Firstly, fiber is good for our large intestine. This is because when fiber reaches our large intestine, it is broken down by millions of bacteria, producing short-chain fatty acids. These acids are a source of energy for the cells of our large intestine. Secondly, certain fibers help us avoid heart related diseases by keeping our blood glucose levels in check. In our stomach, these fibers dissolve in water and form a gel-like substance which holds the food together. This slows down digestion and delays the rate of glucose absorption into our blood, thus preventing unnecessary spikes in the blood glucose. Thirdly, high fiber foods are more filling. Hence, we end up consuming less calories, which is beneficial for weight loss. Lastly, some fibers also help in bowel movements, relieving constipation.