The gut microbiota changes with age, but it is not clear to what degree these changes are due to physiologic changes, age-associated inflammation or immunosenescence, diet, medications, or chronic health conditions. Observational studies in humans find that there are profound differences between the microbiomes of long-lived and frail individuals, but the degree to which these differences promote or prevent late-life health is unclear. Studies in model organisms demonstrate that age-related microbial dysbiosis causes intestinal permeability, systemic inflammation, and premature mortality, but identifying causal relationships have been challenging. Herein, we review how physiological and immune changes contribute to microbial dysbiosis and the degree to which microbial dysbiosis contributes to late-life health conditions. We discuss the features of the aging microbiota that make it more amenable to diet and pre- and probiotic interventions. Health interventions that promote a diverse microbiome could influence the health of older adults.

肠道菌群随年龄变化，但尚不清楚这些变化在多大程度上是由于生理变化，与年龄相关的炎症或免疫衰老，饮食，药物或慢性健康状况所致。对人类的观察研究发现，长寿个体和体弱个体的微生物组之间存在着深远的差异，但是这些差异促进或预防晚年健康的程度尚不清楚。对模型生物的研究表明，与年龄相关的微生物代谢异常会导致肠道通透性，全身性炎症和过早死亡，但是确定因果关系一直具有挑战性。在本文中，我们回顾了生理和免疫变化如何导致微生物营养不良以及微生物营养不良导致晚年健康状况的程度。我们讨论了微生物群老化的特征，这些特征使其更适合饮食以及益生菌和益生菌干预。促进多样化微生物组的健康干预措施可能会影响老年人的健康。