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

Diet definitely has a significant impact on our gut bacteria. But the prebiotics you consume may be far more significant than the probiotics. Prebiotics are the indigestible carbohydrates (aka fiber) and other compounds in our food that provide a food source for those bacteria in the gut.

Your Diet Determines Their Destiny

Just like people, different bacteria have different food preferences. Some bacteria really dig cheeseburgers and fries. Other bacteria really love kale and oat bran. When you eat a steady diet of cheeseburgers and fries, those protein and fat-loving bacteria thrive and grow in number and the fiber-loving bacteria wither away. When you eat a lot of vegetables, legumes, and whole grains, the fiber-loving bacteria throw a party and the cheeseburger- loving bacteria sulk in the corner.

Just like people, different bacteria have different food preferences.

This has been dramatically demonstrated in human trials. Change the composition of your diet from one that’s high in animal fat and protein to one that’s high in plant fiber and you can change the profile of your intestinal bacteria in a couple of weeks or in as little as a day.

This is more than just a parlor trick. It turns out that the fiber-loving bacteria are the ones that are associated with all sorts of positive health benefits, while the cheeseburger-loving bacteria tend to be associated with obesity, colon cancer, ulcerative colitis, and metabolic syndrome.

And here’s an even more sinister possibility: Mouse studies have shown that the effects of diet on gut bacteria can persist for multiple generations.

Probiotic Foods Are Probably Not Enough

Feel free to explore and enjoy all the new (and old) probiotic foods out there. But if you’re looking for the health advantages associated with a healthier microbiome, what you feed your gut bacteria may be far more important.

It’s still OK to enjoy a cheeseburger from time to time. And your diet doesn’t necessarily have to be low in protein or fat; but if you want to encourage a healthy microbiome, your diet does need to contain plenty of fiber-rich foods. Eating a variety of vegetables, whole grains, nuts, and legumes on a daily basis will help to cultivate and nourish the kind of bacteria you want and starve the types you’d be better off without.

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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. 

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