Prebiotics get mentioned constantly in gut-health conversations, but what they actually do is often glossed over. Here's the short version.
Probiotics are live bacteria. Prebiotics are food for those bacteria — specifically, types of fiber your body can't fully digest on its own, which pass through to your gut where beneficial bacteria can use them.
A healthier population of gut bacteria has been linked to better digestion, and increasingly, researchers are finding connections between gut health and things like metabolism and energy that aren't obviously digestive at all.
Resistant starch works similarly to prebiotic fiber — it resists digestion in the small intestine and reaches the colon largely intact, where it becomes fuel for beneficial bacteria rather than being broken down for immediate energy.