Americans are increasingly gulping yogurt drinks and other probiotic-infused foods that promise to treat everything from bad cholesterol and high blood pressure to irritable bowel syndrome. It's hard to escape the TV commercials and even e-mail spam hyping the benefits of these live, "good" bacteria pumped into foods.
But are probiotics really all they’re cracked up to be?
The jury’s still out. Few of the hundreds of products on the market — yogurts, smoothies, cereals and dietary supplements, for example — have actually been clinically tested for their effectiveness in easing gastrointestinal ills. And many of the new foods and beverages that claim to be probiotics may not contain enough of the types of bacteria that have been proven in studies to deliver health benefits. Still, there are several well-controlled human studies that have shown that real probiotics help with a variety of conditions including those related to the gastrointestinal system.
According to Mary Ellen Sanders, a consultant to the probiotic industry, a true probiotic product contains purified strains of specific microbes or yeasts, such as B. Animalis (in Dannon's Activia yogurt for example) or other specific strains of Bifidobacterium or Lactobacillus, and provide amounts shown to have specific beneficial effects.
Normally, trillions of bacteria, yeasts and other microbes are living in your intestinal tract. Many are key players in digestion and in supporting healthy immune function. While you don't need probiotics in your diet to be healthy, people with mild digestive concerns, who are taking antibiotics or those who are lactose intolerant might benefit from certain probiotics, studies suggest.
Probiotics can be helpful for specific conditions such as diarrhea, lactose intolerance or Crohn's disease. While a published report about early research suggested probiotics could help lower blood pressure or blood cholesterol, or reduce postmenopausal disorders, we need many more studies that show probiotics have consistent beneficial health effects in humans before conclusions can be drawn, or specific recommendations made to consumers.
No one-size-fits-all product
If you’re in generally good health,probiotic products shouldn't do any harm. But if you have an underlying illness or a compromised immune system, check with a physician before consuming probiotics since they may increase your risk for infections such as sepsis, an infection of the bloodstream. Although there are several studies done which administer probiotics to newborns, and even premature babies, a newborn does not have an established microbiota or immune system. So caution is suggested.
Unfortunately, there’s no one-size-fits-all approach to choosing a probiotic product. Check the label for the specific genus, species and strain of probiotic used, the amount provided in each serving and the recommended serving of the product found to be beneficial (based on published human studies), advises Jo Ann Hattner, a registered dietitian in San Francisco who is working on a book about probiotics.
While studies have shown that doses between approximately 100 million and 1 billion colony forming units (CFUs) are effective for enhancing immune function, decreasing intestinal infections, and improving digestion and bowel function, the amount of probiotics you’ll need to consume to see a real effect will vary among strains.You need to consume a probiotic food every day to get the desired effect and it may take a week or two to experience specific results — such as a decrease in gas or bloating, or a higher tolerance to dairy foods. If after a few weeks you don’t feel results, try another similar product to see if it works any better.
However, probiotics don’t work the same in everyone. Probiotics may be more effective in older people than in younger ones since more mature bellies may have fewer good bacteria. There’s also some evidence that genetic factors — that is, how much good and bad bacteria you have in your gut — can affect your reaction to probiotics.
Also make sure the bugs are viable through the end of the product's shelf life and not just at the time the item was manufactured. If the bacteria aren’t viable when you eat them, well, they won’t help you.
Even if you don’t see specific results from a healthy probiotic-boosted food such as yogurt, at least you’re still getting the benefits of calcium and other nutrients. But be wary of some products claiming to be loaded with the bacteria. Remember, a chocolate bar with added probiotics is still just candy.
Elisa Zied, RD, is a spokesperson for the American Dietetic Association. She is the co-author of “Feed Your Family Right!” and “So What Can I Eat?!”