Conly J, Stein K
Department of Microbiology, University of Saskatchewan, Saskatoon.
Clin Invest Med. 1994 Dec;17(6):531-9.
It is unclear whether menaquinones produced by the intestinal microflora play any role in human nutrition. Reports of coagulopathy due to vitamin K deficiency occurring in patients receiving broad spectrum antibiotics indirectly suggest that vitamin K2 produced by the gut microflora may be utilized by the host. We analyzed the vitamin K1 (phylloquinone) and vitamin K2 (menaquinone) content in a convenience sample of 22 human post-mortem liver samples, including 9 individuals who had been receiving broad spectrum antimicrobials prior to death and 13 individuals who had been victims of sudden, unexpected deaths. There were no significant differences in the mean (+/- SEM) phylloquinone content between the 2 groups [21.9 (+/- 15.5) vs. 16.0 (+/- 9.3) pmol/g wet weight (excluding those who had received supplemental vitamin K1)] but there was a significant difference (p < 0.05) in the total menaquinone (MK) content, 70.0 (+/- 23.3) vs. 423.1 (+/- 141) pmol/g between the 2 groups. These findings suggest an association between receipt of broad spectrum antibiotics and a reduction in hepatic menaquinone concentration, lending support to the hypothesis that a reduction in the gut microflora responsible for their production leads to reduced hepatic stores of this form of the vitamin.
目前尚不清楚肠道微生物群产生的甲基萘醌是否在人类营养中发挥任何作用。接受广谱抗生素治疗的患者因维生素K缺乏而出现凝血病的报告间接表明，肠道微生物群产生的维生素K2可能被宿主利用。我们分析了22份人类死后肝脏样本的便利样本中的维生素K1（叶绿醌）和维生素K2（甲基萘醌）含量，其中包括9名在死亡前接受过广谱抗菌药物治疗的个体和13名突然意外死亡的个体。两组之间的平均（±SEM）叶绿醌含量没有显著差异[21.9（±15.5）对16.0（±9.3）pmol/g湿重（不包括那些接受过补充维生素K1的个体）]，但两组之间的总甲基萘醌（MK）含量存在显著差异（p<0.05），分别为70.0（±23.3）对423.1（±141）pmol/g。这些发现表明接受广谱抗生素与肝脏甲基萘醌浓度降低之间存在关联，支持了这样的假设，即负责其产生的肠道微生物群减少导致这种形式的维生素在肝脏中的储存减少。
