Davis Eric M
1 Animal Dental Specialists of Upstate New York, Fayetteville, NY, USA.
J Vet Dent. 2016 Jun;33(2):97-107. doi: 10.1177/0898756416657239. Epub 2016 Aug 6.
It has long been accepted that certain oral bacterial species are responsible for the development of periodontal disease. However, the focus of microbial and immunological research is shifting from studying the organisms associated with disease to examining the indigenous microbial inhabitants that are present in health. Microbiome refers to the aggregate genetic material of all microorganisms living in, or on, a defined habitat. Recent developments in gene sequence analysis have enabled detection and identification of bacteria from polymicrobial samples, including subgingival plaque. Diversity surveys utilizing this technology have demonstrated that bacterial culture techniques have vastly underestimated the richness and diversity of microorganisms in vivo, since only certain bacteria grow in vitro. Surveys using gene sequence analysis have demonstrated that the healthy oral microbiome is composed of an unexpectedly high number of diverse species, including putative pathogens. These findings support the view that coevolution microorganisms and macroscopic hosts has occurred in which certain microorganisms have adapted to survive in the oral cavity and host immune tolerance has allowed the establishment of a symbiotic relationship in which both parties receive benefits (mutualism). This review describes gene sequence analysis as an increasingly common, culture-independent tool for detecting bacteria in vivo and describes the results of recent oral microbiome diversity surveys of clinically healthy humans, dogs, and cats. Six bacterial phyla consistently dominated the healthy oral microbiome of all 3 host species. Previous hypotheses on etiology of periodontitis are reviewed in light of new scientific findings. Finally, the consideration that clinically relevant periodontal disease occurs when immune tolerance of the symbiotic oral microbiome is altered to a proinflammatory response will be discussed.
长期以来，人们一直认为某些口腔细菌种类是导致牙周病的原因。然而，微生物学和免疫学研究的重点正在从研究与疾病相关的微生物转向检查健康状态下存在的本土微生物群落。微生物组是指生活在特定栖息地内或之上的所有微生物的总体遗传物质。基因序列分析的最新进展使得能够从包括龈下菌斑在内的多微生物样本中检测和鉴定细菌。利用这项技术进行的多样性调查表明，细菌培养技术极大地低估了体内微生物的丰富度和多样性，因为只有某些细菌能在体外生长。使用基因序列分析的调查表明，健康的口腔微生物组由数量出乎意料的多种不同物种组成，包括潜在病原体。这些发现支持了这样一种观点，即微生物与宏观宿主之间已经发生了共同进化，其中某些微生物已经适应在口腔中生存，并且宿主免疫耐受允许建立一种共生关系，双方都能从中受益（互利共生）。这篇综述将基因序列分析描述为一种越来越常见的、不依赖培养的体内细菌检测工具，并描述了近期对临床健康的人类、犬类和猫类进行的口腔微生物组多样性调查结果。六个细菌门始终在所有三种宿主物种的健康口腔微生物组中占据主导地位。根据新的科学发现，对先前关于牙周炎病因的假设进行了综述。最后，将讨论当共生口腔微生物组的免疫耐受改变为促炎反应时会发生临床相关牙周病这一观点。
