Most people don’t think of onions as brain-enhancing foods, but they are wonderful for your gut. And as we have learned, the two are strongly connected. Onions are high in flavonoids, which have antioxidants properties that fight inflammation. They are also a prebiotic, which is the “fuel” that probiotics need to flourish in the digestive system. Sautéed onions go great on top of a burger, stir fry’s, and in soups or stews. You can also add raw onions to salads.