Probiotics

These beneficial bacteria are vital for digestion and keep harmful bacteria in check.

WHAT THE ARE

"Probiotics" are live bacterial microorganisms that inhabit the human gastrointestinal tract, where they excrete chemicals that are vital for digestion and for keeping harmful bacteria in check. Two strains, Lactobacillus acidophilus and Bifidobacterium bifidum, are native to the human body. Another strain, Lactobacillus bulgaricus, which is not native to humans but is found in certain foods, may also provide benefits.

HEALING CLAIMS

Probiotics Treat a range of conditions, including intestinal infections, vaginal yeast infections, urinary tract infections, acne, and digestive disorders. Researchers believe they act as natural antibiotics, help lower serum cholesterol levels, and may even strengthen the immune system.

Probiotics can also counteract the negative effects of antibiotics, which indiscriminately kill both "good" and "bad" bacteria, making it easier for pathogens to flourish. They are also effective in treating antibiotic-associated diarrhea (AAD).

EVIDENCE

In 1996, the Journal of the American Medical Association (JAMA) published a review of probiotic studies done between 1966 and 1995. These controlled studies show that L. acidophilus, L. bulgaricus, and B. bifidum successfully treated AAD and other forms of diarrhea, and may be effective for vaginal yeast infections. In one study, a mixture of L. acidophilus and L. bulgaricus was given to 79 patients receiving the antibiotic ampicillin. None of the patients who were taking the probiotics developed AAD, compared with six of 43 patients a placebo.

A study published in the journal of Clinical Therapeutics in 1992 supports the use of probiotics to treat urinary tract infections. Other indicate that friendly bacteria may strengthen the body's natural defenses,

HOW THEY WORK WORK

Each strain of good bacteria plays a different role in the body. For example, L. acidophilus manufactures lactic acid, which creates an acidic environment that is inhospitable to disease-causing bacteria; it also makes lactase, an enzyme that aids digestion. In addition, it secretes natural antibiotics, substances that promote the body's elimination A cholesterol, and chemicals that retard the growth of hostile organisms.

L. bulgaricus produces lactic acid and the enzyme lactase.

B. bifidum competes with harmful bacteria for food and space along the intestinal wall.

B. bifidum also produces acids and manufactures B vitamins, including biotin, niacin ([B.sub.3]), and folic acid.

DIETARY SOURCES

Good bacteria are found in many foods, including yogurt, cheese, fortified milk and soymilk, sourdough bread, an pickles. A diet rich in complex carbohydrates (vegetables, fruits, whole grains) promotes the growth of bifidobacteria.

WHEN TO SUPPLEMENT

In some cases, diet alone may not maintain the necessary numbers of friendly bacteria. Certain lifestyle factors--including the use of antibiotics, travel, alcohol consumption, and stress--can damage these delicate microorganisms.

DOSAGE

According to Natasha Trenev, co-author of Probiotics: Nature's Internal Healers (Avery Publishing Group, 1998), the dose for maintaining proper intestinal health is 2 billion microorganisms of both acidophilus and bifidobacteria every day. For therapeutic purposes the daily dosage is about 10 billion of each. Note: Check with your, physician before using probiotics to treat specific conditions, since dosage varies according to age and diet.

HOW TO BUY

Probiotics must survive the manufacturing process. Gary Elmer, Ph.D., co-author of the JAMA research review, offers a number of tips for buying viable probiotics:

1. Check the label to make sure the bottle contains at least I billion live organisms per gram.

2. Check the expiration date.

3. Buy probiotics packaged in well-sealed bottles so moisture can't damage the organisms.

4. Refrigerate supplements if the label recommends it.

Sarah Fremerman is a frequent contributor to Natural Health.

COPYRIGHT 1998 Weider Publications
COPYRIGHT 2008 Gale, Cengage Learning