The Power of Probiotics

By Rachel Meltzer Warren, MS, RD
Clinically Reviewed and Updated By: Amy Magill, MA, RDN on November 29, 2019

From cereals to yogurts to supplements to chocolate (yup, you read that right, chocolate), probiotics seem to be everywhere.

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 microbiota (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 can help keep your digestive tract working correctly, help you process food, and, we think, provide additional benefits (researchers are continuing to study this area).

Here’s what we know so far. Some studies show that certain probiotics may help prevent diarrhea caused by infections or antibiotic use. Other research shows that probiotics may improve some symptoms of irritable bowel syndrome. There is also some evidence that probiotics may be helpful for atopic eczema (a skin condition that affects mostly children). Researchers are still studying if probiotics can help improve immunity, fight against obesity, high cholesterol, yeast and urinary tract infections, and more.

Keep in mind that this research is preliminary. It isn’t known how much of a probiotic a person would have to take or who would be most likely to benefit. Plus, there are many kinds of probiotics and they don’t all work the same way. Some may be more effective than others for certain symptoms or health issues.

While the jury’s still out as to whether probiotics can deliver these health benefits, 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 add helpful bacteria to your system and help foster a healthy gut microbiota. Before you consider taking a probiotic supplement, talk with your health care provider to learn if probiotics are right for you.