Bifidobacteria

Overview

Bifidobacteria are bacteria that exist primarily in the large intestine although some also inhabit the lower part of the small intestine. To date, 28 species of bifidobacteria have been isolated from the intestines of humans and animals. The following five are the predominant species that occur in humans: Bifidobacteria bididum (bifidus), B. infantis, B. breve, B. adolescentis, and B. longum. Bifidobacteria metabolize sugar to produce lactate and acetate. This creates a slightly acidic pH, which is an environment that is unfavorable for the growth of pathologic organisms. Bifidobacteria are the predominant bacteria that inhabit the feces of healthy infants. Mother’s milk contains growth factors that stimulate the proliferation of bifidobacteria in infants. The fecal flora of breast fed infants has been found to be approximately 99 percent bifidobacteria whereas the fecal flora of bottle fed infants is reported to be less than 20 percent bifidobacteria.

Dosage Info

Dosage Range

From 1-2 doses of 10 billion cfu (colony forming units) daily for maintenance. Doses up to 30 billion cfu/day may be required for individuals with bowel problems to recolonize the intestinal microflora following antibiotic therapy.

Most Common Dosage

10 billion cfu daily.

Dosage Forms

Capsules and powder.

Adult RDI

None established

Adult ODA

None established

RDA

  • : None established

Interactions and Depletions

Depletions

Active Forms

Bifidobacteria bifidum (bifidus), B. infantis, B. breve, B. adolescentis, and B. longum.

Absorption

Bifidobacteria are not absorbed, but rather remain within the gastrointestinal tract. In order to be effective, bifidobacteria must survive the acidity of the stomach. The acidity of the empty stomach ranges from a pH of 1 to 2. However, after eating, the stomach contents are diluted with food, which raises its pH to around 4. It has been reported that the decreased acidity following food consumption enables greater numbers of bifidobacteria to successfully pass through the stomach into the small intestine. Therefore, bifidobacteria should ideally be consumed with food. (1)

Toxicities & Precautions

General

There is no known toxicity associated with bifidobacteria.

Functions in the Body

Bacteria Growth Suppression

Digest sugar, which results in the production of short-chain fatty acids (SCFAs). The SCFAs, predominantly lactic and acetic acids, create a slightly acidic pH, which suppresses the growth of bacteria, yeasts, and other unfavorable organisms.

Metabolism

Influence the metabolism of fatty acids, bile acids, cholesterol and steroid hormones in the intestinal tract.

Digestion

Influence colonic blood flow and the secretion of mucin and pancreatic digestive enzymes.

Synthesize the following Vitamins in the Human Intestinal Tract

Vitamin B1, vitamin B2, vitamin B3, vitamin B6, vitamin B12, folic acid, biotin, and vitamin K.

Cholesterol Lowering

Help to lower cholesterol by converting it to a less absorbable form known as coprostanol, which inhibits its absorption from the intestinal tract.

Reduce Cancer Risks

May help to reduce risks because they are able to decompose nitrosamines, which are cancer causing substances, and they can also suppress the production of nitrosamines in the intestines. Researchers found that administration of Lactobacillus acidophilus reduced DNA damage in colon cells indicating a reduced risk of colon cancer. (2)

Energy

The short chain fatty acids produced by bifidobacteria are the main source of energy utilized by the epithelial cells in the colonic mucosa.

Help Protect Against Gastrointestinal Infections (via three mechanisms)

They adhere to the intestinal mucosa, which prevents pathological bacteria from adhering; production of acetic and lactic acids creates an acidic environment, which is unfavorable for pathogens, and they cause the activation of macrophages (immune cells), which suppress pathogenic bacteria.

Inhibitory Effects

Has been reported to exhibit inhibitory effects on pathological organisms including Salmonella, Shigella, Clostridium, Staphylococcus aureus, Candida albicans, and Campylobacter jejuni.

Clinical Applications

Intestinal Gas

Supplementation with B. longum resulted in the production of significantly less hydrogen gas in the intestines and a corresponding decrease in flatulence. (3)

Diarrhea

In a double-blind, placebo-controlled trial, infants with diarrhea were given either a standard infant formula or the same formula supplemented with Bifidobacterium bifidum and S. thermophilus organisms. Infants receiving the supplemented formulas had a substantial reduction in the incidence of diarrhea. (4)

Elevated Cholesterol

Bifidobacteria are able to remove cholesterol from the intestinal tract by two mechanisms: one is by metabolic assimilation of cholesterol and the other is precipitation of cholesterol by converting it to a less soluble substance known as coprostanol. (5)

Enhanced Immunity

Volunteers taking a bifidobacteria supplement for three weeks recorded a doubling of their phagocytic index. Six weeks after discontinuing the supplement, the activity of their phagocytes was still 50 percent higher than it was at the start of the experiment. (6)

Antibiotic Therapy

In a randomized, placebo-controlled trial with erythromycin, volunteers ingesting yogurt with bifidobacteria longum had a significant reduction in diarrhea and intestinal complaints compared to controls taking plain yogurt. (7)

Vaginal Infections

Women with these conditions have been found to have lower tissue levels of bifidobacteria and lactobacillus, and a corresponding increase in several forms of undesirable organisms. (8)

Symptoms and Causes of Deficiency

A deficiency of bifidobacteria can result in the growth and proliferation of pathological organisms in the intestinal tract. This can decrease digestion and absorption of nutrients, as well as increase production of gas, bloating and toxins. The most common cause of a deficiency of bifidobacteria is the use of antibiotic drugs. Other factors that can cause a reduction of bifidobacteria include the use of drugs that increase intestinal pH, stress, diarrhea, intestinal infections, and the presence of toxins in the intestine.

Dietary Sources

Small amounts of bifidobacteria may be found in cultured food products such as yogurt and acidophilus milk. However, in order to be effective, larger quantities are needed in the form of supplements.

References

  1. Yoneda K. Biological Study on Live Bacteria Products in the Market. Med and Pharm. 1987;17(6): 1529-34.
  2. View Abstract: Oberreuther-Moschner DL, Jahreis G, Rechkemmer G, Pool-Zobel BL. Dietary intervention with the probiotics Lactobacillus acidophilus 145 and Bifidobacterium longum 913 modulates the potential of human faecal water to induce damage in HT29clone19A cells. Br J Nutr. Jun2004;91(6):925-32.
  3. View Abstract: Jiang T, et al. Improvement of Lactose Digestion in Humans by Ingestion of Unfermented Milk Containing Bifidobacterium Longum. J Dairy Sci. May1996;79(5):750-57.
  4. View Abstract: Saavedra JM, et al. Feeding of Bifidobacterium bifidum and Streptococcus Thermophilus to Infants in Hospital for Prevention of Diarrhoea and Shedding of Rotavirus. Lancet. Oct1994;344(8929):1046-49.
  5. View Abstract: Tahri K, et al. Bifidobacteria Strain Behavior Toward Cholesterol: Coprecipitation with Bile Salts and Assimilation. Curr Microbiol. Sept1996;33(3):187-93.
  6. View Abstract: Schiffrin EJ, et al. Immune Modulation of Blood Leukocytes in Humans by Lactic Acid Bacteria: Criteria for Strain Selection. Am J Clin Nutr. Aug1997;66(2):515S-20S.
  7. Colombel JF, et al. Yoghurt with Bifidobacterium Longum Reduces Erythromycin-induced gastrointestinal effects. Lancet. Jul1987;2(8549):43.
  8. View Abstract: Bagirova M, et al. The Genital Tract Microflora in Patients with a Papillomavirus Infection. Zh Mikrobiol Epidemiol Immunobiol. Jun1995;(3):113-16.