Ames J M, Wynne A, Hofmann A, Plos S, Gibson G R
Department of Food Science and Technology, University of Reading, Whiteknights, UK.
Br J Nutr. 1999 Dec;82(6):489-95.
The Maillard reaction produces coloured, macromolecular materials (melanoidins) in a variety of foods, on heating. Significant quantities may enter the human gut on a daily basis, but there is little information on their metabolism in the human colon. As the large bowel contains a diverse population of bacteria involved in normal bowel function, it is possible that melanoidins are metabolized therein. Depending on the bacteria involved, there may be disease or health implications. The aim of the present study was to use in vitro models to determine the digestibility of melanoidins and the effect of melanoidins on colonic bacteria in the gastrointestinal tract. Melanoidins were prepared and the effects of simulated upper-gut secretions on their stability determined in a model system. The effects of faecal bacteria were also determined, in batch culture, with a combination of phenotypic and genotypic (probes) criteria being used to identify the microbial diversity involved. Simulation of peptic and pancreatic digestion showed that the melanoidins did not produce detectable amounts of low-molecular-mass degradation products. However, melanoidins affected the growth of gut bacteria during mixed culture growth. The effect was to cause a non-specific increase in the anaerobic bacteria enumerated. This in vitro study indicates that melanoidins can affect the growth of human large-bowel bacteria and serves to demonstrate possible effects that may occur in vivo. Given the large and varied number of food items that contain Maillard reaction products, this may have relevance for lower-gut health.
美拉德反应在多种食物加热过程中会产生有色大分子物质（类黑精）。每天可能有大量此类物质进入人体肠道，但关于它们在人体结肠中的代谢情况却知之甚少。由于大肠中存在多种参与正常肠道功能的细菌，类黑精有可能在其中被代谢。根据所涉及的细菌不同，可能会对疾病或健康产生影响。本研究的目的是使用体外模型来确定类黑精的消化率以及类黑精对胃肠道中结肠细菌的影响。制备了类黑精，并在模型系统中测定了模拟上消化道分泌物对其稳定性的影响。还在分批培养中测定了粪便细菌的影响，使用表型和基因型（探针）标准相结合的方法来鉴定所涉及的微生物多样性。模拟胃蛋白酶和胰蛋白酶消化表明，类黑精不会产生可检测量的低分子量降解产物。然而，类黑精在混合培养生长过程中会影响肠道细菌的生长。其影响是导致所计数的厌氧细菌非特异性增加。这项体外研究表明，类黑精会影响人类大肠细菌的生长，并有助于证明体内可能发生的潜在影响。鉴于含有美拉德反应产物的食物种类繁多且各不相同，这可能与下消化道健康有关。
