科学家们收集了来自亚马逊部落Yanomami族人的口腔、皮肤和粪便细菌样品，发现这些微生物群与我们所知的微生物大不同，这些原始部落的人从未与西方人群接触过。

    研究人员比对了Yanomami人，以及与西方人群少量接触的另外两组人群：非洲的Malawi村庄和委内瑞拉的Guahibo，他们体内微生物组的细菌种类和遗传多样性。结果发现前者微生物组与美国人样品存在几乎两倍的差异，这比后者另外两组人群存在的30%-40%差异要多。在Yanomami人皮肤上发现的许多细菌之前只在泥土中发现过，还没有人体内存在这些细菌。

    “也许他们与现代人群接触的少，因此出现了许多细菌多样性丢失，”文章的作者之一Jose Clemente表示。

    “抗生素耐药性确实是人体微生物的一种自然特征，在使用抗生素后会被激活，产生更大的抗性，”文章作者之一，华盛顿大学的Gautam Dantas说。“从原始部落中找到这些现代人已经不再使用的基因，这令我们感到十分惊讶。”

    这项研究获得的最大惊喜就是研究人员从这些口腔和粪便微生物组中发现了一些能有效抵抗现代合成药物的抗性基因，比如最新的抗生素，第三、第四代的头孢菌。

    原文链接：The microbiome of uncontacted Amerindians

    原文摘要：Most studies of the human microbiome have focused on westernized people with life-style practices that decrease microbial survival and transmission, or on traditional societies that are currently in transition to westernization. We characterize the fecal, oral, and skin bacterial microbiome and resistome of members of an isolated Yanomami Amerindian village with no documented previous contact with Western people. These Yanomami harbor a microbiome with the highest diversity of bacteria and genetic functions ever reported in a human group. Despite their isolation, presumably for >11,000 years since their ancestors arrived in South America, and no known exposure to antibiotics, they harbor bacteria that carry functional antibiotic resistance (AR) genes, including those that confer resistance to synthetic antibiotics and are syntenic with mobilization elements. These results suggest that westernization significantly affects human microbiome diversity and that functional AR genes appear to be a feature of the human microbiome even in the absence of exposure to commercial antibiotics. AR genes are likely poised for mobilization and enrichment upon exposure to pharmacological levels of antibiotics. Our findings emphasize the need for extensive characterization of the function of the microbiome and resistome in remote nonwesternized populations before globalization of modern practices affects potentially beneficial bacteria harbored in the human body.