Fiber is a type of carbohydrate that the body cannot digest. While most carbohydrates are broken down into sugar molecules called glucose, fiber remains intact. Instead of being digested, fiber passes through the digestive tract, making it an important part of stool.
There are two main types of fiber:
- Soluble fiber: This type of fiber dissolves in water and forms a gel-like material in the stomach, slowing down digestion. It is commonly found in oats, beans, lentils, apples, and citrus fruits.
- Insoluble fiber: This type of fiber does not dissolve in water and adds bulk to stool, helping it move through the digestive tract more easily. It is found in foods like whole grains, vegetables, and nuts.
The process of fiber digestion is as follows:
- Fiber enters the digestive tract: When you eat fiber-rich foods, the fiber travels through your esophagus and into your stomach.
- The stomach does not digest fiber: Since the body cannot break down fiber, it remains largely undigested in the stomach.
- Fiber reaches the small intestine: As food moves into the small intestine, the fiber is not significantly broken down or absorbed.
- Fiber reaches the large intestine (colon): This is where fiber plays a crucial role. It is fermented by beneficial bacteria in the colon. This process produces short-chain fatty acids (SCFAs), which have various health benefits.
- Fiber exits the body: The undigested fiber, along with water and other waste products, forms stool and is eliminated from the body.
Fiber, though not digested by the body, is essential for digestive health and overall well-being. It promotes regularity, prevents constipation, and supports a healthy gut microbiome.
