Brandt L J, Bernstein L H, Wagle A
Ann Intern Med. 1977 Nov;87(5):546-51. doi: 10.7326/0003-4819-87-5-546.
We investigated the presence of vitamin B 12 analogues (cobamides) and the bacterial conversion of 57Co-B12 (vitamin B12 cyanocobalamin, [57Co]-CN-Cbl) into cobamides in the intestinal contents of four patients with bacterial overgrowth. The (57Co)-CN-Cbl bound to intrinsic factor was given orally. Jejunal contents were aspirated for 24 h and cultured aerobically and anaerobically. The CN-Cbl and cobamides were separated by electrophoresis and chromatography and identified by bioautography. Radioactivity of cobamide zones from duplicate chromatograms showed bacterial conversion of (57Co)-cn-cbl into cobamides. Cobamides ([Ade]CNCBA, [2-Me Ade] CNCba, [CN]2Cbi and factor E) were found in the intestinal contents in three of the four patients, and in two of three patients cobamides represented more than 25% of the administered CN-Cbl. Thus bacterial production of cobamides, both de novo and from ingested CN-Cbl bound to intrinsic factor, occurs in humans with bacterial overgrowth states and results in a significant loss of vitamin B12 to the host.
我们研究了四名患有细菌过度生长的患者肠道内容物中维生素B12类似物（钴胺素）的存在情况，以及57Co-B12（维生素B12氰钴胺，[57Co]-CN-Cbl）向钴胺素的细菌转化情况。将与内因子结合的（57Co）-CN-Cbl口服给药。抽吸空肠内容物24小时，并进行需氧和厌氧培养。通过电泳和色谱法分离CN-Cbl和钴胺素，并通过生物自显影进行鉴定。来自重复色谱图的钴胺素区域的放射性显示（57Co）-cn-cbl向钴胺素的细菌转化。在四名患者中的三名患者的肠道内容物中发现了钴胺素（[Ade]CNCBA、[2-Me Ade]CNCba、[CN]2Cbi和因子E），在三名患者中的两名患者中，钴胺素占所给予的CN-Cbl的25%以上。因此，在患有细菌过度生长状态的人类中，会发生钴胺素的细菌从头合成以及从与内因子结合的摄入CN-Cbl转化而来的情况，这会导致宿主维生素B12的显著损失。
