Pro-biotics are good bacteria that live in your intestinal tract. Without them, you will feel sick, but it is getting easier to put them back when you are running low.
"They are actually a friendly bacteria and these are indeed bacteria that need to be in the gastrointestinal tract and not only keep us healthy, but ward off particular types of infections," says Leslie Bonci, spokeswoman for theAmerican Dietetic Association.
The most common food containing pro-biotics is yogurt.
"If we are looking for a benefit in a food, it has to say LAC -- live active cultures. It has to not be heat-treated because if it has been heat-treated, those bacteria are dead and not doing the body any good," Bonci says.
Pro-biotics may help to decrease the incidence of yeast infections. They may also have a benefit for people who suffer from acute diarrhea or irritable bowel syndrome.
You may also see supplements called pre-biotics. They are not the same as pro-biotics. Pre-biotics are found in leeks, some grains, bananas, garlic, onions, milk, honey and artichokes. Pre-biotics feed the pro-biotics.
"A pre-biotic is not digested by the human digestive tract, but by the good bacteria that all of us have in our normal natural systems," says registered dietitian Susan Drake.
If you have been on antibiotics, which kill organisms in your body, you may want to talk with your doctor or dietitian about a pro-biotic or pre-biotic supplement.
"What happens with antibiotics is that it wipes out the intestinal flora, the good bacteria as well as the bad bacteria," Drake says.
If your doctor or dietitian says you can use pro-biotics or pre-biotics to repleace belly bacteria, look for labeling on supplements or yogurt that says at least 10 million.