Data_Sheet_1_Elucidation of Akkermansia muciniphila Probiotic Traits Driven by Mucin Depletion.pdf

Akkermansia muciniphila is widely considered a next-generation beneficial microbe. This bacterium resides in the mucus layer of its host and regulates intestinal homeostasis and intestinal barrier integrity by affecting host signaling pathways. However, it remains unknown how the expression of genes encoding extracellular proteins is regulated in response to dynamic mucosal environments. In this study, we elucidated the effect of mucin on the gene expression and probiotic traits of A. muciniphila. Transcriptome analysis showed that the genes encoding most mucin-degrading enzymes were significantly upregulated in the presence of mucin. By contrast, most genes involved in glycolysis and energy metabolic pathways were upregulated under mucin-depleted conditions. Interestingly, the absence of mucin resulted in the upregulation of 79 genes encoding secreted protein candidates, including Amuc-1100 as well as members of major protein secretion systems. These transcript level changes were consistent with the fact that administration of A. muciniphila grown under mucin-depleted conditions to high-fat diet-induced diabetic mice reduced obesity and improved intestinal barrier integrity more efficiently than administration of A. muciniphila grown under mucin-containing conditions. In conclusion, mucin content in the growth medium plays a critical role in the improvement by A. muciniphila of high-fat diet-induced obesity, intestinal inflammation, and compromised intestinal barrier integrity related to a decrease in goblet cell density. Our findings suggest the depletion of animal-derived mucin in growth medium as a novel principle for the development of A. muciniphila for human therapeutics.

嗜黏蛋白阿克曼氏菌（Akkermansia muciniphila）被广泛认定为下一代有益微生物。该菌定殖于宿主的黏液层内，通过调控宿主信号通路以维持肠道稳态与肠道屏障完整性。然而，当前学界尚未明确其编码细胞外蛋白的基因如何响应动态变化的黏膜环境完成表达调控。本研究阐明了黏蛋白对嗜黏蛋白阿克曼氏菌基因表达及益生特性的影响。转录组分析结果显示，在黏蛋白存在的培养条件下，绝大多数黏蛋白降解酶的编码基因均显著上调。与之相对，在黏蛋白匮乏的培养环境中，参与糖酵解与能量代谢通路的多数基因呈现上调表达。值得关注的是，黏蛋白缺失会诱导79个编码分泌蛋白候选物的基因表达上调，其中涵盖Amuc-1100以及主要蛋白分泌系统的相关成员。上述转录水平的变化与一项实验结果相契合：将在黏蛋白匮乏条件下培养的嗜黏蛋白阿克曼氏菌施用于高脂饮食诱导的糖尿病小鼠，其减轻肥胖、改善肠道屏障完整性的效果，显著优于以含黏蛋白培养基培养的菌株。综上，培养基中的黏蛋白含量在嗜黏蛋白阿克曼氏菌改善高脂饮食诱导的肥胖、肠道炎症以及由杯状细胞密度降低引发的肠道屏障受损过程中发挥关键作用。本研究结果提示，在培养过程中去除动物源黏蛋白，可作为开发用于人类治疗的嗜黏蛋白阿克曼氏菌制剂的全新策略。