Paleo, keto, vegetarian, vegan? These days, sorting out what we’re supposed to eat for optimal health can be incredibly confusing—with seemingly contradictory dietary approaches being touted as the end-all-be-all approach to wellness by different groups. But while we may never be able to agree on one “best” diet for everyone, we do know that supporting the gut is crucial.
That’s because the trillions of microbes living inside our digestive tract create all sorts of compounds essential for optimal functioning, like neurotransmitters and short-chain fatty acids—but they can only do their job if we give them the proper fuel.
So, what’s the most basic but effective way that people following any number of dietary approaches can fuel their microbiome? After interviewing a number of world-renowned microbiome researchers at the recent Gut Microbiota for Health World Summit 2019, I came to discover that one thing was quite clear: Sugar is out, and plants (lots of plants) are in.
Ditch the sugar—it’s wrecking your gut.
Did you know the average American is consuming 17 teaspoons of sugar every day, whereas the recommended daily limit is just 6 teaspoons for women and 9 teaspoons for men? In addition to the known long-term consequences of high blood sugar (heart attacks, stroke, and infections, to name a few), there is no evidence directly linking hyperglycemia to leaky gut.
Even more complicated is the fact that sugar can be hidden under as many as 56 different names—from the deliberate “cane sugar” to more innocuous names like “maltodextrin.” And, as you likely already know, sugar can be found in massive amounts in seemingly healthy foods such as yogurt, protein bars, and kombucha.
New forms of processed sugars are also being added to our foods that are not completely benign. Trehalose, for example, has been found to enhance the strength of a nasty diarrheal illness called C. difficile. And, don’t forget about artificial sweeteners—they, too, seem to exert a negative impact on the microbiome, by altering the microbes that influence sugar metabolism.
Load up on 30+ different plant foods per week.
Now that we know scaling way back on sugar is key, what should we actually eat to promote health and microbial diversity within the gut? Drawing from the American Gut Project and their work with the microbiome, one of the best guides is to start eating at least 30 different plant foods per week.
That’s because eating more than 30 different plants per week has been associated with greater microbial diversity, in part because all these plants contain loads of fiber, and fiber is an essential fuel for good gut bugs. Additionally, eating a wide variety of plants helps feed specific microbes known as the short-chain fatty acid fermenters—aka the protectors of the gut that control inflammation and help regulate the immune system.
Plus, people who eat 30 plant foods per week have been shown to have significantly fewer antibiotic-resistance genes (which is important, given the rise of superbugs); a lower intake of linoleic acid, which is associated with increased risk of cardiovascular disease and obesity in large amounts; and a greater intake of antioxidant, anti-inflammatory, and otherwise health-promoting micronutrients like beta-carotene, folate, and vitamins A, K, and C.