Diets rich in animal source foods vs plant-based diets have different macronutrient composition, and they have been shown to have differential effects on the gut microbiome. In this study, we hypothesized that diets with very different nutrient composition are able to change gut microbiome composition and metabolites in a very short period. We compared a fast food (FF) diet (ie, burgers and fries) with a Mediterranean (Med) diet, which is rich in vegetables, whole grains, olive oil, nuts, and fish. Ten healthy subjects participated in a controlled crossover study in which they consumed a Med diet and FF diet in randomized order for 4 days each, with a 4-day washout between treatments. Fecal DNA was extracted and the 16S V4 region amplified using polymerase chain reaction followed by sequencing on an Illumina MiSeq. Plasma metabolites and bile acids were analyzed using liquid chromatography-mass spectrometry. Certain bile-tolerant microbial genera and species including Collinsella, Parabacteroides, and Bilophila wadsworthia significantly increased after the FF diet. Some fiber-fermenting bacteria, including Lachnospiraceae and Butyricicoccus, increased significantly after the Med diet and decreased after the FF diet. Bacterially produced metabolites indole-3-lactic acid and indole-3-propionic acid, which have been shown to confer beneficial effects on neuronal cells, increased after the Med diet and decreased after the FF diet. Interindividual variability in response to the treatments may be related to differences in background diet, for example as shown by differences in Bilophila response in relationship to the saturated fat content of the baseline diet. In conclusion, an animal fat-rich, low-fiber FF diet v. a high-fiber Med diet altered human gut microbiome composition and its metabolites after just 4 days.

中文翻译：

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快餐和地中海饮食在四天内改变了人体肠道微生物组组成和色氨酸代谢物：一项初步研究

富含动物源食物的饮食与植物性饮食具有不同的常量营养素组成，并且它们已被证明对肠道微生物群有不同的影响。在这项研究中，我们假设营养成分非常不同的饮食能够在很短的时间内改变肠道微生物组的组成和代谢物。我们将快餐 (FF) 饮食（即汉堡和薯条）与地中海 (Med) 饮食进行了比较，后者富含蔬菜、全谷物、橄榄油、坚果和鱼。10 名健康受试者参与了一项对照交叉研究，其中他们以随机顺序食用 Med 饮食和 FF 饮食，每次 4 天，治疗之间有 4 天的洗脱期。提取粪便 DNA 并使用聚合酶链反应扩增 16S V4 区域，然后在 Illumina MiSeq 上测序。使用液相色谱-质谱法分析血浆代谢物和胆汁酸。在 FF 饮食后，某些耐胆汁微生物属和种，包括柯林斯氏菌、副杆菌属和 Bilophila wadsworthia 显着增加。一些纤维发酵细菌，包括毛螺菌科和 Butyricicoccus，在 Med 饮食后显着增加，在 FF 饮食后减少。细菌产生的代谢物 indole-3-乳酸和 indole-3-丙酸，已被证明对神经元细胞有益，在 Med 饮食后增加，在 FF 饮食后减少。对治疗的反应的个体间差异可能与背景饮食的差异有关，例如与基线饮食的饱和脂肪含量相关的嗜胆菌反应的差异所示。