The gut microbiota (GM) composition varies among individuals and is influenced by intrinsic (genetics, age) and extrinsic (environment, diet, lifestyle) factors. An imbalance or dysbiosis is directly associated with the development of several illnesses, due to the potential increase in intestinal permeability leading to a systemic inflammation triggered by higher levels of circulating lipopolysaccharides and changes in the immune response caused by an overgrowth of a specific genus or of pathogens. These mechanisms may increase symptoms in gastrointestinal disorders or reduce glucose tolerance in metabolic diseases. Diet also has a significant impact on GM, and functional foods, namely prebiotics and probiotics, are a novel approach to reestablish the indigenous microbiota. Prebiotics, like inulin and polyphenols, are selectively utilized by GM, releasing short-chain fatty acids (SCFA) and other metabolites which may reduce the intestinal lumen pH, inhibit growth of pathogens, and enhance mineral and vitamin bioavailability. Probiotic microorganism may increase the microbial diversity of GM and improve the integrity of the intestinal barrier, leading to an improvement of baseline and pathologic inflammation. In this chapter, we will discuss the potential roles of prebiotics and probiotics in health and diseases throughout an individual's lifetime and proposed mechanisms of action.

肠道菌群（GM）的组成因个体而异，并受内在（遗传，年龄）和外在（环境，饮食，生活方式）因素的影响。不平衡或营养不良与几种疾病的发展直接相关，这是由于肠道通透性的潜在增加导致循环性脂多糖水平升高引发的全身性炎症，以及特定属或特定属的过度生长引起的免疫应答改变。病原体。这些机制可能会增加胃肠道疾病的症状或降低代谢疾病中的葡萄糖耐量。饮食对转基因也有重大影响，功能性食品，即益生元和益生菌，是重建本地微生物群的一种新颖方法。GM选择性地使用了菊粉和多酚等益生元，释放短链脂肪酸（SCFA）和其他代谢产物，这些代谢产物可能会降低肠道管腔的pH值，抑制病原体的生长并增强矿物质和维生素的生物利用度。益生菌微生物可以增加GM的微生物多样性，并改善肠屏障的完整性，从而改善基线和病理性炎症。在本章中，我们将讨论益生元和益生菌在个人一生中在健康和疾病中的潜在作用，以及拟议的作用机制。导致基线和病理炎症的改善。在本章中，我们将讨论益生元和益生菌在个人一生中在健康和疾病中的潜在作用，以及拟议的作用机制。导致基线和病理炎症的改善。在本章中，我们将讨论益生元和益生菌在个人一生中在健康和疾病中的潜在作用，以及拟议的作用机制。