牛奶是一种营养丰富的食物来源，而在各种乳类中，母乳是许多哺乳动物母亲为新生儿提供的营养来源。外泌体是纳米大小的膜状细胞外囊泡，在细胞间通讯中发挥重要作用。外泌体源自内源合成和饮食来源，例如牛奶。通过电子显微镜发现外泌体为漂浮囊泡，由于蔗糖梯度中的密度在 1.10 至 1.18 g/mL 之间，对应于已知的外泌体密度，并且检测到了 I 类和 II 类 MHC、CD63、囊泡上的 CD81 和 CD86。迄今为止，乳外泌体已被用于治疗包括癌症在内的许多疾病，并被广泛认为是有前途的化疗药物递送载体。然而，很少有关于乳外泌体的研究关注老年健康，特别是与骨骼和肌肉相关的肌肉减少症和骨质疏松症。因此，本研究重点关注牛奶外泌体及其货物，它们是膳食补充剂的潜在候选者，当与药物结合时，它们可以有效治疗肌肉骨骼疾病。在这篇综述中，我们介绍了基本概念，包括乳外泌体的定义、各种来源和货物，以及外泌体的分离和表征方法。此外，我们回顾了有关肌肉骨骼系统和乳外泌体的最新文献。由于炎症和氧化应激是肌肉骨骼疾病的基础，因此还总结了报告乳外泌体的抗氧化和抗炎特性的研究。最后，提出了乳外泌体在针对肌肉和骨骼健康方面的治疗潜力。

Milk is a nutrient-rich food source, and among the various milks, breast milk is a nutrient source provided by mothers to newborns in many mammals. Exosomes are nano-sized membranous extracellular vesicles that play important roles in cell-to-cell communication. Exosomes originate from endogenous synthesis and dietary sources such as milk. Discovered through electron microscopy as floating vesicles, the existence of exosomes in human milk was confirmed owing to a density between 1.10 and 1.18 g/mL in a sucrose gradient corresponding to the known density of exosomes and detection of MHC classes I and II, CD63, CD81, and CD86 on the vesicles. To date, milk exosomes have been used for treating many diseases, including cancers, and are widely proposed as promising carriers for the delivery of chemotherapeutic agents. However, few studies on milk exosomes focus on geriatric health, especially sarcopenia and osteoporosis related to bone and muscle. Therefore, the present study focused on milk exosomes and their cargoes, which are potential candidates for dietary supplements, and when combined with drugs, they can be effective in treating musculoskeletal diseases. In this review, we introduce the basic concepts, including the definition, various sources, and cargoes of milk exosomes, and exosome isolation and characterization methods. Additionally, we review recent literature on the musculoskeletal system and milk exosomes. Since inflammation and oxidative stress underly musculoskeletal disorders, studies reporting the antioxidant and anti-inflammatory properties of milk exosomes are also summarized. Finally, the therapeutic potential of milk exosomes in targeting muscle and bone health is proposed.