Interactions of probiotics and gut microbes with the immune system: examining roles of food components, microbial metabolites and neurochemical mediators

益生菌和肠道微生物与免疫系统的相互作用：检查食物成分、微生物代谢物和神经化学介质的作用

• 批准号: RGPIN-2016-04585
• 负责人: GreenJohnson, Julia
• 金额: $ 2.04万
• 依托单位: University of Ontario Institute of Technology
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=615160
• 关键词: Interactions; probiotics; gut; microbes; immune

Interactions between gut microbes and their hosts are now known to be important in many aspects of host defence, playing roles in choreographing immune activity and in immune system development. Nevertheless, many questions remain related to the mechanisms of gut microbes’ interactions with host cells that are important for host defence and immune homeostasis at the intestinal barrier. Host cells at the intestinal interface encounter not only gut microbes, but also products of microbial metabolism, and varied food components. Lactic acid bacteria (LAB) are gut microbes that are often consumed in fermented foods and as probiotics. Understanding the mechanisms through which LAB influence the immune system provides valuable insight into specific mechanisms of probiotic action as well as the actions of gut microbes on a broader scale. LAB in fermented foods are both influenced by, and cause changes in, food components; this in turn can alter their impact on the immune system when these foods are consumed. One objective of this work is to examine how LAB in fermented milk interact with host cells, and how these interactions are influenced by microbial products made during milk fermentation. Dietary fibres and prebiotics are often consumed in foods for their potential health benefits, mediated in part through their impact on gut microbial activity. Fermentation of fibres and prebiotics leads to microbial metabolite production, including short chain fatty acids with downstream effects on the immune system. Another objective of this research is to determine how these products modulate actions of gut microbes such as LAB and alter their impact on the immune system. Since components of several dietary fibres and prebiotics can also directly activate cells of the immune system, information about direct and indirect effects is useful for understanding their impact on host defence. In addition, current evidence indicating that effects of fibres and prebiotics on the immune system differ between sexes points to an important role for host factors such as estrogen in diet-microbe interactions. Thus, it is important to test differences in the impact of dietary components and supplements on females and males. A third objective of this research is to analyze direct and indirect effects of dietary fibres and prebiotics on the immune system, taking sex-based differences into account. Anticipated outcomes of this research will be new insight into how the immune system is affected by food components, LAB, microbial products, the interactions between them, and a clearer understanding of differences in impact between sexes. Students involved in this research will gain experience and knowledge that can contribute to better understanding of applications for food components, probiotics and the outcomes of gut microbial activity on host defence, elements important for dietary strategies in the daily lives of Canadians.

肠道微生物和它们的宿主之间的相互作用现在被认为在宿主防御的许多方面都很重要，在编排免疫活动和免疫系统发展中发挥作用。然而，许多问题仍然与肠道微生物与宿主细胞相互作用的机制有关，这些机制对于宿主防御和肠道屏障的免疫动态平衡非常重要。肠道界面的宿主细胞不仅会遇到肠道微生物，还会遇到微生物代谢的产物，以及各种食物成分。乳酸菌(LAB)是一种肠道微生物，常被用作发酵食品和益生菌。通过了解实验室影响免疫系统的机制，可以在更广泛的范围内深入了解益生菌作用的具体机制以及肠道微生物的作用。发酵食品中的乳酸菌既受食物成分的影响，也会引起食物成分的变化；当人们食用这些食物时，这反过来又会改变它们对免疫系统的影响。这项工作的一个目标是研究发酵牛奶中的LAB如何与宿主细胞相互作用，以及这些相互作用如何受到牛奶发酵过程中产生的微生物产品的影响。膳食纤维和益生元经常被消费在食品中，以获得潜在的健康益处，部分原因是它们对肠道微生物活动的影响。纤维和益生元的发酵导致微生物代谢物的产生，包括对免疫系统产生下游影响的短链脂肪酸。这项研究的另一个目标是确定这些产品如何调节肠道微生物的活动，如LAB，并改变它们对免疫系统的影响。由于几种膳食纤维和益生素的成分也可以直接激活免疫系统的细胞，有关直接和间接影响的信息有助于了解它们对宿主防御的影响。此外，目前的证据表明，纤维和益生元对免疫系统的影响在性别之间存在差异，这表明宿主因素，如雌激素，在饮食-微生物相互作用中发挥着重要作用。因此，重要的是测试饮食成分和补充剂对女性和男性的影响差异。这项研究的第三个目标是分析膳食纤维和益生元对免疫系统的直接和间接影响，同时考虑到性别差异。这项研究的预期结果将是对食品成分、实验室、微生物产品如何影响免疫系统的新见解，以及它们之间的相互作用，以及对性别影响差异的更清晰理解。参与这项研究的学生将获得经验和知识，有助于更好地了解食品成分、益生菌和肠道微生物活动对宿主防御的结果，这些元素对加拿大人日常生活中的饮食策略非常重要。