Probiotic vs Prebiotic

So yesterday, Regina from the top-notch blog Weight of the Evidence pointed out that I had referred to inulin as a probiotic when, actually, it is a prebiotic. And, as another reader asked: What's the difference?

Good question, actually, because we're seeing these terms thrown around a lot these days as more "functional foods" come online. And when you see TV commercials talking about Dannon yogurt with "L casei Immunitas," I guess it's time to find out just what the terms mean. (More on "L casei Immunitas" later.)

For a definitive answer, I went to the godfather of all references, the Oxford English Dictionary--one bonus of working for a university is online access to this beautiful monstrosity.

And here we have it. A "prebiotic" is a non-digestible food ingredient that selectively promotes the growth of beneficial bacteria in the intestine. The beneficial bacteria themselves are "probiotics." So inulin, which I wrote about yesterday, is a prebiotic because it promotes the healthy bacteria. The term "probiotic" first appeared in 1995 in a Journal of Nutrition article--which is the kind of trivia one obtains from reading the OED. We also find that the two main prebiotics are the non-digestible oligosaccharides inulin and oligofructose, the richest nutritional sources of which are chicory root, Jerusalem artichokes, leeks and onions.

Oligofructose is used in what I personally think is the best low-carb chocolate, made by Maine Cottage Foods, which is sweetened with a blend of erythritol, Splenda and Ace-K.

But I digress, which I tend to do when there's chocolate around :-)

What Dannon touts in its Activia and DanActive yogurts--even the "plain" also contains sugar, by the way, so don't go rushing out to buy any--are "L casei Immunitas" and "Bifidus Regularis," which are really the company's own blends of probiotics (bacteria, or live cultures) that they claim promote a healthy immune system (immunitas) and bowel health (regularis). They don't tell us what the blend is--it's their "trade secret"--and tout that they're the only yogurts to have it. (Well, of course they are--Dannon made the blends up, including their "official" fake Latin names. Duh.)

But I don't eat that sugar-laden junk anyway. What I DO eat is plain Lifeway Kefir, which with a splash of DaVinci syrup makes a great yogurt smoothie. It contains 10 active probiotics: 

• Lactobacillius Lactis
• Lactobacillus Rhamnosus
• Streptococcus Diacetylactis
• Lactobacillus Plantarum
• Lactobacillius Casei
• Saccharomyces Florentinus
• Leuconostoc Cremoris
• Bifidobacterium Longum
• Bifidobacterium Breve
• Lactobacillus Acidophilus

What do all those probiotic bugs do for me? Couldn't tell you. But it tastes really good with some DaVinci Sugar-Free Irish Cream or Kahlua. And, yes, we could talk about spiking healthy yogurt with chemical-laden artificial sweetener. But that's a biology lesson for another day. Class is dismissed!