Activia is Dannon's "functional" yogurt -- the company claims that the patented Bifidus regularis probiotic helps regulate your digestive system, reducing the occurrence or severity of digestive complaints. You may have noticed an increase in gas and bloating since you began eating Activia, but that doesn't mean it's not working. These are normal side effects that usually fade with continued use. The cause of the side effects, however, is more interesting than most -- it's the result of a battle of good versus evil being waged in your gut.
Good Versus Evil
Probiotics like Bifidus regularis are simply "good" bacteria. Your body has its own unique intestinal bacterial population, comprised of both good and bad bacteria. Usually, the good bacteria outnumber the bad -- but in times of stress or illness, the bad bacteria can take over and you begin to experience digestive problems. Using a probiotic is like sending in reinforcement troops for the good bacteria. Eventually, the proper balance is restored, and the good bacteria can subdue the bad bacteria, ending your digestive complaints.
Send In the Troops
You can take probiotics in pill form, or you can find them in fermented foods like yogurt. You may notice a temporary increase in your symptoms at first, because you are basically introducing a new strain of bacteria into your body, and the good bacteria might mistake it for bad bacteria at first. Once the new bacteria get to work defeating the bad bacteria, the good bacteria realizes they're all on the same team, and accept the new bacteria as an ally. Depending upon your body's natural intestinal bacteria population, this can take anywhere from a few days to a few weeks. There are many strains of probiotic bacteria, and if your body doesn't immediately recognize the Bifidus strain, your symptoms may last longer.
Activia isn't the only yogurt that contains probiotics -- any yogurt labeled as containing "live, active cultures" contains one strain or another. But Activia is the only one that contains Bifidus regularis, a particular Bifidus bacteria strain patented by Dannon. Dannon claims that Bifidus regularis is more effective than other probiotic strains because it survives the digestive process intact, which allows it to reach its base of operations alive, but this isn't as unique of a situation as the company makes it sound. According to the World Health Organization, most recognized probiotic strains also survive digestion -- testing to determine this is a standard part of probiotic development.
The many probiotic strains have different characteristics and are effective at different things. If your gas and bloating continue after eating Activia daily for two weeks as recommended by Dannon, switch to another yogurt. Many yogurts contain Lactobacillus acidophilus bacteria, which has been more widely studied because it is not a patented strain and is older and more well-known. It could be that a different probiotic strain simply agrees better with your personal gut army, or that Bifidus regularis isn't effective for your particular digestive problem.