Most people think of bacteria as bad. That's because some bacteria are linked with infection and disease. But there's a growing interest in "good" bacteria called probiotics. These bacteria live peacefully inside your intestines, where they feed off of carbohydrates and fiber that your body can't completely digest. By taking up residence in your intestines, they make it more difficult for disease-causing bacteria to move in. This creates a healthier environment inside your stomach.
There's still much to learn about these gut-friendly bacteria. Plus, there are lots of myths and misconceptions about probiotics, what they do, and the best way to get their benefits. Here are some of the most common ones dispelled.
Fact: Yogurt may be a good source of probiotic bacteria—but not always. Some yogurt has been heat-treated to temperatures that probiotic bacteria can't survive. Even for yogurt that hasn't been heat-treated you don't know how many active probiotic cultures it contains. Look for a yogurt labeled "active or live cultures." This means it hasn't been heat-treated and contains probiotic bacteria.
Fact: Yogurt is only one source of probiotic bacteria. Fermented foods like miso, tempeh, fermented cheeses, Korean kimchee, kefir, and acidophilus milk are other good sources. Sauerkraut is also a source, but canned sauerkraut has been heat-treated and probably doesn't have a significant number of probiotic strains. If you make your own sauerkraut at home, it can be a very good source of good bacteria. You can also get probiotics by taking a probiotic supplement.
Fact: There are hundreds of types of probiotic bacteria, and different strains of probiotic bacteria have different health benefits. The problem is the distinct benefits of each strain of probiotic bacteria haven't been categorized at this point. That means it's best to get a diverse mix of probiotic bacteria until more is known about the role each bacteria plays and what the distinct health benefits of each are.
Fact: Consumer Reports tested probiotic supplements and found the ones they tested contained fewer active probiotic strains than what you could get from yogurt with active cultures. Plus, there's little regulation of the supplement industry. What's printed on the label may not be what you're actually getting. The same goes for food products you buy in the supermarket that are "fortified" with probiotics, like cereals and juices.
Fact: Probiotic research is still in its infancy, but preliminary studies suggest that probiotics are beneficial for treating infectious diarrhea, diarrhea resulting from antibiotic use, irritable bowel syndrome, and possibly atopic dermatitis in babies. There's also some evidence they may reduce the frequency of colds and may be helpful for treating vaginal yeast infections and inflammatory bowel disease, but it's too early to say.
Fact: Probiotic supplements appear to be safe if you have a healthy, functioning immune system. If you have an immune-deficiency disease, check with your doctor first. Some medications like steroids and cancer chemotherapy drugs cripple the immune system. Taking probiotics while on these medications could increase your risk for illness.
If you're on a medication that suppresses your immune system, avoid probiotic supplements unless your doctor gives the OK. It's also not clear whether they're safe for young children, the elderly, or pregnant women. Some people also experience mild intestinal upset and bloating when they take probiotic supplements.
Probiotics appear to have benefits, but there's a lot of misinformation out there. Keep these guidelines in mind when considering their potential benefits.