Today, tomorrow, learn English naturally. 天天自然学英语
Study finds that ketone bodies, as alternative cellular fuels, boost immunity
A metabolic by-product that is more prevalent during fasting may supercharge immune cells as they fight infection and disease, reports an early stage study by Van Andel Institute scientists and collaborators.
The findings, published July 28 in Immunity, may pave the way for future personalized dietary recommendations to augment treatments for infection, cancer and other diseases.
"This study helps us better understand how nutrition affects the immune system," said VAI Professor Russell Jones, Ph.D., the study's corresponding author. "This is an exciting first step and we look forward to one day translating this knowledge into dietary recommendations to boost immune function."
The findings center on ketone bodies, which are regularly produced by the liver but become more numerous when glucose, a sugar that acts as the main power source for cells, is in short supply. This can occur during exertion such as exercise, when cells are rapidly burning through fuel, or during fasting, when there is little food available to be broken down into glucose.
To compensate, the liver steps up production of ketone bodies to feed the brain and other organs. The study shows that ketone bodies also power immune cells, a surprise finding that illuminates new connections between diet and immunity.
Like other cells in the body, T cells—the soldiers of the immune system—absorb nutrients like glucose from our diets to generate the energy required to do their jobs. Jones and colleagues demonstrated that T cells prefer ketone bodies over glucose as a fuel source. They also found that ketone bodies improve T cell function by reprogramming them to better neutralize threats. Conversely, loss of the ability to process ketone bodies causes defects in T cell function and hampers their ability to combat infection.
The authors hypothesize that ketone bodies may be an evolutionary failsafe that boosts the immune system when nutrient resources are limited, such as when one's appetite is suppressed during illness.
"This work underscores how different nutrient fuels source distinct cellular functions," said Peter Crawford, M.D., Ph.D., Vice Dean for Research and Professor of Medicine at University of Minnesota Medical School and study co-author. "It also fosters future interest in considering the diversity of nutrient fuel utilization patterns among different immune cell types in varying infectious disease or cancer contexts."
Although the study suggests increasing ketone bodies through fasting or intermittent fasting regimens may enhance T cell function in certain circumstances, other studies suggest that fasting may suppress immune function. Rather than being at odds with one another, these studies illuminate the intricate interactions between diet and the immune system and underscore the need for further research into this complex relationship.
Going forward, Jones and colleagues will explore how fasting and ketone body supplementation impacts immune function, with a focus on T cells' ability to fight cancer.
注释：
ketone: n
表示" 酮"，means "any of a class of organic compounds having a carbonyl group linked to a carbon atom in each of two hydrocarbon radicals"，如：But in starvation ketone bodies replace glucose to an increasing extent. 但在饥饿期，酮体就越来越多地取代了葡萄糖。
augment: v; n
表示""，means " (cause to) become bigger, more valuable, better etc."，如：They hit upon another idea to augment their income. 他们又想出一个增加收入的办法。
glucose: n
表示" 葡萄糖"，means "an important source of physiological energy"，如：We injected the glucose into the patient's vein.我们给病人的静脉里注射了葡萄糖。
exertion: n
表示" 努力；发挥；运用"，means "the use of power to make sth happen"，如：Using these expressing devices appropriately redounds to the exertion of banter's social functions. 适当运用各类玩笑表达方式能充分发挥玩笑的交际功能。
neutralize: v
表示"中和"，means "make politically neutral and thus inoffensive"，如：High taxes will neutralize increased wages. 高税收将抵销增加了的工资。
hamper: v
表示" 妨碍；阻止"，means "cause difficulty in movement or activity"，如：Our progress was hampered by the bad weather. 我们前进时受到了恶劣天气的阻碍。
failsafe: n
表示"故障保险"，如：Does your stateful business process need to be failsafe? 您的有状态业务过程需要故障保护吗?
underscore: v
表示"强调"，means "give extra weight to (a communication)"，如：Please underscore the word three times for emphasis. 为了强调起见，请在该词下面划三条线。
intermittent: adj
表示"断断续续的"，means " happening, then stopping, then happening again; not continuous"，如：They saw the intermittent flashes from a lighthouse. 他们看见了灯塔发出一闪一灭的光。
regimen: n
表示" 养生法；生活规则"，means "(medicine) a systematic plan for therapy (often including diet)"，如：Under such a regimen you'll certainly live long. 你这样养生一定可以长寿。
intricate: adj
表示" 复杂的；难懂的"，means "containing many small parts or details that all work or fit together"，如：It was an intricate and ingenious system. 这是一个复杂而精致的体系。
中文简要说明：
生病的时候，我们总是会食欲不振，这时就出现两难，是勉强扒个几口饭增加营养重要? 还是吃不下就别勉强，等精神好一点再吃饭呢? 一项研究终于破解了生病食欲不振的原因，科学家表示，还是先顺从身体的意见，吃不下就别勉强，因为肝脏正在分泌酮体，可以增强免疫细胞对付病原体。
医疗讯息(MedicalxPress)报导，美国密执安州范安德研究中心(Van Andel Institute)的科学团队一项早期研究报告称，禁食期间的肝脏的代谢副产物「酮体」(ketone)，可以增强免疫细胞对抗感染和疾病的能力。
这项研究的报导发表在7月28日出刊的《免疫》杂志(Immunity)上，研究团队主持人琼斯博士(Russell Jones)表示，这是我们更好地了解营养如何影响免疫系统，我们期待有一天，可将这些知识转化更有利的饮食建议，同时恢复营养也强化免疫力。
研究人员发现，当葡萄糖供应短缺时，肝藏会分泌更多的酮体，这些酮体像是细胞代谢的加力器，能够驱动细胞快速工作。虽然酮体不是常规的营养，但颇为特别的是，免疫细胞会倾向吸收酮体做为动力来源。琼斯博士与其他同事证明，包括T细胞这样的免疫细胞，与葡萄糖相比，它们更喜欢酮体当燃料。
进一步研究发现，酮体可以使T细胞重新活化，以更好的效率来消除威胁，而丧失处理酮体的能力，会导致T细胞功能缺陷，反而妨碍对抗抵抗感染的能力。
琼斯博猜测，酮体可能是一种进化的安全机制，遭到病原体入侵时，此时身体警报讯号会希望先阻断病原体的持续进入，而每一次的饮食，对身体来说，也都有病原体入侵的风险，因此会先阻断食欲，以减低持续感染的风险。另一方面，病原体不容易使用酮体做为养料，而体细胞与免疫细胞却可以，这就增加了对抗病原体的优势。
另一位论文作者-明尼苏达大学医学院营养学研究所副院长科拉福特博士(Peter Crawford ) 说：「这项研究了解了不同的营养燃料，如何驱动不同的细胞功能。这也触发人们对于不同传染病、癌症的免疫疗法新方向，我们或许可以合成酮体，来加快这一过程。」
留言微信公众号《自然学英语LearnNaturally》，可咨询更多！