Obesity and the brain are linked since the brain can control the weight of the body through its neurotransmitters. The aim of the present study was to investigate the effect of high-fat diet (HFD)-induced obesity on brain functioning through the measurement of brain glutamate, dopamine, and serotonin metabolic pools. In the present study, two groups of rats served as subjects. Group 1 was fed a normal diet and named as the lean group. Group 2 was fed an HFD for 4 weeks and named as the obese group. Markers of oxidative stress (malondialdehyde, glutathione, glutathione-s-transferase, and vitamin C), inflammatory cytokines (interleukin [IL]-6 and IL-12), and leptin along with a lipid profile (cholesterol, triglycerides, high-density lipoprotein, and low-density lipoprotein levels) were measured in the serum. Neurotransmitters dopamine, serotonin, and glutamate were measured in brain tissue. Fecal samples were collected for observing changes in gut flora. In brain tissue, significantly high levels of dopamine and glutamate as well as significantly low levels of serotonin were found in the obese group compared to those in the lean group (P > 0.001) and were discussed in relation to the biochemical profile in the serum. It was also noted that the HFD affected bacterial gut composition in comparison to the control group with gram-positive cocci dominance in the control group compared to obese. The results of the present study confirm that obesity is linked to inflammation, oxidative stress, dyslipidemic processes, and altered brain neurotransmitter levels that can cause obesity-related neuropsychiatric complications.

中文翻译：

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高脂饮食引起的肥胖和脑神经递质池受损

肥胖与大脑息息相关，因为大脑可以通过其神经递质控制体重。本研究的目的是通过测量大脑谷氨酸，多巴胺和5-羟色胺代谢池来研究高脂饮食（HFD）诱导的肥胖对脑功能的影响。在本研究中，两组大鼠为受试者。第1组以正常饮食喂养，并称为瘦肉组。第2组接受HFD喂养4周，并命名为肥胖组。氧化应激（丙二醛，谷胱甘肽，谷胱甘肽的标记小号-转移酶和维生素C），炎性细胞因子（白介素[IL] -6和IL-12）和瘦素以及脂质谱（胆固醇，甘油三酸酯，高密度脂蛋白和低密度脂蛋白水平）在血清。在脑组织中测量了神经递质多巴胺，5-羟色胺和谷氨酸。收集粪便样品以观察肠道菌群的变化。与瘦肉组相比，肥胖组的脑组织中多巴胺和谷氨酸水平显着升高，而血清素水平显着降低（P> 0.001），并针对血清中的生化特征进行了讨论。还应注意的是，与对照组相比，HFD影响细菌肠道组成，与肥胖相比，对照组的革兰氏阳性球菌占优势。本研究的结果证实，肥胖与炎症，氧化应激，血脂异常过程和脑神经递质水平改变有关，后者可能导致肥胖相关的神经精神病学并发症。