State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, PR China.
Food Funct. 2018 Jul 17;9(7):3718-3731. doi: 10.1039/c8fo00685g.
Methionine-restricted diets (MRD) show an integrated series of beneficial health effects, including improving insulin sensitivity, limiting fat deposition, and decreasing oxidative stress, and inflammation responses. We aimed to explore the systemic responses to a MRD in mice fed with a high fat (HFD) and clarify the possible mechanism. Mice were fed with a control diet (0.86% methionine + 4% fat, CON), HFD (0.86% methionine + 20% fat), or MRD (0.17% methionine + 20% fat) for 22 consecutive weeks. HFD-fed mice showed widespread systemic metabolic disorders and thyroid dysfunction. A MRD significantly increased energy expenditure (e.g. fatty acid oxidation, glycolysis, and tricarboxylic acid cycle metabolism), regulated protein homeostasis, improved gut microbiota functions, prevented thyroid dysfunction, increased plasma thyroxine and triiodothyronine levels, decreased plasma thyroid stimulating hormone levels, increased type 2 deiodinase (DIO2) activity, and up-regulated mRNA and protein expression levels of DIO2 and thyroid hormone receptor α1 in the skeletal muscle. These results suggest that a MRD can improve the metabolic disorders induced by a HFD, and especially regulate energy and protein homeostasis likely through improved thyroid function. Thus, reducing methionine intake (e.g. through a vegan diet) may improve metabolic health in animals and humans.
限制蛋氨酸饮食（MRD）显示出一系列综合的有益健康效果，包括改善胰岛素敏感性、限制脂肪沉积、降低氧化应激和炎症反应。我们旨在探索高脂肪饮食（HFD）喂养的小鼠对 MRD 的系统反应，并阐明可能的机制。小鼠连续 22 周喂食对照饮食（0.86%蛋氨酸+4%脂肪，CON）、HFD（0.86%蛋氨酸+20%脂肪）或 MRD（0.17%蛋氨酸+20%脂肪）。HFD 喂养的小鼠表现出广泛的全身代谢紊乱和甲状腺功能障碍。MRD 显著增加能量消耗（例如脂肪酸氧化、糖酵解和三羧酸循环代谢），调节蛋白质稳态，改善肠道微生物群功能，预防甲状腺功能障碍，增加血浆甲状腺素和三碘甲状腺原氨酸水平，降低血浆促甲状腺激素水平，增加 2 型脱碘酶（DIO2）活性，并上调骨骼肌中 DIO2 和甲状腺激素受体α1 的 mRNA 和蛋白表达水平。这些结果表明，MRD 可以改善 HFD 引起的代谢紊乱，特别是通过改善甲状腺功能来调节能量和蛋白质稳态。因此，减少蛋氨酸摄入（例如通过素食饮食）可能会改善动物和人类的代谢健康。
