Tong Lingjun, Hao Haining, Zhang Xinyi, Zhang Zhe, Lv Youyou, Zhang Lanwei, Yi Huaxi
Department of Food Science, College of Food Science and Engineering, Ocean University of China, 5 Yushan Road, Qingdao, 266003, P. R. China.
Mol Nutr Food Res. 2020 Apr;64(8):e1901251. doi: 10.1002/mnfr.201901251. Epub 2020 Mar 29.
Milk-derived extracellular vesicles (mEVs) as nanoparticles are being developed as novel drug vehicles due to their pivotal role in cell-cell communication. As an important bioactive component in milk, little is known about their effect on the gut microbiota and intestinal immunity. Therefore, the effects of mEVs on gut microbiota and intestinal immunity in mice are investigated.
First, a new method to obtain high-yield mEVs is developed. Afterward, the colonic contents from C57BL/6 mice fed different doses of mEVs (8 weeks) are collected and the microbial composition via 16S rRNA gene sequencing is analyzed. It is found that mEVs could alter the gut microbiota composition and modulate their metabolites-short-chain fatty acids (SCFAs). Furthermore, the effects of mEVs on intestinal immunity are evaluated. It is observed that the expression levels of Muc2, RegIIIγ, Myd88, GATA4 genes, and IgA, sIgA are increased in the intestine, which are significant for the integrity of the mucus layer.
These findings reveal that the genes with critical importance for intestinal barrier function and immune regulation are modified in mice by oral administration mEVs, which also result in the changes of the relative composition of gut microbiome and SCFAs.
作为纳米颗粒的乳源细胞外囊泡（mEVs）因其在细胞间通讯中的关键作用而被开发为新型药物载体。作为牛奶中的一种重要生物活性成分，人们对其对肠道微生物群和肠道免疫的影响知之甚少。因此，研究了mEVs对小鼠肠道微生物群和肠道免疫的影响。
首先，开发了一种获得高产mEVs的新方法。随后，收集喂食不同剂量mEVs（8周）的C57BL/6小鼠的结肠内容物，并通过16S rRNA基因测序分析微生物组成。发现mEVs可以改变肠道微生物群组成并调节其代谢产物——短链脂肪酸（SCFAs）。此外，评估了mEVs对肠道免疫的影响。观察到肠道中Muc2、RegIIIγ、Myd88、GATA4基因以及IgA、sIgA的表达水平升高，这对黏液层的完整性很重要。
这些发现表明，口服mEVs可使小鼠体内对肠道屏障功能和免疫调节至关重要的基因发生改变，这也导致肠道微生物群和SCFAs的相对组成发生变化。
