Issue 3 November 2009

Bifidobacteria

influence the whole of the intestine(3). Thirdly, there is evidence that people over the age of 50 have alterations to their intestinal microflora, and those changes include a decline in the number of bifidobacteria(4). Potential exists for influencing these changed microflora by consuming bifidobacteria. Characteristics of bifidobacteria The form that Bifidobacterium cells take varies between species, but generally 3d rendered close up of Bifidobacteria they are rod-shaped, slim, and with Bifidobacteria are the second stimulates the growth of bifidobacteria, slightly bulbous or clubbed ends. When nutrients are short, bifidobacteria tend most popular type of bacterium and this effect is a clear indication (5) (after lactobacilli) used in that bifidobacteria are protective of to fork at one or both ends . These products. They are included for vulnerable individuals(2). split ends give the bacterium its name, several reasons. Firstly, bifidobacteria from the Latin word bifidus, meaning Secondly, bifidobacteria tend to live are found naturally in the intestines of ‘split in two’. in a different part of the intestine breast-fed infants at very high levels. to lactobacilli and therefore these Currently, thirty-two species of On average they constitute about (6) two types of probiotic microbe bifidobacteria have been identified , three-quarters of all the bacterial complement each other. Members mostly from the intestines of mammals. cells in the gut of such infants, of the can grow The species discovered from human which compares with a much lower with or without oxygen (aerobic or intestines are: B. adolescentis, B. proportion (about 3%) found in the anaerobic), and prefer environments angulatum, B. bifidum, B. breve, B. gut microflora of adults(1). Breast catenulatum, B. gallicum, B. infantis, B. with small amounts of oxygen. As (7) such, they live comfortably in the small longum and B. pseudocatenulatum . intestine. The main by-products of the In comparison, members of the metabolism of bifidobacteria are acetic Bifidobacterium genus only grow acid and , in about equal without oxygen. They thrive in the large proportion. These two acids lower intestine, because the small amounts the pH (increase acidity) within the of oxygen present in the small intestine, especially in the caecum and intestine are gradually consumed the ascending (right-sided) colon. It is by aerobic , leaving the likely that the ability of bifidobacteria to an almost completely increase the acidity of the intestine is a anaerobic environment. Furthermore, factor in their probiotic effects, as many harmful microbes are inhibited in a low the large intestine has plenty of food (8) suitable for bifidobacteria. They pH environment . are adept at breaking down more There is also some evidence that complex , and these bifidobacteria produce anti-bacterial are abundant in the large intestine substances that inhibit harmful bacteria, (mostly derived from the parts of plant- such as Yersinia and Shigella species(6). based foods that human enzymes Eight different Bifidobacterium species are unable to digest). A probiotic showed this effect in laboratory product that contains both lactobacilli experiments(9). The anti-bacterial and bifidobacteria is therefore able to substances have not yet been

Published by: Protexin, Matts Lane, Stoke sub Hamdon, Somerset, TA14 6QE, UK. Tel: +44 (0) 1935 822921 Email: [email protected] www.bio-kult.com Probiotic News Issue 3 November 2009 identified, but may be similar to References bacteriocins produced by lactobacilli. 1. Macfarlane, G.T., Gibson, G.R., Drasar, B.S. & Cummings, J.H. (1995) Metabolic significance of the Other useful characteristics of gut microflora. In Gastrointestinal and Oesophagal bifidobacteria are the production of Pathology (Whitehead, R., ed.) Churchill Livingstone, various B , and a tendency to Edinburgh, Scotland.: 249-274. adhere well to the intestinal wall, thus 2. Ballongue, J. (1998) Bifidobacteria and Probiotic excluding pathogenic bacteria(10). Action. In (Salminen, S. & von Bifidobacteria do not produce any Wright, A., eds.). Marcel Dekker. New York, U.S.A.: 519-587. gas and therefore may be helpful for people suffering from bloating and 3. Axelsson, L. (2004) Lactic Acid Bacteria: Classification and Physiology. In Lactic Acid Bacteria: flatulence. Microbiological and Functional Aspects, Third Edition (Salminen, S., von Wright, A., Ouwehand, A., Evidence of probiotic effects eds.). Marcel Dekker, New York, U.S.A.: 1-66.

Much of the clinical research 4. Woodmansey, E.J. (2007) Intestinal bacteria and involving bifidobacteria has been ageing. Journal of Applied Microbiology 102: 1178- undertaken with the bifidobacteria 1186. being part of a probiotic mixture 5. Hoover, D.G. (2000) Bifidobacterium. In with lactobacilli or another type of Encyclopedia of Food Microbiology, Vol. 1 microbe. Although such research (Robinson, R.K., Batt, C.A. & Patel, P.D., eds.). has produced positive results, in Academic Press, San Diego, U.S.A.: 210-217. almost all cases, it is not possible to 6. Biavati, B., Vescovo, M., Torriani, S. & Bottazzi, V. separate out the specific contribution (2000) Bifidobacteria: history, ecology, physiology of the bifidobacteria. and applications. Annals of Microbiology 50: 117- 131. There has, however, been some 7. Ventura, M, O’Connell-Motherway, M., Leahy, S. et human research undertaken with al. (2007) From bacterial genome to functionality; bifidobacteria alone. This research case bifidobacteria. International Journal of Food points to bifidobacteria lessening Microbiology 120: 2-12. the effects of lactose intolerance, 8. Rasic, J.L. & Kurmann, J.A. (1983) Bifidobacteria and reducing cholesterol levels, their Role. Experientia Supplementum 39: 1-295. improving the gut immune system, 9. Gibson, G.R. & Wang, X. (1994) Regulatory effects of reducing diarrhoea (both rotavirus bifidobacteria on the growth of other colonic bacteria. and antibiotic-associated) and Journal of Applied Bacteriology 77: 412-420. reducing constipation(6,11,12). Also, 10. Bernet, M-F., Brassart, D., Neeser, J-R. & Servin, bifidobacteria appear to be helpful A.L. (1993) Adhesion of Human Bifidobacterial in preventing infections of the gut Strains to Cultured Human Intestinal Epithelial Cells in infants(5). And there has been and Inhibition of Enteropathogen–Cell Ineractions. one good study which found that Applied and Environmental Microbiology 59: 4121- a B. infantis significantly reduced 4128. symptoms in IBS patients, and was 11. Leahy, S.C., Higgins, D.G., Fitzgerald, G.F. & van more effective than a Lactobacillus Sinderen, D. (2005) Getting better with bifidobacteria. Journal of Applied Microbiology 98: 1303-1315. salivarius(13). 12. Picard, C, Fioramonti, J., Francois, A. et al. Safety (2005) Review article: bifidobacteria as probiotic agents - physiological effects and clinical benefits. Bifidobacteria have been studied Alimentary Pharmacology and Therapeutics 22: for a long time, and were first 495-512. identified in 1899 (by Henry Tissier 13. O’Mahony, L., McCarthy, J., Kelly, P. et al. (2005) at the Pasteur Institute, Paris). Lactobacillus and Bifidobacterium in Irritable Bowel Their high numbers in pre-weaning syndrome: Symptom Responses and Relationship to infants (as mentioned above) is Cytokine Profiles. Gastroenterology 128: 541-551. a good indicator of the safety of 14. Meile, L., Le Blay, G. & Thierry, A. (2008) bifidobacteria. A recent review Safety assessment of dairy microorganisms: reported that there is no record of Propionibacterium and Bifidobacterium. anyone developing a Bifidobacterium International Journal of Food Microbiology 126: infection from consuming a probiotic 316-320. product “despite their widespread consumption in Europe and Japan”. The review concluded that the “Bifidobacterium genus is certainly among the safest genera”(14).

Published by: Protexin, Matts Lane, Stoke sub Hamdon, Somerset, TA14 6QE, UK. Tel: +44 (0) 1935 822921 Email: [email protected] www.bio-kult.com