Faculty of Pharmacy and Center for Neuroscience and Cell Biology, University of Coimbra, Health Sciences Campus, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal.
Faculty of Pharmacy and Center for Neuroscience and Cell Biology, University of Coimbra, Health Sciences Campus, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal.
Free Radic Biol Med. 2020 Mar;149:37-43. doi: 10.1016/j.freeradbiomed.2020.02.001. Epub 2020 Feb 8.
The gut microbiota has been recently interpreted in terms of a metabolic organ that influences the host through reciprocal interactions, encompassing metabolic and immune pathways, genetic and epigenetic programming in host mammal tissues in a diet-depended manner, that shape virtually all aspects of host physiology. In this scenario, dietary nitrate, a major component of leafy green vegetables known for their health benefits, might fuel microbiota metabolism with ensued consequences for microbiota-host interaction. Cumulating evidence support that nitrate shapes oral microbiome communities with impact on the kinetics and systemic levels of both nitrate and nitrite. However, the impact of nitrate, which is steadily delivered into the lower gastrointestinal tract after a vegetable-rich meal, in the intestinal microbiome communities and their functional capacity remains largely elusive. Several mechanisms reinforce the notion that nitrate may be a nutrient for the lower microbiome and might participate in local redox interactions with relevance for bacteria-host interactions, among these nitric oxide-dependent mechanisms along the nitrate-nitrite-nitric oxide pathway. Also, by allowing bacteria to thrive, either by increasing microbial biomass or by acting as a respiratory substrate for the existing communities, nitrate ensures the production of bacterial metabolites (e.g., pathogen-associated molecular patterns, PAMP, short chain fatty acids, among other) that are recognised by host receptors (such as toll-like, TLR, and formyl peptide receptors, FPR) thereby activating local signalling pathways. Here, we elaborate on the notion that via modulation of intestinal microbiota metabolism, dietary nitrate impacts on host-microbiota metabolic and redox interactions, thereby contributing as an essential nutrient to optimal health.
肠道微生物群最近被解释为一个代谢器官，通过互惠的相互作用影响宿主，包括代谢和免疫途径，以及宿主哺乳动物组织的遗传和表观遗传编程，以饮食依赖的方式塑造宿主生理学的几乎所有方面。在这种情况下，膳食硝酸盐，一种绿叶蔬菜的主要成分，以其对健康的益处而闻名，可能通过随后的微生物群-宿主相互作用影响微生物群的代谢。越来越多的证据支持硝酸盐塑造口腔微生物组群落，对硝酸盐和亚硝酸盐的动力学和系统水平都有影响。然而，在肠道微生物组群落及其功能能力方面，蔬菜餐后稳定输送到下胃肠道的硝酸盐的影响在很大程度上仍难以捉摸。有几个机制强化了硝酸盐可能是下微生物群的一种营养物质的观点，并可能参与与细菌-宿主相互作用相关的局部氧化还原相互作用，其中包括沿硝酸盐-亚硝酸盐-一氧化氮途径的一氧化氮依赖机制。此外，通过允许细菌增殖，无论是通过增加微生物生物量还是作为现有群落的呼吸底物，硝酸盐都能确保细菌代谢物（例如，与病原体相关的分子模式、PAMP、短链脂肪酸等）的产生，这些代谢物被宿主受体（如 toll 样受体、TLR 和甲酰肽受体、FPR）识别，从而激活局部信号通路。在这里，我们详细阐述了这样一种观点，即通过调节肠道微生物群的代谢，膳食硝酸盐会影响宿主-微生物群的代谢和氧化还原相互作用，从而作为一种必需营养物质促进最佳健康。
