Probiotics: man alive! Live microorganisms may be the secret to good health.(CLOSE UP)

Ever notice the phrase on a cup of yogurt: "Contains live active cultures"? While this statement may worry the squeamish, it shouldn't. These single-celled bacteria happen to be an effective means of ensuring digestive health, and they may have more far-reaching benefits.

In this day of antibacterial everything, it's hard to imagine bacteria being beneficial. However, certain bacteria--including the yogurt-dwelling L. acidophilus--are, in fact, good. They belong to a group of healthy, live microorganisms called probiotics.

Don't let their long scientific names scare you because they can make even the most science savvy tongue-tied. When reading labels, it is the probiotics' category name that comes first, and then the species name follows. In our yogurt example, Lactobacillus is the genus or category--abbreviated L.--and acidophilus is the species.

Research on each of these main categories has shown that certain strains can relieve digestive ailments such as diarrhea, irritable bowel syndrome (IBS) and lactose intolerance. Other studies suggest that probiotics may be able to boost immunity, prevent colon cancer and lower cholesterol. Here's the scoop.

You want to: Improve digestion and heart health

Reach for: Lactobacillus acidophilus

What the research says: L. acidophilus got a thorough research review in the February 2001 issue of the Journal of Dairy Science. Conclusion? Taken daily, this probiotic seems to help people who are lactose-intolerant digest dairy foods.