Científicos describen por primera vez la microbiota de la placa dentobacteriana preservada en esqueletos ancestrales de más de 1,000 años de antigüedad.
Resumen: Una ‘Pompeya microbiana’ fue descubierta, conservada en dientes de esqueletos que datan de alrededor de un milenio. El equipo de investigadores descubrió que la cavidad oral ancestral albergaba patógenos oportunistas y que la enfermedad periodontal era causada por las mismas especies que la causan en la actualidad, a pesar de los importantes cambios en la dieta y la higiene bucal. “El estudio de los microbiomas ancestrales nos ayuda a entender la historia evolutiva de la salud y la enfermedad en los seres humanos”, dijo uno de los autores principales del trabajo. Este estudio tiene implicaciones relevantes sobre el entendimiento de la evolución del microbioma oral humano y sobre los orígenes de la enfermedad periodontal. En la actualidad, la enfermedad periodontal moderada y severa, afecta a más del 10% de la población mundial y está ligada a varias condiciones sistémicas de importancia como las enfermedades cardiovasculares, pulmonares y la diabetes mellitus tipo 2.
Scientists describe for the first time, the microbiota of dental plaque preserved on ancient skeletons dating back over 1,000 years.
Summary: A ‘microbial Pompeii’ has been discovered, preserved on the teeth of skeletons around 1,000 years old. The research team discovered that the ancient human oral cavity carries numerous opportunistic pathogens and that periodontal disease is caused by the same bacteria today as in the past, despite major changes in human diet and hygiene. “The study of ancient microbiomes helps us understand the evolutionary history of human health and disease,” says a senior author of the study. This study has significant implications for understanding the evolution of the human oral microbiome and the origins of periodontal disease. Today, moderate to severe periodontal disease affects more than 10 percent of the world’s population and is linked to a series of systemic diseases, such as cardiovascular disease, pulmonary disease and type 2 diabetes.
An international team of researchers have discovered a ‘microbial Pompeii’ preserved on the teeth of skeletons around 1,000 years old. The key to the discovery is the dental calculus (plaque) which preserves bacteria and microscopic particles of food on the surfaces of teeth, effectively creating a mineral tomb for microbiomes.
The research team discovered that the ancient human oral cavity carries numerous opportunistic pathogens and that periodontal disease is caused by the same bacteria today as in the past, despite major changes in human diet and hygiene.
The researchers discovered that the ancient human oral microbiome already contained the basic genetic machinery for antibiotic resistance more than eight centuries before the invention of the first therapeutic antibiotics in the 1940s. As well as health information, the scientists recovered dietary DNA from ancient dental calculus, allowing the identification of dietary components, such as vegetables, that leave few traces in the archaeological record.
Led by the University of Zürich, the University of Copenhagen, and the University of York, this pioneering analysis of ancient oral microbiome ecology and function involved the contributions of 32 scientists at twelve institutions in seven countries.
The research published in Nature Genetics reveals that unlike bone which rapidly loses much of its molecular information when buried, calculus grows slowly in the mouth and enters the soil in a much more stable state helping it to preserve biomolecules. This enabled the researchers, led by Dr Christina Warinner, to analyze ancient DNA that was not compromised by the burial environment.
They applied shotgun DNA sequencing to dental calculus for the first time. They reconstructed the genome of a major periodontal pathogen and produced possibly the first genetic evidence of dietary biomolecules to be recovered from ancient dental calculus.
Analyzing this wealth of data required overcoming the formidable bioinformatics challenge of sorting and identifying millions of genetic sequences like puzzle pieces in order to reconstruct the complex biology of the ancient oral microbiome.
“Dental calculus is a window into the past and may well turn out to be one of the best-preserved records of human-associated microbes,” says Professor Christian von Mering, an author of the study and Group Director at the SIB Swiss Institute of Bioinformatics, which performed the bioinformatics analysis Professor Matthew Collins, of the University of York, said: “We knew that calculus preserved microscopic particles of food and other debris but the level of preservation of biomolecules is remarkable. A microbiome entombed and preserved in a mineral matrix, a microbial Pompeii.”
Dr Warinner, of the University of Zurich and the University of Oklahoma, added: “Dental calculus acts both as a long-term reservoir of the oral microbiome and as a trap for dietary and environmental debris. This allows us to investigate health and disease, as well as reconstruct aspects of an individual’s life history and activities. Never before have we been able to retrieve so much information from one small sample.”
The study has wide reaching implications for understanding the evolution of the human oral microbiome and the origins of periodontal disease. Periodontal disease causes distinctive proteomic changes in the dentition and is characterized by chronic inflammation resulting in tooth and bone loss. Dr. Enrico Cappellini of the University of Copenhagen, a senior author of the study, describes the dental calculus analyzed in this study as a kind of “battlefield archaeological site, just at the molecular scale.”
Today, moderate to severe periodontal disease affects more than 10% of the world’s population and is linked to diverse systemic diseases, including cardiovascular disease, stroke, pulmonary disease, and type II diabetes. Although common in humans, domestic pets, and zoo animals, periodontal disease does not typically develop in wild animals, leading to speculation that it is an oral microbiome disease resulting from modern human lifestyles.
“As we learn more about the evolution of this microbiome in response to migration and changes in diet, health and medicine, I can imagine a future in which most archaeologists regard calculus as more interesting than the teeth themselves,” says Prof. Collins.
“The study of ancient microbiomes helps us understand the evolutionary history of human health and disease,” says Prof. Frank Rühli, a senior author of the study and Head of the Centre for Evolutionary Medicine at the University of Zürich. “It informs modern medicine.”
Journal reference: Warinner C, Rodrigues JFM, Vyas R, Trachsel C, Shved N, Grossmann J, Radini A, Hancock Y, Tito RY, Fiddyment S, Speller C, Hendy J, Charlton S, Luder HU, Salazar-Garcia DC, Eppler E, Seiler R, Hansen LH, Samaniego Castruita JA, Barkow-Oesterreicher S, Teoh KY, Kelstrup CD, Olsen JV, Nanni P, Kawai T, Willerslev E, von Mering C, Lewis Jr CM, Collins MJ, Gilbert MTP, Ruhli F, Cappellini E. Pathogens and host immunity in the ancient human oral cavity. Nat Genet 2014. doi:10.1038/ng.2906.
Journal abstract: Calcified dental plaque (dental calculus) preserves for millennia and entraps biomolecules from all domains of life and viruses. We report the first, to our knowledge, high-resolution taxonomic and protein functional characterization of the ancient oral microbiome and demonstrate that the oral cavity has long served as a reservoir for bacteria implicated in both local and systemic disease. We characterize (i) the ancient oral microbiome in a diseased state, (ii) 40 opportunistic pathogens, (iii) ancient human–associated putative antibiotic resistance genes, (iv) a genome reconstruction of the periodontal pathogen Tannerella forsythia, (v) 239 bacterial and 43 human proteins, allowing confirmation of a long-term association between host immune factors, ‘red complex’ pathogens and periodontal disease, and (vi) DNA sequences matching dietary sources. Directly datable and nearly ubiquitous, dental calculus permits the simultaneous investigation of pathogen activity, host immunity and diet, thereby extending direct investigation of common diseases into the human evolutionary past.