Are Probiotic Foods a Waste of Time?

Are you stocking the pond but starving the fish? When it comes to a healthy gut, prebiotics may be way more important than probiotics.

Monica Reinagel, MS, LD/N, CNS
3-minute read
Episode #404

Probiotic foods and supplements are among the fastest growing sectors in the health food marketplace, thanks to an explosion of popular and scientific interest in the “microbiome.” It’s clear that the bacteria that live in and on our bodies have an enormous impact on our health—one that we are only just beginning to explore.

But commerce isn’t one to wait around for all the data to come in. Although we have a long way to go to before we understand exactly how to influence and interact with our microbiota, we’re already being bombarded with new products: probiotic powders, juices, teas, fizzy vegetables, funky soybeans, and fermented grains. Some of these are traditional foods that have been around for thousands of years, of course. But until a year or two ago, you wouldn’t have found them on your grocer’s shelf with a bar code.

All of these probiotic foods, by definition, contain beneficial bacteria. And the hope is that by eating more of them, we will end up with more of them in our intestines. Stocking the pond, as it were.

Do Beneficial Bacteria Survive Digestion?

The problem is that, in order to get from our mouths to our intestines, the bacteria have to survive the rigors of our digestive system, where they’ll be bathed in acid and then worked over by enzymes. How many and which ones survive? That is very much an open question.

Some of the bacteria in our kimchi or kombucha make it to the intestines alive but may be relatively short-lived there. Even if they don’t set up permanent housekeeping, however, these food-based bacteria can have anti-inflammatory and immune-modulating effects and can influence the health and behavior of the gut’s more permanent residents.

Other food-borne beneficial bacteria don’t survive digestion. But that doesn’t mean that they don't do anything for us. Most traditionally fermented foods are nutrient-dense foods to begin with. The fermentation process increases the levels of some nutrients and makes others—particularly minerals—more bioavailable. Probiotic foods also often contain prebiotic nutrients which serve as nourishment for the bacteria in our intestines.

Prebiotics Are Where It’s At

And that actually brings me to the punchline: If you’re looking for a more reliable way to increase the health and diversity of your gut bacteria, don’t worry so much about stocking the pond. Instead, focus on the care and feeding of the bacteria that are already in there.


About the Author

Monica Reinagel, MS, LD/N, CNS

Monica Reinagel is a board-certified licensed nutritionist, author, and the creator of one of iTunes' most highly ranked health and fitness podcasts. Her advice is regularly featured on the TODAY show, Dr. Oz, NPR, and in the nation's leading newspapers, magazines, and websites. Do you have a nutrition question? Call the Nutrition Diva listener line at 443-961-6206. Your question could be featured on the show.