When thinking about your nutrition, it's best to try and consume as much natural fibre as possible. Natural fibre is going to mostly come from real foods rather than from supplemental products.
There are a vast selection of options out there for those who cannot consume the foods however keep in mind that you will be missing out on good nutrition when you take these.
One of the best things about real food is that along with the natural fibre they contain, they also provide the body with plenty of vitamins and minerals which are important because they act as antioxidants to protect you from disease. You'll also get macronutrients like carbohydrates and protein, which supply the body with a usable source of energy and amino acids that you will use to repair any damaged bodily tissues.
A second large benefit to consuming real foods rather than supplemental sources is that when a meal is high in this nutrient, it will slow its release into the body. You likely will notice this effect more than if you were just drinking a Metamucil drink for example. While you can definitely add those products to your diet, focus on at the very least trying to get in a source from real food at breakfast and at dinner. This is easily accomplished by having a whole grain cereal in the morning and then having a serving of vegetables with your meat and pasta in the evening.