Helmholtz-Centre for Environmental Research - UFZ, Department of Environmental Immunology, Leipzig, Germany.
Helmholtz-Centre for Environmental Research - UFZ, Department of Molecular Systems Biology, Leipzig, Germany.
Sci Total Environ. 2020 Nov 25;745:140932. doi: 10.1016/j.scitotenv.2020.140932. Epub 2020 Jul 17.
Glyphosate is the world's most widely used herbicide, and its potential side effects on the intestinal microbiota of various animals, from honeybees to livestock and humans, are currently under discussion. Pigs are among the most abundant livestock animals worldwide and an impact of glyphosate on their intestinal microbiota function can have serious consequences on their health, not to mention the economic effects. Recent studies that addressed microbiota-disrupting effects focused on microbial taxonomy but lacked functional information. Therefore, we chose an experimental design with a short incubation time in which effects on the community structure are not expected, but functional effects can be detected. We cultivated intestinal microbiota derived from pig colon in chemostats and investigated the acute effect of 228 mg/d glyphosate acid equivalents from Roundup® LB plus, a frequently applied glyphosate formulation. The applied glyphosate concentration resembles a worst-case scenario for an 8-9 week-old pig and relates to the maximum residue levels of glyphosate on animal fodder. The effects were determined on the functional level by metaproteomics, targeted and untargeted meta-metabolomics, while variations in community structure were analyzed by 16S rRNA gene profiling and on the single cell level by microbiota flow cytometry. Roundup® LB plus did not affect the community taxonomy or the enzymatic repertoire of the cultivated microbiota in general or on the expression of the glyphosate target enzyme 5-enolpyruvylshikimate-3-phosphate synthase in detail. On the functional level, targeted metabolite analysis of short chain fatty acids (SCFAs), free amino acids and bile acids did not reveal significant changes, whereas untargeted meta-metabolomics did identify some effects on the functional level. This multi-omics approach provides evidence for subtle metabolic effects of Roundup® LB plus under the conditions applied.
草甘膦是世界上使用最广泛的除草剂，其对各种动物（从蜜蜂到牲畜和人类）的肠道微生物群的潜在副作用目前正在讨论中。猪是全球最丰富的牲畜之一，如果草甘膦对其肠道微生物群功能产生影响，可能会对它们的健康产生严重后果，更不用说经济影响了。最近的研究集中在微生物分类学上，但缺乏功能信息，因此，我们选择了一种实验设计，其短时间孵育预计不会对群落结构产生影响，但可以检测到功能影响。我们在恒化器中培养来自猪结肠的肠道微生物群，并研究了来自 Roundup® LB plus 的 228 mg/d 草甘膦酸当量对其的急性影响，Roundup® LB plus 是一种常用的草甘膦制剂。应用的草甘膦浓度类似于 8-9 周龄猪的最坏情况，与动物饲料中草甘膦的最大残留水平有关。通过代谢组学、靶向和非靶向代谢组学在功能水平上确定了影响，而 16S rRNA 基因谱和微生物群流动 cytometry 在群落结构变化方面进行了分析。总的来说，Roundup® LB plus 没有影响培养微生物群的群落分类或酶谱，也没有详细影响草甘膦靶酶 5-烯醇式丙酮酸-3-磷酸合酶的表达。在功能水平上，短链脂肪酸（SCFAs）、游离氨基酸和胆汁酸的靶向代谢物分析没有显示出显著变化，而非靶向代谢组学确实在功能水平上确定了一些影响。这种多组学方法为在应用条件下 Roundup® LB plus 的微妙代谢影响提供了证据。
