It all started with a cold. Then a cough. By the time I saw my physician, who was more than happy to share her "If-you-had-seen-me-sooner" lecture, I realized that even with a hefty dose of an antibiotic, an inhaler and other medicinal potions, this gunk had taken hold of my physical being. I was sick, sicker than I had been for a long time.

I'd overheard conversations in the grocery store about sick kids and spouses. Colleagues expressed sympathy even as they gingerly moved away. "There's some nasty stuff going around," they agreed.

Yet somewhere between taking a snort on the Advair disc and downing a few OTC meds, I realized how healthy I had felt before I got sick. Not just well -- healthy. Weeks before I succumbed to this illness, I had been in Greece for most of the summer eating a daily regimen of ridiculously thick Greek yogurt and local honey.

Hmmm ...

As I was recovering, an acquaintance of mine, who is a physician, said that she and her husband, also a physician, had been partaking of probiotic dairy drinks daily and hadn't been sick in two years.

Probiotics are not antibiotics. Probiotic means "for life." The World Health Organization defines probiotics as "live microorganisms, which when administered in adequate amounts confer a health benefit on the host" beyond nutrition. In other words, these are bacteria introduced into the human host's digestive tract that provide health benefits. More than 400 different probiotic strains have been identified. The most common of these are Lactobacillus, Bifidobacterium and non-pathogenic strains of Streptococcus.

Are probiotics new? The word, yes; the concept, no. Humans used to ingest bacteria from the soil foods were grown in, as well as from the milk products of animals. We used to live in a dirty world. Now food may be grown in soils devoid of these bacteria, and we may be wiping, with disinfectant wipes, our way into a new diet of avoiding the bacteria we may have ingested naturally in the past.

Probiotics are trendy in the United States, but other cultures, from ancient Greece to modern-day Japan, promoted health through diet, and certain foods have been universally accepted to produce beneficial results. Kefir, a Turkish word meaning "good feeling," is a fermented milk drink. It is believed that the prophet Mohammed gave the residents of northern Caucasus Mountains grains of kefir to make a fermented drink in order to stay healthy over 1,400 years ago.

More recently in this country actress Jamie Lee Curtis publicized Activa, a Dannon Company probiotic product, promoted to "help regulate the digestive system." But not all probiotics have the Activa end result.

How do these other types of probiotics work in the human diet? It is suggested that they help to promote immunity in the digestive tract. The idea, then, is to crowd the room with faces you do know so that strangers, and some of these may be violent, can't get into the room. This room, the digestive tract, is already filled with a complex system of 100,000 billion "good" and "bad" bacteria. The key is to keep it balanced. By introducing good organisms into the gut, they can out-populate the bad bacteria, and eat all their food. Without the dangerous stains, the human host stays healthy.

The problem with probiotics has been the delivery system. Probiotics need either a dry or refrigerated environment. Yogurt has a high water level, but refrigeration sustains the viability of the probiotics. The high acid content of the stomach can harm the probiotics, which is why dairy products such as yogurt have been successful to deliver the probiotic to the gut.

Some of these refrigerated products include DanActive, another Dannon product, a probiotic dairy drink that states on its label that it "helps strengthen your body defenses." This product contains L. casei Immunitas™, a trademarked culture, and Stonyfield, which adds a bevy of helpful bacteria to their yogurts: Lactobacillus rhamnosus, L. bulgaricus, Streptococcus thermophilus, L. acidophilus, Bifidus, L. casei, and L. rhamnosus. Another company, Applegate Farms, launched a yogurt cheese with probiotics last August.

Although it's more difficult to create a longer shelf life environment, some dry probiotics products do exist. Vive is a cereal by Kashi, a company owned by the Kellogg Company, and recently Vidazorb, a line of patent-pending chewable probiotics products, was released in the United States.

Currently, studies have been and are being conducted to show the reliability of many of the health claims suggested by probiotic products. These studies have their own problems, however. As Dr. Mary Etta Moorachian, professor of Nutrition at Johnson & Wales University, clarifies, "Much of the challenge is related to the fact that in human trials, people are alike but still heterogeneous."

So more studies will be done. But the real proof may be in the pudding, er, yogurt. Years ago in Hong Kong, I got suckered into drinking a glass of snake gall bladder wine. "This will keep you healthy for a year," the snake bleeder claimed. I didn't think that much about it at the time, downed the substance, and didn't realize until 14 months later that I had not even caught a cold.