Nutrients reach the digestive tract through food and, when needed, supplements. Fibre and prebiotic compounds provide substrates that some gut microbes can use; probiotics are specific live microorganisms, and digestive enzymes have particular roles in breaking down food. These supports are not interchangeable.
Needs vary. Food patterns, symptoms, health conditions, medicines and diagnosed deficiencies all affect what may be appropriate. A supplement can have side effects or interact with medicines, and more is not always better.
This lesson is educational, not a product recommendation. If you are considering a supplement for persistent symptoms or a health condition, discuss it with a qualified clinician or dietitian.