根据一项最新研究的结果，由于控制摄入食物的热量而引起的肠道微生物的变化或许能部分解释为什么控制饮食能延长寿命。这项研究主要对象是拉布拉多猎犬。??
肠道微生物和人类以及动物形成一种共生关系，它们在新陈代谢过程中起着非常重要的作用。而一些最新研究显示，这些为微生物的一些异常和很多疾病相关，其中包括糖尿病和肥胖等。??
研究结果发表在4月12日的《Journal of Proteome Research》上，科学家研究了24只猎犬，它们被两两配对，其中一只的进食量比另一只要少25%。研究结果表明，这些摄入能量较少的个体平均寿命要比同组中另外一只长1.8岁，而且它们的疾病也更少，老年性疾病出现得更晚。??
来自伦敦帝国理工学院Nestle研究中心的这些科学家发现，在控制饮食的狗和未控制的个体间存在长期的代谢差异。代谢在决定动物对疾病的免疫以及易感性方面起着重要作用。科学家相信，肠道中微生物的差异是其中部分原因，未控制饮食的狗尿中潜在不健康的脂族胺较多，这反映了一种脂类代谢的重要物质缺乏——它和肠道微生物相关。??
研究小组认为，健康的代谢和狗的控制饮食相关，这会改变肠道微生物的活跃性，从而提升健康状态，延长寿命。科学家表示，此项研究成果的一个重要应用是模拟狗类的饮食控制来设计人类产品的营养特性。
部分英文原文：
J. Proteome Res., ASAP Article 10.1021/pr060685n S1535-3893(06)00685-3
Web Release Date: April 6, 2007 Copyright © 2007 American Chemical Society
Metabonomic Investigations of Aging and Caloric Restriction in a Life-Long Dog Study
Yulan Wang, Dennis Lawler, Brian Larson, Ziad Ramadan, Sunil Kochhar, Elaine Holmes, and Jeremy K. Nicholson*
Department of Biomolecular Medicine, SORA Division, Faculty of Medicine, Imperial College London, Sir Alexander Fleming Building, South Kensington, London SW7 2AZ, United Kingdom, Nestlé Research Center, Lausanne, NESTEC Ltd., Vers-Chez-Les-Blanc, 1000 Lausanne 26, Switzerland, and The Nestle Research Center-St. Louis, St. Louis, Missouri 63164
Received December 20, 2006
Abstract:
Long-term restriction of energy intake without malnutrition is a robust intervention that has been shown to prolong life and delay age-related morbidity. A 1H NMR-based metabonomic strategy was used to monitor urinary metabolic profiles throughout the lifetimes of control-fed and diet-restricted dogs. Urinary metabolic trajectories were constructed for each dog, and metabolic variation was found to be predominantly influenced by age. Urinary excretion of creatinine increased with age, reaching a maximum between ages 5 and 9 years and declining thereafter. Excretion of mixed glycoproteins was noted at earlier ages, which may be a reflection of growth patterns. In addition, consistent metabolic variation related to diet was also characterized, and energy-associated metabolites, such as creatine, 1-methylnicotinamide, lactate, acetate, and succinate, were depleted in urine from diet-restricted dogs. Both aging and diet restriction altered activities of the gut microbiotia, manifested by variation of aromatic metabolites and aliphatic amine compounds. This analysis allowed the metabolic response to two different physiological processes to be monitored throughout the lifetime of the canine population and may form part of a strategy to monitor and reduce the impact of age related diseases in the dog, as well as providing more general insights into extension of longevity in higher mammals.
Keywords: metabonomics aging restricted diet multivariate data analysis 1H NMR spectroscopy
英文全文链接：http://pubs.acs.org/cgi-bin/sample.cgi/jprobs/asap/html/pr060685n.html
