During the course of evolution, bacteria have developed an intimate relationship with humans colonizing specific body sites at the interface with the body exterior and invaginations such as nose, mouth, lung, gut, vagina, genito-urinary tract, and skin and thus constituting an integrated meta-organism. The final result has been a mutual adaptation and functional integration which confers significant advantages to humans and bacteria. The immune system of the host co-evolved with the microbiota to develop complex mechanisms to recognize and destroy invading microbes, while preserving its own bacteria. Composition and diversity of the microbiota change according to development and aging and contribute to humans’ health and fitness by modulating the immune system response and inflammaging and vice versa. In the last decades, we experienced an explosion of studies on the role of gut microbiota in aging, age-related diseases, and longevity; however, less reports are present on the role of the microbiota at different body sites. In this review, we describe the key steps of the co-evolution between Homo sapiens and microbiome and how this adaptation can impact on immunosenescence and inflammaging. We briefly summarized the role of gut microbiota in aging and longevity while bringing out the involvement of the other microbiota.

在进化过程中，细菌与人类建立了密切的关系，在与身体外部和内陷的交界处定殖特定的身体部位，如鼻子、口腔、肺、肠道、阴道、泌尿生殖道和皮肤，从而构成了整合的元有机体。最终的结果是相互适应和功能整合，这为人类和细菌带来了显着的优势。宿主的免疫系统与微生物群共同进化，形成复杂的机制来识别和消灭入侵的微生物，同时保留自身的细菌。微生物群的组成和多样性会随着发育和衰老而变化，并通过调节免疫系统反应和炎症来促进人类的健康和健身，反之亦然。在过去的几十年里，我们经历了关于肠道微生物群在衰老、与年龄相关的疾病和长寿中的作用的大量研究。然而，关于微生物群在不同身体部位的作用的报道较少。在这篇综述中，我们描述了智人与微生物组之间共同进化的关键步骤，以及这种适应如何影响免疫衰老和炎症。我们简要总结了肠道微生物群在衰老和长寿中的作用，同时指出了其他微生物群的参与。