INRA, MICALIS-UMR1319, Domaine de Vilvert, Jouy-en-Josas, France.
Dig Dis. 2012;30 Suppl 3:33-9. doi: 10.1159/000342595. Epub 2013 Jan 3.
Human biology can only be fully assessed by combining an analysis of both the host and its surrounding environment. As a part of the environment, the human gastrointestinal tract hosts more than 100 trillion bacteria making up the gut microbiota. The human host provides a nutrient-rich environment while the microbiota provides indispensable functions that humans cannot exert themselves. Shifts in the bacterial makeup of the human gut microbiota have been associated with disorders such as inflammatory bowel disease (IBD), irritable bowel syndrome and obesity. However, since most bacteria inhabiting our gut are not cultivable to date, until recently little was known about their individual functions. Metagenomics, i.e. the analysis of the collective genomes present in a defined ecosystem, gives insight into these specific functions. The first extensive catalogue of the intestinal metagenome outnumbers the size of the human genome by a factor of 150. Recently, 3 distinct 'types' of gut composition within the human population have been highlighted. These so-called 'enterotypes' are characterized by the dominant genera (Bacteroides, Prevotella and Ruminococcus) and their co-occurring phylogenetic groups. In accordance with the previously described impact of nutritional behavior (diet, probiotics and prebiotics) on specific bacterial populations, an association has been observed between long-term dietary habits and enterotypes. This recent discovery, i.e. that belonging to one or the other enterotype might be modulated by the diet opens up new perspectives in the fields of IBD, nutrition and therapeutic strategies.
人类生物学只有通过对宿主及其周围环境进行综合分析才能得到全面评估。作为环境的一部分，人类胃肠道中栖息着超过 1000 万亿的细菌，构成了肠道微生物群。人类宿主提供了富含营养的环境，而微生物群则提供了人类自身无法发挥的不可或缺的功能。人类肠道微生物群中细菌组成的变化与炎症性肠病（IBD）、肠易激综合征和肥胖等疾病有关。然而，由于迄今为止大多数栖息在我们肠道中的细菌还不能培养，因此人们对它们的个别功能知之甚少。宏基因组学，即对特定生态系统中存在的集体基因组的分析，为这些特定功能提供了深入了解。第一个广泛的肠道宏基因组目录数量是人类基因组的 150 倍。最近，已经突出了人类群体中肠道组成的 3 种不同“类型”。这些所谓的“肠型”以优势属（拟杆菌属、普雷沃氏菌属和瘤胃球菌属）及其共存的系统发育群为特征。根据先前描述的营养行为（饮食、益生菌和益生元）对特定细菌群体的影响，已经观察到长期饮食习惯与肠型之间存在关联。这一最近的发现，即属于一个或另一个肠型可能会受到饮食的调节，为 IBD、营养和治疗策略领域开辟了新的前景。
