Related Experiment Video
Updated: Jun 18, 2026

Using Multi-fluorinated Bile Acids and In Vivo Magnetic Resonance Imaging to Measure Bile Acid Transport
Published on: November 27, 2016
Production of vitamin B 12 analogues in patients with small-bowel bacterial overgrowth
Abstract:
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.
More Related Videos
Related Concept Videos
Drugs Affecting GI Tract Motility: Antimicrobials as Antidiarrheal Agents
Drugs for Treatment of Diarrhea-Predominant IBS
Two specific drugs used in the treatment are alosetron (Lotronex) and eluxadoline (Viberzi). Alosetron, a 5-HT3 antagonist, works by slowing the movement of stools in the gut, reducing bowel...
Bacterial Flora of the Large Intestine
The normal gut flora of the colon plays a critical role in generating essential vitamins such as vitamins K, B5, and B7.
Inflammatory Bowel Disease III: Diagnostic Studies and Management I-Nutritional Therapy
Diagnostic studies
A colonoscopy is the definitive screening test, distinguishing ulcerative colitis from other colon diseases with similar symptoms. During a colonoscopy test, inflamed mucosa with exudate ulcerations can be observed, and biopsies are taken to determine the histologic characteristics of the colonic...
Inflammatory Bowel Disease IV: Pharmacological Management
Pharmacologic...
Microbiota Modulation by Antibiotics

