Psyllium is a natural fiber derived from the seeds of the Plantago ovata plant. It is commonly used as a dietary supplement to improve digestive health, particularly for relieving constipation. When mixed with water, psyllium forms a gel-like substance that helps to bulk up stool and promote regular bowel movements. In addition to its digestive benefits, psyllium can also support heart health by helping to lower cholesterol levels. It is often found in over-the-counter laxatives and fiber supplements, making it a popular choice for those looking to increase their fiber intake in a convenient way.