Metabolic reprogramming is associated with the adaptation of host cells to the disease environment, such as inflammation and cancer. However, little is known about microbial metabolic reprogramming or the role it plays in regulating the fitness of commensal and pathogenic bacteria in the gut. Here, we report that intestinal inflammation reprograms the metabolic pathways of Enterobacteriaceae, such as Escherichia coli LF82, in the gut to adapt to the inflammatory environment. We found that E. coli LF82 shifts its metabolism to catabolize L-serine in the inflamed gut in order to maximize its growth potential. However, L-serine catabolism has a minimal effect on its fitness in the healthy gut. In fact, the absence of genes involved in L-serine utilization reduces the competitive fitness of E. coli LF82 and Citrobacter rodentium only during inflammation. The concentration of luminal L-serine is largely dependent on dietary intake. Accordingly, withholding amino acids from the diet markedly reduces their availability in the gut lumen. Hence, inflammation-induced blooms of E. coli LF82 are significantly blunted when amino acids-particularly L-serine-are removed from the diet. Thus, the ability to catabolize L-serine increases bacterial fitness and provides Enterobacteriaceae with a growth advantage against competitors in the inflamed gut.

中文翻译：

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膳食 L-丝氨酸赋予发炎肠道中的肠杆菌科竞争优势。

代谢重编程与宿主细胞适应疾病环境有关，例如炎症和癌症。然而，人们对微生物代谢重编程或其在调节肠道共生菌和病原菌适应性方面的作用知之甚少。在这里，我们报告肠道炎症会重新编程肠道中肠杆菌科（例如大肠杆菌 LF82）的代谢途径以适应炎症环境。我们发现大肠杆菌 LF82 改变其新陈代谢以分解代谢发炎肠道中的 L-丝氨酸，以最大限度地发挥其生长潜力。然而，L-丝氨酸分解代谢对其在健康肠道中的适应性影响很小。事实上，缺乏参与 L-丝氨酸利用的基因会降低大肠杆菌的竞争适应性。大肠杆菌 LF82 和柠檬酸杆菌仅在炎症期间。鲁米那 L-丝氨酸的浓度在很大程度上取决于饮食摄入量。因此，从饮食中抑制氨基酸显着降低了它们在肠腔中的可用性。因此，当从饮食中去除氨基酸（尤其是 L-丝氨酸）时，炎症诱导的大肠杆菌 LF82 大量繁殖会显着减弱。因此，分解代谢 L-丝氨酸的能力增加了细菌适应性，并为肠杆菌科提供了在发炎肠道中对抗竞争者的生长优势。当氨基酸——尤其是 L-丝氨酸——从饮食中去除时，大肠杆菌 LF82 显着减弱。因此，分解代谢 L-丝氨酸的能力增加了细菌适应性，并为肠杆菌科提供了在发炎肠道中对抗竞争者的生长优势。当氨基酸——尤其是 L-丝氨酸——从饮食中去除时，大肠杆菌 LF82 显着减弱。因此，分解代谢 L-丝氨酸的能力增加了细菌适应性，并为肠杆菌科提供了在发炎肠道中对抗竞争者的生长优势。