The effect of antibiotics on rats receiving a vitamin B12-deficient diet

Vitamin B(12) deficiency is linked with long-term use of proton pump inhibitors in institutionalized older adults: could a cyanocobalamin nasal spray be beneficial?

The purpose of this study was to determine whether institutionalized older individuals taking proton pump inhibitors (PPI) for more than 12 months were more likely to have vitamin B(12) deficiency than individuals not taking PPI, and whether cyanocobalamin nasal spray would improve their vitamin B(12) status. Participants were long-term care residents aged 60-89 years. PPI users (n = 17) were treated with cyanocobalamin nasal spray for 8 weeks; non-PPI users (n = 19) were not treated but were followed for the same time duration. Serum samples from all subjects were analyzed for vitamin B(12) and serum methylmalonic acid (sMMA) at baseline and the end of the 8-week treatment. There was a significant difference in mean vitamin B(12), sMMA, and frequency of deficiency between control and intervention groups at baseline. After treatment, there was an increase (p = 0.012) in serum vitamin B(12) concentration, and a decrease (p = 0.004) in frequency of deficiency in PPI users. Thus, we found that institutionalized older individuals on PPI for more than 12 months may be more likely to be vitamin B(12) deficient than non-PPI users. Additionally, treatment of PPI users with cyanocobalamin nasal spray for 8 weeks could improve vitamin B(12) status.

Fermentable fibers and vitamin B12 dependency

Addition of the fermentable fiber pectin to a B12-deficient diet accelerates development of deficiency symptoms. This appears to be the result of changes in the intestinal bacteria that bind vitamin B12, interfere with enterohepatic circulation, and accelerate depletion of this vitamin.

Contribution of gut bacterial metabolism to human metabolic disease

Metronidazole, an antibiotic with specific activity against anaerobic bacteria, was of clinical and biochemical benefit in two patients with methylmalonic aciduria. The virtual elimination of propionic acid from the stool suggested that propionic acid derived from faecal bacterial metabolism contributes substantially to methylmalonate production. These findings point to a novel avenue of treatment for these disorders of intermediary metabolism, and indicate the importance of microbial gut flora in normal human metabolism.