I’m a doctor — these are the best and worst fermented foods for digestion
Gut it out.
Tangy fermented foods may not be your first choice for filling fare, but they are great for gut health since the fermentation process produces probiotics that aid in digestion.
Now, gastroenterologist Will Bulsiewicz is dishing on his two picks for fermented food and one to avoid. He told EatingWell this week, “There’s always a hierarchy in food; there’s the foods that I would put at the top and the ones that [I] would put at the bottom.”
He explains why he prefers kimchi and sauerkraut and eschews kombucha.
Best fermented food for gut health
“When it comes to fermented food, I would put the fermented plants at the top; examples would be kimchi and sauerkraut,” Bulsiewicz said.
Cabbage, the base for kimchi and sauerkraut, is packed with antioxidants and vitamin C and has justly been dubbed a “superfood.”
The fermentation process that takes raw cabbage to kimchi or kraut creates probiotics that support the gut microbiome, which is key to the body’s immune response.
And kimchi may have benefits beyond digestion. A study published in January in BMJ Open found that the traditional Korean dish of fermented vegetables may help reduce fat in the stomach area — and potentially decrease the risk of Type 2 diabetes.
The fermented superfood is also known to cure a raging hangover.
Kimchi is made by salting and fermenting vegetables, typically cabbage and radish, and adding seasonings such as garlic, onion and fish sauce. Cabbage and radish are rich in dietary fibers, microbiome-enhancing lactic acid bacteria, vitamins and polyphenols.
Sauerkraut, made by fermenting shredded cabbage, is equally beneficial and nutrient-dense.
Nutritionist Claire Sorlie even recommends it over pricey probiotic supplements, “If we’re just trying to get a daily dose of probiotics, food sources like sauerkraut are a much better option and often contain more strains. You can start with just one teaspoon per day,” she said on TikTok in April.
Bulsiewicz explains that kimchi and sauerkraut contain both pre- and probiotics as well as fiber.
“Fermentation is about transformation, and transformation is not just adding bacteria to this process. It also includes the creation of acid,” he noted to EatingWell. “This is why sauerkraut is bitter, not just salty cabbage. The fiber is transformed and becomes brand-new forms of fiber [that support your gut].”
The cons of kombucha
Kombucha, a fermented, sweetened black tea drink beloved by Gwyneth Paltrow and Madonna, is produced from a symbiotic culture of bacteria and yeast, or SCOBY.
The SCOBY is placed in a vat of sweet tea. During fermentation, the mother culture devours the sugar, producing lactic and acetic acids.
Kombucha has long been celebrated as a health tonic. Devotees claim it enhances immunity and energy levels, reduces food cravings, promotes liver health and alleviates gut inflammation.
Despite the hype and the health benefits, Bulsiewicz is cautious about consuming kombucha as a prepackaged product: “The base of kombucha is basically sweet tea, and that sweet tea does get transformed — the sugar, much of it gets consumed by the bacteria as a part of fermentation — but there’s still quite a bit of sugar left over.”
He recommends those big on the “booch” make their own fermented version at home to control the sugar content.
