The Common Gut Microbe Eubacterium hallii also Contributes to Intestinal Propionate Formation.
The Common Gut Microbe Eubacterium hallii also Contributes to Intestinal Propionate Formation.
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DOI：
10.3389/fmicb.2016.00713
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发表时间：
2016
影响因子：
5.2
通讯作者：
Schwab C
中科院分区：
文献类型：
--
作者：
Engels C;Ruscheweyh HJ;Beerenwinkel N;Lacroix C;Schwab C
哈利真杆菌能够利用葡萄糖和发酵中间体醋酸盐和乳酸盐形成丁酸盐和氢气，因此被认为是肠道代谢平衡的重要微生物。最近，我们观察到哈里伊杆菌能够将甘油代谢为3-羟基丙醛（3-HPA, reuterin），并具有报道的抗菌性能。甘油转化为3-HPA的关键酶是钴胺依赖的甘油/二醇脱水酶PduCDE，该酶也利用1,2-丙二醇（1,2- pd）形成丙酸盐。因此，我们的主要目标是研究E. hallii对甘油到3-HPA的代谢和1,2- pd的利用，以及它产生钴胺素的能力。我们还利用16S rRNA和基于producde的基因筛选，研究了成人粪便中哈利伊杆菌的相对丰度，以确定哈利伊杆菌对肠道丙酸形成的贡献。我们发现，E. hallii利用甘油产生高达9 mM的3-HPA，但不会进一步将3-HPA代谢为1,3-丙二醇。在葡萄糖存在和不存在的情况下，1,2- pd的利用导致丙醇、丙醇和丙酸的形成。以16S rRNA基因为标记基因，在74%的成人粪便中检测到哈利伊杆菌形成钴胺素（n = 325）。该基因的相对丰度为0 ~ 0.59%，平均相对丰度为0.044%。根据亚基的不同，在63%至81%的宏基因组中检测到哈里伊菌的PduCDE，此外还有其他分类群，如Ruminococcus obeum、R. gnavus、黄酮因子plautii、butyricproducens和Veillonella spp。总之，我们确定哈里伊菌是一种常见的肠道微生物，具有将甘油转化为3-HPA的能力，这一步骤需要生产钴胺素，并利用1,2- pd形成丙酸盐。我们的研究结果以及它使用广泛底物的能力表明，哈里杆菌是肠道营养链中的关键物种，有可能通过形成不同的短链脂肪酸来高度影响代谢平衡以及肠道微生物群/宿主的稳态。
Eubacterium hallii is considered an important microbe in regard to intestinal metabolic balance due to its ability to utilize glucose and the fermentation intermediates acetate and lactate, to form butyrate and hydrogen. Recently, we observed that E. hallii is capable of metabolizing glycerol to 3-hydroxypropionaldehyde (3-HPA, reuterin) with reported antimicrobial properties. The key enzyme for glycerol to 3-HPA conversion is the cobalamin-dependent glycerol/diol dehydratase PduCDE which also utilizes 1,2-propanediol (1,2-PD) to form propionate. Therefore our primary goal was to investigate glycerol to 3-HPA metabolism and 1,2-PD utilization by E. hallii along with its ability to produce cobalamin. We also investigated the relative abundance of E. hallii in stool of adults using 16S rRNA and pduCDE based gene screening to determine the contribution of E. hallii to intestinal propionate formation. We found that E. hallii utilizes glycerol to produce up to 9 mM 3-HPA but did not further metabolize 3-HPA to 1,3-propanediol. Utilization of 1,2-PD in the presence and absence of glucose led to the formation of propanal, propanol and propionate. E. hallii formed cobalamin and was detected in stool of 74% of adults using 16S rRNA gene as marker gene (n = 325). Relative abundance of the E. hallii 16S rRNA gene ranged from 0 to 0.59% with a mean relative abundance of 0.044%. E. hallii PduCDE was detected in 63 to 81% of the metagenomes depending on which subunit was investigated beside other taxons such as Ruminococcus obeum, R. gnavus, Flavonifractor plautii, Intestinimonas butyriciproducens, and Veillonella spp. In conclusion, we identified E. hallii as a common gut microbe with the ability to convert glycerol to 3-HPA, a step that requires the production of cobalamin, and to utilize 1,2-PD to form propionate. Our results along with its ability to use a broad range of substrates point at E. hallii as a key species within the intestinal trophic chain with the potential to highly impact the metabolic balance as well as the gut microbiota/host homeostasis by the formation of different short chain fatty acids.