背景:肥胖通常与免疫反应受损有关,包括脾脏肿大,炎症增加,T细胞介导的功能受损,这可能导致对感染的易感性增加。在各种水果和蔬菜(F&V)中发现的生物活性化合物已被证明具有很强的抗炎作用。然而,很少有前瞻性研究研究F&V在预防肥胖相关的免疫和炎症反应失调方面的作用.
目的:确定在高脂饮食(HFD)中掺入不同水平的F&V混合物对饮食诱导的肥胖动物模型免疫功能变化的影响。
方法:将六周大的雄性C57BL/6J小鼠随机分为五组(n=12/组):匹配的低脂对照(LF,10%大卡脂肪)或高脂肪饮食(HFD,45%千卡脂肪)补充0%,5%,10%,或消耗最多的F&V的15%(wt/wt)冻干粉末(人类当量为0、3、5-7、8-9份/d,分别)20周。记录脾脏重量,并通过流式细胞术评估脾细胞的免疫表型。通过胸苷掺入评估离体脾淋巴细胞增殖,并通过MesoScaleDiscovery测量血清细胞因子。
结果:喂食HFD的小鼠的脾脏重量明显更高,脾CD8+淋巴细胞减少,抑制T淋巴细胞增殖,与饲喂LF饮食的人相比,血清IL-1β和IFN-γ水平降低。与仅饲喂HFD的小鼠相比,饲喂补充有10%或15%F&V的HFD的小鼠恢复了这些受影响的生物标志物的HFD相关变化。Further,免疫标志物与F&V水平存在显著相关性。
结论:这些结果表明,增加F&V的消耗在预防HFD相关的免疫功能失调方面具有有益作用。
BACKGROUND: Obesity is often associated with impaired immune responses, including enlarged spleen, increased inflammation, and impaired T-cell-mediated function, which may lead to increased susceptibility to infections. Bioactive compounds found in various fruits and vegetables (F&V) have been shown to have strong anti-inflammatory effects. However, few prospective studies have examined the effects of F&V on preventing obesity-associated dysregulation of immune and inflammatory responses.
OBJECTIVE: The objective of this was to determine the impact of different levels of a mixture of F&V incorporated in a high-fat diet (HFD) on immune function changes in a diet-induced obesity animal model.
METHODS: Six-wk-old male C57BL/6J mice were randomly assigned to 1 of 5 groups (n = 12/group): matched low-fat control (LF, 10% kcal fat) or HFD (45% kcal fat) supplemented with 0%, 5%, 10%, or 15% (wt/wt) freeze-dried powder of the most consumed F&V (human equivalent of 0, 3, 5-7, 8-9 servings/d, respectively) for 20 wk. Spleen weight was recorded, and the immunophenotype of splenocytes was evaluated by flow cytometry. Ex vivo splenic lymphocyte proliferation was assessed by thymidine incorporation and serum cytokines concentrations were measured by Meso Scale Discovery.
RESULTS: Mice fed the HFD exhibited significantly higher spleen weight, decreased splenic CD8+ lymphocytes, suppressed T lymphocyte proliferation, and reduced serum IL-1ß and IFN-γ concentrations compared with those fed the LF diet. Feeding mice with the HFD supplemented with 10% or 15% F&V restored HFD-associated changes of these affected biomarkers compared with those fed HFD only. Furthermore, a significant correlation was found between immunologic markers and F&V level.
CONCLUSIONS: These results suggest that increased consumption of F&V has beneficial effects in preventing HFD-associated dysregulation of immune function.