Division of Gastroenterology & Liver Diseases, School of Medicine, Case Western Reserve University, Cleveland, OH, USA.
Digestive Health Research Institute, University Hospitals Cleveland Medical Center, Cleveland, OH, USA.
J Nutr. 2021 Mar 11;151(3):579-590. doi: 10.1093/jn/nxaa386.
The current nutritional composition of the "American diet" (AD; also known as Western diet) has been linked to the increasing incidence of chronic diseases, including inflammatory bowel disease (IBD), namely Crohn disease (CD).
This study investigated which of the 3 major macronutrients (protein, fat, carbohydrates) in the AD has the greatest impact on preventing chronic inflammation in experimental IBD mouse models.
We compared 5 rodent diets designed to mirror the 2011-2012 "What We Eat in America" NHANES. Each diet had 1 macronutrient dietary source replaced. The formulated diets were AD, AD-soy-pea (animal protein replaced by soy + pea protein), AD-CHO ("refined carbohydrate" by polysaccharides), AD-fat [redistribution of the ω-6:ω-3 (n-6:n-3) PUFA ratio; ∼10:1 to 1:1], and AD-mix (all 3 "healthier" macronutrients combined). In 3 separate experiments, 8-wk-old germ-free SAMP1/YitFC mice (SAMP) colonized with human gut microbiota ("hGF-SAMP") from CD or healthy donors were fed an AD, an AD-"modified," or laboratory rodent diet for 24 wk. Two subsequent dextran sodium sulfate-colitis experiments in hGF-SAMP (12-wk-old) and specific-pathogen-free (SPF) C57BL/6 (20-wk-old) mice, and a 6-wk feeding trial in 24-wk-old SPF SAMP were performed. Intestinal inflammation, gut metagenomics, and MS profiles were assessed.
The AD-soy-pea diet resulted in lower histology scores [mean ± SD (56.1% ± 20.7% reduction)] in all feeding trials and IBD mouse models than did other diets (P < 0.05). Compared with the AD, the AD-soy-pea correlated with increased abundance in Lactobacillaceae and Leuconostraceae (1.5-4.7 log2 and 3.0-5.1 log2 difference, respectively), glutamine (6.5 ± 0.8 compared with 3.9 ± 0.3 ng/μg stool, P = 0.0005) and butyric acid (4:0; 3.3 ± 0.5 compared with 2.54 ± 0.4 ng/μg stool, P = 0.006) concentrations, and decreased linoleic acid (18:2n-6; 5.4 ± 0.4 compared with 8.6 ± 0.3 ng/μL plasma, P = 0.01).
Replacement of animal protein in an AD by plant-based sources reduced the severity of experimental IBD in all mouse models studied, suggesting that similar, feasible adjustments to the daily human diet could help control/prevent IBD in humans.
当前的“美式饮食”（AD；也称为西方饮食）的营养成分与慢性疾病（包括炎症性肠病（IBD））的发病率不断上升有关，例如克罗恩病（CD）。
本研究旨在调查 AD 中的 3 种主要宏量营养素（蛋白质、脂肪、碳水化合物）中，哪一种对预防实验性 IBD 小鼠模型中的慢性炎症有最大影响。
我们比较了 5 种旨在模拟 2011-2012 年“我们在美国吃什么”NHANES 的啮齿动物饮食。每种饮食都用 1 种宏量营养素饮食来源替代。配方饮食是 AD、AD-大豆-豌豆（动物蛋白被大豆+豌豆蛋白替代）、AD-CHO（“精制碳水化合物”被多糖替代）、AD-脂肪[ω-6：ω-3（n-6：n-3）PUFA 比的重新分配；从 ∼10:1 到 1:1]和 AD-混合（所有 3 种“更健康”的宏量营养素组合）。在 3 个单独的实验中，用来自 CD 或健康供体的人类肠道微生物群（“hGF-SAMP”）定植的 8 周龄无菌 SAMP1/YitFC 小鼠（SAMP）喂食 AD、AD-“改良”或实验室啮齿动物饮食 24 周。随后在 hGF-SAMP（12 周龄）和无特定病原体（SPF）C57BL/6（20 周龄）小鼠中进行了 2 次葡聚糖硫酸钠结肠炎实验，以及在 24 周龄 SPF SAMP 中进行了 6 周的喂养试验。评估了肠道炎症、肠道宏基因组和 MS 谱。
在所有喂养试验和 IBD 小鼠模型中，AD-大豆-豌豆饮食导致的组织学评分（平均值±标准差（56.1%±20.7%降低））均低于其他饮食（P<0.05）。与 AD 相比，AD-大豆-豌豆与乳杆菌科和肠球菌科的丰度增加相关（分别为 1.5-4.7 log2 和 3.0-5.1 log2），谷氨酰胺（6.5±0.8 与 3.9±0.3 ng/μg 粪便相比，P=0.0005）和丁酸（4:0；3.3±0.5 与 2.54±0.4 ng/μg 粪便相比，P=0.006）浓度增加，亚油酸（18:2n-6；5.4±0.4 与 8.6±0.3 ng/μL 血浆相比，P=0.01）减少。
AD 中动物蛋白被植物性来源替代可降低所有研究的实验性 IBD 严重程度，表明对人类日常饮食进行类似的、可行的调整可能有助于控制/预防人类的 IBD。
