Molecular Nutrition Group, Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen AB21 9SB, UK.
Proc Nutr Soc. 2011 Aug;70(3):389-96. doi: 10.1017/S0029665111000152.
Plant-based diets contain a plethora of secondary metabolites that may impact on health and disease prevention. Much attention has been focused on the potential bioactivity and nutritional relevance of several classes of phytochemicals such as flavonoids, carotenoids, phyto-oestrogens and glucosinolates. Less attention has been paid to simple phenolic acids that are widely found in fruit, vegetables, herbs, spices and beverages. Daily intakes may exceed 100 mg. In addition, bacteria in the gut can perform reactions that transform more complex plant phenolics such as anthocyanins, procyanidins, flavanones, flavonols, tannins and isoflavones into simple phenolic metabolites. The colon is thus a rich source of potentially active phenolic acids that may impact both locally and systemically on gut health. Both the small and large intestine (colon) contain absorption sites for phenolic acids but low post-prandial concentrations in plasma indicate minimal absorption early in the gastrointestinal tract and/or rapid hepatic metabolism and excretion. Therefore, any bioactivity that contributes to gut health may predominantly occur in the colon. Several phenolic acids affect the expression and activity of enzymes involved in the production of inflammatory mediators of pathways thought to be important in the development of gut disorders including colon cancer. However, at present, we remain largely ignorant as to which of these compounds are beneficial to gut health. Until we can elucidate which pro-inflammatory and potentially carcinogenetic changes in gene expression can be moderated by simple phenolic acids, it is not possible to recommend specific plant-based foods rich in particular phenolics to optimise gut health.
植物性饮食中含有丰富的次生代谢产物，可能对健康和疾病预防产生影响。人们对许多类植物化学物质的潜在生物活性和营养相关性给予了高度关注，如类黄酮、类胡萝卜素、植物雌激素和硫代葡萄糖苷等。而对广泛存在于水果、蔬菜、草药、香料和饮料中的简单酚酸的关注较少。人们的日常摄入量可能超过 100 毫克。此外，肠道中的细菌可以进行反应，将更复杂的植物酚类物质如花青素、原花青素、黄烷酮、黄酮醇、单宁和异黄酮转化为简单的酚酸代谢物。因此，结肠是潜在具有活性的酚酸的丰富来源，这些酚酸可能会对肠道健康产生局部和全身影响。小肠和大肠（结肠）都含有酚酸的吸收部位，但血浆中餐后浓度低表明在胃肠道的早期吸收很少，或者肝脏代谢和排泄迅速。因此，任何对肠道健康有贡献的生物活性可能主要发生在结肠。一些酚酸会影响参与炎症介质产生的酶的表达和活性，这些酶的功能与被认为对肠道疾病（包括结肠癌）发展很重要的途径有关。然而，目前我们对哪些化合物对肠道健康有益还知之甚少。在我们能够阐明简单酚酸可以调节哪些促炎和潜在致癌基因表达的变化之前，我们不可能推荐富含特定酚类化合物的特定植物性食物来优化肠道健康。
