You may have heard of prebiotics before—they're basically substances that you can't digest, so they reach your stomach whole, where they act as food for your gut bugs. They're in foods like Jerusalem artichokes and raw chicory root (things you probably don't eat that much of, TBH). If you don't eat enough, your gut bacteria can end up malnourished—not a good thing. Thankfully, now prebiotics are showing up in more and more supplements. One good option: ISOThrive ($40, isothrive.com) is a naturally fermented prebiotic nectar that feeds your gut bugs to keep your GI tract in healthy shape.