Probiotics: The Beneficial Bacteria

The growing number of antibacterial soaps, sponges, bandages, and other products on the market send a strong message that bacteria are something you want to eliminate from your life. But not all bacteria are harmful. More than 400 types of microbes--friendly and foul--naturally coexist in the intestinal tract. Having an adequate supply of "good" bacteria, called Probiotics, will keep the disease-causing organisms in check. What's more, they help the body break down foods, synthesize vitamins, process hormones such as estrogen, and possibly even prevent or treat a number of illnesses.

The best-known probiotic is Lactobacillus acidophilus, which is often added to yogurt. But L. reuteri, bifidus, and other bacteria can also promote health. Here's how probiotics can help.

Digestive Troubles

"Replenishing good bacteria in your intestine helps relieve diarrhea caused by antibiotics, food poisoning, or cancer treatment," says Manfred Kroger, Ph.D., professor of food science at Pennsylvania State University. In particular, studies show that L. reuteri may protect against salmonella and E. coli, the most common causes of food poisoning. And, though studies are lacking, some people experience relief from flatulence and constipation after boosting probiotic intake.


Most ulcers are caused by a bacterium called Helicobacter pylori. A Swedish study that compared the dietary habits of 322 people with ulcers to 264 without ulcers found that those who ate the most yogurt and other fermented milk products had an 18% lower risk of developing an ulcer.

Colon Cancer

Probiotics create an acid environment in the gut, which may neutralize compounds thought to lead to colon cancer. However, most of the research that points to this benefit has been done in animals. Further investigation is needed.


In a University of Kentucky study, people who ate yogurt laced with L. acidophilus daily for three weeks had a 3 to 4% drop in cholesterol levels. That may not seem like much, but it translates to a 6 to 10% reduction in heart-disease risk.

Vaginal Yeast Infections

In a study, women with recurrent yeast infections had a three-fold decrease in infections when they ate yogurt with L. acidophilus every day for six months. The women were then supposed to switch to a yogurt-free diet for a six-month comparison, but many refused to give up the yogurt, so the study's conclusions have been criticized.

Immune System Health

A study from the University of California at Davis shows that eating yogurt daily results in a four-fold increase in the body's production of gamma Interferon, a substance believed to enhance immune function.

Can I Take a Pill?

Yogurt and other fermented milk products are the best and least expensive source of probiotics. Probiotic supplements are available, but Dr. Kroger says there's no way to guarantee that the bacteria are alive. "Supplements may sit on the shelf for months. At least with yogurt you know it's only a week or two old." If you prefer supplements, refrigerated ones are more likely to be alive. Look for products supplying at least 1 billion live organisms per day, and take with food to minimize damage from stomach acids. If you're taking antibiotics, allow a two-hour window between the drug and the probiotic.

Post a Comment