BACKGROUND During aging, alterations of the intestinal microbial ecosystem can occur contributing to immunosenescence, inflamm-aging and impairment of intestinal barrier function (increased intestinal permeability; IP). In the context of a diet-microbiota-IP axis in older subjects, food bioactives such as polyphenols may play a beneficial modulatory role. METHODS MaPLE is a project centered on a randomized, controlled cross-over dietary intervention trial [polyphenol-rich diet (PR-diet) versus control diet (C-diet)] targeted to older people (≥ 60 y) living in a well-controlled setting (i.e. nursing home). The 8-week interventions are separated by an 8-week wash-out period. Three small portions per day of selected polyphenol-rich foods are consumed during intervention in substitution of other comparable products within the C-diet. Biological samples are collected before and after each treatment period to evaluate markers related to IP, inflammation, vascular function, oxidative stress, gut and blood microbiomics, metabolomics. A sample size of 50 subjects was defined based on IP as primary outcome. DISCUSSION Evidence that increasing the consumption of polyphenol-rich food products can positively affect intestinal microbial ecosystem resulting in reduced IP and decreased translocation of inflammogenic bacterial factors into the bloodstream will be provided. The integration of data from gut and blood microbiomics, metabolomics and other IP-related markers will improve the understanding of the beneficial effect of the intervention in the context of polyphenols-microbiota-IP interactions. Finally, findings obtained will provide a proof of concept of the reliability of the dietary intervention, also contributing to future implementations of dietary guidelines directed to IP management in the older and other at risk subjects. TRIAL REGISTRATION The trial is registered at (ISRCTN10214981); April 28, 2017.

中文翻译：

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富含多酚的饮食模式对老年受试者肠道通透性以及肠道和血液微生物的影响：MaPLE随机对照试验的研究方案。

背景技术在衰老期间，可能发生肠道微生物生态系统的变化，从而导致免疫衰老，炎症老化和肠屏障功能受损（肠通透性增加； IP）。在老年受试者的饮食-微生物-IP轴的背景下，食物生物活性物质（例如多酚）可能发挥有益的调节作用。方法MaPLE是一个针对随机，对照交叉饮食干预试验[富含多酚的饮食（PR-饮食）与对照饮食（C-饮食）]的项目，针对生活在健康饮食中的老年人（≥60岁）控制设置（即养老院）。8周的干预由8周的清除期分隔。在干预期间，每天要消耗三小份选定的富含多酚的食物，以替代C饮食中的其他可比较产品。在每个治疗期之前和之后收集生物样品，以评估与IP，炎症，血管功能，氧化应激，肠道和血液微生物组学，代谢组学有关的标志物。基于IP作为主要结果，定义了50名受试者的样本量。讨论将提供证据，证明富含多酚的食品的消费量增加可以对肠道微生物生态系统产生积极影响，从而导致IP降低以及炎性细菌因子向血液中的转移减少。来自肠道和血液微生物组学，代谢组学和其他IP相关标记的数据的整合将增进对多酚-微生物-IP相互作用背景下干预措施有益作用的了解。最后，所获得的发现将提供饮食干预可靠性概念的证明，也有助于将来针对老年人和其他高危人群的IP管理的饮食指导方针的实施。试验注册该试验在（ISRCTN10214981）进行了注册；2017年4月28日。