Phytochemicals in fruits and vegetables produce health benefits, but questions remain regarding their bioavailability, molecular targets, and mechanism of action. Here, we address these issues by considering the prebiotic and biological properties of phytochemicals. A fraction of phytochemicals consumed orally passes through the gut lumen, where it modulates the composition of the gut microbiota and maintains intestinal integrity. Phytochemicals and microbiota-derived metabolites that are absorbed by the organism comprise compounds that, at low doses, induce stress resistance mechanisms, including autophagy, DNA repair, and expression of detoxifying and antioxidant enzymes. We propose that these mechanisms improve cellular and organ function and can account for the promiscuous bioactivities of phytochemicals, despite their limited bioavailability and extremely varied chemical structures.

中文翻译：

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植物化学物质作为益生元和生物应激诱导剂。

水果和蔬菜中的植物化学物质可带来健康益处，但有关其生物利用度，分子靶标和作用机理的问题仍然存在。在这里，我们通过考虑植物化学物质的益生元和生物学特性来解决这些问题。口服消耗的一部分植物化学物质穿过肠道内腔，在那里调节肠道菌群的组成并维持肠道完整性。被生物体吸收的植物化学物质和微生物来源的代谢产物包含低剂量时可诱导抗逆性机制的化合物，包括自噬，DNA修复以及解毒和抗氧化酶的表达。我们认为这些机制可改善细胞和器官功能，并可解释植物化学物质的混杂生物活性，