Fiber is the indigestible part of plant foods. As it travels through the digestive system it will absorb water to help with your bowel movements. Fiber breaks down into 2 types soluble and insoluble.
Soluble Fiber dissolves in water. As it passes through your digestive system it will absorb water and become a gelatinous substance.
Insoluble fiber does not change form and it does not dissolve.
The benefits of eating soluble fiber reduces cholesterol which lowers the risk of heart disease, regulates sugar intake which helps people with diabetes to need less insulin.
Fiber also has benefits for controlling weight, because fiber makes you feel full without adding a lot of calories hence your intake of calories are much less.