Probiotic cheeses and yogurts are said to contain good bacteria providing health benefits to consumers, but medical experts are asking for scientific proof to back up those advertising claims.

Danone claims its Activia yogurt with the bacteria B.L. regularis will "naturally regulate your slow intestinal transit," while Kraft's Liveactive brands are said to "help you with your healthy lifestyle."

What are probiotics?
The Food and Agriculture Organization of the United Nations (FAO) has defined probiotics as "live micro-organisms administered in adequate amounts which confer a beneficial health effect on the host."

While no one has suggested the products are unsafe, medical researchers say further studies are needed to determine any benefits of probiotics.

Dr. John Bienenstock, a probiotics researcher, told CBC News the problem is a lack of independent research. Many of the current research studies supporting the claims originate from the companies.

"Much more information needs to be gathered and much more research needs to be done, before many of the claims which were made are in fact reproduced," he said.

Health Canada has not yet verified the claims because the products are not covered under existing regulations.  

"We have not approved or authorized any claims surrounding probiotics in Canada," said Health Canada spokeswoman Mary L'Abbé.

The organization is currently wrapping up public consultations to help develop regulation guidelines.

"We recognized last year that we really did need to take a look at our framework surrounding health claims; there are a number of health claims that really weren't used in years previously," L'Abbé said.

The health claims of probiotics have also come under question in the United States, with the filing of a lawsuit in January against Dannon yogurt, the U.S. branch of the France-based yogurt marker, known as Danone in Canada.

The California woman behind the lawsuit, which is seeking class-action status, contends Danone's clinical studies failed to support the advertised claims and asks for compensation for all U.S. customers who purchased the products based on the marketing campaign. It also asks Dannon to launch a new advertising campaign correcting the claims.