Most people think about gut health in terms of which bacteria they have. The emerging science says it’s more about what those bacteria are doing together.
Cross-feeding is the process by which one bacterial species produces compounds that neighboring species use as food. Lactate, formate, acetate— these metabolic byproducts circulate through your colon like currency in a thriving economy. The more diverse your plant intake, the richer and more functional that economy becomes.
This is why you don’t just need fiber. You need different kinds of fiber from different kinds of plants— because different bacterial strains specialize in different substrates. Rotating through the same few foods, even healthy ones, is like funding one sector of an economy and wondering why everything else is struggling.
The goal isn’t a complete dietary overhaul overnight. It’s expansion. Add one new plant this week. A different legume, an unfamiliar grain, a vegetable you haven’t bought in years. Your microbial community will notice.
Hot take: most people think they eat a diverse diet. Most people are wrong. How many different plants did you actually eat this week? Be honest.