In man, physiological amounts of vitamin B12 (cyanocobalamin) are absorbed by the intrinsic factor mediated mechanism exclusively in the ileum1. Human faeces contain appreciable quantities of vitamin B12 or vitamin B12-like material presumably produced by bacteria in the colon2, but this is unavailable to the non-coprophagic individual. However, the human small intestine also often harbours a considerable microflora3–6 and this is even more extensive in apparently healthy southern Indian subjects6. We now show that at least two groups of organisms in the small bowel, Pseudomonas and Klebsiella sp., may synthesise significant amounts of the vitamin.
This is a preview of subscription content, access via your institution
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Rent or buy this article
Prices vary by article type
Prices may be subject to local taxes which are calculated during checkout
Booth, C. C. & Mollin, D. L. Lancet i, 18–21 (1959).
Girdwood, R. H. Blood 5, 1009–1016 (1950).
Kalser, M. H. et al. New Engl. J. Med. 274, 500–505 (1966).
Gorbach, S. L., Plaut, A. G., Nahas, L. & Weinstein, L. Gastroenterology 53, 856–867 (1967).
Hamilton, J. D. et al. Q. Jl Med. 154, 265–285 (1970).
Bhat, P. et al. Gastroenterology 62, 11–21 (1972).
Nishio, N., Yano, T. & Kamikubo, T. Agr. Biol. Chem. 39, 21–29 (1975).
Albert, M. J. thesis, Univ. Madras (1979).
Hutner, S. H., Bach, M. K. & Ross, G. I. M. J. Protozool. 3, 101–112 (1956).
Ford, J. E. Br. J. Nutr. 7, 299–306 (1953).
Barker, H. A. et al. J. biol. Chem. 235, 181–190 (1960).
Linnel, J. C., Mackenzie, H. M., Wilson, J. & Matthews, D. M. J. clin. Path. 22, 545–550 (1969).
Kapadia, C. R., Mathan, V. I. & Baker, S J. Gastroenterology 70, 704–706 (1976).
Sullivan, L. W. & Herbert, V. New Engl. J. Med. 272, 340–346 (1965).
Bunge, M. M. & Schilling, R. F. Proc. Soc. exp. Biol. Med. 96, 587–592 (1957).
Mathan, V. I., Babior, B. M. & Donaldson, R. M. J. clin. Invest. 54, 598–608 (1974).
Cameron, D. G., Watson, G. M. & Witts, L. J. Blood 4, 793–802 (1949).
Mollin, D. L. & Baker, S. J. Biochem. Soc. Symp. 13, 52–68 (1955).
Gannella, R.A., Broitman, S. A. & Zamcheck, N. Gastroenterology 62, 255–260 (1972).
Donaldson, R. M. Gastroenterology 43, 271–281 (1962).
Schjönsby, H., Drasar, B. S., Tabaqchali, S. & Booth, C. C. Scand. J. Gastroenterol. 8, 41–47 (1973).
Schjönsby, H. & Tabaqchali, S. Scand. J. Gastroenterol. 6, 707–713 (1971).
Drexler, J. Blood 13, 239–244 (1958).
Kapadia, C., Bhat, P., Jacob, E. & Baker, S. J. Gut 16, 988–993 (1975).
Brandt, L. J., Bernstein, L. H. & Wagle, A. Ann. intern. Med. 87, 546–551 (1977).
Donaldson, R. M. New Engl. J. Med. 270, 1050–1056 (1964).
Stewart, J. S., Roberts, P. D. & Hoffbrand, A. V. Lancet ii, 542–545 (1970).
Britt, R. P., Harper, C. & Spray, G. H. Q. Jl Med. 40, 499–520 (1971).
Roberts, P. D., James, H., Petrie, A., Morgan, J. O. & Hoffbrand, A. V. Br. med. J. iii, 67–72 (1973).
Britt, R. P. & Harper, C. Lancet ii, 799 (1976).
Baker, S.J. World Rev. Nutr. Diet. 8, 62–126 (1967).
About this article
Cite this article
Albert, M., Mathan, V. & Baker, S. Vitamin B12 synthesis by human small intestinal bacteria. Nature 283, 781–782 (1980). https://doi.org/10.1038/283781a0
This article is cited by
Vitamin B12 produced by Cetobacterium somerae improves host resistance against pathogen infection through strengthening the interactions within gut microbiota
Vitamin B12 may play a preventive role in esophageal precancerous lesions: a case–control study based on markers in blood and 3-day duplicate diet samples
European Journal of Nutrition (2021)
Diet Alters Micronutrient Pathways in the Gut and Placenta that Regulate Fetal Growth and Development in Pregnant Mice
Reproductive Sciences (2021)
Current Gastroenterology Reports (2020)
Association of Vitamin B12, Lactate Dehydrogenase, and Regulation of NF-κB in the Mitigation of Sodium Arsenite-Induced ROS Generation in Uterine Tissue by Commercially Available Probiotics
Probiotics and Antimicrobial Proteins (2019)