My enzyme, prebiotic and probiotic are from Klaire Labs. My chiropractor recommended them as high quality... having the needed ingredients etc. You can order them online. Also another thing I've started doing every day, as recommended by chiropractor, is to put a tablespoon of Braggs vinegar and a bit of lemon juice in a glass of water. She has me do this each morning 15 min before eating anything.

I have long Covid for 2 1/2 years, bur only lately realizing it is all Covid related. Lost 30 pounds, (down to 74 pounds) rarely left the house for two years, just too weak, too sick, and in so much pain. Mostly GI symptoms and stomach. The motility of my GI tract is all messed up and often my stomach just does not move the food. So I can eat only a little at a time and I get full (no appetite anyways). Also, my intestines freak out with food, diarrhea, bloating, cramping and lots of pain.
Digestive enzymes have reduced my symptoms so much.
Holozyme from the "Healthy Gut" company are the best and it is a good company.