Fiber is the nutrient most closely associated with supporting digestion and gut health. Found in plant-based foods like fruits, vegetables, whole grains, legumes, and nuts, fiber adds bulk to the stool, making it easier to pass and helping to prevent constipation. There are two types: soluble fiber, which dissolves in water and helps regulate blood sugar and cholesterol levels, and insoluble fiber, which passes through the digestive tract and promotes regular bowel movements. In addition to aiding digestion, fiber acts as a prebiotic, feeding the healthy bacteria in your gut microbiome, which supports immune health and may reduce the risk of chronic diseases. A high-fiber diet has been linked to lower rates of heart disease, type 2 diabetes, obesity, and even some types of cancer. The average adult should aim for 25–35 grams of fiber per day, but most people fall short. Incorporating more whole plant foods is an easy way to improve both digestion and overall well-being.