The elucidation of the mechanisms of ageing and the identification of methods to control it have long been anticipated. Recently, two factors associated with ageing—the accumulation of senescent cells and the change in the composition of gut microbiota—have been shown to play key roles in ageing. However, little is known about how these phenomena occur and are related during ageing. Here we show that the persistent presence of commensal bacteria gradually induces cellular senescence in gut germinal centre B cells. Importantly, this reduces both the production and diversity of immunoglobulin A (IgA) antibodies that target gut bacteria, thereby changing the composition of gut microbiota in aged mice. These results have revealed the existence of IgA-mediated crosstalk between the gut microbiota and cellular senescence and thus extend our understanding of the mechanism of gut microbiota changes with age, opening up possibilities for their control.

人们长期以来一直期待阐明衰老机制并确定控制衰老的方法。最近，与衰老相关的两个因素——衰老细胞的积累和肠道微生物群组成的变化——已被证明在衰老中发挥着关键作用。然而，人们对这些现象在衰老过程中如何发生以及它们之间的关系知之甚少。在这里，我们发现共生细菌的持续存在逐渐诱导肠道生发中心 B 细胞的细胞衰老。重要的是，这减少了针对肠道细菌的免疫球蛋白 A (IgA) 抗体的产生和多样性，从而改变了老年小鼠肠道微生物群的组成。这些结果揭示了肠道微生物群和细胞衰老之间存在 IgA 介导的串扰，从而扩展了我们对肠道微生物群随年龄变化机制的理解，为控制肠道微生物群开辟了可能性。