What probiotics do for your gut and beyond

Here’s what probiotics really do, why they work and how to get more of them in your diet.

Probiotics have become a buzzword in grocery aisles and on social media, in part because of a growing body of research highlighting the importance of a healthy gut microbiome – the body’s vast ecosystem of bacteria and other microbes that helps regulate digestion, metabolism and immune function.

Research shows that when this ecosystem is disrupted by stress, antibiotics, illness or a highly processed diet, problems can follow. In many cases, probiotics can help prevent or relieve some of those issues “by providing a myriad of health benefits including improved mood, boosted immunity, cardiovascular health and more,” says Christine Palumbo, a registered dietitian and nutrition expert based in Chicago.

Here’s what probiotics really do, why they work and how to get more of them in your diet.

At their core, probiotics are living, beneficial microbes that help support the balance of organisms in your digestive system. “Think of them as friendly bacteria our digestive tract thrives on,” says Palumbo. They can also be thought of as helpful microorganisms that crowd out harmful bacteria and help maintain a stable, diverse gut environment.

Prebiotics, by contrast, are not bacteria at all. Instead, they are specific types of nondigestible fiber that “feed the good bacteria already living in your gut,” says LeeAnn Weintraub, a registered dietitian and nutrition consultant based in Los Angeles. In other words, “probiotics introduce helpful microbes and prebiotics help them grow and thrive," she says.