
16. Leeks
Leeks are not popular among Americans, but people in the United Kingdom commonly consume them. A leek is like a cousin of the more familiar garlic and onion, but with a milder taste. The fibers in leeks pass all of the tests to be a good prebiotic, so they are a great way of improving the health of your microbiome. Consuming leeks and other members of the allium family can help reduce the risk of colorectal cancer, so if you are looking to boost the health of your gut, there is no excuse for not adding leeks to your diet. They can be a great ingredient for soups, or you can eat them whole when roasted with herbs.