Center for Human Nutrition, David Geffen School of Medicine, Department of Medicine, University of California Los Angeles, California, CA, USA.
Sci Rep. 2017 May 19;7(1):2167. doi: 10.1038/s41598-017-02200-6.
The gut microbiota is an important contributor to human health. Vegetable/fruit juices provide polyphenols, oligosaccharides, fiber and nitrate (beet juice), which may induce a prebiotic-like effect. Juice-based diets are becoming popular. However, there is a lack of scientific evidence of their health benefits. It was our hypothesis that changes in the intestinal microbiota induced by a juice-based diet play an important role in their health benefits. Twenty healthy adults consumed only vegetable/fruit juices for 3 days followed by 14 days of customary diet. On day 4 we observed a significant decrease in weight and body mass index (p = 2.0E), which was maintained until day 17 (p = 3.0E). On day 4 the proportion of the phylum Firmicutes and Proteobacteria in stool was significantly decreased and Bacteroidetes and Cyanobacteria was increased compared to baseline and was partially reversed on day 17. On day 4 plasma and urine nitric oxide was increased by 244 ± 89% and 450 ± 360%, respectively, and urinary lipid peroxidation marker malondialdehyde was decreased by 32 ± 21% compared to baseline. General well-being score was increased at the end of the study. In summary a 3-day juice-based diet altered the intestinal microbiota associated with weight loss, increase in the vasodilator NO, and decrease in lipid oxidation.
肠道微生物群是人类健康的重要贡献者。蔬菜/果汁提供多酚、低聚糖、纤维和硝酸盐（甜菜汁），可能会产生类似益生元的作用。基于果汁的饮食正在变得流行。然而，它们对健康的益处缺乏科学证据。我们的假设是，基于果汁的饮食引起的肠道微生物群的变化在其健康益处中起着重要作用。二十名健康成年人仅连续 3 天饮用蔬菜/果汁，然后恢复 14 天的常规饮食。在第 4 天，我们观察到体重和体重指数（BMI）显著下降（p=2.0E），直到第 17 天（p=3.0E）仍保持下降。第 4 天，粪便中厚壁菌门和变形菌门的比例与基线相比显著降低，拟杆菌门和蓝细菌门的比例增加，并在第 17 天部分恢复。第 4 天，血浆和尿液中的一氧化氮分别增加了 244±89%和 450±360%，与基线相比，尿液脂质过氧化标志物丙二醛降低了 32±21%。研究结束时整体健康状况评分增加。总之，为期 3 天的基于果汁的饮食改变了与体重减轻相关的肠道微生物群，增加了血管扩张剂一氧化氮，并减少了脂质氧化。
