Handling stress may confound murine gut microbiota studies.
Handling stress may confound murine gut microbiota studies.
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作者：
Allen-Blevins CR;You X;Hinde K;Sela DA
越来越多的证据表明人乳成分，特别是糖（人乳低聚糖或HMO），人类婴儿的肠道微生物群和行为影响之间的相互作用。人乳中分泌的一些HMO不能被人类婴儿内源性消化，但能够被某些种类的肠道微生物群代谢，包括长双歧杆菌亚种（Bifidobacterium longum subsp.（B.（Bailey & Coe，2004）。暴露于肠道细菌如B。婴儿在生命早期的关键神经发育窗口期似乎具有行为后果;然而，在此期间的环境，身体和社会压力也可能具有行为和微生物后果。虽然啮齿动物模型是确定HMO，肠道微生物群和行为之间因果关系的有用方法，但肠道微生物群的小鼠研究通常采用口服灌胃法，这是一种对小鼠有压力的技术。我们的目的是开发一种微创的HMO给药技术，以消除灌胃应激的潜在混淆。假设压力会影响肠道菌群，特别是B。因此，我们预测以侵入性较低的方式接受益生元溶液的幼崽将在其肠道中具有最高量的Biobacterium细菌。本研究旨在测试对小鼠进行溶液给药的两种方法（主动和被动）及其对肠道微生物组的影响。在无特定病原体的设施中饲养的新生C57 BL/6 J小鼠接受增加剂量的低聚果糖（FOS）溶液或去离子蒸馏水。在4个时间点从5只母鼠、6只公畜和41只幼仔中采集胃肠道（GI）。还收集了7个来自未处理幼仔的粪粒和2个来自未处理母鼠的粪粒。使用定性实时聚合酶链反应（qRT-PCR）定量并比较双歧杆菌、拟杆菌、拟杆菌和厚壁菌的量。我们的研究结果表明，在被动接受水和主动接受FOS的幼崽中厚壁菌门的数量之间存在显着差异（p值= 0.009）。此外，我们发现处理和非处理小鼠幼仔的粪便微生物群之间存在显着差异。从我们的结果中，我们得出结论，即使出于实验目的处理幼崽，而不进行灌胃，也可能引起足够的压力来改变小鼠肠道微生物群。我们建议进一步研究实验技术对肠道微生物群的潜在应激影响。来自实验技术的压力可能需要在未来的肠道微生物群研究中考虑。
Accumulating evidence indicates interactions between human milk composition, particularly sugars (human milk oligosaccharides or HMO), the gut microbiota of human infants, and behavioral effects. Some HMO secreted in human milk are unable to be endogenously digested by the human infant but are able to be metabolized by certain species of gut microbiota, including Bifidobacterium longum subsp. infantis (B. infantis), a species sensitive to host stress (Bailey & Coe, 2004). Exposure to gut bacteria like B. infantisduring critical neurodevelopment windows in early life appears to have behavioral consequences; however, environmental, physical, and social stress during this period can also have behavioral and microbial consequences. While rodent models are a useful method for determining causal relationships between HMO, gut microbiota, and behavior, murine studies of gut microbiota usually employ oral gavage, a technique stressful to the mouse. Our aim was to develop a less-invasive technique for HMO administration to remove the potential confound of gavage stress. Under the hypothesis that stress affects gut microbiota, particularly B. infantis, we predicted the pups receiving a prebiotic solution in a less-invasive manner would have the highest amount of Bifidobacteria in their gut. This study was designed to test two methods, active and passive, of solution administration to mice and the effects on their gut microbiome. Neonatal C57BL/6J mice housed in a specific-pathogen free facility received increasing doses of fructooligosaccharide (FOS) solution or deionized, distilled water. Gastrointestinal (GI) tracts were collected from five dams, six sires, and 41 pups over four time points. Seven fecal pellets from unhandled pups and two pellets from unhandled dams were also collected. Qualitative real-time polymerase chain reaction (qRT-PCR) was used to quantify and compare the amount of Bifidobacterium, Bacteroides, Bacteroidetes, and Firmicutes. Our results demonstrate a significant difference between the amount of Firmicutes in pups receiving water passively and those receiving FOS actively (p-value = 0.009). Additionally, we found significant differences between the fecal microbiota from handled and non-handled mouse pups. From our results, we conclude even handling pups for experimental purposes, without gavage, may induce enough stress to alter the murine gut microbiota profile. We suggest further studies to examine potential stress effects on gut microbiota caused by experimental techniques. Stress from experimental techniques may need to be accounted for in future gut microbiota studies.