation alone explains only a limited proportion of microbial composition. Larger and more balanced studies are required to further evaluate geographic influences on the root canal microbiome and their potential clinical relevance.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1111\/iej.70277","type":"journal-article","created":{"date-parts":[[2026,9,28]],"date-time":"2026-09-28T10:13:12Z","timestamp":1790590392000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Geographic Variation and Core Signatures of the Root Canal Microbiome: A Cross\u2010Country Comparative Study"],"prefix":"10.1111","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2454-2862","authenticated-orcid":false,"given":"Naorem","family":"Leimarembi Devi","sequence":"first","affiliation":[{"name":"Department of Odontology Ume\u00e5 University  Ume\u00e5 Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3536-4467","authenticated-orcid":false,"given":"Olena","family":"Rakhimova","sequence":"additional","affiliation":[{"name":"Department of Odontology Ume\u00e5 University  Ume\u00e5 Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2309-0083","authenticated-orcid":false,"given":"Christopher","family":"Staley","sequence":"additional","affiliation":[{"name":"University of Minnesota  Minneapolis Minnesota USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9738-0828","authenticated-orcid":false,"given":"Ronald","family":"Ordinola\u2010Zapata","sequence":"additional","affiliation":[{"name":"University of Minnesota  Minneapolis Minnesota USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0559-2159","authenticated-orcid":false,"given":"Maria Teresa Arias","family":"Moliz","sequence":"additional","affiliation":[{"name":"Department of Microbiology University of Granada  Granada Spain"},{"name":"Instituto de Investigaci\u00f3n Biosanitaria Ibs.GRANADA  Granada Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4233-8969","authenticated-orcid":false,"given":"Virginia","family":"P\u00e9rez\u2010Carrasco","sequence":"additional","affiliation":[{"name":"Instituto de Investigaci\u00f3n Biosanitaria Ibs.GRANADA  Granada Spain"},{"name":"GENYO. 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