The use of fiber in your cat's diet
The right mix of fibers in your cat's food can contribute significantly to the health of their gastrointestinal tract. A high-fiber diet can help prevent hairballs from forming—a particular problem with indoor cats—as well as encouraging the natural motions of the gut. Soluble fiber can have a beneficial effect on the gastro-intestinal flow, and also regulate the microflora that live in your cat's digestive system.
Vitamins, minerals, and other nutrients in your cat's food
Your cat needs a complex mix of minerals and vitamins in trace amounts to help support the effective functioning of its body. Every vitamin and mineral has several different functions, such as vitamin E which works as a powerful antioxidant and nourishes the skin.
Pre- and pro-biotics can also be beneficial in managing your cat's digestive sensitivities. Prebiotics are non-digestible substrates or "platforms" on which beneficial gut bacteria are encouraged to grow, while probiotics are living organisms which positively impact the microflora in your cat's system. Both of these can be used to rebalance the bacteria present in your cat's digestive tract, supporting their continuing health.
Make sure to visit your vet if you believe you cat is experiencing digestive difficulties—they'll be able to advise on the best course of action and the right, balanced food to support your pet's health.