(NaturalNews) Yogurt maker Dannon has been hit with a class-action lawsuit alleging that the company has made false and misleading claims about the health benefits of its probiotic line of yogurts."Deceptive advertising has enabled Dannon to sell hundreds of millions of dollars worth of ordinary yogurt at inflated prices to responsible, health- conscious consumers," said attorney Timothy G. Blood."All of Dannon's claims for Activia and DanActive are completely supported by peer-reviewed science and are in accordance with all laws and regulations,'' the company responded.Dannon advertises its Activia and DanActive yogurts as containing probiotic bacteria that help boost the immune system and regulate digestion. An aggressive marketing campaign by the company includes a high-profile ad campaign and a Web site with links to studies showing the benefits of the probiotic bacteria used in Activia products.The studies cited by Dannon were all funded by the company.Filed in the United States District Court in California, the lawsuit says that there is no evidence that the yogurt itself functions as advertised, regardless of what various varieties of probiotic bacteria may do in the laboratory.Probiotics are microorganisms that provide health benefits inside the body, but some scientists say that probiotics remain poorly understood. Of the thousands of probiotics that exist, very few have been tested for their effects when consumed by humans as part of their diets. Laboratory research does not necessarily translate into real health benefits, these researchers say."At present, the quality of probiotics available to consumers in food products around the world is unreliable," says a 2006 report by the American Society for Microbiology.There are few FDA regulations on marketing claims made on probiotic products, as long as those products do not claim to be equivalent to drugs that have the ability to cure diseases.