If you're interested in seeing whether eating probiotic-infused foods might improve your digestive health, look for foods (or supplements) with one of many species of lactobacillus or bifidobacterium.
"There are something like 400 different probiotics, so it's hard to recommend a specific one, but these two have been widely studied," says Bethany Thayer, a registered dietitian at the
Dairy products contain probiotics to aid in fermentation, but some processes to prolong shelf life, such as pasteurization, can kill off the bacteria. Yogurt that bears the "Live and Active Cultures" seal contains at least 100 million cultures per gram, which works out to about 22 million live cultures in an 8-ounce serving.
"Other foods that contain probiotics include kefir, pickled vegetables, sauerkraut, pickles and some dark chocolates," says Jeannie Gazzaniga-Moloo, a registered dietitian in Sacramento and a spokeswoman for the Academy of Nutrition and Dietetics. "Miso contains probiotics, generally lactobacillus and bifidobacteria."
The catch with all of this is that the counts of active cultures in specific foods vary greatly, depending on type of bacteria and processing.