Colombo Ana Paula Vieira, Lourenço Talita Gomes Baêta, de Oliveira Adriana Miranda, da Costa André Luiz Amorim
Oral Microbiology Laboratory, Institute of Microbiology Paulo de Góes, UFRJ, Rio de Janeiro, Brazil.
School of Dentistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
Adv Exp Med Biol. 2025;1472:71-87. doi: 10.1007/978-3-031-79146-8_5.
In the last decades, groundbreaking research on the human microbiome has changed our reductionist conception of the etiology and pathogenesis of several chronic diseases. As a result, we have come to appreciate the significance of a balanced microbiome in maintaining human health. In this context, the upper and lower gastrointestinal tracts (GITs) comprise the most abundant and diverse microbiotas of the human body. In addition to its diversity, functional redundancy, and temporal stability, a healthy GIT microbiome is characterized by its body site specificity. In fact, current evidence has indicated that the translocation of oral species to the gut environment through the oral-gut axis is increased in an array of illnesses, including chronic inflammatory and metabolic diseases, neurological disorders, and cancer. Oral pathogens have also been shown to promote gut dysbiosis and systemic inflammation in animal models. Yet, some level of overlapping between oral and gut microbiomes may occur without disruption of these microbial communities and loss of site specificity. The uniqueness of each host-microbiome entity may hinder our ability to define a "universal" normal GIT microbiome. Despite that, this chapter summarizes the predominant health-related taxa along the human GIT, as well as their role in the physiology and immunity of the digestive system. Some mechanisms that may lead to disturbances and relevant shifts in the oral and gut microbiomes of major inflammatory chronic diseases are also pointed out. Lastly, oral-fecal microbial signatures are presented as potential biomarkers for several oral and systemic disorders. The recognition of such symbiotic/dysbiotic microbial profiles may provide insights into the development of more accurate early diagnosis and therapeutic ecological approaches to restore the balance of the GIT microbiome.
在过去几十年中，关于人类微生物组的开创性研究改变了我们对几种慢性疾病病因和发病机制的还原论观念。因此，我们开始认识到平衡的微生物组在维持人类健康方面的重要性。在这种背景下，上、下胃肠道（GIT）包含了人体中最丰富多样的微生物群。除了其多样性、功能冗余性和时间稳定性外，健康的GIT微生物组还具有身体部位特异性。事实上，目前的证据表明，在一系列疾病中，包括慢性炎症和代谢性疾病、神经系统疾病和癌症，口腔微生物通过口-肠轴转移到肠道环境的情况有所增加。在动物模型中，口腔病原体也被证明会促进肠道微生物群失调和全身炎症。然而，口腔和肠道微生物组之间可能会有一定程度的重叠，而不会破坏这些微生物群落和丧失部位特异性。每个宿主-微生物组实体的独特性可能会阻碍我们定义“通用”正常GIT微生物组的能力。尽管如此，本章总结了人类GIT中主要的与健康相关的分类群，以及它们在消化系统生理和免疫中的作用。还指出了一些可能导致主要炎症性慢性病口腔和肠道微生物组紊乱及相关变化的机制。最后，介绍了口腔-粪便微生物特征作为几种口腔和全身疾病的潜在生物标志物。认识到这种共生/失调的微生物特征可能有助于深入了解更准确的早期诊断和治疗生态方法的发展，以恢复GIT微生物组的平衡。
