Conny Waters – AncientPages.com – <\/strong>Researchers have found well-preserved evidence of oral bacteria, in two 4,000-year-old human teeth in a limestone cave in County Limerick, Ireland.<\/p>\n \u00a0A tooth specimen prior to ancient DNA sampling. Credit: Lara Cassidy\/Trinity College Dublin\/PA<\/em><\/p>\n The cave is cool, dry, and alkaline, and the teeth are believed to have belonged to a man from the Bronze Age period.<\/p>\n The bacteria samples show the bacteria is a leading cause of tooth decay and is also responsible for gum disease.<\/p>\n They also found \u201cthe first high-quality DNA from\u00a0Streptococcus mutans<\/em>), an oral and harmful bacteria that contributes to cavities in the human mouth.<\/p>\n The cave\u2019s conditions may have contributed to the exceptional preservation of\u00a0S. mutans\u00a0<\/em>DNA.\u00a0While other teeth in the cave showed advanced dental decay, there was no evidence of caries on the sampled teeth. However, an exceptional amount of mutans sequences were found in one tooth root.<\/p>\n \u201cWe were very surprised to see such a large abundance of\u00a0mutans<\/em>\u00a0in this 4,000 year old tooth\u201d said Lara Cassidy, an assistant professor at Trinity College Dublin and senior author of the study.<\/p>\n Killuragh Cave, County Limerick, Ireland. Image credit:\u00a0Sam Moore and Marion Dowd\/Molecular Biology and Evolution<\/em><\/p>\n<\/div>\n \u201cIt is a remarkably rare find and suggests this man was at high risk of developing cavities right before his death.\u201d<\/p>\n \u201cA large abundance\u201d of S. mutans also indicates imbalance because, as they wrote, \u201cother streptococcal species were virtually absent from the tooth sample.\u201d This means the natural balance of all bacteria in the mouth from the pre-disease state – has been disrupted.<\/p>\n Alongside the\u00a0S. mutans\u00a0<\/em>genome, the authors reconstructed two genomes for\u00a0T. forsythia<\/em> (Tannerella forsythia), a bacteria involved in gum disease \u2013 and found them to be highly divergent from one another, implying much higher levels of strain diversity in prehistoric populations.<\/p>\n Alongside the\u00a0S. mutans\u00a0<\/em>genome, the authors reconstructed two genomes for\u00a0T. forsythia<\/em>\u00a0\u2013 a bacteria involved in gum disease \u2013 and found them to be highly divergent from one another, implying much higher levels of strain diversity in prehistoric populations.<\/p>\n \u201cThe two sampled teeth contained quite divergent strains of\u00a0T. forsythia<\/em>\u201d explained Iseult Jackson, a PhD candidate and first author of the study. \u201cThese strains from a single ancient mouth were more genetically different from one another than any pair of modern strains in our dataset, despite these modern samples deriving from Europe, Japan, and the USA. This is interesting because a loss of biodiversity can have negative impacts on the oral environment and human health.\u201d<\/p>\n The study of DNA related to the teeth found in the cave shows that these disease-causing bacteria have changed significantly from the Bronze Age to today,<\/p>\n These changes include the consumption of sugar, which is widespread today and may largely affect our teeth.<\/p>\n The study was published in the journal Molecular Biology and Evolution<\/a><\/p>\n Written by\u00a0Conny Waters – AncientPages.com\u00a0Staff Writer<\/strong><\/p>\n \n\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n![\"Bacteria](\"https:\/\/www.ancientpages.com\/wp-content\/uploads\/2024\/03\/cvetoeethmarch30.jpg\")
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