Time once again for the Word of the Day. This is where we teach you a simple word from the annals of science and explain what it means. Today's word is Lactobacillus bulgaricus; or, if you'd like an easier word of the day: yogurt.

Have you ever wondered what qualifies as yogurt? You've probably heard people saying that yogurt is health food, but did you ever wonder why that is?

To qualify as actual yogurt, two live strains of bacteria have to be present: Lactobacillus bulgaricus and Streptococcus thermophilus. The bacteria are added to turn the milk into yogurt. That's right! When eating yogurt, you're actually consuming bacteria.

A lot of people don't understand that there are good bacteria and bad bacteria. The good ones live in our digestive systems and help us break down the food we eat. They also produce natural antibiotics that drive out the bad bacteria--kinds that can give you diarrhea, cramps, and worse. In addition, the bacteria in yogurt break down lactose, which makes yogurt easier to tolerate for people who are lactose intolerant and don't drink milk.

The point is, some bacteria are good for you--and real yogurt is chock-full of 'em. Just be sure to look for the word 'active' on the label, to be certain you're getting the kind that's both yummy . . . and alive.