Proteins are an important part of our regular diet. During food processing, their amino acid composition can be chemically altered by the reaction of free amino groups with sugars — a process termed glycation. The resulting Maillard reaction products (MRPs) have low bioavailability and thus predominantly end up in the colon where they encounter our gut microbiota. In the following review, we summarize bacterial strategies to efficiently metabolize these non-canonical amino acids. A particular focus will be on the complex regulatory mechanisms that allow a tightly controlled expression of metabolic genes to successfully occupy the ecological niches that result from the chemical diversity of MRPs.

蛋白质是我们日常饮食的重要组成部分。在食品加工过程中，它们的氨基酸组成可以通过游离氨基与糖的反应而发生化学改变，这一过程称为糖化。由此产生的美拉德反应产物 (MRP) 的生物利用度较低，因此主要最终到达结肠，在那里它们会遇到我们的肠道微生物群。在下面的综述中，我们总结了有效代谢这些非规范氨基酸的细菌策略。特别关注的是复杂的调节机制，这些机制允许严格控制的代谢基因的表达成功地占据由 MRP 的化学多样性产生的生态位。