We’ve found so far that people who eat 30 or more different types of plants each week tend to have higher gut microbiota diversity than those who eat fewer [1]. This observation comes from 66.0 supporting assertions, with no refuting evidence in our current review. Gut microbiota diversity refers to the variety of different bacteria living in the digestive tract — a higher number of types is often linked to better digestive and immune function, though we don’t claim this causes better health. The evidence we’ve reviewed suggests that eating a wide range of plant foods — like fruits, vegetables, legumes, nuts, seeds, whole grains, herbs, and spices — may support a more varied gut environment. Each type of plant contains different fibers, polyphenols, and compounds that can feed different kinds of gut bacteria. Eating 30 different plants doesn’t mean 30 servings — it could mean one apple, a handful of spinach, a few almonds, some lentils, and a sprinkle of turmeric across the week. We don’t know yet if this diversity directly improves health outcomes, or if other lifestyle factors might be involved. The data we’ve analyzed doesn’t explain how much variety is needed, or whether the effect lasts over time. It also doesn’t say whether this applies to everyone, or if certain diets or health conditions change the results. What we’ve found so far leans toward the idea that eating a broad mix of plant foods is associated with greater gut microbiota diversity. For now, the simplest takeaway is this: if you want to support your gut bacteria, try adding a little more variety to your plant-based meals — even small changes, like swapping one vegetable for another or adding a new spice, might help.