So what are these mysterious organisms that companies tout as beneficial for digestion, immunity, and more—and do you really need to consume them? Here's the lowdown on probiotics.
Probiotics are beneficial bacteria that play an important role in balancing the microflora (in other words, the microscopic bugs that inhabit all living things) in the gut. And while they've gained loads of attention and fans in the last few years, they're anything but new. We've been consuming probiotic bacteria through fermented foods like sauerkraut, kimchi (a spicy fermented cabbage dish, ubiquitous in Korean cuisine), sourdough bread, buttermilk, and yogurt since roughly forever. These days, you'll also find foods that are fortified with probiotics (like that chocolate), as well as probiotic supplements.
The human body—and specifically the large intestine—houses trillions and trillions of bacteria. And while bacteria have the reputation of being undesirable, there are actually many different types of bacteria—some good, some not so good, and some neutral. The so-called good bacteria, also known as probiotics, keep bad bacteria in your gut from multiplying to an unhealthy amount. As a result, they help keep your digestive tract working correctly, boost your immunity, help you process food, and, we think, additional benefits (researchers are continuing to study this area). You may want to try upping your intake (or popping a pill) if:
*You have irritable bowel syndrome (IBS). In one recent study, 68% of adults with IBS who took a probiotic supplement (a mixture of Bifidobacterium longum, B. bifidum, B. lactis, Lactobacillus acidophilus, L. rhamnosus, and Streptococcus thermophilus) experienced significant relief from symptoms; while only 38% of adults who took the dummy pill felt better. The probiotic group also had a significant increase in the amount of healthy bacteria in their stool.
*You have an irritable bowel disease like ulcerative colitis or a complication like pouchitis (yes, IBD is different than IBS). In guidelines released in 2012, the American Society for Nutrition supported the use of the probiotics E. coli Nissle 1917 and VSL #3 (a brand of supplement that contains several probiotic strains) for in people with those diseases, based on recent research. The research, however, does not support the use of probiotics in those with Crohn's Disease.
*You're trying to get through cold season. In one study published in the British Journal of Nutrition, students who took probiotic supplements containing the strains Lactobacillus rhamnosus GG and Bifidobacterium animalus lactis BB12 experienced shorter and less severe colds than students who took a sugar pill.
*You're taking antibiotics. In a 2012 review of 63 studies, adults who took a probiotic along with an antibiotic prescription were 42% less likely to experience diarrhea as a side effect of the antibiotic.
Including fermented foods like tempeh, kombucha, or kefir (as well as those foods mentioned above) in your balanced diet is probably the best route to go if you're looking to support general health and wellbeing. If you're aiming to treat a specific condition or prevent side effects of taking an antibiotic, you may want to turn to supplements that contain the specific strains that are useful for you. Probiotic supplements can contain a single strain or several; since different strains may work better in different situations, ask your doctor or registered dietitian, or do some research on your own to determine which product is right for you.