Eating right, not supplements, is a sure way of keeping your good bacteria in fine fettle

It is best to get the bacteria you need from healthy food, rather than taking expensive and potentially ineffective supplements, says Gail Cresci, author of a new study and dietician and assistant professor of surgery, Medical College of Georgia (MCG).

"Consumers are buying stuff like crazy that is probably not even helping them and could potentially hurt them," says Cresci, who bagged this year's 'Excellence in Practice Award for Clinical Nutrition by the American Dietetic Association.

There is even mounting evidence that a healthy bug in the gut 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.

Increasing awareness of the benefit some of these organisms play in sickness and in health has resulted in an explosion of prebiotic and probiotic additives and products marketed directly to consumers.

It's also created confusion -- even among nutrition and other healthcare experts -- about how best to use them, says Cresci, who prescribes them to help surgery patients recover and works in the lab to learn more about their potential.

She equates the good bacteria in your gastrointestinal tract to another living being inside that helps keep you healthy. "If you do good by your bacteria, they will do good by you," Cresci says.

There are about 800 bacterial species with more than 7,000 strains inhabiting the average gut. Even though many sound similar they likely aren't.

For instance, a little Lactobacillus acidophilus combined with some Lactobacillus bifidus, for example, has been shown extremely beneficial in preventing antibiotic-induced diarrhoea while Lactobacillus bulgaricus with some Streptococcus thermophilus is useless.