Fiber is a carbohydrate that is resistant to digestion by cats. When a cat eats food, most of the nutrients it gets is digested either in the stomach or the small intestine. That is not the case with fiber. It is not readily digestible like protein.
However, a little fiber in the diet is good. Cats do have bacteria present in the larger intestine that can break down the chains of fiber via a process called fermentation. Fermentation is the breaking down of these fiber chains into simpler substances. Fermentation normally occurs lower down the GI tract. This process allows the cat to digest the fiber.
There are two types of fiber dealing with fermentation:
Fiber that is fermentable can be broken down by the bacteria present in the intestines. Once broken down into smaller chains, it can be used by the cat. This type of fiber provides nourishment for the intestines.
This fiber cannot be broken down as easily in the intestines. Instead, it passes through the digestive tract. It doesn’t provide any nourishment for cells in the GI tract. It does act as a bulking agent for stool and helps clean out the GI tract.
Another way of classifying fibers is by its water solubility.
Fibers that are soluble are more easily digestible because they can dissolve in water. These fibers form a kind of gel that can aid in the passage of food. The gel formation also allows the passage of food to slow down digestion and help increase the feeling of fullness.
These fibers do not easily dissolve in water, if at all. They do not form gels and have no effect on nutrient absorption. Insoluble fibers act as a bulking agent and tend to speed up passage through the cat’s body.
If you notice, fermentable fibers tend to be soluble and non-fermentable fibers tend to be insoluble.
The correct amount and type of fiber is definitely beneficial to cats. It is when cats receive too much fiber or too much of the wrong type that problems may occur. Fiber levels of more than 3% can be considered too high for cats. If the fiber is somewhat fermentable and combined with non-fermentable fiber, then it can be beneficial.
For example, it can help move hair through the intestines, thus preventing hairballs.
High levels of fibers can do the following:
- Decrease the digestibility of protein, fat, and other carbohydrates
- Hold water and prevent its absorption.
- Increases the amount of feces and frequency of pooping
- Can trap minerals and vitamins in the poop
- Can lead to gas production and flatulence
- Lead to dry stools and constipation
Fermentable fiber is found in soybeans, oats, and rye.
Non-fermentable fiber is found in flax seeds, whole grains, and corn.
It is good to get a good mix of both in the diet.
A well balanced high fiber diet assists with cats that overeat/are overweight. The fiber gives the cat a feeling of fullness after eating the right amount, thus allowing it to eat fewer calories. This is because moderately fermenting fiber takes longer to digest, giving the cat the feeling that it doesn’t need to eat anymore than it has to. This is why you see so many diets that are high in fiber and low in calories.
This can also help the prevention of diabetes. One of the most common causes of diabetes in cats is obesity. High fiber diets help to control the cat’s weight and prevent obesity. Also, diets high in fiber seem to lessen blood glucose spikes.