Good gut bacteria means more than just probiotics.
Last year, we were reminded that a balanced, flourishing gut microbiome is the cornerstone of a high-functioning body. Hence all the probiotic-rich kefir and kimchi we've been spooning ever since. But those probiotic bacteria need fuel to survive, which is where prebiotics come in.
“Prebiotics are the foods and nutrients that the healthy bacteria in our gut eat and need to be sustained and to flourish,” explains Raphael Kellman, M.D., a New York City-based integrative and functional physician and the author of The Microbiome Diet.
The good news is that you’re likely already eating some of them, and that they’re generally great for your overall health, too. “They’re fiber-rich, nutrient-dense foods from the vegetable, fruit and legume families,” says Bethany Snodgrass, a Tier 4 Equinox trainer in New York City and holistic health coach. These include asparagus, garlic, onions, carrots, Jerusalem artichokes, jicama, leeks, radishes, tomatoes and dandelion greens.
Kellman says that a generally healthy person should aim to eat prebiotic foods once a day, with a caveat: If your gut is out of sorts, causing symptoms like chronic bloating or recurring indigestion, you should start by focusing on probiotics. In doing so, you're first encouraging the good gut bacteria to flourish and start to push out the bad bacteria, which makes you feel better. If you add a prebiotic to the mix at this stage, you're unwittingly encouraging the bad bacteria to multiply along with the good. “If you want the ecology of the microbiome to improve, you first have to prune the vineyard,” he explains.
Similarly, Snodgrass emphasizes the importance of a balanced relationship between probiotics and prebiotics. “If you don’t have the bacteria in your gut to help utilize the prebiotic, it’s not going to be effective,” she says. "Conversely, if your diet is not fiber rich, your body isn’t going to absorb and utilize the bacteria you’re bringing in.”
To help emphasize that symbiosis, she likes to create healthy gut-focused meals that pair prebiotic and probiotic foods, such as yogurt with banana, kimchi with beans, or kefir with berries. While it’s not essential that you pair the fermented and fibrous in the same meal, it’s a helpful way to make sure you’re getting both in your diet. (You may need to supplement in order to get enough probiotics, but that you should be able to get enough prebiotics from food, except for in special cases, like someone with an immune deficiency.)
One more pro tip for the active: Since exercise can cause gastrointestinal stress, Snodgrass recommends timing your daily high-fiber prebiotic feast so that it doesn’t fall right before or after a workout. “Keep it for the meals outside the three- to four-hour window around training,” she says.
To get you started, here's a recipe complete with a balanced helping of both pre- and probiotics (and it's light and delicious to boot).