Department of Food and Nutrition, Chungbuk National University, Chungdae-ro 1, Seowon-gu, Cheongju 28644, Republic of Korea.
Department of Biological Sciences, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 61186, Republic of Korea.
Nutrients. 2023 Jun 2;15(11):2617. doi: 10.3390/nu15112617.
Time-restricted feeding (TRF) has been shown to improve the disordered metabolic and immunologic functions associated with obesity, however little is known about its post-effects after the cessation of TRF practice. In the current study, we determined how long the effects of TRF persist, and whether the effects are tissue-dependent. There were four groups of mice in this study: overweight and obese mice were randomized into (1) TRF group (TRF for 6 weeks), (2) post-TRF group (TRF for 4 weeks and later ad libitum), (3) continuous ad libitum of high-fat diet (HFD-AL), and (4) the lean control-fed low-fat diet ad libitum. Blood, liver, and adipose tissues were collected to measure the metabolic, inflammatory, and immune cell parameters. The results showed that TRF withdrawal quickly led to increased body weight/adiposity and reversed fasting blood glucose. However, fasting insulin and insulin resistance index HOMA-IR remained lower in the post-TRF than in the HFD-AL group. In addition, TRF-induced reduction in blood monocytes waned in the post-TRF group, but the TRF effects on mRNA levels of proinflammatory immune cells (macrophages and ) and cytokine () in adipose tissue remained lower in the post-TRF group than in the HFD-AL group. Furthermore, the TRF group was protected from the down-regulation of mRNA expression in adipose tissue, which was also observed in the post-TRF group to a lesser extent. The post-TRF animals displayed liver mass similar to those in the TRF group, but the TRF effects on the mRNA of inflammation markers in the liver vanished completely. Together, these results indicate that, although the lasting effects of TRF may differ by tissues and genes, the impact of TRF on adipose tissue inflammation and immune cell infiltration could last a couple of weeks, which may, in part, contribute to the maintenance of insulin sensitivity even after the cessation of TRF.
限时喂养 (TRF) 已被证明可改善与肥胖相关的代谢和免疫功能紊乱，但对于 TRF 停止后其持续效果知之甚少。在本研究中，我们确定了 TRF 的持续效果有多长，以及这些效果是否与组织有关。该研究有四组小鼠：超重和肥胖小鼠随机分为 (1) TRF 组（TRF 喂养 6 周）、(2) 停 TRF 组（TRF 喂养 4 周后改为自由饮食）、(3) 持续高脂饮食自由饮食组（HFD-AL）和 (4) 瘦鼠低脂饮食自由饮食组。采集血液、肝脏和脂肪组织，以测量代谢、炎症和免疫细胞参数。结果表明，TRF 停止后，体重/体脂迅速增加，空腹血糖恢复正常。然而，停 TRF 组的空腹胰岛素和胰岛素抵抗指数 HOMA-IR 仍低于 HFD-AL 组。此外，TRF 诱导的血液单核细胞减少在停 TRF 组减弱，但 TRF 对脂肪组织中促炎免疫细胞（巨噬细胞和 ) 和细胞因子 ()mRNA 水平的影响在停 TRF 组仍低于 HFD-AL 组。此外，TRF 组脂肪组织中 mRNA 表达下调得到保护，停 TRF 组也观察到这种现象，但程度较轻。停 TRF 动物的肝脏质量与 TRF 组相似，但 TRF 对肝脏炎症标志物 mRNA 的影响完全消失。综上所述，尽管 TRF 的持续效果可能因组织和基因而异，但 TRF 对脂肪组织炎症和免疫细胞浸润的影响可能持续数周，这可能部分有助于维持胰岛素敏感性，即使在 TRF 停止后也是如此。
