Study: Diet makes a difference in fight against hospital-acquired infection 飲食在抵抗醫院獲得性感染方面發揮了重要作用

News Release 12-Feb-2020

新闻稿2020年2月12日

研究：饮食在对抗医院获得性感染方面有所作为

UNLV的新研究表明，高碳水化合物，低蛋白和低脂饮食抵抗艰难梭菌感染方面的作用有望实现

内华达大学，拉斯维加斯

拉斯维加斯-2020年2月11日-低碳水化合物，高脂肪和高蛋白质的流行饮食可能对腰围有益，但UNLV的一项新研究表明，相反的饮食习惯可能有助于缓解医院获得的艰难梭菌感染。

在美国微生物学会的开放存取期刊mSystems上发表的一项研究中，UNLV科学家发现，抗生素的使用与高脂/高蛋白饮食之间的相互作用加剧了小鼠的C. diff感染。相反，他们发现高碳水化合物饮食-相应地脂肪和蛋白质含量低-几乎消除了症状。

diff。C. diff是一种被美国疾病控制与预防中心指定为紧急威胁的肠道感染，通常是在抗生素消灭了肠道中的“好”细菌后才获得的。每年有数十万人被诊断出感染艰难梭菌，超过10,000人死亡。

UNLV微生物学家和研究合著者Brian Hedlund说：“每天，我们都在了解有关人类微生物组及其在人类健康中的重要性的更多信息。 “肠道微生物组受到饮食的强烈影响，但diff。C. diff研究界尚未就饮食对其风险或严重程度的影响达成共识。我们的研究通过测试几种营养成分含量差异很大的饮食来解决这一问题。也就是说，饮食中碳水化合物，蛋白质和脂肪的平衡差异很大。”

尽管研究表明饮食中的蛋白质会加重C. diff。，但很少有研究探讨高脂/高蛋白饮食与感染的相互作用。 Hedlund和该研究的合著者，UNLV生物化学家Ernesto Abel-Santos警告说，该研究是使用动物模型进行的，并且正在进行更多工作来建立这些饮食与人类感染之间的联系。

阿贝尔·桑托斯说：“极端饮食正变得非常流行，但我们不知道对人类健康，特别是对人类肠道菌群健康的长期影响。” “我们必须研究人类，看看它们是否相关。”

最近的研究表明，由于抗生素会不加区别地杀死细菌，因此药物会淘汰竞争氨基酸的生物种群，从而使艰难梭菌得以自由繁殖。

但是赫德伦德说，这个故事更加复杂。他说：“很明显，这不仅仅是数字游戏。”这项新的研究表明，饮食可以促进即使在使用抗生素后也可以起到保护作用的微生物群。为了使感染旺盛，他说：“您可能需要将抗生素的竞争差异消灭，然后再饮食以促进过度生长和疾病。”

这项新研究也提出了其他问题。例如：高碳水化合物饮食可以预防diff。C. diff。感染，从而引起了最少的微生物群落。

Abel-Santos说：“许多论文说，降低微生物多样性始终是一件坏事，但在这种情况下，它具有最佳的疾病结果。”但是，他告诫说，高碳水化合物饮食可能导致动物成为无症状携带者，并可以将感染传播给易感人群。

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Abel-Santos实验室已经与diff。C. diff合作了12年，其目标是开发可以预防这种细菌感染的化合物。 Hedlund实验室已经与diff。C. diff合作了五年，专注于饮食在感染中的作用。这项合作得到了美国国立卫生研究院的资助。

出版物详细信息
“高脂/高蛋白阿特金斯型饮食加重了梭状芽孢杆菌（梭状芽孢杆菌）在小鼠中的难感染性，而高碳水化合物饮食保护着小鼠”于2月11日在mSystems（美国微生物学杂志）上发表。

New UNLV research shows promise for role of a high-carb, low-protein, and low-fat diet in fighting off C. diff infections

University of Nevada, Las Vegas

LAS VEGAS – February 11, 2020 – Popular diets low in carbs and high in fat and protein might be good for the waistline, but a new UNLV study shows that just the opposite may help to alleviate the hospital-acquired infection Clostridioides difficile.

In a study published in mSystems, an open access journal of the American Society for Microbiology, UNLV scientists found that an interaction between antibiotic use and a high-fat/high-protein diet exacerbate C. diff infections in mice. Conversely, they found that a high-carbohydrate diet – which was correspondingly low in fat and protein – nearly eliminated symptoms.

C. diff, an intestinal infection designated as an urgent threat by the U.S. Centers for Disease Control and Prevention, is often acquired when antibiotics have wiped out the “good” bacteria in the gut. Hundreds of thousands of people are diagnosed with C. diff infections each year and more than 10,000 die.

“Every day, we are learning more about the human microbiome and its importance in human health,” said Brian Hedlund, a UNLV microbiologist and study co-author. “The gut microbiome is strongly affected by diet, but the C. diff research community hasn’t come to a consensus yet on the effects of diet on its risk or severity. Our study helps address this by testing several diets with very different macronutrient content. That is, the balance of dietary carbohydrate, protein, and fat were very different.” 

Though studies suggest dietary protein exacerbates C. diff, there’s little or no existing research exploring the interaction of a high-fat/high-protein diet with the infection. Hedlund and study co-author Ernesto Abel-Santos, a UNLV biochemist, caution that the study was conducted using an animal model, and more work is underway to begin to establish a link between these diets and infections in people.

“Extreme diets are becoming very popular but we do not know the long-term effects on human health and specifically on the health of the human gut flora,” Abel-Santos said. “We have to look at humans to see if it correlates.”

Recent studies suggest that because antibiotics kill bacterial species indiscriminately, the medications decimate populations of organisms that compete for amino acids, leaving C. diff free to propagate.

But Hedlund said the story is even more complex. “It’s clear that it’s not just a numbers game,” he said. The new work suggests that diet may promote microbial groups that can be protective, even after antibiotics. For an infection to flourish, he said, “you might need this combination of wiping out C. diff competitors with antibiotics and then a diet that promotes overgrowth and disease.”

The new study raised other questions as well. For example: The high-carb diet, which was protective against C. diff infection, gave rise to the least diverse community of microbes.

“Lots of papers say that a lower microbial diversity is always a bad thing, but in this case, it had the best disease outcome,” said Abel-Santos. However, he cautions that a high-carb diet could lead to animals becoming asymptomatic carriers that can disseminate the infection to susceptible subjects.

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The Abel-Santos lab has been working with C. diff for 12 years with the goal of developing compounds that could prevent infections from this bacterium. The Hedlund lab has been working with C. diff for five years, focusing on the role of diet in infection. This collaboration was supported by a grant from the National Institutes of Health.

Publication Details

“A High-Fat/High-Protein, Atkins-Type Diet Exacerbates Clostridioides (Clostridium) Difficile Infection in Mice, Whereas a High-Carbohydrate Diet Protects” appeared Feb. 11 in mSystems, a journal of the American Society for Microbiology