Ross Alastair B
Food and Nutrition Science,Department of Life Science Engineering,Chalmers University of Technology,Kemivägen 10,412 96 Gothenburg,Sweden.
Proc Nutr Soc. 2015 Aug;74(3):320-7. doi: 10.1017/S0029665114001542. Epub 2014 Oct 23.
Dietary fibre alone does not fully explain the frequent association between greater intake of whole grains and reduced risk of disease in observational studies, and other phytochemicals or food structure may also play an important role. For all the observational evidence for the benefits of a whole-grain-rich diet, we have only limited knowledge of the mechanisms behind this reduction in disease risk, aside from the action of specific cereal fibres on reduction of blood cholesterol and the post-prandial glucose peak. Nutritional metabolomics, the global measurement and interpretation of metabolic profiles, assesses the interaction of food with the endogenous gene-protein cascade and the gut microbiome. This approach allows the generation of new hypotheses which account for systemic effects, rather than just focusing on one or two mechanisms or metabolic pathways. To date, animal and human trials using metabolomics to investigate mechanistic changes to metabolism on eating whole grains and cereal fractions have led to new hypotheses around mechanistic effects of whole grains. These include the role of cereals as a major source of dietary glycine betaine, a possible effect on phospholipid synthesis or metabolism, the role of branched-chain amino acids and improvements in insulin sensitivity, and the possibility that whole grains may have an effect on protein metabolism. These hypotheses help explain some of the observed effects of whole grains, although mechanistic studies using stable isotopes and fully quantitative measures are required to confirm these potential mechanisms.
在观察性研究中，仅膳食纤维并不能完全解释全谷物摄入量增加与疾病风险降低之间的频繁关联，其他植物化学物质或食物结构可能也起着重要作用。尽管有大量观察性证据表明富含全谷物的饮食有益健康，但除了特定谷物纤维对降低血液胆固醇和餐后血糖峰值的作用外，我们对这种疾病风险降低背后的机制了解有限。营养代谢组学是对代谢谱进行全面测量和解读，它评估食物与内源性基因 - 蛋白质级联反应以及肠道微生物群之间的相互作用。这种方法能够产生新的假设，这些假设考虑到了全身效应，而不仅仅关注一两种机制或代谢途径。迄今为止，利用代谢组学研究食用全谷物和谷物组分后代谢机制变化的动物和人体试验，已经产生了关于全谷物机制效应的新假设。这些假设包括谷物作为膳食甘氨酸甜菜碱主要来源的作用、对磷脂合成或代谢的可能影响、支链氨基酸的作用以及胰岛素敏感性的改善，还有全谷物可能对蛋白质代谢产生影响的可能性。这些假设有助于解释一些观察到的全谷物的作用，不过需要使用稳定同位素和完全定量测量的机制研究来证实这些潜在机制。
