Nutritional Immunology Laboratory, JM USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA, United States.
Nutritional Immunology Laboratory, JM USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA, United States.
J Nutr. 2024 Oct;154(10):3144-3150. doi: 10.1016/j.tjnut.2024.08.009. Epub 2024 Aug 21.
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.
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.
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.
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.
These results suggest that increased consumption of F&V has beneficial effects in preventing HFD-associated dysregulation of immune function.
肥胖常与免疫应答受损相关，包括脾脏增大、炎症增加和 T 细胞介导功能受损，这可能导致感染易感性增加。各种水果和蔬菜（F&V）中的生物活性化合物已被证明具有很强的抗炎作用。然而，很少有前瞻性研究检查 F&V 对预防肥胖相关免疫和炎症反应失调的影响。
本研究旨在确定高脂肪饮食（HFD）中不同水平的 F&V 混合物对饮食诱导肥胖动物模型中免疫功能变化的影响。
6 周龄雄性 C57BL/6J 小鼠被随机分为 5 组中的 1 组（n = 12/组）：匹配的低脂对照（LF，10%热量脂肪）或 HFD（45%热量脂肪），分别补充 0%、5%、10%或 15%（wt/wt）最常食用的 F&V 冷冻干燥粉末（相当于人类 0、3、5-7、8-9 份/d），共 20 周。记录脾脏重量，并通过流式细胞术评估脾细胞免疫表型。通过胸苷掺入评估体外脾淋巴细胞增殖，通过 Meso Scale Discovery 测量血清细胞因子浓度。
与 LF 饮食组相比，喂食 HFD 的小鼠脾脏重量显著增加，CD8+淋巴细胞减少，T 淋巴细胞增殖受到抑制，血清 IL-1β和 IFN-γ浓度降低。与仅喂食 HFD 的小鼠相比，喂食 HFD 并补充 10%或 15% F&V 的小鼠恢复了这些受影响生物标志物与 HFD 相关的变化。此外，免疫标志物与 F&V 水平之间存在显著相关性。
这些结果表明，增加 F&V 的摄入量可预防 HFD 相关的免疫功能失调。
