The most common impulse when someone decides to improve their gut health is to start eliminating things. Research consistently shows that what you add matters as much as — and often more than — what you remove.
Add first, remove later
A diverse, fiber-rich diet naturally creates conditions where beneficial bacteria thrive and crowd out the ones that cause problems. Before removing anything, think about what you could meaningfully add: a daily serving of a fermented food, one more vegetable at dinner, a tablespoon of seeds in morning oats, a tin of legumes in lunch. Addition is less psychologically demanding than restriction, more compatible with social eating, and has strong research support.
The 30-plant-food target
The American Gut Project found that people eating 30 or more different plant foods per week had significantly more diverse gut microbiomes than those eating fewer than 10. Every different vegetable, fruit, legume, grain, nut, seed, herb, and spice counts as a separate plant food. You get to 30 faster than you might think once you start deliberately counting.
Make fermented food a daily habit
A 2021 clinical trial found that a high-fermented-food diet increased gut bacteria diversity and reduced markers of inflammation more effectively than a high-fiber diet alone over a 17-week period. The two together were even better.
The distinction that actually matters
Ultra-processed foods specifically disrupt the gut through additives that damage the protective mucus layer lining the gut. But not all processed food is ultra-processed. Tinned legumes, frozen vegetables, canned fish, natural yogurt, and whole grain bread are all fine from a gut health perspective.
Your next steps: Count your plant food variety across seven days — every distinct plant food you eat. Most people find the number sits between 8 and 15. Then identify the single easiest addition: a new vegetable each shopping trip, fresh herbs on dishes you already cook, a different grain than your usual one, seeds sprinkled on breakfast. At the same time, add one fermented food daily. Start by adding — do not restrict anything yet. After four weeks of consistent additions, reassess which ultra-processed foods are still worth keeping.
This content is for educational purposes only and is not a substitute for professional medical advice.