Bifidobacterium Introduction

Every human has billions of bacteria living in their colon and small intestine. Most of the bacteria (95%) are obligate floras that provide benefit in human physiology, while a small percentage can be harmful if they are allowed to propagate. [1] These bacteria are commonly referred to as Probiotics. Bifidobacterium categorized as one of these obligate friendly bacteria located within our colon.

Bifidobacterium is a gram positive, non-motile, non-spore forming bacteria. It can exists in several different shapes, including short curved rods, club shaped rods, and bifurcated Y shaped rods (how Bifidobacterium got its name). There are over 30 species of Bifidobacterium isolated so far.

It is one of the first bacteria to colonize in the large intestine and can be found within the first few days of life in a breast fed newborn infant. Its numbers remain stable throughout an individual’s lifespan until old age when they begin to decline. Bifidobacterium populations can be influenced by a multitude of factors, including stress, diet, and antibiotic usage. Bifidobacterium and other friendly flora serve several purposes in our digestive system:

  • They help maintain the immune system outpost that exists only in our GI tract
  • Are mediators in the immune response that begins in the large intestine
  • They also help to maintain normal structure and function of the cells of the large and small intestine

Bifidobacterium provide another layer of protection and reinforce the barrier of the GI tract from the outside world, limiting the passage of potential allergens and pathological organisms into our blood. Normal floras like Bifidobacterium also contribute to the availability of vitamins such as Vitamin K, Biotin, Pantothenic acid, and Vitamin B12.

One of the mechanisms that allow Bifidobacterium to provide protection against other microorganisms is the fact that it produces lactic acid and acetic acid. These two acids make the environment unsuitable for many different types of bacteria. Another mechanism that Bifidobacterium use to provide protection is as simple as overcrowding. They grow so well and in such great numbers that other pathological bacteria do not have any space to grow. This is the reason that antibiotics provide a means for infection in the GI tract because they kill off the healthy protective flora normally present in the colon.

Bifidobacterium and other friendly flora are anti-microbial, immunomodulating, anti-carcinogenic, anti-diarrhea, anti-allergic, and anti-oxidants.

Bifidobacterium Uses

Bifidobacterium species provide a direct defense against the growth of pathological microorganisms in the GI tract. [2] It is especially helpful against bacteria such as Clostridium difficile, which cause a very serious condition known as pseudomembranous colitis. Clostridium difficile infections often develop in the young and elderly, and also immunocompromised individuals after antibiotic usage. Supplementation with Bifidobacterium can decrease the incidence of Clostridium infection and associated diarrhea. [3]

Bifidobacterium is also effective against the virulent and deadly strain of E.coli 0157:H7. This is a common pathogen found in many food-borne illnesses and is obtained from undercooked meats. It can cause a massive infection in the GI tract that can easily spread to the blood and can even result in death. Bifidobacterium species inhibit this strain of E.coli and limit its ability to attach to the lining of the colon. [4]

Two other bacteria that Bifidobacterium has anti-microbial capabilities towards are Listeria and Bacteroides. [5, 6] These also cause serious cases of diarrhea and dehydration. They usually develop after antibiotic use as well.

It is also effective against diarrhea due to a virus, in particular, rotavirus. Bifidobacterium is very effective against rotavirus-induced diarrhea in children. [7]

  • Bifidobacterium has also been shown to suppress Helicobacter pylori. [8] H.pylori is the bacteria responsible for peptic ulcer disease and can lead to serious conditions such as anemia and gastric cancer. Bifidobacterium is able to suppress H.pylori due to its production of lactic acid.
  • Bifidobacterium species are a helpful adjunctive treatment for Irritable Bowel Syndrome (IBS). Many of the symptoms of IBS are thought to be due to abnormal fermentation in the colon. Treatment with probiotics like Bifidobacterium, may decrease the severity of symptoms in individuals with IBS. [9]
  • Bifidobacterium is also helpful for Ulcerative Colitis, another inflammatory bowel disease. [10] It was found to decrease the incidence of relapse and was beneficial for maintaining remission.
  • Bifidobacterium has also shown anti-allergic activity. It reinforces the barrier and limits the passage of allergens from food into the blood stream. In study, Bifidobacterium was shown to be effective at decreasing skin symptoms in children with atopic eczema. [11] These improvements continued to increase over the treatment period. It was equally effective at counteracting the inflammatory response.
  • Bifidobacterium has also been shown to effectively lower total cholesterol. [12] Interestingly, the individuals with the highest total cholesterol had the greatest percentage decrease. Although the direct mechanism is not fully understood, total cholesterol was significantly lowered and HDL, or good cholesterol, was not affected. These results were long standing and not only for the duration of the study.
  • Bifidobacterium and other probiotics have been shown to possess certain anti-cancer properties. In some studies probiotics have increased the breakdown and removal of carcinogenic substances in the GI tract and limited their absorption into the blood.
  • Bifidobacterium species have also shown anti-proliferative effects on tumor cells in vitro as well as in animal studies. With regards to human subjects, Bifidobacterium has been shown to modulate immune response to protect against the growth of certain cancers. [13]

Bifidobacterium Dosages

The usual dosage is 1 - 10 million colony-forming units (CFU) per day. Some studies have used as much as 30 million CFU per day with no adverse effects. In order for beneficial long term effects, probiotics must be taken at least a few times per week to maintain colonization in the intestine.

Bifidobacterium can be taken in a supplement. It is also available in fermented foods such as yogurt, cheese, kefir, and fermented milks. Check the package insert for types of probiotics and relative amounts contained per serving.

Bifidobacterium Toxicities and Deficiencies

There are no contraindications when including food or supplement sources of Bifidobacterium into diet, unless you have a known allergy to the bacteria.

Again, there is little toxicity or side effects associated with use. Mild GI distress, with gas and constipation, can occur. Additionally, one case study of meningitis in an infant due to Bifidobacterium was reported, but this infection was not caused by supplementation.


[1] Probiotics. January 2005.

[2] Servin AL. Antagonistic activities of lactobacilli and Bifidobacterium against microbial pathogens. FEMS Microbial Rev. 2004 Oct; 28(4): 405-440.

[3] Plummer S, Weaver MA, Harris JC, Dee P, Hunter J. Clostridium difficile pilot study: effects of probiotics supplementation on the incidence of Clostridium difficile diarrhea. Int Microbiol. 2004 Mar; 7(1): 59-62.

[4] Gagnon M, Kheadr EE, Le Blay G, Fliss I. In vitro inhibition of Escherichia coli 0157:H7 by bifidobacterial strains of human origin. Int J Food Microbiol. 2004 Apr 1; 92(1): 69-78.

[5] Toure R, Kheadr E, Lacroix C, Moroni O, Fliss I. Production of antibacterial substances by bifidobacterial isolates from infant stool active against Listeria monocytogenes. J Appl Microbiol. 2003; 95(5): 1058-1069.

[6] Sullivan A, Barkholt L, Nord CE. Lactobacillus acidophilus, Bifidobacterium lactis, and Lactobacillus F19 prevent antibiotic associated ecological disturbances of Bacteroides fragilis in the intestine. J Antimicrob Chemother. 2003 Aug; 52(2): 308-311.

[7] Probiotics. January 2005.

[8] Wang KY et al. Effects of ingesting lactobacillus and Bifidobacterium containing yogurt in subjects with colonized Helicobacter pylori. Am J Clin Nutr. 2004 Sep; 80(3): 737-741.

[9] Saggioro A. Probiotics in the treatment of IBS. J Clin Gastroenterol. 2004 Jul; 38(6 Suppl): S104-106.

[10] Ishikawa H, Akedo I, Umesaki Y, Tanakaa R, Imaoka A, Otani T. Randomized controlled trial of the effects of Bifidobacterium fermented milk on ulcerative colitis. J Am Coll Nutr. 2003 Feb; 22(1): 56-63.

[11] Isolauri E, Arvola T, Sutas Y, Moilanen E, Salminen S. Probiotics in the management of atopic eczema. Clin Exp Allergy. 2000 Nov; 30(11): 1604-1610.

[12] Xiao JZ et al. Effects of milk products fermented by Bifidobacterium longum on blood lipids in rats and healthy adult male volunteers. J Dairy Sci. 2003 Jul; 86(7): 2452-2461.

[13] Lee JW et al. Immunomodulatory and anti-tumor effects in vivo by the cytoplasmic fraction of Lactobacillus casei and Bifidobacterium longum. J Vet Sci. 2004 Mar; 5(1): 41-48.


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