It's hard to miss TV commercials and ads promoting probiotics. Relatively unheard of just a few years ago, probiotics are in the media spotlight. But what are they? Probiotics are live microorganisms – usually bacteria – that are similar in structure to the “good” bacteria found in the human gut. Friendly bacteria are vital to the immune system and assist in digestion and the absorption of nutrients, thereby improving the health of your digestive tract.

The bacteria help regulate and restore the rhythmic motion of the intestines that push digested food through. It doesn’t matter if you are constipated or the opposite, these bacteria can help to make you more regular.

Several outside influences can upset the balance of bacteria, including the use of antibiotics which kill both the friendly and unfriendly bacteria in the gut. Some people also use probiotics to balance the effects of lactose intolerance.

Probiotics are found in foods such as yogurt, milk, miso and some juices and soy beverages. They are also available in dietary supplements.

To date, the U.S. Food and Drug Administration has taken a neutral stance on probiotic products, but is cautioning food makers not to pitch their products as a cure for any sort of specific disease. While most people can add probiotic foods or supplements to their diet with little to no side effects, the USDA says some people should avoid probiotics completely, including people with weakened immune systems, the very ill and those in the hospital.

Before adding probiotics to your regimen, check with your physician to see if they are right for you.