The American Gut Project, one of the largest microbiome studies, found that people who ate more than 30 different plant types per week had noticeably more diverse gut microbiomes than those eating 10 or fewer. Different plants feed different microbes, so variety — not just quantity — seems to matter.
The count is broader than it sounds: it includes vegetables, fruits, whole grains, legumes, nuts, seeds, herbs, and spices. A handful of mixed seeds, a spoonful of herbs, or a different bean each meal all count. Aiming for variety across the week is an easy, evidence-based way to support gut health.