Schneeman Barbara O
Department of Nutrition, University of California, Davis 95616, USA.
Br J Nutr. 2002 Nov;88 Suppl 2:S159-63. doi: 10.1079/BJN2002681.
While the health benefit of a functional food may be a metabolic response that lowers risk for disease, the actual target for the food or food component may be on the functioning of the gastrointestinal tract (GIT). For example, slowing absorption from the intestine, as measured by examining the appearance of the nutrient or food component in the blood, the hormone response associated with absorption of the compound or excretion of the compound, may provide a health benefit. However, the food component may slow absorption by delaying gastric emptying, altering the mixing within the intestinal contents or decreasing the availability of digestive enzymes in the intestine. These measures of GIT function provide validation of the mechanisms by which the functional food or food components affect metabolism. Bioavailability of physiologically active compounds from foods will be determined by the digestibility of foods that contain these compounds, their subsequent absorption and utilization by tissues. The physical structure of foods contributes to the functional effects of foods as well as to the availability of compounds from foods. For example, recent studies have demonstrated that changing the viscosity of the gut contents alters absorption and GIT response. Additionally, food structures such as the plant cell wall change the availability of absorbable compounds along the gastrointestinal contents. The areas of probiotics and prebiotics have highlighted the potential importance of gut microflora in health. While evidence suggests biological activity relevant to disease risk reduction, the long-term implications of the microbial activity have yet to be established.
虽然功能性食品对健康的益处可能是一种降低疾病风险的代谢反应，但该食品或食品成分的实际作用靶点可能是胃肠道（GIT）的功能。例如，通过检测血液中营养物质或食品成分的出现情况、与该化合物吸收或排泄相关的激素反应来衡量，减缓肠道吸收可能带来健康益处。然而，食品成分可能通过延迟胃排空、改变肠内容物的混合或降低肠道内消化酶的活性来减缓吸收。这些胃肠道功能的指标验证了功能性食品或食品成分影响新陈代谢的机制。食物中生理活性化合物的生物利用度将取决于含有这些化合物的食物的消化率、它们随后被组织吸收和利用的情况。食物的物理结构既影响食物的功能效果，也影响食物中化合物的可利用性。例如，最近的研究表明，改变肠道内容物的粘度会改变吸收和胃肠道反应。此外，诸如植物细胞壁等食物结构会改变沿胃肠道内容物的可吸收化合物的可利用性。益生菌和益生元领域凸显了肠道微生物群在健康方面的潜在重要性。虽然有证据表明其与降低疾病风险相关的生物活性，但微生物活性的长期影响尚未确定。
