Here is an article from Mayo Clinic's website on this topic, https://www.mayoclinic.org/healthy-lifestyle/consumer-health/expert-answers/probiotics/faq-20058065. As I mentioned before I don't take a lot of supplements and I prefer to get my nutrition through foods and not supplements.

As I've had three surgeries of the upper digestive tract I have a number or digestive issues that are helped by probiotics. I use Kefir as a natural probiotic. It is quite sour so I mix it in a blender with fruit (bananas, blueberries, whatever I have on hand) and a nutritional drink that has some flavoring. I sometimes add a bit of unsweetened cocoa or a few granules of instant coffee. All of the add-ins makes it more palatable.

You can certainly buy probiotics as well. Most GI doctors recommend Align as it was developed by GI doctors.