Rutgers, The State University of New Jersey, Department of Plant Biology, Foran Hall, New Brunswick, NJ, United States of America.
Rutgers, The State University of New Jersey, Department of Food Science, Institute for Food Nutrition and Health, Center for Digestive Health, New Brunswick, NJ, United States of America.
PLoS One. 2018 Oct 11;13(10):e0198716. doi: 10.1371/journal.pone.0198716. eCollection 2018.
High-fat diet (HFD)-induced leaky gut syndrome combined with low-grade inflammation increase reactive oxygen species (ROS) in the intestine and may contribute to dysbiosis and metabolic syndrome (MetS). Poorly bioavailable and only partially metabolizable dietary polyphenols, such as proanthocyanidins (PACs), may exert their beneficial effects on metabolic health by scavenging intestinal ROS. To test this hypothesis, we developed and validated a novel, noninvasive, in situ method for visualizing intestinal ROS using orally administered ROS-sensitive indocyanine green (ICG) dye. C57BL/6J mice fed HFD for 10 weeks accumulated high levels of intestinal ROS compared to mice fed low-fat diet (LFD). Oral administration of poorly bioavailable grape polyphenol extract (GPE) and β-carotene decreased HFD-induced ROS in the gut to levels comparable to LFD-fed mice, while administration of more bioavailable dietary antioxidants (α-lipoic acid, vitamin C, vitamin E) did not. Forty percent of administered GPE antioxidant activity was measured in feces collected over 24 h, confirming poor bioavailability and persistence in the gut. The bloom of beneficial anaerobic gut bacteria, such as Akkermansia muciniphila, associated with improved metabolic status in rodents and humans may be directly linked to protective antioxidant activity of some dietary components. These findings suggest a possible mechanistic explanation for the beneficial effects of poorly bioavailable polyphenols on metabolic health.
高脂肪饮食（HFD）诱导的肠道渗漏综合征伴低水平炎症会增加肠道内的活性氧（ROS），可能导致肠道菌群失调和代谢综合征（MetS）。生物利用度差且仅部分可代谢的膳食多酚，如原花青素（PACs），可能通过清除肠道 ROS 发挥其对代谢健康的有益作用。为了验证这一假设，我们开发并验证了一种使用口服 ROS 敏感吲哚菁绿（ICG）染料可视化肠道 ROS 的新型非侵入性原位方法。与低脂饮食（LFD）喂养的小鼠相比，喂养 HFD 10 周的 C57BL/6J 小鼠肠道内 ROS 水平升高。口服生物利用度差的葡萄多酚提取物（GPE）和β-胡萝卜素可降低 HFD 诱导的肠道 ROS，使其水平与 LFD 喂养的小鼠相当，而生物利用度更高的膳食抗氧化剂（α-硫辛酸、维生素 C、维生素 E）则没有。在 24 小时内收集的粪便中检测到 40%给予的 GPE 抗氧化活性，证实了其在肠道内的生物利用度差和持久性。与啮齿动物和人类代谢状态改善相关的有益厌氧肠道细菌（如 Akkermansia muciniphila）的大量繁殖可能与某些膳食成分的保护性抗氧化活性直接相关。这些发现为生物利用度差的多酚对代谢健康的有益作用提供了一种可能的机制解释。
