Gail Cresci, Medical College of Georgia dietician and researcher, said that as with vitamins, it's best to get the bacteria you need from healthy food rather than taking often expensive and potentially ineffective supplements.
"Consumers are buying stuff like crazy that is probably not even helping them and could potentially hurt them," said Cresci.
There is even mounting evidence that a healthy gut microbiota helps maintain a healthy weight.
Studies have shown, for example, that when bacteria from a genetically fat mouse are placed in a lean germ-free mouse, it gains weight without changing its food intake.
Unfortunately poor diets are hurting the bacteria in many of us and the overuse of antibiotics is taking its toll as well, she says, particularly the common, broad spectrum antibiotics that wipe out anything in their path, good and bad bacteria included.
Cresci said that if you eat right, you likely wouldn't need such extremes.
"If you do good by your bacteria, they will do good by you," she said.
The latest findings were discussed at the American Dietetic Association's 2009 Food and Nutrition Conference and Expo in Denver, Oct. 17-20.