Zhang Yu, Li Yong, Yuan Yilin, Wang Jun, Zhang Shiyu, Zhu Run, Wang Yan, Wu Yinbao, Liao Xindi, Mi Jiandui
College of Animal Science, South China Agricultural University, Guangzhou 510642, China.
College of Animal Science, South China Agricultural University, Guangzhou 510642, China; Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou 510642, China; National-Local Joint Engineering Research Center for Livestock Breeding, Guangzhou 510642, China.
Sci Total Environ. 2023 Feb 1;858(Pt 3):160041. doi: 10.1016/j.scitotenv.2022.160041. Epub 2022 Nov 8.
Light mainly synergistically regulates the central biological clock system. In farming, long-term light exposure may induce metabolic disorders and increase the load on the liver in laying hens. In contrast, intermittent photoperiods can reduce light exposure and increase rest time to improve the health of laying hens. The circadian rhythms of gut microbes are essential for the health of the host. However, the circadian rhythms of gut microbes and how those microbes interact with the host under intermittent photoperiods are not clear. We used laying hens as a model to evaluate the circadian rhythms of gut microbes and biological clock genes under different intermittent photoperiods. Intermittent photoperiod 1 (IP1, 16 [3 h -L/1 h -D]: 8 D) enhanced the circadian rhythms of cBmal1, cBmal2, cCry1, and cCry2 in the hypothalamus and increased the expression of cClock, cBmal1, and cCry2 in the liver and seven clock genes in the cecal wall. The intermittent photoperiod also significantly altered the composition and metabolic function of the cecal microbiota via the melatonin pathway. The concentrations of short-chain fatty acids (SCFAs) and the abundance of SCFA-producing genera such as Odoribacter significantly increased under the IP1 treatment and might have further fed back into and strengthened the peripheral and central rhythms by activating the SCFA receptor gene pathway in cecal wall. These findings clarify the mediation mechanisms for the circadian rhythms of the central circadian clock and highlight the role of intermittent photoperiod-induced regulation of the interaction between the host clock and the cecal microbial community.
光照主要协同调节中枢生物钟系统。在养殖中，长期光照可能会诱发蛋鸡的代谢紊乱并增加肝脏负担。相比之下，间歇性光照周期可以减少光照时间并增加休息时间，从而改善蛋鸡健康。肠道微生物的昼夜节律对宿主健康至关重要。然而，肠道微生物的昼夜节律以及在间歇性光照周期下这些微生物如何与宿主相互作用尚不清楚。我们以蛋鸡为模型，评估不同间歇性光照周期下肠道微生物和生物钟基因的昼夜节律。间歇性光照周期1（IP1，16 [3小时光照/1小时黑暗]：8小时黑暗）增强了下丘脑cBmal1、cBmal2、cCry1和cCry2的昼夜节律，并增加了肝脏中cClock、cBmal1和cCry2以及盲肠壁中7个生物钟基因的表达。间歇性光照周期还通过褪黑素途径显著改变了盲肠微生物群的组成和代谢功能。在IP1处理下，短链脂肪酸（SCFAs）的浓度以及产SCFA的菌属（如Odoribacter）的丰度显著增加，并且可能通过激活盲肠壁中的SCFA受体基因途径进一步反馈并加强外周和中枢节律。这些发现阐明了中枢生物钟昼夜节律的介导机制，并突出了间歇性光照周期诱导的宿主生物钟与盲肠微生物群落相互作用调节的作用。
